A pressure measuring device for mechanical experiments

Abstract

The application discloses a pressure measuring device for mechanics experiments, which comprises an L-shaped box body, a measuring table, a gas pressure system and a control system. The upper half of the pressure measuring tank is provided with a cylindrical chute at four corners, and the sidewall of the cylindrical chute is communicated with the pressure measuring tank. The gas pressure system comprises a measuring piston cylinder in the lower half of the pressure measuring tank and a variable gas mechanism in the vertical lower half of the L-shaped box body. The control system comprises a control panel, a gas pressure detector, a control panel, a display screen and a storage battery. The gas pressure detector is installed in a gas pressure detection cylinder, and the gas pressure detection cylinder is communicated with the variable gas mechanism. The variable gas mechanism is used for adjusting the total volume of the compressed gas to adjust the error value of the error of the generated pressure of the compressed gas, so that the pressure error value is reduced by ensuring that the pressure in different pressure ranges is measured by the gas pressure measurement of the gas pressure change caused by the gas compression in a certain gas cavity, and the accuracy of the pressure measurement is improved.

Description

Technical Field

[0001] This invention relates to the field of mechanical experimental apparatus technology, and in particular to a pressure measuring device for mechanical experiments. Background Technology

[0002] Mechanics is an independent fundamental discipline concerning force, motion, and media, including macroscopic, microscopic, and macroscopic mechanical properties. It primarily studies mechanical motion and its coupling with physical, chemical, and biological phenomena. Current mechanical experimental apparatuses generally use pressure sensors to detect pressure changes and values ​​generated by mechanical compression. Some methods detect pressure by changing gas pressure, specifically by compressing a cylinder and gas chamber to alter the gas volume and pressure within the chamber. However, with a constant gas volume within the chamber, different pressure ranges produce varying errors during gas compression. In small-capacity chambers with high pressure, even minute changes in gas volume can produce significant pressure variations, leading to large errors and inaccurate measurements. Conversely, in large-capacity chambers with low pressure, minute changes in gas volume do not affect the chamber. Furthermore, piston friction further amplifies these errors, resulting in even larger variations in force. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, one objective of this invention is to provide a pressure measuring device for mechanical experiments that solves the problem of large errors in pressure measurement based on changes in air pressure, and the inability to adjust the error range according to different pressure ranges.

[0004] According to the present invention, a pressure measuring device for mechanical experiments includes an L-shaped box, a measuring platform, a pneumatic system, and a control system. The L-shaped box has a pressure measuring groove on its horizontal side. The upper half of the pressure measuring groove has cylindrical sliding grooves at its four corners, with the sidewalls of the cylindrical sliding grooves communicating with the pressure measuring groove. The measuring platform has sliding balls at its four corners, which are mounted on the corners of the measuring platform by connecting rods. The pneumatic system includes a measuring piston cylinder in the lower half of the pressure measuring groove and a variable gas mechanism in the lower vertical half of the L-shaped box. The control system includes a control board, a pressure detector, a control panel, a display screen, and a battery. The pressure detector is installed inside a pressure detection cylinder, which communicates with the variable gas mechanism. The pressure detector, control panel, display screen, and electrical control devices within the variable gas mechanism are electrically connected to the control board. The battery supplies power to the control board.

[0005] The lower surface of the metering platform is mounted on the upper surface of the metering piston inside the metering piston cylinder, and the bottom of the metering piston cylinder is connected to one end of the variable gas mechanism through a gas guide pipe.

[0006] In some embodiments of the present invention, the variable gas mechanism includes a lower housing, multiple gas cylinders, and an upper housing. Each of the multiple gas cylinders has a connecting pipe at its bottom and top. A solenoid valve is installed inside the connecting pipe. The connecting pipe at the bottom of the gas cylinder is connected to the upper surface of the lower housing, and the connecting pipe at the top of the gas cylinder is connected to the lower surface of the upper housing. Two solenoid valves on the same gas cylinder are grouped together and numbered. The gas pressure detection cylinder is connected to the upper housing, and the solenoid valve is electrically connected to the control board.

[0007] In other embodiments of the invention, the plurality of gas cylinders are configured as four, and the total gas capacity in the four gas cylinders is -1 times the gas capacity in the metering piston cylinder.

[0008] In some other embodiments of the present invention, the lower surface of the measuring platform is provided with a cone, the tip of the bottom of the cone is provided with a hemisphere, the upper surface of the measuring piston in the measuring piston cylinder is provided with a hemispherical groove block, the hemisphere is disposed in the concave hemispherical groove on the hemispherical groove block, and the maximum width of the cone is smaller than the inner diameter of the measuring piston cylinder.

[0009] In other embodiments of the present invention, the air pressure system is disposed in the heat preservation cavity, the heat preservation cavity is provided with a heating plate, and the heating plate is electrically connected to the control board.

[0010] In some other embodiments of the present invention, a balance plate is provided on both sides of the metering platform, and a buffer mechanism is provided below the balance plate. The buffer mechanism includes a buffer gas box, a piston cylinder and a buffer rod. The bottom of the piston cylinder is connected to the buffer gas box, the bottom end of the buffer rod is fixed to the upper surface of the piston inside the piston cylinder, and the top end of the buffer rod is fixed to the lower surface of the balance plate.

[0011] In some other embodiments of the present invention, the pressure metering tank is provided with an air replenishment device, which includes an air pump and an exhaust pipe. The air outlet of the air pump is connected to one end of the exhaust pipe, and the other end of the exhaust pipe is connected to the bottom of the metering piston cylinder. An air replenishment solenoid valve is provided on the exhaust pipe.

[0012] In other embodiments of the invention, the measuring stage is made of lightweight plastic.

[0013] In other embodiments of the present invention, the sliding sphere is a steel ball with a polished surface, and the inner wall of the cylindrical groove is a metal wall with a polished surface.

[0014] In some other embodiments of the present invention, the bottom of the L-shaped box is provided with four sets of universal rollers.

[0015] In this invention, the total volume of compressed gas is adjusted by a variable gas mechanism to reduce the error value in the calculation of the compressed gas pressure. A large-volume gas chamber is used for larger pressures, and a small-volume gas chamber is used for smaller pressures. This ensures that the pressure changes caused by gas compression within a certain gas chamber are measured, thereby reducing the error value in the pressure calculation and improving the accuracy of pressure measurement. Attached Figure Description

[0016] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0017] Figure 1 This is a schematic diagram of the structure of a pressure measuring device for mechanical experiments proposed in this invention.

[0018] Figure 2 This is a schematic cross-sectional view of the pneumatic system proposed in this invention.

[0019] Figure 3 This is a schematic diagram of the sliding sphere and cylindrical groove proposed in this invention.

[0020] Figure 4 This is a schematic diagram of the variable gas mechanism proposed in this invention.

[0021] Figure 5 This is a schematic diagram of the buffer mechanism proposed in this invention.

[0022] In the diagram: 1. L-shaped box; 2. Measuring platform; 21. Sliding ball; 211. Connecting rod; 212. Cylindrical groove; 22. Balance plate; 23. Cone; 24. Hemisphere; 3. Control panel; 4. Display screen; 5. Measuring piston cylinder; 51. Measuring piston; 52. Hemispherical groove block; 53. Air guide pipe; 6. Lower box; 7. Gas cylinder; 70. Connecting pipe; 71. Solenoid valve; 8. Upper box; 9. Air pressure detection cylinder; 91. Air pressure detector; 10. Buffer gas box; 101. Piston cylinder; 102. Buffer rod; 11. Insulation chamber; 110. Heating plate. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0024] This invention proposes a pressure measuring device for mechanical experiments, comprising an L-shaped box 1, a measuring platform 2, a pneumatic system, and a control system. The L-shaped box 1 has a pressure measuring groove on its horizontal side. The upper half of the pressure measuring groove has four corners with cylindrical sliding grooves 212, the sidewalls of which communicate with the pressure measuring groove. The measuring platform 2 has four corners with sliding balls 21, which are mounted on the corners of the measuring platform 2 by connecting rods 211. The pneumatic system includes a measuring piston cylinder 5 in the lower half of the pressure measuring groove and a variable gas mechanism in the lower vertical half of the L-shaped box 1. The control system includes a control board, a pressure detector 91, a control panel 3, a display screen 4, and a battery. The pressure detector 91 is installed inside a pressure detection cylinder 9, which communicates with the variable gas mechanism. The pressure detector 91, control panel 3, display screen 4, and electrical control devices within the variable gas mechanism are electrically connected to the control board. The battery supplies power to the control board.

[0025] The lower surface of the metering platform 2 is mounted on the upper surface of the metering piston 51 inside the metering piston cylinder 5. The bottom of the metering piston cylinder 5 is connected to one end of the variable gas mechanism through the gas guide pipe 53.

[0026] When a pressure-generating device or heavy object is placed on the measuring platform 2, it is pressed down. The descending measuring platform 2 will press down the measuring piston 51 in the measuring piston cylinder 5, compressing the gas in the measuring piston cylinder 5. Some of the gas will be forced into the variable gas mechanism. The gas in the measuring piston cylinder 5 and the gas in the variable gas mechanism are integrated and compressed as a whole. The pressure detection cylinder 9 is connected to the variable gas mechanism. The pressure detector 91 inside the pressure detection cylinder 9 will check the pressure change (pressure per unit surface area) at any time. The pressure measured is the multiple of the lower surface area of ​​the measuring piston 51 per unit surface area.

[0027] Since the pressure-generating device or weight is not placed in the center when it is placed on the measuring platform 2, the friction at the four corners of the measuring platform 2 will greatly affect the pressure measurement. Therefore, a sliding ball 21 is used to slide in the cylindrical groove 212, and the measuring platform 2 will not produce a large change in friction even if it is tilted, which greatly reduces the error caused by friction.

[0028] The variable gas mechanism includes a lower housing 6, multiple gas cylinders 7, and an upper housing 8. Each of the gas cylinders 7 has a connecting pipe 70 at its bottom and top. A solenoid valve 71 is installed inside the connecting pipe 70. The connecting pipe 70 at the bottom of the gas cylinder 7 is connected to the upper surface of the lower housing 6, and the connecting pipe 70 at the top of the gas cylinder 7 is connected to the lower surface of the upper housing 8. Two solenoid valves 71 on the same gas cylinder 7 are grouped together and numbered. The pressure detection cylinder 9 is connected to the upper housing 8, and the solenoid valve 71 is electrically connected to the control board.

[0029] At least one gas cylinder 7 is connected to the entire gas system. By increasing the number of gas cylinders 7, the weight of the changing gas in the gas chamber is increased, thereby adjusting the amount of compressed gas and changing the pressure error coefficient.

[0030] Since mechanical friction has a greater impact at lower pressures, and the mechanical friction of the system is generally a constant value, and because the metering piston 51 remains constant, the downward movement of the metering piston 51 is relatively small at low pressures. If the gas volume of the entire system is large (i.e., multiple gas cylinders 7 are used), the accuracy of the gas change will decrease. Therefore, small-volume gas chambers are suitable for low pressures to improve accuracy, while large-volume gas chambers are suitable for high pressures. This is because the pressure detector 91 detects changes in pressure, and small-volume gas chambers are more sensitive to changes in gas volume.

[0031] The gas cylinders 7 are configured as four, and the total gas capacity of the four gas cylinders 7 is 1-1.5 times the gas capacity of the metering piston cylinder 5. This ensures that the gas volume in the overall gas chamber is reduced by half, thus minimizing the downward movement distance of the metering piston 51 and ensuring accuracy in low-pressure measurements.

[0032] The lower surface of the measuring platform 2 is provided with a cone 23, and the bottom tip of the cone 23 is provided with a hemisphere 24. The upper surface of the measuring piston 51 in the measuring piston cylinder 5 is provided with a hemispherical groove block 52, and the hemisphere 24 is disposed in the concave hemispherical groove on the hemispherical groove block 52. The maximum width of the cone 23 is smaller than the inner diameter of the measuring piston cylinder 5. The cone 23 ensures that no matter what angle the measuring platform 2 is subjected to force, the bottom hemisphere 24 applies the downward force, ensuring that the center position of the upper surface of the measuring piston 51 is subjected to force, and the measuring piston 51 will not be tilted or moved downward, making the measurement of the downward force more accurate.

[0033] The pneumatic system is housed within the insulation chamber 11, which contains a heating plate 110 electrically connected to the control board. Since gas temperature variations affect gas compression measurements, maintaining a constant temperature ensures measurement accuracy.

[0034] The metering platform 2 is provided with balance plates 22 on both sides, and a buffer mechanism is provided below the balance plates 22. The buffer mechanism includes a buffer gas box 10, a piston cylinder 101 and a buffer rod 102. The bottom of the piston cylinder 101 is connected to the buffer gas box 10. The bottom end of the buffer rod 102 is fixed to the upper surface of the piston inside the piston cylinder 101, and the top end of the buffer rod 102 is fixed to the lower surface of the balance plate 22.

[0035] The downward movement of the measuring platform 2 requires a rebound force. However, the force varies depending on the degree of compression of the traditional spring. The greater the downward pressure of the balance plate, the greater the upward thrust of the spring, and the greater the measurement error. In contrast, the piston cylinder 101 experiences relatively little change in the gas within the entire buffer gas box 10. That is, the upward thrust of the piston inside the piston cylinder 101 remains basically constant. Even after a significant downward pressure, the upward thrust remains essentially unchanged, thus maintaining a balance between the gravity of the measuring platform 2 and the upward thrust. The downward pressure is essentially the same as the test pressure.

[0036] The pressure metering tank is equipped with an air replenishment device, which includes an air pump and an exhaust pipe. The air outlet of the air pump is connected to one end of the exhaust pipe, and the other end of the exhaust pipe is connected to the bottom of the metering piston cylinder. An air replenishment solenoid valve is provided on the exhaust pipe.

[0037] Since the entire system uses a gas chamber, the gas inside the metering piston cylinder will change over time. The gas is periodically replenished to the metering piston cylinder by an air pump to ensure the accuracy of the gas calculation.

[0038] The measuring platform 2 is made of lightweight plastic. This prevents the measuring platform 2 from becoming too heavy and from undergoing oxidation, which could cause a change in its mass.

[0039] The sliding ball 21 is a steel ball with a polished surface, and the inner wall of the cylindrical groove 212 is a metal wall with a polished surface. This greatly reduces the contact friction between the sliding ball 21 and the cylindrical groove 212, thus reducing the error caused by friction.

[0040] The L-shaped box 1 is equipped with four sets of universal casters at its bottom for easy movement.

[0041] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A pressure measuring device for mechanical experiments, characterized in that: The system includes an L-shaped box (1), a metering platform (2), a pneumatic system, and a control system. The L-shaped box (1) has a pressure metering groove on its horizontal side. The upper half of the pressure metering groove has four corners with cylindrical sliding grooves (212) whose sidewalls communicate with the pressure metering groove. The metering platform (2) has four corners with sliding balls (21) which are mounted on the corners of the metering platform (2) using connecting rods (211). The pneumatic system includes the metering system located in the lower half of the pressure metering groove. The variable gas mechanism is located in the lower half of the vertical box of the piston cylinder (5) and the L-shaped box (1). The control system includes a control board, a pressure detector (91), a control panel (3), a display screen (4), and a storage battery. The pressure detector (91) is installed in the pressure detection cylinder (9). The pressure detection cylinder (9) is connected to the variable gas mechanism. The pressure detector (91), the control panel (3), the display screen (4), and the electrical control devices in the variable gas mechanism are electrically connected to the control board. The storage battery supplies power to the control board. The lower surface of the metering platform (2) is mounted on the upper surface of the metering piston (51) inside the metering piston cylinder (5), and the bottom of the metering piston cylinder (5) is connected to one end of the variable gas mechanism through the gas guide pipe (53). The variable gas mechanism includes a lower box (6), multiple gas cylinders (7) and an upper box (8). Each of the multiple gas cylinders (7) has a connecting pipe (70) at its bottom and top. The connecting pipe (70) contains a solenoid valve (71). The connecting pipe (70) at the bottom of the gas cylinder (7) is connected to the upper surface of the lower box (6), and the connecting pipe (70) at the top of the gas cylinder (7) is connected to the lower surface of the upper box (8). Two solenoid valves (71) on the same gas cylinder (7) are grouped together and numbered. The pressure detection cylinder (9) is connected to the upper box (8), and the solenoid valve (71) is electrically connected to the control board. The gas cylinders (7) are configured as four, and the total gas capacity in the four gas cylinders (7) is 1-1.5 times the gas capacity in the metering piston cylinder (5).

2. The pressure measuring device for mechanical experiments according to claim 1, characterized in that: The lower surface of the measuring platform (2) is provided with a cone (23), and a hemisphere (24) is provided at the tip of the bottom of the cone (23). The upper surface of the measuring piston (51) in the measuring piston cylinder (5) is provided with a hemisphere groove block (52). The hemisphere (24) is set in the concave hemisphere groove on the hemisphere groove block (52). The maximum width of the cone (23) is smaller than the inner diameter of the measuring piston cylinder (5).

3. The pressure measuring device for mechanical experiments according to claim 1, characterized in that: The air pressure system is installed in the heat preservation cavity (11), and the heat preservation cavity (11) is provided with a heating plate (110), which is electrically connected to the control board.

4. The pressure measuring device for mechanical experiments according to claim 1, characterized in that: The metering platform (2) is provided with balance plates (22) on both sides. A buffer mechanism is provided below the balance plate (22). The buffer mechanism includes a buffer gas box (10), a piston cylinder (101) and a buffer rod (102). The bottom of the piston cylinder (101) is connected to the buffer gas box (10). The bottom end of the buffer rod (102) is fixed to the upper surface of the piston inside the piston cylinder (101), and the top end of the buffer rod (102) is fixed to the lower surface of the balance plate (22).

5. A pressure measuring device for mechanical experiments according to claim 1, characterized in that: The pressure metering tank is equipped with an air replenishment device, which includes an air pump and an exhaust pipe. The air outlet of the air pump is connected to one end of the exhaust pipe, and the other end of the exhaust pipe is connected to the bottom of the metering piston cylinder. An air replenishment solenoid valve is provided on the exhaust pipe.

6. A pressure measuring device for mechanical experiments according to claim 1, characterized in that: The measuring table (2) is made of lightweight plastic.

7. A pressure measuring device for mechanical experiments according to claim 1, characterized in that: The sliding sphere (21) is a steel ball with a polished surface, and the inner wall of the cylindrical groove (212) is a metal wall with a polished surface.

8. A pressure measuring device for mechanical experiments according to claim 1, characterized in that: The bottom of the L-shaped box (1) is provided with four sets of universal rollers.

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