A mask gas exchange pressure difference testing device

Abstract

The utility model discloses a kind of mask gas exchange pressure difference testing device, including mask pressure difference tester, fixed test head and mobile test head. Driving structure is driven by driving motor to drive worm gear transmission, drives eccentric wheel to push movable rod and mobile test head to realize automatic clamping, its worm lead angle design makes it have self-locking characteristic, guarantee clamping stability. Pressure sensor monitors clamping force in real time, ensure that test condition is consistent. Fixed test head and mobile test head end portion are equipped with sealing structure, including rubber ring and annular elastic lip, lip elastic deformation is closely attached mask surface when clamping, form effective sealing to prevent air leakage. The utility model realizes the automation clamping and accurate force control of mask test, improves test efficiency and data accuracy.

Description

Technical Field

[0001] This utility model relates to the field of mask testing technology, specifically a mask gas exchange pressure difference testing device. Background Technology

[0002] As an important personal protective equipment, the gas exchange performance of face masks, especially their ventilation resistance (pressure difference), is one of the key indicators for evaluating wearing comfort and safety. Currently, the industry typically uses a face mask pressure difference tester to test the gas exchange pressure difference of face mask samples. This tester generally includes a fixed test head and a movable test head. During testing, the face mask sample is clamped and fixed between the two test heads to simulate actual wearing conditions, and a specified flow rate of gas is introduced. The ventilation resistance is evaluated by measuring the pressure difference between the two sides of the face mask.

[0003] However, existing mask pressure differential testing devices mostly rely on manual operation of the clamps to drive the moving test head during the clamping and fixing of mask samples. This manual clamping method has obvious shortcomings: First, manual operation is inefficient; second, the manually applied clamping force is difficult to control precisely and maintain a constant level, which may lead to inconsistent clamping forces between different tests, affecting the repeatability and accuracy of the test results; third, uneven clamping force may also cause poor sealing between the mask sample and the test head, posing a risk of air leakage, which in turn affects the accuracy of the pressure differential measurement.

[0004] To address this, we propose a device for testing the gas exchange pressure difference in face masks. Utility Model Content

[0005] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a mask gas exchange pressure difference testing device. It achieves automated and stable clamping and precise force control through a drive mechanism, and effectively improves sealing performance by utilizing a lip sealing structure. This improves the efficiency, accuracy, and reliability of mask pressure difference testing, and can effectively solve the problems in the background technology.

[0006] (II) Technical Solution To achieve the above objectives, the technical solution adopted by this utility model is as follows: a mask gas exchange pressure difference testing device, including a mask pressure difference tester, a fixed test head is provided at the left end of the upper outer surface of the mask pressure difference tester, a movable test head is provided at the right side of the fixed test head, and a drive structure is fixedly installed at the right end of the upper outer surface of the mask pressure difference tester. The drive structure includes a mounting box, a partition, a drive motor, a worm gear, a driven shaft, a worm wheel, an eccentric wheel, a movable block, a movable rod, a guide ring, a helical spring, a pressure sensor, and a connecting rod. The mounting box is fixed at the right end of the upper outer surface of the mask pressure difference tester, and a sealing structure is fixed to the outer wall of the right end of the fixed test head and the outer wall of the left end of the movable test head.

[0007] Preferably, the partition is fixed in the middle of the inner cavity of the mounting box, the drive motor is fixed on the rear side of the upper end of the right outer surface of the mounting box, the worm is located on the rear side of the upper end of the inner cavity of the mounting box, the worm wheel is located on one side of the worm and the worm wheel is fixed on the outer wall of the upper part of the driven shaft, the driven shaft passes through the partition, and the eccentric wheel is fixed on the outer wall of the lower part of the driven shaft.

[0008] Preferably, a coupling is provided between the worm and the drive motor, and one end of the outer surface of the worm is fixedly connected to one end of the outer surface of the output shaft of the drive motor through the coupling. One side of the outer surface of the worm meshes with one side of the outer surface of the worm wheel. A bearing is provided between the worm and the mounting box, and the worm is rotatably connected to the mounting box through the bearing.

[0009] Preferably, the lead angle of the worm is less than or equal to its equivalent friction angle when meshing with the worm wheel.

[0010] Preferably, the driven shaft, the mounting box, and the partition are all equipped with bearings, and the driven shaft is rotatably connected to the mounting box and the partition through the bearings; the movable block is located to the left of the eccentric wheel, the guide ring is fixed to the lower part of the left outer surface of the mounting box, the movable rod passes through the guide ring, the outer wall of the movable rod is slidably connected to the guide ring, the movable rod is fixed to the middle of the left outer surface of the movable block, the helical spring is movably sleeved on the outer wall of the right end of the movable rod, the helical spring is fixed between the left outer surface of the movable block and the left side of the bottom of the inner cavity of the mounting box, the pressure sensor is fixed between the left outer surface of the movable rod and the right outer surface of the connecting rod, and the left outer surface of the connecting rod is fixedly connected to the right outer surface of the moving test head.

[0011] Preferably, there are two sets of sealing structures, which are respectively disposed on the right outer wall of the fixed test head and the left outer wall of the movable test head; each set of sealing structures includes a rubber ring and an annular elastic lip, the rubber ring is fixedly connected to the end of the corresponding test head, and the annular elastic lip is integrally formed on the extrusion surface of the rubber ring facing the test area.

[0012] (III) Beneficial Effects Compared with the prior art, this utility model provides a mask gas exchange pressure difference testing device, which has the following beneficial effects: 1. This mask gas exchange pressure difference testing device, through a set drive structure, utilizes a drive motor via a worm gear transmission, ultimately driving the movable rod and moving the test head via an eccentric wheel; this method replaces the traditional manual clamp, realizing the automation of mask clamping and effectively improving testing efficiency; at the same time, the pressure sensor integrated in the structure can monitor and provide feedback control on the clamping force in real time, ensuring that the same and stable clamping force is applied in each test, improving the repeatability and accuracy of the test results.

[0013] 2. The gas exchange pressure difference testing device for masks uses a worm gear pair in its drive structure. The lead angle of the worm is specially designed (less than or equal to the equivalent friction angle when it meshes with the worm wheel), which makes the transmission have a self-locking characteristic. This characteristic can prevent the moving test head from accidentally retracting due to the reaction force of the mask in the clamping state, thus ensuring the stability and reliability of the clamping state during the test.

[0014] 3. This mask gas exchange pressure difference testing device, through its sealing structure, includes a sealing element comprising a rubber ring and an annular elastic lip at the ends of both the fixed and movable test heads. When the two test heads clamp the mask, the annular elastic lip undergoes elastic deformation, tightly adhering to the surface of the mask sample to form an effective sealing ring. This improves the sealing performance of the test area, effectively preventing gas leakage during the test process, thereby further ensuring the accuracy of the pressure difference test data. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of a mask gas exchange pressure difference testing device according to the present invention.

[0016] Figure 2 This is a side cross-sectional view of the driving structure in the gas exchange pressure difference testing device for a mask according to this utility model.

[0017] Figure 3 This is a partial top view cross-sectional view of the driving structure in the gas exchange pressure difference testing device for a mask according to this utility model.

[0018] Figure 4 This is a schematic diagram of the sealing structure in a mask gas exchange pressure difference testing device of this utility model.

[0019] In the diagram: 1. Mask pressure differential tester; 2. Fixed test head; 3. Moving test head; 4. Sealing structure; 5. Drive structure; 6. Mounting box; 7. Partition plate; 8. Drive motor; 9. Worm gear; 10. Driven shaft; 11. Worm wheel; 12. Eccentric wheel; 13. Moving block; 14. Moving rod; 15. Guide ring; 16. Helical spring; 17. Pressure sensor; 18. Connecting rod; 19. Rubber ring; 20. Annular elastic lip. Detailed Implementation

[0020] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0021] like Figure 1-4 As shown, this utility model discloses a mask gas exchange pressure difference testing device, including a mask pressure difference tester 1. A fixed test head 2 is fixedly disposed on the left end of the upper outer surface of the mask pressure difference tester 1, and a movable test head 3 is disposed on the right side of the fixed test head 2. A driving structure 5 for driving the movable test head 3 to move horizontally is fixedly installed on the right end of the upper outer surface of the mask pressure difference tester 1. A sealing structure 4 for sealing contact with the mask sample is fixedly disposed on the outer wall of the right end of the fixed test head 2 and the outer wall of the left end of the movable test head 3.

[0022] Specifically, the drive structure 5 includes a mounting box 6, a partition 7, a drive motor 8, a worm gear 9, a driven shaft 10, a worm wheel 11, an eccentric wheel 12, a movable block 13, a movable rod 14, a guide ring 15, a helical spring 16, a pressure sensor 17, and a connecting rod 18. The mounting box 6 is fixed to the right end of the upper outer surface of the mask pressure differential tester 1. The partition 7 is horizontally fixed in the middle of the inner cavity of the mounting box 6, dividing its interior into upper and lower chambers. The drive motor 8 is fixed to the rear side of the upper right outer surface of the mounting box 6 via a mounting bracket. The worm gear 9 is horizontally arranged on the rear side of the upper end of the inner cavity of the mounting box 6, and is fixedly connected to the output shaft of the drive motor 8 via a coupling. Both ends of the worm gear 9 are rotatably connected to the side wall of the mounting box 6 via bearings. The driven shaft 10 is vertically arranged, and its upper part is rotatably connected to the top of the mounting box 6 and the partition 7 via bearings, extending through the partition 7 to the lower chamber. The worm gear 11 is fixedly mounted on the outer wall of the upper part of the driven shaft 10 and meshes with one side of the outer surface of the worm 9. The eccentric wheel 12 is fixedly mounted on the outer wall of the lower part of the driven shaft 10 and is located in the lower cavity of the mounting box 6.

[0023] Furthermore, the lead angle of the worm 9 is designed to be less than or equal to the equivalent friction angle when it meshes with the worm wheel 11. This gives the worm gear pair a self-locking function, which can prevent the moving test head 3 from moving backward due to the reaction force of the mask sample in the clamping state, thus ensuring the stability of the clamping state.

[0024] The movable block 13 is located on the left side of the eccentric wheel 12, and its right side can contact the outer edge of the eccentric wheel 12. The guide ring 15 is fixed to the lower part of the left outer wall of the mounting box 6, and a guide hole is opened in its center. The movable rod 14 is horizontally set, and its right end is fixedly connected to the middle of the left outer surface of the movable block 13. Its left end passes through the guide hole of the guide ring 15 and the pressure sensor 17 in sequence, and is fixedly connected to the right outer surface of the moving test head 3 through the connecting rod 18. The outer wall of the movable rod 14 and the inner wall of the guide hole of the guide ring 15 are in sliding fit, ensuring that the movable rod 14 can only perform horizontal left and right reciprocating motion. The helical spring 16 is movably sleeved on the outer wall of the right end of the movable rod 14. Its right end is fixed to the left outer surface of the movable block 13, and its left end is fixed to the left side of the bottom of the inner cavity of the mounting box 6. In the natural state, the elastic force of the helical spring 16 drives the movable block 13 to move to the right, so that it keeps in contact with the eccentric wheel 12. The pressure sensor 17 is fixed between the outer surface of the left end of the movable rod 14 and the outer surface of the right end of the connecting rod 18, and is used to monitor and provide feedback on the pressure signal transmitted by the movable rod 14 when clamping the mask in real time.

[0025] There are two sets of sealing structures 4, respectively located on the right outer wall of the fixed test head 2 and the left outer wall of the movable test head 3. Each set of sealing structures 4 includes a rubber ring 19 and an annular elastic lip 20. The rubber ring 19 is fixedly connected to the end of the corresponding test head by means of bonding or interference fit. The annular elastic lip 20 is integrally formed on the compression surface of the rubber ring 19 facing the test area (i.e., facing the mask sample). When the two test heads clamp the mask, the annular elastic lip 20 will elastically deform and tightly fit against the surface of the mask sample, forming an effective sealing ring.

[0026] The working principle of this utility model is as follows: During testing, the operator first places the mask sample between the fixed test head 2 and the moving test head 3. The drive motor 8 is started, and its output shaft rotates the worm gear 9. The worm gear 9 drives the meshing worm wheel 11 to rotate, which in turn drives the driven shaft 10 and the eccentric wheel 12 fixed below it to rotate together. As the eccentric wheel 12 rotates, its protruding part periodically presses against the movable block 13, pushing the movable block 13, movable rod 14, pressure sensor 17, connecting rod 18, and moving test head 3 to the left, thus clamping the mask sample. During this process, the helical spring 16 is compressed. The clamping force is monitored in real time by the pressure sensor 17. When a preset, stable clamping force value is reached, the control system can control the drive motor 8 to stop operating or maintain a specific state. Due to the self-locking characteristics of the worm gear pair, the clamping state is stably maintained. Subsequently, the pressure difference between the two sides of the mask sample is measured and recorded using a mask pressure difference tester 1. After the test, the drive motor 8 reverses, and with the assistance of the restoring force of the helical spring 16, the movable block 13 and movable rod 14, among other components, return to their original position to the right. The moving test head 3 separates from the fixed test head 2, allowing the tested mask sample to be removed. Throughout the clamping process, the sealing structure 4 at the ends of the two test heads undergoes elastic deformation of its annular elastic lip 20 under pressure, tightly fitting the mask surface and effectively preventing leakage of test gas, thus ensuring the accuracy of the test results.

[0027] It should be noted that the mask pressure difference tester 1, fixed test head 2 and moving test head 3 described in the article and their basic testing principles are existing technologies and can be effectively understood by those skilled in the art. The improvement of this utility model lies in the clamping drive method and sealing structure.

[0028] It should be noted that, in this document, relational terms such as first and second (number one, number two), etc., are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0029] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model.

Claims

1. A mask gas exchange pressure difference testing device, comprising a mask pressure difference tester (1), wherein a fixed test head (2) is provided on the left end of the upper outer surface of the mask pressure difference tester (1), and a movable test head (3) is provided on the right side of the fixed test head (2), characterized in that: The upper outer surface of the mask pressure difference tester (1) is fixedly equipped with a drive structure (5). The drive structure (5) includes a mounting box (6), a partition (7), a drive motor (8), a worm gear (9), a driven shaft (10), a worm wheel (11), an eccentric wheel (12), a movable block (13), a movable rod (14), a guide ring (15), a helical spring (16), a pressure sensor (17), and a connecting rod (18). The mounting box (6) is fixed to the upper outer surface of the mask pressure difference tester (1). The outer wall of the right end of the fixed test head (2) and the outer wall of the left end of the moving test head (3) are both fixed with a sealing structure (4).

2. The mask gas exchange pressure difference testing device according to claim 1, characterized in that: The partition (7) is fixed in the middle of the inner cavity of the mounting box (6). The drive motor (8) is fixed on the rear side of the upper end of the right outer surface of the mounting box (6). The worm (9) is located on the rear side of the upper end of the inner cavity of the mounting box (6). The worm wheel (11) is located on one side of the worm (9) and is fixed on the outer wall of the upper part of the driven shaft (10). The driven shaft (10) passes through the partition (7) and the eccentric wheel (12) is fixed on the outer wall of the lower part of the driven shaft (10).

3. The mask gas exchange pressure difference testing device according to claim 2, characterized in that: A coupling is provided between the worm (9) and the drive motor (8). One end of the outer surface of the worm (9) is fixedly connected to one end of the outer surface of the output shaft of the drive motor (8) through the coupling. One side of the outer surface of the worm (9) meshes with one side of the outer surface of the worm wheel (11). A bearing is provided between the worm (9) and the mounting box (6). The worm (9) is rotatably connected to the mounting box (6) through the bearing.

4. The mask gas exchange pressure difference testing device according to claim 3, characterized in that: The lead angle of the worm (9) is less than or equal to the equivalent friction angle when it meshes with the worm wheel (11).

5. The mask gas exchange pressure difference testing device according to claim 4, characterized in that: The driven shaft (10), the mounting box (6), and the partition plate (7) are all equipped with bearings. The driven shaft (10) is rotatably connected to the mounting box (6) and the partition plate (7) through the bearings. The movable block (13) is located to the left of the eccentric wheel (12). The guide ring (15) is fixed to the lower part of the outer surface of the left side of the mounting box (6). The movable rod (14) passes through the guide ring (15). The outer wall of the movable rod (14) is slidably connected to the guide ring (15). The movable rod (14) is fixed. At the middle of the left outer surface of the movable block (13), the helical spring (16) is movably sleeved on the outer wall of the right end of the movable rod (14). The helical spring (16) is fixed between the left outer surface of the movable block (13) and the left side of the bottom of the inner cavity of the mounting box (6). The pressure sensor (17) is fixed between the left outer surface of the movable rod (14) and the right outer surface of the connecting rod (18). The left outer surface of the connecting rod (18) is fixedly connected to the right outer surface of the moving test head (3).

6. The mask gas exchange pressure difference testing device according to claim 1, characterized in that: The number of sealing structures (4) is two sets, respectively set on the right outer wall of the fixed test head (2) and the left outer wall of the movable test head (3); each set of sealing structures (4) includes a rubber ring (19) and an annular elastic lip (20). The rubber ring (19) is fixedly connected to the end of the corresponding test head, and the annular elastic lip (20) is integrally formed on the extrusion surface of the rubber ring (19) facing the test area.

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