A helmet puncture testing device

Abstract

This utility model provides a helmet puncture testing device, including a top plate and a base, with the top plate positioned directly above the base. The device is characterized by having a puncture test piece on the lower surface of the top plate and a release mechanism on the same surface, used to fix or release the puncture test piece. A head mold is mounted on the base, supporting the helmet to be tested. A detection circuit is connected in series with the head mold, detecting changes in current or resistance of the head mold after the puncture test piece penetrates it. Utilizing the resistivity difference between two conductive materials, a parallel circuit is formed when puncture is successful, significantly reducing the total resistance for easier detection. A multimeter detects the decrease in resistance and increase in current, accurately determining whether the helmet has been punctured. An electromagnet controls the release, achieving true free-fall motion to simulate real-world conditions. There is no cable interference, avoiding cable length limitations on the maximum height of the top plate.

Description

Technical Field

[0001] This utility model relates to the technical field, specifically to a safety helmet puncture test device. Background Technology

[0002] To complete the puncture resistance test of a safety helmet, a puncture hammer must be dropped freely from a certain height onto the helmet placed on the head mold. The equipment uses a wired connection to ensure that the information after puncturing the helmet can be received. However, during the test, the wired puncture hammer is difficult to install for subsequent tests, and the wire may directly or indirectly affect the test data, leading to inaccuracies. Therefore, it is necessary to eliminate this drawback and avoid introducing errors into the test and unnecessary damage to the equipment. Currently, safety helmet puncture instruments on the market all have a wired connection at the instrument end that connects to the puncture hammer to receive the feedback signal after puncturing the helmet and contacting the metal head mold. After several tests, the wired puncture hammer is at risk of wire fatigue breakage or poor contact, which will affect the test data. Furthermore, the wire may become tangled and difficult to manage. During the test, the falling puncture hammer may pull on the instrument, posing a risk of damage. Utility Model Content

[0003] This utility model provides a safety helmet puncture test device, the purpose of which is to solve the technical problem that the cable between the puncture hammer and the instrument affects the puncture test in the prior art.

[0004] This utility model provides a helmet puncture testing device, including a top plate and a base, with the top plate positioned directly above the base; characterized in that a puncture test piece is disposed on the lower surface of the top plate, and a release mechanism is disposed on the lower surface of the top plate, the release mechanism being used to fix or release the puncture test piece; a head mold is disposed on the base, the head mold being used to support the helmet to be tested, and a detection circuit is connected in series with the head mold, the detection circuit being used to detect the change in current or resistance of the head mold after the puncture test piece punctures the head mold.

[0005] Furthermore, the release structure is a magnetic lock, which includes an electromagnet and a metal plate. The electromagnet is fixedly connected to the lower surface of the top plate, and the metal plate is fixedly connected to the top of the puncture test piece. The electromagnet is used to fix or release the metal plate.

[0006] Furthermore, the puncture test specimen includes a counterweight and a puncture hammer, with the top of the counterweight fixedly connected to the metal plate and the bottom of the counterweight fixedly connected to the top of the puncture hammer.

[0007] Furthermore, a rotating frame is fixedly connected to the base, the horizontal side of the rotating frame and the top of the frame are hollowed out, and a support column is rotatably connected inside the rotating frame, the top of the support column is fixedly connected to the bottom of the head mold.

[0008] Furthermore, a support platform is fixedly connected to the top of the support column, and a clamp is fixedly connected to the support platform for holding the head mold.

[0009] Furthermore, a groove is provided on the upper surface of the support platform, and two sliders are slidably arranged in the groove. The two sliders are respectively provided with threaded holes with opposite threads. The threaded holes are provided with a lead screw. A clamping plate is fixedly connected to the upper surface of the slider. The head mold is clamped between the clamping plates. Two pull nuts are sleeved on the lead screw and are located outside the slider.

[0010] Furthermore, a fixing block is fixedly connected to the center of the slide groove, the fixing block has a through groove, a second bearing is fixedly connected to the center of the through groove, and the through groove is fixedly connected to the center of the lead screw through the second bearing.

[0011] Furthermore, the slide groove is a convex slide groove, the slider is a convex slider, and the slider matches the slide groove.

[0012] This utility model has at least the following beneficial effects:

[0013] This invention provides a helmet puncture testing device. It utilizes the resistivity difference between two conductive materials to form a parallel circuit when puncture is successful, significantly reducing the total resistance and facilitating detection. A multimeter detects the decrease in resistance and the increase in current, accurately determining whether the helmet has been punctured. Compared to traditional visual inspection, changes in electrical parameters provide objective and quantitative puncture results. The release is controlled by an electromagnet, achieving true free fall motion and simulating real-world conditions. There is no cable interference, and the trajectory of the punctured part will not deviate, avoiding the limitation of cable length on the maximum height setting of the top plate. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the safety helmet puncture testing device of this utility model;

[0015] Figure 2 This is a schematic diagram of the top plate of the safety helmet puncture testing device of the present invention;

[0016] Figure 3 This is a schematic diagram of the structure of the puncture test piece of the safety helmet puncture testing device of the present invention, in Embodiment 2.

[0017] Figure 4 This is a schematic diagram of the structure of the puncture test piece of the safety helmet puncture testing device of the present invention, in embodiment 4.

[0018] Figure 5This is a schematic diagram of the support platform for Embodiment 4 of the puncture test piece of the safety helmet puncture testing device of this utility model.

[0019] In the diagram: 1. Top plate; 2. Base; 3. Puncture test specimen; 4. Head mold; 5. Telescopic rod; 6. Electromagnet; 7. Metal plate; 8. Counterweight; 9. Puncture hammer; 10. Rotating frame; 11. Rotating rod; 12. Motor; 13. Support column; 14. Clamp; 15. Support platform; 16. Slide groove; 17. Sliding block; 18. Lead screw; 19. Pull nut; 20. Clamping plate; 21. Fixing block. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] Example 1:

[0022] See Figures 1 to 3 This utility model provides a helmet puncture testing device, including a top plate 1 and a base 2. The top plate 1 is positioned directly above the base 2. A puncture test piece 3 is disposed on the lower surface of the top plate 1. A release mechanism is provided between the lower surface of the top plate 1 and the top of the puncture test piece 3. The top of the release mechanism is fixedly connected to the top plate 1, and the bottom of the release mechanism is fixedly connected to the top of the puncture test piece 3. The release mechanism is used to fix or release the puncture test piece 3. The puncture test piece 3 is made of a high-hardness conductive material. The puncture test piece 3 can be selected from T10 tool steel, 65Mn spring steel, or cemented carbide, with a hardness HRC≥58, and as a conductor, its resistivity is approximately 10. -6 Ωm, maintaining shape and conductivity after multiple impacts. A head mold 4 is mounted on the base 2, positioned directly below the puncture test specimen 3. The head mold 4 supports the safety helmet to be tested. A detection circuit is installed within the base, including a multimeter connected in series with wires and a power supply. The detection circuit is connected in series with the head mold, and the power supply is located within the base. The head mold 4 is made of a low-hardness conductive material, such as carbon black-filled silicone rubber. Its matrix is ​​industrial-grade silicone rubber, and the conductive filler can be 8%-15% conductive carbon black. The hardener can be 10%-15% silica or silica powder. This type of material can simulate the hardness of a skull and has a conductivity of 10. -1 The conductivity of the two materials ranges from Ωm to 1Ωm, and the cost is low, allowing for repeated use and remaking. A significant difference in conductivity between the two materials can cause substantial changes in both current and resistance.

[0023] The multimeter is used to detect the change in electrical parameters of the head mold. A plurality of telescopic rods 5 are fixedly connected between the base 2 and the top plate 1, and each telescopic rod 5 is connected with a controller and a cylinder.

[0024] The head mold 4 has a resistor R1 which is a conductor as a whole and can be regarded as a conductor with a certain resistance. The puncture test piece 3 has a resistor R2 which is a conductor as a whole. When the metal cone is inserted into the inner space of the metal head mold, a parallel conductive path is formed by the contact between the two conductors, and the resistance is R1. After the metal cone is inserted into it, an overall conductive connection is formed with the inner wall of the head mold, which is equivalent to the parallel connection of the two.

[0025] At this time, the resistance of the puncture test piece 3 itself is R2, and the total resistance formed by the two together is: where R 总 is the total resistance formed by the puncture test piece 3 and the head mold 4 together.

[0026] Since both R1 and R2 are conductor resistances and the resistance of a metal conductor is usually small, the total resistance R 总 will be less than R1 and R2.

[0027] Before insertion, the multimeter only measures the resistance R1 of the metal head mold. After the puncture test piece 3 is inserted into the head mold 4: the multimeter measures the parallel resistance R 总 of R1 and R2, and the resistance value decreases.

[0028] After the metal cone is inserted: the total resistance decreases by R 总 < R1. According to Ohm's law and there is no increase in the circuit current I 总 = I1, where I 总 is the total current of the puncture test piece 3 and the head mold 4, and I1 is the current when the puncture test piece 3 is not inserted into the head mold 4. The total resistance after the parallel connection of the two conductors is less than the resistance of any one conductor, and the displayed value when the multimeter measures the resistance decreases. The tester can raise the top plate 1 according to the actual situation to simulate the reliability of the helmet to be tested at different heights. When the puncture test piece 3 is released from the fixing by the release mechanism, the puncture test piece 3 falls due to gravity. When the multimeter detects the change in the electrical parameters of the head mold 4, it means that the puncture test piece 4 has penetrated the head mold 3. If the multimeter does not detect the change in the electrical parameters of the head mold 4, it means that the puncture test piece 3 has not penetrated the head mold 4.

[0029] When the parameters detected by the multimeter are a decrease in resistance and an increase in current, it means that the puncture test piece 3 has penetrated the head mold 4; integrating the battery and the current generator into the head mold 4 avoids affecting the falling trajectory of the puncture test piece 3 by connecting the cable, and at the same time avoids the cable length limiting the maximum height that the top plate 1 can be set.

[0030] The release structure is a magnetic lock, which includes an electromagnet 6 and a metal plate 7. The electromagnet 6 is fixedly connected to the lower surface of the top plate 1, and the metal plate 7 is fixedly connected to the top of the puncture test piece 3. The electromagnet 6 is used to fix or release the metal plate 7. The release structure allows the puncture test piece 3 to fall freely, simulating the actual situation faced by the safety helmet under real conditions. This replaces the motion mechanism that simulates the free fall of the puncture test piece 3, avoiding the problem of distortion in the movement process of the puncture test piece 3.

[0031] The puncture test piece 3 includes a counterweight 8 and a puncture hammer 9. The top of the counterweight 8 is fixedly connected to the metal plate 7, and the bottom of the counterweight 8 is fixedly connected to the top of the puncture hammer 9. The puncture hammer 9 is equivalent to a resistor R2.

[0032] Example 2:

[0033] See Figure 3 The difference from Embodiment 1 is that a rotating frame 15 is fixedly connected to the base 2. The rotating frame 10 has a horizontal surface and a hollowed-out top. A support column 13 is rotatably connected inside the rotating frame 10, and the top of the support column 13 is fixedly connected to the bottom of the head mold 4. A motor 12 is fixedly connected to one side of the rotating frame 10. A rotating rod 11 is fixedly connected to the output end of the electrode 12. The rotating rod 11 passes through the rotating frame 10 and the support column 3. The bottom of the support column 13 is fixedly connected to the rotating rod 11, and there is a gap between the bottom of the support column 13 and the base 2 to allow the support column 13 to rotate. First bearings are connected between the rotating rod 11 and both sides of the rotating frame 10. The inner ring of the first bearing is fixedly connected to the rotating rod 11, and the outer ring of the first bearing is fixedly connected to the rotating frame 10. Rotating the head mold 4 changes the tilt angle of the helmet, allowing the pointed cone to pierce different points on the helmet. This structure facilitates omnidirectional puncture testing of the helmet, ensuring its safety.

[0034] The motor drives the head mold to rotate at any angle, testing the protective performance of different parts of the helmet without the need for manual adjustment of the head mold position, thus improving testing efficiency and ensuring that the puncture resistance of the helmet in all directions meets the standards.

[0035] Example 3:

[0036] The difference from Embodiment 1 is that a protective wall is fixedly connected to the edge of the upper surface of the base. This protective wall can be a tempered glass wall or an elastic protective net. The tempered glass wall or elastic protective net prevents injury from shards; the transparent protective wall does not obstruct observation of the testing process; it effectively protects operators from accidental injury and prevents the puncture device from ejecting and damaging surrounding equipment.

[0037] Example 4:

[0038] See Figures 4 to 5 The difference from Embodiment 2 is that a support platform 14 is fixedly connected to the top of the support column 13, and a clamp 15 is fixedly connected to the upper surface of the support platform 14. The clamp 15 is used to hold the head mold 4.

[0039] The support platform 14 has a sliding groove 16, in which two opposing sliders 17 are arranged. Clamping plates 20 are fixedly connected to the ends of the upper surfaces of the two sliders 17 that are far apart from each other. The opposing sides of the two clamping plates 20 are both arc-shaped. Each slider 17 has a threaded hole with opposite internal threads. A lead screw 18 is connected to the internal threads of the threaded hole. Each slider 17 is symmetrically arranged around the midpoint of the lead screw 18. When the lead screw 18 rotates, the two sliders 17 move symmetrically away from or closer to each other. Two counter-pull nuts 19 are threaded onto the lead screw 18, each counter-pull nut 19 located on the side of each slider 17 away from the other slider 17. By rotating the lead screw 18, the two sliders are separated, and the head mold 4 is placed on top of the sliders 17. Rotating the lead screw 18 in the opposite direction clamps the head mold 4 with the clamping plates 20 and locks the counter-pull nuts 19, thus completing the clamping process.

[0040] A fixing block 21 is located at the center of the slide groove 16. A through groove is formed in the fixing block 21. A second bearing is fixedly connected to the center of the through groove. The outer ring of the second bearing is fixedly connected to the through groove, and the inner ring of the second bearing is fixedly connected to the midpoint of the lead screw 18. The direction of the through groove is parallel to the slide groove 16. The lead screw 18 passes through the threaded hole and the through groove.

[0041] The slide groove 16 is a convex slide groove, and each slider 17 is a convex slider. The slider 17 matches the slide groove 16, and the two sliders 17 are slidably disposed on both sides of the fixed block 21.

[0042] The pull-nut design adapts to different sized head molds; the arc-shaped clamping plate fits the curved surface of the head mold, ensuring uniform clamping force distribution; the rotating lead screw enables quick clamping / unclamping, making operation convenient; the reverse thread of the threaded hole ensures symmetrical movement of the two sliders; the convex groove cooperates with the convex slider to prevent jamming and disengagement; the second bearing supports the midpoint of the lead screw to ensure transmission accuracy; the mechanical transmission has high reliability and low maintenance costs; each component is independent, facilitating replacement and maintenance.

Claims

1. A safety helmet puncture test device comprising a top plate (1) and a base (2), the top plate (1) being disposed directly above the base (2); characterized in that, The top plate (1) is provided with a puncture test piece on its lower surface and a release mechanism is provided on its lower surface. The release mechanism is used to fix or release the puncture test piece (3). The base (2) is provided with a head mold (4). The head mold (4) is used to support the safety helmet to be tested. The head mold (4) is connected in series with a detection circuit. The detection circuit is used to detect the change in current or resistance of the head mold (4) after the puncture test piece (3) punctures the head mold (4).

2. A safety hat penetration testing apparatus as claimed in claim 1, wherein, The release mechanism is a magnetic lock, which includes an electromagnet (6) and a metal plate (7). The electromagnet (6) is fixedly connected to the lower surface of the top plate (1), and the metal plate (7) is fixedly connected to the top of the puncture test piece (3). The electromagnet (6) is used to fix or release the metal plate (7).

3. A device for testing the penetration resistance of a safety hat according to claim 2, wherein The puncture test piece includes a counterweight (8) and a puncture hammer (9). The top of the counterweight (8) is fixedly connected to the metal plate (7), and the bottom of the counterweight (8) is fixedly connected to the top of the puncture hammer (9).

4. A device for testing the penetration resistance of a safety helmet according to claim 1, characterized in that A rotating frame (10) is fixedly connected to the base (2). The rotating frame (10) has a horizontal side and a hollowed-out top. A support column (13) is rotatably connected inside the rotating frame (10). The top of the support column (13) is fixedly connected to the bottom of the head mold (4).

5. A device for testing the penetration resistance of a safety hat according to claim 4, wherein The top of the support column (13) is fixedly connected to a support platform (14), and the support platform (14) is fixedly connected to a clamp (15), which is used to hold the head mold (4).

6. A safety hat penetration testing apparatus as claimed in claim 5, wherein, The upper surface of the support platform (14) is provided with a sliding groove (16), and two sliders (17) are slidably arranged in the sliding groove (16). The two sliders (17) are respectively provided with threaded holes with opposite threads. The threaded holes are provided on a lead screw (18). A clamping plate (20) is fixedly connected to the upper surface of the slider (17). The head mold (4) is clamped between the clamping plates (20). Two counter-pull nuts (19) are sleeved on the lead screw (18). The counter-pull nuts (19) are located outside the slider (17).

7. A device for testing the penetration resistance of a safety hat according to claim 6, characterised in that A fixing block (21) is fixedly connected to the center of the slide groove (16). The fixing block (21) has a through groove. A second bearing is fixedly connected to the center of the through groove. The through groove is fixedly connected to the center of the lead screw (18) through the second bearing.

8. A safety hat penetration testing apparatus as claimed in claim 6, wherein, The groove (16) is a convex groove, and the slider (17) is a convex slider. The slider (17) matches the groove (16).

Images