A drop hammer impact test device to prevent secondary impact

Abstract

This invention relates to the technical field of building structure testing devices, and discloses a device for preventing secondary impacts in a drop hammer impact test. The device includes an impact section encircling the outer ring of the drop hammer and a support ring positioned above the specimen. The impact section includes a fixing ring fixed to the outside of the drop hammer. Several pairs of side plates are arranged around the outer ring of the fixing ring. The diameter of the circle containing the outer edge of the side plates is smaller than the diameter of the support ring. A connecting plate is fixed between the pairs of side plates, and a pin is provided between the pairs of side plates. A torsion spring is ring-mounted on the pin. One torsion foot of the torsion spring presses against the lower outer side of the connecting plate, and the other torsion foot presses against the inner side of a pop-out support foot rotatably mounted on the pin. The lower end of the pop-out support foot pops out from between the two side plates and is secured to the support ring. A limit ring is ring-mounted around the outer edge of the side plate in the pop-out direction of the pop-out support foot.

Description

Technical Field

[0001] This invention relates to the field of building structure testing equipment technology, specifically a drop hammer impact test device to prevent secondary impact. Background Technology

[0002] Accidents can cause localized or overall deformation of structural components, and in severe cases, structural collapse. In current testing systems, the drop hammer test is a crucial step in evaluating the impact resistance of specimens. A drop hammer impact testing machine can lift a hammer of a certain mass to a predetermined height, allow it to fall freely and impact the specimen, and then evaluate its impact resistance and other indicators.

[0003] However, the drop hammer in the drop hammer impact test weighs as much as 500 kg. After the initial impact on the specimen, due to the enormous impact force, the drop hammer is often bounced up. Because of its extremely large weight, its subsequent trajectory is very difficult to control. After bouncing up, the drop hammer will quickly fall again, thus generating a secondary impact.

[0004] The occurrence of such secondary impacts directly and negatively affects the accuracy of the impact resistance analysis of the specimens. During impact resistance analysis, the data interference caused by secondary impacts makes it extremely difficult to accurately assess the true impact resistance of the specimens, thus severely impacting the reliability of design methods based on test results. Even more serious is the possibility that the rebounding hammer may cause severe secondary and multiple damages to the specimen. Due to the enormous weight of the hammer, subsequent impacts apply further force to already damaged areas, exacerbating the damage and leading to more complex and unpredictable failure modes within the specimen's internal structure.

[0005] To address this issue, existing technologies typically employ a method of holding the falling hammer in place to prevent secondary impacts. However, in practice, this method has proven infeasible. Due to the immense weight of the falling hammer, the powerful tensile force generated upon impact places a tremendous load on the devices or structures used to hold it in place, easily leading to damage to the equipment and making this control scheme difficult to implement effectively.

[0006] In summary, in existing drop hammer testing systems, the hammer bounces back and falls again after impacting the specimen, causing a secondary impact. This directly affects the accuracy of the specimen's impact resistance analysis and the reliability of the design method. Furthermore, the rebound and subsequent impact can lead to severe secondary and multiple damages. Therefore, it is necessary to invent a drop hammer impact testing system that prevents secondary impacts. Summary of the Invention

[0007] To address the problems of secondary impact in current drop hammer impact testing devices, where the drop hammer bounces back and falls again after impacting the specimen, causing secondary impacts that affect the accuracy of impact resistance analysis and the reliability of design methods, and may lead to serious secondary and multiple damages, this invention provides a drop hammer impact testing device to prevent secondary impacts.

[0008] The present invention is achieved by the following technical solution: it includes an impact part ring mounted on the outer ring of a falling hammer and a support ring set above the specimen. The impact part includes a fixing ring ring fixed to the outside of the falling hammer. Several pairs of side plates are arranged around the outer ring of the fixing ring. The diameter of the circle containing the outer edge of the side plate is smaller than the diameter of the support ring. A connecting plate is fixed between the two pairs of side plates. A pin is provided between the two pairs of side plates. A torsion spring is ring-mounted on the pin. One torsion foot of the torsion spring presses against the lower outer side of the connecting plate. The other torsion foot of the torsion spring presses against the inner side of the pop-out support foot rotatably mounted on the pin. The lower end of the pop-out support foot pops out from between the two side plates and is locked onto the support ring. A limit sliding ring is ring-mounted on the outer edge of the side plate in the pop-out direction of the pop-out support foot.

[0009] In practice, the device includes an impact section encircled by the outer ring of the falling hammer and a support ring positioned above the specimen. The support ring can be fixed above the specimen restraint device and remains fixed at all times; this fixing method is not restricted. The impact section includes a fixing ring fixed to the outside of the falling hammer. The fixing ring is fixed to the outer ring of the falling hammer, and several pairs of side plates are arranged around the outer ring of the fixing ring. There are six pairs of side plates, arranged axially along the fixing ring. The side plates are welded to the outer edge of the fixing ring and are vertical. The diameter of the circle containing the outer edge of the side plate is smaller than the diameter of the support ring, meaning the impact section can pass through the support ring. A connecting plate is fixed between two pairs of side plates, and a pin is provided between two pairs of side plates. That is, pin holes are opened at the same position on both side plates, and the pin passes through the pin holes. A torsion spring and a pop-out support foot are installed through the pin. A torsion spring is ringed on the pin shaft. One torsion foot of the torsion spring presses against the lower outer side of the connecting plate. That is, the upper part of the connecting plate cooperates with the upper part of the pop-out support foot, and the lower part of the connecting plate cooperates with the torsion spring. The other torsion foot of the torsion spring presses against the inner side of the pop-out support foot, which is rotatably mounted on the pin shaft. The lower end of the pop-out support foot pops out from between the two side plates and is locked onto the support ring. The side plates, pop-out support foot, pin shaft, and connecting plate together form a falling stop device, which keeps the falling hammer and impact part above the support ring to avoid secondary impact. The outer edge of the side plate is ringed with a limiting slip ring in the pop-out direction of the pop-out support foot. The inner edge of the limiting slip ring has a groove. When the torsion spring is pressed, the lower end of the pop-out support foot presses against the groove in the limiting slip ring. That is, the limiting slip ring restrains the lower end of the pop-out support foot and prevents the pop-out support foot from popping out under the action of the spring force.

[0010] Specifically, the pop-out support includes two identical side mounting plates with mounting holes that mate with pins. The edges of the two side mounting plates are connected by a top pressure plate. A torsion spring is installed between the two side mounting plates, and the torsion foot of the torsion spring is installed on the top pressure plate. When the torsion spring is relaxed, the edge of the side mounting plate presses against the upper part of the connecting plate.

[0011] In use, the fixed ring and the drop hammer are integrated and move downwards together, passing through the support ring. At this time, the torsion spring is compressed and pushes outwards against the pop-out support foot. The lower end of the pop-out support foot is pressed into the groove in the limiting slip ring and is constrained by the limiting slip ring. The lower end of the pop-out support foot is retracted between the two side plates. When the drop hammer contacts the specimen, the fixed ring and the drop hammer are popped up simultaneously, while the limiting slip ring continues to move downwards under the action of inertia, overcoming the maximum static friction. At this time, the deceleration effect on the limiting slip ring is much smaller than that on the fixed ring, which causes the limiting slip ring to slip off the pop-out support foot. The pop-out support foot loses the constraint of the limiting slip ring and pops out under the action of the torsion spring. After popping out, the pop-out support foot hangs on the outer fixed support ring, thus preventing the device from continuing to move downwards and causing a secondary impact.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] This invention provides a device for preventing secondary impacts in a drop hammer impact test. This device fully utilizes the dynamic performance of the apparatus during the drop hammer impact test. By using a limiting slip ring and a fixing ring, the different deceleration effects after the drop hammer contacts the specimen cause the limiting slip ring, which originally held the support leg, to disengage. This allows the support leg to spring out under the force of a spring and contact the outermost support ring, thus preventing it from continuing to move downwards and causing a secondary impact. This device is easy to operate, highly safe, and effectively prevents secondary impacts. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall invention.

[0015] Figure 2 This is a diagram of the triggering process of the present invention, where a and b represent the falling process, and c represents the rebound process after the start.

[0016] Figure 3 This is a top view of the present invention.

[0017] Figure 4 This is a schematic diagram of the installation of the fixing ring and side plate.

[0018] Figure 5 This is a structural diagram of the side panel.

[0019] Figure 6 This is a schematic diagram of the pop-out support legs.

[0020] Figure 7This is a structural schematic diagram of the connecting plate.

[0021] Figure 8 This is a schematic diagram of the installation of the pop-out support legs.

[0022] Figure 9 This is a schematic diagram of the limiting slip ring.

[0023] In the diagram: 1-fixed ring, 2-limiting sliding ring, 3-support ring, 4-side plate, 5-connecting plate, 6-pop-out support foot, 601-side mounting plate, 602-top pressure plate, 7-pin, 8-torsion spring. Detailed Implementation

[0024] Specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0025] A drop hammer impact test anti-secondary impact device, such as Figures 1-9 As shown, the device includes an impact section encircling the outer ring of the drop hammer and a support ring 3 positioned above the specimen. In this embodiment, the drop hammer and impact section together weigh 566.55 kg, with the drop hammer weighing 486.5 kg. Using conventional methods, it would be difficult to stop the drop hammer of this weight in time, potentially causing a secondary impact. Even if the drop hammer is stopped, it could easily damage the equipment. The support ring 3 can be fixed above the specimen restraint device, and it remains fixed at all times. This fixing method is not restricted. The impact section includes a fixing ring that is encircled and fixed outside the drop hammer. 1. A fixing ring 1 is fixed to the outer ring of the drop hammer. The outer ring of the fixing ring 1 has several pairs of side plates 4, with 6 pairs of side plates 4 arranged axially along the fixing ring 1. The side plates 4 are welded to the outer edge of the fixing ring 1 and are vertical. The diameter of the circle containing the outer edge of the side plate 4 is smaller than the diameter of the support ring 3, meaning the impact part can pass through the support ring 3. A connecting plate 5 is fixed between two pairs of side plates, and a pin 7 is provided between two pairs of side plates 4, meaning pin holes are opened at the same positions on both side plates 4. The pin 7 passes through the pin hole and a torsion spring 8 and a pop-out support leg 6 are installed. The torsion spring 8 is looped around the pin 7. One torsion leg of the torsion spring 8 presses against the lower outer side of the connecting plate 5. That is, the upper part of the connecting plate 5 cooperates with the upper part of the pop-out support leg 6, and the lower part of the connecting plate 5 cooperates with the torsion spring 8. In this embodiment, the upper and lower parts of the connecting plate 5 form an obtuse angle. The other torsion leg of the torsion spring 8 presses against the inner side of the pop-out support leg 6, which is rotatably mounted on the pin 7, and the lower end of the pop-out support leg 6 pops out from between the two side plates 4. Secured to the support ring 3, the side plate 4, pop-out support leg 6, pin 7, and connecting plate 5 together form a falling stop device, keeping the falling hammer and impact part above the support ring 3 to avoid secondary impact; the outer edge of the side plate 4 is fitted with a limiting slip ring 2 in the pop-out direction of the pop-out support leg 6. The inner edge of the limiting slip ring 2 is provided with a groove. When the torsion spring 8 is pressed, the lower end of the pop-out support leg 6 is pressed against the groove in the limiting slip ring 2, that is, the limiting slip ring 2 constrains the lower end of the pop-out support leg 6 to prevent the pop-out support leg 6 from popping out under the action of the spring force.

[0026] like Figure 8 As shown, the pop-out support leg 6 includes two identical side mounting plates 601. The two side mounting plates 601 have mounting holes that mate with the pin 7. The edges of the two side mounting plates 601 are connected by a top pressure plate 602. A torsion spring 8 is installed between the two side mounting plates 601, and the torsion foot of the torsion spring 8 is installed on the top pressure plate 602. When the torsion spring 8 is relaxed, the edge of the side mounting plate 601 presses against the upper part of the connecting plate 5.

[0027] In use, the fixed ring 1 and the drop hammer are integrated and move downward together, passing through the support ring 3. At this time, the torsion spring 8 is in a compressed state and pushes outward against the pop-out support leg 6. The lower end of the pop-out support leg 6 is pressed into the groove in the limiting slide ring 2 and is constrained by the limiting slide ring 2. The lower end of the pop-out support leg 6 is retracted between the two side plates 4. When the drop hammer contacts the specimen, the fixed ring 1 and the drop hammer are popped up synchronously. Under the action of inertia, the limiting slide ring 2 overcomes the maximum static friction and continues to move downward. At this time, the deceleration effect on the limiting slide ring 2 is much smaller than that on the fixed ring 1, which causes the limiting slide ring 2 to slide off the pop-out support leg 6. The pop-out support leg 6 loses the constraint of the limiting slide ring 2 and pops out under the action of the elastic force of the torsion spring 8. After popping out, the pop-out support leg 6 hangs on the outer fixed support ring 3, thereby preventing the device from continuing to move downward and causing a secondary impact.

[0028] The scope of protection claimed by this invention is not limited to the specific embodiments described above. Moreover, for those skilled in the art, this invention can have various modifications and alterations. Any modifications, improvements, and equivalent substitutions made within the concept and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A device for preventing secondary impact in a drop hammer impact test, characterized in that: The test specimen includes an impact part encircling the outer ring of the drop hammer and a support ring (3) positioned above the specimen. The impact part includes a fixing ring (1) fixed around the outside of the drop hammer. The fixing ring (1) has several pairs of side plates (4) arranged around its outer ring. The diameter of the circle containing the outer edge of the side plate is smaller than the diameter of the support ring (3). A connecting plate (5) is fixed between the pairs of side plates. A pin (7) is provided between the pairs of side plates (4). A torsion spring (8) is encircled on the pin (7). One torsion foot of the torsion spring (8) presses against the lower outer side of the connecting plate (5), and the other torsion foot of the torsion spring (8) presses against the inner side of the pop-out support foot (6) rotatably mounted on the pin (7). The lower end of the pop-out support foot (6) pops out from between the two side plates (4) and is secured to the support ring (3). The outer edge of the side plate (4) is located at the pop-out position of the pop-out support foot (6). The ring is fitted with a limiting slip ring (2). When in use, the fixed ring (1) and the drop hammer are integrated and move downward together, passing through the support ring (3). At this time, the torsion spring (8) is in a compressed state and is constrained by the limiting slip ring (2). The lower end of the pop-out support leg (6) is between the two side plates (4). When the drop hammer contacts the specimen, the fixed ring (1) and the drop hammer are popped up synchronously. Under the action of inertia, the limiting slip ring (2) overcomes the maximum static friction and continues to move downward. At this time, the deceleration effect of the limiting slip ring (2) is much smaller than that of the fixed ring (1), which causes the limiting slip ring (2) to slide off the pop-out support leg (6). The pop-out support leg (6) loses the constraint of the limiting slip ring (2) and pops out under the action of the elastic force of the torsion spring (8). After popping out, the pop-out support leg (6) hangs on the outer fixed support ring (3).

2. The drop hammer impact test anti-secondary impact device according to claim 1, characterized in that: The inner edge of the limiting slide ring (2) is provided with a groove. When the torsion spring (8) is pressed, the lower end of the pop-out support foot (6) presses against the groove in the limiting slide ring (2).

3. The drop hammer impact test anti-secondary impact device according to claim 1, characterized in that: The upper part of the connecting plate (5) is engaged with the upper part of the pop-out support leg (6), and the lower part of the connecting plate (5) is engaged with the torsion spring (8).

4. The drop hammer impact test anti-secondary impact device according to claim 1, characterized in that: The pop-out support (6) includes two identical side mounting plates (601), with mounting holes on the two side mounting plates (601) that mate with the pin (7). The edges of the two side mounting plates (601) are connected by a top pressure plate (602). The torsion spring (8) is installed between the two side mounting plates (601), and the torsion foot of the torsion spring (8) is installed on the top pressure plate (602).

5. The drop hammer impact test anti-secondary impact device according to claim 4, characterized in that: When the torsion spring (8) is in a relaxed state, the edge of the side mounting plate (601) presses against the upper part of the connecting plate (5).

6. The drop hammer impact test anti-secondary impact device according to claim 1, characterized in that: The side plate (4) is provided in 6 pairs, and the pairs of side plates (4) are arranged axially along the fixing ring (1).

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