A drop weight impact testing machine for testing the impact resistance of drainage pipes

Abstract

This invention relates to the technical field of engineering experimental equipment and discloses a drop hammer impact testing machine for testing the impact resistance of drainage pipes. To solve the problem of local deceleration due to friction during the downward movement of the experimental hammer, an inner hammer and an experimental hammer are installed on a platform. Both the inner hammer and the experimental hammer descend synchronously under their own weight. During the downward movement of the platform, it moves directionally downward along the emergency stop guide rod and the one-way limiting guide rod. According to the law of free fall, if the resistance between the platform and the emergency stop guide rod and the one-way limiting guide rod causes the downward speed of the platform to decrease, the inner hammer will continue to descend under its own weight, and the movement restriction on the detection push rod will be released. The locking frame finally abuts against the limiting tooth row on the outer side of the one-way limiting guide rod through the locking push rod, thereby obstructing the downward movement of the platform and preventing it from impacting the drainage pipe again after deceleration. Ultimately, the downward speed of the experimental hammer and the inner hammer can be compared in real time.

Description

Technical Field

[0001] This invention relates to the technical field of engineering experimental equipment, and in particular to a drop hammer impact testing machine for testing the impact resistance of drainage pipes. Background Technology

[0002] The drop hammer impact testing machine, used for testing the impact resistance of drainage pipes, is a key piece of equipment that assesses the failure resistance of pipe materials by simulating external impact. Its core principle is based on the law of conservation of energy. An electromagnetic braking system controls the drop hammer to fall freely from a preset height, converting gravitational potential energy into kinetic energy to deliver a momentary impact to a drainage pipe sample fixed on a test platform. By adjusting the drop hammer mass (typically ranging from 2-70 kg) and impact height (up to 3.4 meters), the equipment can perform impact tests at different energy levels.

[0003] However, in practical applications, relative friction inevitably occurs between the experimental hammer and the guide rod. When the frictional resistance between them is relatively small, this friction has little impact on the experimental results, and the resulting error is within the allowable error range of a normal hammer impact experiment, without significantly interfering with the final experimental results. However, after prolonged and frequent use, the guide rod may experience localized deformation due to the long-term impact force of the falling hammer and its own weight; some parts may gradually bend and deform. Furthermore, the guide rod's surface may become contaminated with dirt, such as dust and oil, in the usage environment. When the guide rod experiences localized deformation or becomes dirty, it alters the frictional state between the experimental hammer and the guide rod, causing the experimental hammer to decelerate momentarily during its descent.

[0004] This instantaneous deceleration phenomenon is quite subtle, making it difficult for operators to accurately measure using conventional methods. Because this deceleration cannot be detected and measured in a timely manner, the actual downward impact intensity of the experimental hammer will differ from the predicted impact intensity. When the actual downward impact intensity exceeds the normal error range of the experiment, it ultimately leads to deviations in the overall impact experiment results, affecting the accuracy of the experimental data. Summary of the Invention

[0005] This invention proposes a drop hammer impact testing machine for testing the impact resistance of drainage pipes. It has the advantage of real-time comparison of the downward speed of the test hammer and the inner hammer, and can effectively solve the problem of local instantaneous deceleration caused by friction when a single test hammer descends, as mentioned in the background art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a drop hammer impact testing machine for testing the impact resistance of drainage pipes, comprising: a test platform, an inner bracket for restricting the movement of a guide rod assembly, and a platform and an electromagnet slide located above the platform, the platform being movably mounted on the outer side of the guide rod assembly; a connecting seat is installed at the bottom of the platform, and a protective cylinder is clamped and fastened between the connecting seat and the platform, and a test hammer is threadedly connected to the bottom of the connecting seat; a switching shaft is fitted in the middle of the platform, a traction disc is installed at the top of the switching shaft, and an inner hammer is fixedly installed at the bottom; a locking frame is movably mounted on the surface of the platform, a spring is provided between the locking frame and the platform, and a detection push rod is fixedly connected to one end of the locking frame, and a locking push rod is fixedly installed at the other end, the locking push rod passing through the platform and abutting against the guide rod assembly; when the test hammer pulls the platform downward along the guide rod assembly and is obstructed, the inner hammer continuing to move downward releases the movement restriction of the detection push rod, and the locking frame, under the action of the spring, causes the locking push rod to abut against the guide rod assembly, thereby locking the platform downward.

[0007] Furthermore, the guide rod assembly includes an emergency stop guide rod and a one-way movement limiting guide rod.

[0008] Furthermore, a counterweight ring is fitted on top of the experimental hammer.

[0009] Furthermore, the axis is switched to a stepped axis.

[0010] Furthermore, a limiting toothed section is provided on the side of the one-way limiting guide rod, and a reset inclined section is provided on the side of the one-way limiting guide rod and at the top of the limiting toothed section.

[0011] Furthermore, the tooth profile of the limiting tooth row is a right-angled triangle.

[0012] Furthermore, one end of the detection push rod has a striking head that is pushed outward by a spring, and a bell body located on one side of the striking head is fixedly installed on the surface of the platform.

[0013] Furthermore, the outer side of the emergency stop guide rod has a locking arc block that is pulled by a tension spring, and an emergency stop motor that drives the emergency stop guide rod to rotate is fixedly installed on the top of the bracket.

[0014] Furthermore, a positioning base for placing pipes is installed on the bottom inner side of the experimental platform.

[0015] The present invention has the following beneficial effects:

[0016] This invention provides a drop hammer impact testing machine for testing the impact resistance of drainage pipes, comprising an inner hammer and a test hammer mounted on a platform. Upon entering the testing phase, both the inner hammer and the test hammer are simultaneously subjected to their own gravity, thus beginning their downward movement synchronously. During the downward movement of the platform, it moves directionally downward along an emergency stop guide rod and a one-way limiting guide rod, ensuring the platform descends stably along a predetermined trajectory.

[0017] According to the law of free fall, when the frictional resistance between the platform and the emergency stop guide rod and the one-way limiting guide rod is relatively small, the experimental hammer and the inner hammer will simultaneously undergo free fall under the action of gravity and eventually land at the same time. After landing, the experimental hammer will impact the drainage pipe at a predetermined point according to preset requirements. Through this fixed-point impact method, the impact conditions that the drainage pipe may suffer during actual use can be accurately simulated, thereby providing reliable data for evaluating the impact resistance performance of the drainage pipe.

[0018] If the resistance between the platform and the emergency stop guide rod and the one-way limiting guide rod is significant, causing a noticeable decrease in the platform's downward speed, the inner hammer will continue its downward trend due to the ongoing effect of its own weight. When the inner hammer reaches a certain position, it will release the movement restriction on the detection push rod. After gaining freedom of movement, the detection push rod will engage with the limiting gear on the outer side of the one-way limiting guide rod via the locking push rod. The structural design of the limiting gear effectively prevents the platform from continuing to descend, thus hindering its descent and avoiding unnecessary impact on the drainage pipe. Attached Figure Description

[0019] The accompanying drawings, which form part of this specification, illustrate embodiments of the invention and, together with the specification, serve to explain the principles of the invention.

[0020] The invention will be more clearly understood with reference to the accompanying drawings and the following detailed description, wherein:

[0021] Figure 1 This is a schematic diagram of the overall external three-dimensional structure of the present invention;

[0022] Figure 2 This is a schematic diagram of the installation position and three-dimensional structure of the positioning base of the present invention;

[0023] Figure 3 This is a schematic diagram of the overall front view of the invention and its enlarged partial structure;

[0024] Figure 4 This is a schematic diagram of the external three-dimensional structure of each component on the platform of the present invention;

[0025] Figure 5 This is a schematic diagram showing the positions and three-dimensional structure of the components inside the platform of the present invention;

[0026] Figure 6 For the present invention Figure 5 Enlarged structural diagram of the area at point E in the middle;

[0027] Figure 7 This is a schematic diagram of the cross-sectional structure of the emergency stop guide rod of the present invention.

[0028] In the diagram: 1. Experimental table; 2. Support; 3. Emergency stop guide rod; 301. Locking arc block; 4. One-way movement limiting guide rod; 401. Movement limiting gear row; 402. Reset inclined part; 5. Electromagnet slide; 6. Emergency stop motor; 7. Platform; 8. Protective cylinder; 9. Connecting seat; 10. Experimental hammer; 11. Counterweight ring; 12. Traction disc; 13. Positioning base; 14. Locking frame; 141. Locking push rod; 142. Detection push rod; 143. Striking head; 15. Bell body; 16. Switching shaft; 161. Inner hammer. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1, please refer to Figures 1-3 As can be seen, there is a positioning base 13 installed on the inner bottom of the experimental platform 1, which is fastened with bolts. The positioning base 13 cooperates with the cylinder pressure rod, which is not shown in the figure. When the drainage pipe is placed on the positioning base 13, the cylinder pressure rod limits the drainage pipe, ensuring that the drainage pipe can be stably placed on the positioning base 13.

[0031] The inner wall of the experimental table 1 has a bracket 2 that is bolted on. Figure 2 and Figure 3 As can be seen, an emergency stop guide rod 3 and a one-way limiting guide rod 4 are vertically and movably installed on both sides of the positioning base 13 between the support 2 and the experimental platform 1. Preferably, the emergency stop guide rod 3 and the one-way limiting guide rod 4 are round rods. A platform 7 and an electromagnet slide 5 located above the platform 7 are movably installed on the outer side of the emergency stop guide rod 3 and the one-way limiting guide rod 4. The electromagnet slide 5 is connected to a motor-driven rope drum via a traction rope. The traction rope controls the up-and-down movement of the electromagnet slide 5, and the electromagnet slide 5, when energized, generates magnetism that pulls the platform 7 to move upwards synchronously. Specifically, in conjunction with... Figures 3-5It can be seen that the bottom of the platform 7 has a connecting seat 9 that is bolted on, and a protective sleeve 8 is clamped and secured between the connecting seat 9 and the platform 7. The bottom of the connecting seat 9 is threadedly connected to the experimental hammer 10 located above the positioning base 13. When the experimental hammer 10 is vertically guided and limited by the platform 7, the emergency stop guide rod 3, and the one-way limiting guide rod 4, the experimental hammer 10 can finally accurately strike the drainage pipe on the positioning base 13. In order to adjust the hammering force of the experimental hammer 10, a counterweight ring 11 is fitted on the top of the experimental hammer 10, and the threaded connection between the nut and the experimental hammer 10 ensures that the counterweight ring 11 and the experimental hammer 10 are always tightly fitted together, so that the downward impact intensity of the experimental hammer 10 can be freely adjusted.

[0032] from Figures 3-4 As can be seen, a switching shaft 16 located inside the protective cylinder 8 is mounted in the middle of the platform 7. The switching shaft 16 is a stepped shaft. A traction disc 12 is fastened to the top of the switching shaft 16 by bolts, and an inner hammer 161 located inside the protective cylinder 8 is fixedly mounted to the bottom of the switching shaft 16. Under normal conditions, when the electromagnet slide 5 moves downward and approaches the traction disc 12, the magnetism generated by the energized electromagnet slide 5 attracts the traction disc 12. As the traction disc 12 drives the switching shaft 16 upward, the platform 7 simultaneously pulls the experimental hammer 10 upward, thus ensuring that the experimental hammer 10 can obtain initial kinetic energy.

[0033] Furthermore, a locking frame 14 is movably mounted on the surface of the platform 7, and the locking frame 14 can only move horizontally back and forth along the platform 7. A spring is provided between the locking frame 14 and the platform 7, and a detection push rod 142 is fixedly connected to one end of the locking frame 14. A ball is provided at one end of the detection push rod 142. Under normal conditions, when the spring pushes the locking frame 14 to move to one side, the locking frame 14 pulls the detection push rod 142, causing the ball at its end to abut against the outer side of the switching shaft 16. At the same time, a locking push rod 141 is fixedly mounted on the end of the locking frame 14 away from the detection push rod 142. The locking push rod 141 passes through the platform 7 and can abut against the side of the one-way limiting guide rod 4.

[0034] Combination Figure 2 and Figure 3 It is evident that the one-way limiting guide rod 4 has a limiting tooth row 401 on its side relative to the locking push rod 141. The tooth shape of the limiting tooth row 401 is a right-angled triangle. Furthermore, a reset slope 402 is provided on the side of the one-way limiting guide rod 4 and at the top of the limiting tooth row 401. When the platform 7 drives the locking push rod 141 to move upward, the locking push rod 141 eventually moves along the reset slope 402 and abuts against the outer side of the one-way limiting guide rod 4. This enables the locking frame 14 to drive the detection push rod 142 from the top of the switching shaft 16 with a small diameter to the outer side with a large bottom diameter.

[0035] Specifically, in the actual application of this embodiment, the electromagnet slide 5 is lowered using a traction rope and positioned above the traction disc 12. After the electromagnet slide 5 is energized and generates magnetism, it attracts the traction disc 12. Subsequently, the traction rope causes the electromagnet slide 5 to pull the traction disc 12 upward synchronously. The traction disc 12 also causes the platform 7 to move vertically upward along the emergency stop guide rod 3 and the one-way limiting guide rod 4. When the platform 7 approaches the reset slope 402, the locking push rod 141 moves along the slope and eventually reaches the outer side of the one-way limiting guide rod 4. At this time, the locking push rod 141 causes the locking frame 14 to further compress the spring, while the detection push rod 142 moves away from the switching shaft 16. As the traction disc 12 pulls the switching shaft 16 further upward, the top of the detection push rod 142 finally reaches the outer side of the bottom of the switching shaft 16 with a larger diameter.

[0036] Afterwards, the operator fixes the drainage pipe to be tested onto the positioning base 13. Then, using the traction rope, the electromagnet slide 5 is driven downwards. At this time, the platform 7, under the gravity of the experimental hammer 10, moves vertically downwards along the emergency stop guide rod 3 and the one-way limiting guide rod 4. The electromagnet slide 5 remains energized. Furthermore, during the downward movement of the platform 7, if the detection push rod 142 fails to properly reach the outer side of the larger diameter of the switching shaft 16, the locking push rod 141, after passing the reset slope 402, will be forced to abut against the limiting gear rack 401 due to the spring pushing the locking frame 14 outwards. Combined with the downward limiting characteristic of the limiting gear rack 401, this prevents the platform 7 from moving downwards, thus warning the operator that the locking frame 14 on the platform 7 has not been fully reset and needs to be reset and adjusted again. If the locking frame 14 is reset normally, the top of the detection push rod 142 will also abut against the outer bottom of the larger diameter of the switching shaft 16. As the electromagnet slide 5 controls the platform 7 to descend to the designated height... The traction force between the electromagnet slide 5 and the traction disc 12 is cut off by de-energizing the electromagnet slide 5.

[0037] As the experimental hammer 10 pulls the platform 7 downwards, the inner hammer 161 synchronously tends to pull the switching shaft 16 downwards. Under normal conditions, according to the law of free fall, the experimental hammer 10 and the inner hammer 161 will descend synchronously until the experimental hammer 10 finally impacts the drainage pipe. If, during the descent, motion resistance occurs between the platform 7 and the emergency stop guide rod 3 and the one-way limiting guide rod 4, this resistance will cause the downward speed of the experimental hammer 10 pulling the platform 7 to decrease, but the inner hammer 161 will always move downwards under gravity. Therefore, the inner hammer 161 moves downwards relative to the platform 7. After the inner hammer 161 pulls the switching shaft 16 downwards, the bottom of the switching shaft 16 with the larger diameter descends, and the top with the larger diameter moves to the side of the detection push rod 142. The locking frame 14, pushed by the spring, will cause the detection push rod 142 to abut against the top of the outer side of the switching shaft 16 with a smaller diameter, and at the same time, the locking push rod 141 will abut against the limiting gear rack 401. The locking push rod 141 and the limiting gear rack 401 are used to lock the platform 7 downward, ensuring that the platform 7 can lock itself after encountering significant resistance downward, thereby avoiding useless impact on the drainage pipe below.

[0038] Finally, since the switching shaft 16 is a stepped shaft, the traction disc 12 can only be pulled upward by the electromagnet slide 5, and the locking push rod 141 can only move and pass the reset slope 402 before the detection push rod 142 can pass the stepped shaft and return to the detection state. In this way, the structure set in this application can ensure that the platform 7 and the inner hammer 161 can be compared in real time during the downward movement. When the platform 7 decelerates, the locking push rod 141 can reach the limiting tooth row 401 in time and lock the position of the platform 7.

[0039] Not limited to this, after the experimental hammer 10 descends normally, upon impact, it will rebound upwards. At this moment, the inner hammer 161 will continue to move downwards due to gravity, thus releasing the movement restriction of the detection push rod 142. During the upward rebound of the platform 7 driven by the experimental hammer 10, the locking frame 14 pushes the locking push rod 141 against the limiting gear row 401 and moves upwards along it. When the experimental hammer 10 pushes the platform 7 back to its highest position, the locking push rod 141, against the limiting gear row 401, achieves downward locking, preventing the experimental hammer 10 from pulling the platform 7 downwards again, thus avoiding a secondary impact on the drainage pipe by the experimental hammer 10.

[0040] Example 2 is a further improvement on Example 1. Please refer to Example 1. Figures 3-6 It can be seen that the end of the detection push rod 142, which is far from the switching axis 16, has a striking head 143 that is pushed outward by a spring. Correspondingly, a bell body 15 located on one side of the striking head 143 is fixedly installed on the surface of the platform 7.

[0041] Under normal conditions, when the detection push rod 142 reaches the outer side of the bottom with the larger diameter of the switching shaft 16, the striking head 143 reaches the bell body 15 and compresses the spring. When the switching shaft 16 moves downward, the locking bracket 14 drives the detection push rod 142 to move towards the top of the outer side with the smaller diameter of the switching shaft 16. At this time, the detection push rod 142 will also drive the striking head 143 away from the bell body 15. At this time, the spring between the detection push rod 142 and the striking head 143 is in a free extension state.

[0042] Based on this, it can be seen that if the platform 7 decelerates during the descent, the locking frame 14 will push out the detection push rod 142 and the locking push rod 141. As the switching shaft 16 pulls the traction disc 12 down, the traction disc 12 will eventually hit the bell body 15. The single impact of the traction disc 12 on the bell body 15 serves as a warning to the operator that the platform 7 has automatically locked due to the descent deceleration.

[0043] Similarly, if the test hammer 10 impacts the drainage pipe normally, during the process of the test hammer 10 pushing the platform 7 upward and rebounding, the locking push rod 141 continuously moves back and forth along the limiting tooth row 401, and through the detection push rod 142, drives the striking head 143 to frequently strike the bell body 15, causing the bell body 15 to emit a continuous sound, thereby alerting the operator that the impact test on the drainage pipe has been completed.

[0044] In summary, it can be seen that operators can quickly determine whether the experimental hammer 10 is correctly impacting the drainage pipe based on the length of the sound source. If the operator does not hear a sound, it indicates that the experimental hammer 10 is in the process of descending, which will also warn the operator to avoid approaching.

[0045] Example 3, as a supplement to Example 2 and Example 1, addresses the situation in practical applications where, if the operator needs to stop hammering while the platform 7 is falling, [further details are needed]. Figure 2 , Figure 3 and Figure 7 It can be seen that the outer side of the emergency stop guide rod 3 has a locking arc block 301 that is pulled by a tension spring. Under normal conditions, the locking arc block 301 and the emergency stop guide rod 3 form a complete cylinder, thereby realizing the guiding function when the platform 7 moves vertically up and down. The emergency stop motor 6 is fixedly installed on the top of the bracket 2, and its output shaft is fixedly connected to the emergency stop guide rod 3.

[0046] If it is necessary to stop the descending platform 7 urgently, the operator can press the emergency stop button on the control panel, and the control system will make the emergency stop motor 6 rotate rapidly. When the emergency stop guide rod 3 drives the locking arc block 301 to rotate, the locking arc block 301 is thrown outward by centrifugal force. On the one hand, the speed is reduced by increasing the friction between the locking arc block 301 and the platform 7. On the other hand, when the descending speed of the platform 7 decreases, the platform 7 is suspended and locked in the manner described in Embodiment 1, and finally the platform 7 can be stopped and locked in real time during the descent.

Claims

1. A drop hammer impact testing machine for testing the impact resistance of drainage pipes, characterized in that, include: The experimental table (1) has a bracket (2) installed on the inside to restrict the movement of the guide rod assembly, and a platform (7) and an electromagnet slide (5) located above the platform (7) are movably installed on the outside of the guide rod assembly. A connecting seat (9) is installed at the bottom of the stage (7), and a protective cylinder (8) is clamped and fastened between the connecting seat (9) and the stage (7). A test hammer (10) is threadedly connected to the bottom of the connecting seat (9). A switching shaft (16) is fitted in the middle of the platform (7). A traction disc (12) is installed on the top of the switching shaft (16), and an inner hammer (161) is fixedly installed at the bottom. A locking frame (14) is movably installed on the surface of the platform (7). A spring is provided between the locking frame (14) and the platform (7). One end of the locking frame (14) is fixedly connected to a detection push rod (142), and the other end is fixedly installed with a locking push rod (141). The locking push rod (141) passes through the platform (7) and abuts against the guide rod assembly. The guide rod assembly includes an emergency stop guide rod (3) and a one-way movement limiting guide rod (4). A limited movement toothed rack (401) is provided on the side of the one-way limited movement guide rod (4), and a reset inclined part (402) is provided on the side of the one-way limited movement guide rod (4) and at the top of the limited movement toothed rack (401). The tooth profile of the limiting tooth row (401) is a right-angled triangle; When the experimental hammer (10) pulls the platform (7) down along the guide rod assembly and is blocked, the inner hammer (161) continues to descend and releases the movement restriction of the detection push rod (142). The locking frame (14) is subjected to the action of the spring and causes the locking push rod (141) to abut against the guide rod assembly. At the same time, the locking push rod (141) abuts against the limiting tooth row (401). The platform (7) is locked down by the locking push rod (141) and the limiting tooth row (401), thus realizing the downward locking of the platform (7). When the downward speed of the platform (7) decreases, the platform (7) can finally be suspended and locked in real time during the falling process.

2. The drop hammer impact testing machine for testing the impact resistance of drainage pipes according to claim 1, characterized in that, The experimental hammer (10) is fitted with a counterweight ring (11) on top.

3. The drop hammer impact testing machine for testing the impact resistance of drainage pipes according to claim 1, characterized in that, Switch axis (16) to a stepped axis.

4. The drop hammer impact testing machine for testing the impact resistance of drainage pipes according to claim 1, characterized in that, The detection push rod (142) has a striking head (143) that is pushed outward by a spring at one end, and a bell body (15) located on one side of the striking head (143) is fixedly installed on the surface of the platform (7).

5. The drop hammer impact testing machine for testing the impact resistance of drainage pipes according to claim 1, characterized in that, The outer side of the emergency stop guide rod (3) has a locking arc block (301) pulled by a tension spring, and the top of the bracket (2) is fixedly installed with an emergency stop motor (6) that drives the emergency stop guide rod (3) to rotate.

6. The drop hammer impact testing machine for testing the impact resistance of drainage pipes according to claim 1, characterized in that, The bottom inner side of the experimental table (1) is equipped with a positioning base (13) for placing pipes.

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