Novel multi-angle head drop hammer impact device and test method

Abstract

The invention discloses a novel multi-angle head drop hammer impact device and a test method. According to the device, a steering engine is adopted to drive a clamp to assemble a drop hammer, electromagnetic interference is avoided, friction of a motor shaft is also avoided, and repeatability and accuracy of an experimental result are improved; the supporting arc plate for clamping the head model and the bottom plate are fastened through meshing of teeth in two directions, so that the fastening effect is extremely high, movement is not prone to occurring when the head model bears impact of a drop hammer, the fastening mode is simple and easy to operate, and rapid and repeated testing is facilitated; a movable mounting structure is arranged between the hammer head and the impact plate, so that the position of the hammer head can be finely adjusted in all directions, the position deviation caused by tooth meshing can be conveniently adjusted, in addition, a gel ice and snow plate is arranged around the head model, the actual temperature on the head model is controlled, and the impact effect at the low temperature can be simulated.

Description

Technical Field

[0001] The invention belongs to the technical field of impact testing, and in particular relates to a novel multi-angle head drop hammer impact device and a testing method. Background Art

[0002] As the most important part of the human body, the protection of the human brain is highly valued in daily life. People have taken a variety of protective measures to prevent sudden external impacts. For example, wearing a helmet when driving and a hard hat when working. These protective measures are all to resist impacts from uncertain directions from all directions, such as falling objects from high altitudes, falls and collisions.

[0003] In order to better understand the head when subjected to various impact forces, it is important to develop a device that can simulate the sudden impact that the head may be subjected to. At present, although there are some drop weight measurement devices, few can be used to simulate head impact, and these devices have many shortcomings in actual operation.

[0004] The current drop weight measurement device generally requires manual installation of the drop weight and manual adjustment of the drop weight height. For example, patent CN118730765A. This method has the following problems in actual operation: when the drop weight is heavy, manual installation will be very cumbersome. If the drop weight needs to be adjusted to a higher height, manual adjustment will become troublesome and dangerous, and the operator needs to use a ladder or other auxiliary tools to reach a higher position for adjustment. On the other hand, the accuracy of manual adjustment is also difficult to guarantee, which may affect the accuracy of the experimental results.

[0005] Some devices release the hammer head by turning on and off the electromagnetic field, that is, the hammer head is adsorbed on the electromagnet, and the electromagnet is de-energized and demagnetized to release the hammer head. For example, patent CN118362384A. This release method will cause the electromagnet to generate a large amount of electromagnetic interference to the hammer head and surrounding sensors. In the process of drop hammer impact measurement, the sensor is the core hardware, and its accuracy has a huge impact on the measurement results. Electromagnetic interference will cause inaccurate measurement data of the sensor, thereby affecting the assessment of the impact condition of the head.

[0006] Some other devices release by powering off the motor, such as patent CN221765160A. This method also has some problems: when the motor is powered off, the release by the rotation of the motor shaft will have a certain resistance, so the free fall effect cannot be formed. The friction of the motor shaft will affect the falling speed, causing the experimental results to deviate from the actual situation. This release method will also shorten the life of the motor. Frequent motor power-off release will cause wear on the motor, reduce the service life of the motor, and increase the maintenance cost of the equipment.

[0007] At present, almost all drop weight impact equipment uses clamps to clamp the two sides of the sample to fix the sample. This fixing method has the following limitations: it can only achieve single-angle impact. This fixing method is not suitable for measuring the situation where the simulated head is impacted at different angles.

[0008] In view of the above problems, a drop weight impact test device has been studied in the hope of designing a new drop weight impact test device and method that can solve the above problems. Summary of the invention

[0009] In order to overcome the above problems, a novel multi-angle head drop hammer impact device and testing method are designed. The device adopts a servo drive fixture to assemble the drop hammer, which avoids electromagnetic interference and friction of the motor shaft, thereby improving the repeatability and accuracy of the experimental results; the supporting arc plate and the bottom plate that clamp the head model are fastened by tooth engagement in two directions, so that the fastening effect is extremely high, and it is not easy to move when subjected to the impact of the drop hammer, and the fastening method is simple and easy to operate, which is convenient for rapid repeated testing; a movable mounting structure is provided between the hammer head and the impact plate, so that the position of the hammer head can be fine-tuned in all directions, so as to adjust the position deviation caused by tooth engagement, and in addition, a gel ice and snow plate is arranged around the head model to control the actual temperature on the head model, so as to simulate the impact effect at low temperature, thereby completing the present invention.

[0010] Specifically, the object of the present invention is to provide a novel multi-angle head drop hammer impact device, which includes a lifting platform located at the top and an impact platform located at the bottom; The lifting platform comprises a lifting plate capable of moving up and down, a hammer head capable of falling freely is arranged on the lifting plate, and the falling starting height of the hammer head can be adjusted; The impact platform includes a supporting arc plate, which can move in the horizontal direction; a groove is opened on the supporting arc plate along its circumference, a connecting rod mechanism is installed on the groove, and a head model is arranged at the end of the connecting rod mechanism. The angle of the head model is adjusted by controlling the connecting rod mechanism to rotate along the groove and the connecting rod mechanism itself.

[0011] The lifting platform further comprises a lifting motor, a main shaft of the lifting motor is connected with a sprocket, a chain connected with the lifting plate is arranged on the sprocket, and the lifting motor controls the lifting plate to move up and down through the sprocket and the chain; Preferably, the lifting platform further comprises a longitudinal guide rail, and the lifting plate is provided with a guide sleeve sleeved on the outer side of the longitudinal guide rail, and the cooperation between the longitudinal guide rail and the guide sleeve provides a limit for the up and down movement of the lifting plate.

[0012] Wherein, a clamp consisting of two clamping rods is arranged on the lifting plate, An impact plate is connected above the hammer head, and a terminal is arranged above the impact plate. The clamp can open and close to clamp the end head. When the clamp releases the end head, the hammer head, the impact plate and the end head are free to fall synchronously, and the hammer head impacts the head model.

[0013] Wherein, a steering gear is arranged on the lifting plate, a cam is connected to the steering gear, and the cam is arranged between two clamping rods. The steering gear drives the cam to rotate to open the clamp, so that the clamp releases the end.

[0014] The impact plate and the hammer are connected via a piezoelectric dynamic force sensor, the hammer can translate along the X-axis in the horizontal direction relative to the piezoelectric dynamic force sensor, and the piezoelectric dynamic force sensor can translate along the Y-axis in the horizontal direction relative to the impact plate, and the X-axis is perpendicular to the Y-axis; The height distance between the impact plate and the hammer head can be adjusted by rotating the piezoelectric dynamic force sensor.

[0015] A lower groove with a T-shaped cross section is provided at the top of the hammer head along the X-axis direction, the lower groove is narrow at the top and wide at the bottom, a T-shaped nut is installed in the lower groove, and the T-shaped nut can slide in the lower groove along the X-axis direction; An upper groove with a T-shaped cross section is provided at the bottom of the impact plate along the Y-axis direction. The upper groove is wide at the top and narrow at the bottom. A square nut is installed in the upper groove. The square nut can slide in the upper groove along the Y-axis direction. An upper bolt is arranged above the piezoelectric dynamic force sensor, and a lower bolt is arranged below the piezoelectric dynamic force sensor. The upper bolt and the lower bolt have opposite rotation directions. The upper bolt is screwed into the square nut, and the lower bolt is screwed into the T-shaped nut.

[0016] The impact table further comprises an X-axis tooth surface bottom plate at the bottom, on which racks with densely arranged triangular cross-sections and extending along the X-axis direction are arranged; horizontal guide rails extending along the Y-axis direction are arranged on both sides of the X-axis tooth surface bottom plate, and guide rail sliders capable of reciprocating along the horizontal guide rails are arranged on the horizontal guide rails; On the guide rail slider, a Y-axis tooth surface bottom plate is arranged along the length direction of the guide rail slider, and the Y-axis tooth surface bottom plate is provided with densely arranged racks with triangular cross-sections and extending along the Y-axis direction; The guide rail slider is also provided with an embedded slider that can slide back and forth along the length direction of the guide rail slider, and the supporting arc plate is installed on the embedded slider, and the supporting arc plate is driven to move in the horizontal direction by sliding the guide rail slider and the embedded slider; Preferably, a fixed rod capable of reciprocating in the vertical direction is also provided on the embedded slider; a horizontal fixed rotary lock knob screwed with the embedded slider is provided above the fixed rod, and a Y-axis toothed insert and an X-axis toothed insert are provided below the fixed rod; when the fixed rod is pressed downward by the horizontal fixed rotary lock knob, the Y-axis toothed insert engages with the Y-axis toothed bottom plate, and the X-axis toothed insert engages with the X-axis toothed bottom plate, thereby locking the embedded slider and supporting the arc plate in the horizontal direction.

[0017] The connecting rod mechanism includes a fixing bolt, the head model is screwed and fixed on the end of the fixing bolt, and an arc fixing lock knob, an arc plate inner slider and a fixing sleeve are arranged on the fixing bolt; the arc fixing lock knob is integrated with the fixing bolt and rotates synchronously, and the arc plate inner slider is in an arc shape as a whole, and a rack with a triangular cross section is provided on it; In the supporting arc plate, a cavity with an overall arc shape for accommodating the slider in the arc plate is provided on both sides of the slot; a rack with a triangular cross section is provided on the arc-shaped top surface of the cavity, and the slider in the arc plate can move in the cavity to facilitate adjustment of the angle of the connecting rod mechanism and the head model; The connecting rod mechanism is fixed and locked to the supporting circular arc plate by meshing the sliding block in the circular arc plate with the arc-shaped top surface of the cavity.

[0018] The present invention also provides a novel multi-angle head drop hammer impact test method, which is implemented by the novel multi-angle head drop hammer impact device described above.

[0019] The method comprises the following steps: Step 1, control the steering gear to rotate 90 degrees to open the clamp; control the lifting plate to descend through the lifting motor so that the clamp can clamp the end; then control the steering gear to rotate 90 degrees so that the clamping rod clamps the clamping end; Step 2: Move the guide rail slider and the embedded slider to the predetermined position, and then control the fixing rod to move downward by the horizontal fixing lock knob to lock the embedded slider and the supporting arc plate in the horizontal direction; Step 3, install the head model on the fixing bolt and lock it with the fixing sleeve; after the slider in the arc plate slides to the predetermined position in the cavity, that is, after adjusting the installation angle of the connecting rod mechanism, tighten the slider in the arc plate through the arc fixing locking knob, so that the slider in the arc plate engages with the arc-shaped top surface of the cavity, and locks the connecting rod mechanism to the supporting arc plate; Step 4, install the piezoelectric dynamic force sensor and the hammer head on the impact plate, fine-tune the position of the hammer head in the horizontal direction to eliminate the error caused by the tooth meshing on the impact table; and fine-tune the height of the hammer head by rotating the piezoelectric dynamic force sensor; Step 5, embed the gel ice snow board into the groove of the baffle frame, and then install the baffle frame into the support frame so that the gel ice snow board surrounds the head model; Step 6, control the servo to rotate and open the clamp, and the impact plate falls freely along the falling wire, and the hammer impacts the head model, and the data information is obtained by measuring the piezoelectric dynamic force sensor and the optical displacement sensor.

[0020] The beneficial effects of the present invention include: (1) According to the novel multi-angle head drop hammer impact device and impact method provided by the present invention, a servo-driven fixture is used to assemble the drop hammer. The fixture has a simple structure and can be quickly installed by simply controlling the rotation of the servo. (2) According to the novel multi-angle head drop hammer impact device and impact method provided by the present invention, the hammer head is released by the cooperation of the servo and the fixture, thereby avoiding the interference of the strong electromagnetic property of the electromagnet on the sensor; the measurement accuracy of the sensor can be ensured, and the reliability and repeatability of the experiment can be improved; (3) According to the novel multi-angle head drop hammer impact device and impact method provided by the present invention, the device uses a motor to drive a sprocket chain for lifting, has no limit on the lifting height, is very safe, and can more accurately control the lifting height of the drop hammer to meet different experimental requirements; (4) According to the novel multi-angle head drop hammer impact device and impact method provided by the present invention, a gel ice snow board is installed around the support frame. The gel ice snow board is simple and quick to install and can be disassembled and installed at any time as needed. It can effectively simulate the impact under low temperature conditions, and the low temperature lasts for a long time. There is no need for long-term refrigeration preparation before the experiment, which can greatly improve the experimental efficiency. (5) According to the novel multi-angle head drop hammer impact device and impact method provided by the present invention, the sample fixing table of the device adopts the cooperation of guide rails, slide grooves and sliders, which can impact the head and samples similar to the head model in all directions and angles, and better simulate the various angles of impact that the head is subjected to in actual situations; (6) According to the novel multi-angle head drop hammer impact device and impact method provided by the present invention, the impact table only needs to be tightened twice to fix the movement of four degrees of freedom, and the disassembly and assembly are very convenient. This design can improve the experimental efficiency and reduce the operation time; (7) According to the novel multi-angle head drop hammer impact device and impact method provided by the present invention, the four degrees of freedom of the impact table, such as sliding and rotating, are fixed by tooth meshing, which is more stable than friction and can withstand greater impact force, thus ensuring the accuracy of the experimental results; (8) According to the novel multi-angle head drop hammer impact device and impact method provided by the present invention, a nut and a groove are arranged between the hammer head and the impact plate to cooperate with each other so as to eliminate the slight error caused by the tooth meshing fixation and improve the accuracy of the experiment; (9) According to the novel multi-angle head drop hammer impact device and impact method provided by the present invention, the helmet can be mounted on the impact platform to measure the force displacement change during the impact process in real time, thereby evaluating the helmet's impact resistance, buffering effect and other safety performance indicators; (10) According to the novel multi-angle head drop hammer impact device and impact method provided by the present invention, by measuring the stress-strain parameters of different materials under the drop hammer impact, the most suitable material for simulating the human head can be screened out. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The overall structure diagram of the novel multi-angle head drop hammer impact device in the present application is shown; Figure 2 A schematic diagram showing the structure of a lifting platform of a novel multi-angle head drop hammer impact device in the present application; Figure 3 A schematic diagram showing the structure of the bottom of the impact plate on the lifting platform of the novel multi-angle head drop hammer impact device in the present application; Figure 4 The explosive head at the hammer head and the piezoelectric dynamic force sensor on the lifting platform of the novel multi-angle head drop hammer impact device in the present application is shown; Figure 5 A schematic diagram showing the structure of an impact platform of a novel multi-angle head drop hammer impact device in the present application; Figure 6 A cross-sectional view showing one side of an impact platform of a novel multi-angle head drop hammer impact device in the present application; Figure 7 A cross-sectional view showing the other side of the impact platform of the novel multi-angle head drop hammer impact device in the present application; Figure 8 A schematic diagram showing the structure of the supporting arc plate and the connecting rod mechanism on the impact table of the novel multi-angle head drop hammer impact device in the present application; Fig. 9 A schematic diagram showing the structure of the connecting rod mechanism on the impact platform of the novel multi-angle head drop hammer impact device in the present application; Fig.10 A schematic structural diagram of a baffle frame of a novel multi-angle head drop hammer impact device in the present application is shown.

[0022] 1-lifting plate, 2-hammer, 3-support arc plate, 4-slot, 5-connecting rod mechanism, 6-head model, 7-lifting motor, 8-sprocket, 9-chain, 10-longitudinal guide rail, 11-guide sleeve, 12-clamping rod, 13-impact plate, 14-end, 15-servo, 16-cam, 17-piezoelectric dynamic force sensor, 18-lower groove, 19-T-nut, 20-upper groove, 21-square nut, 22-upper bolt, 23-lower bolt, 24-through hole, 25-bottom of X-axis tooth surface Plate, 26-horizontal guide rail, 27-guide rail slider, 28-Y-axis tooth surface bottom plate, 29-embedded slider, 30-fixing rod, 31-horizontal fixed rotary lock knob, 32-Y-axis tooth pattern insert, 33-X-axis tooth pattern insert, 34-fixing bolt, 35-arc fixed rotary lock knob, 36-arc plate inner slider, 37-fixing sleeve, 38-cavity, 39-baffle frame, 40-groove, 41-support frame, 42-mounting boss, 43-mounting groove, 44-optical displacement sensor, 45-falling wire. DETAILED DESCRIPTION

[0023] The present invention will be further described in detail below through the accompanying drawings and embodiments. Through these descriptions, the characteristics and advantages of the present invention will become more clear and distinct.

[0024] The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise noted.

[0025] The present invention provides a novel pendulum impact device, such as Figure 1 As shown in , the device includes a lifting table located at the top and an impact table located at the bottom; The lifting platform comprises a lifting plate 1 which can move up and down, on which a hammer head 2 which can fall freely is arranged, and the falling starting height of the hammer head 2 can be adjusted; The impact platform includes a supporting arc plate 3, which can move in the horizontal direction; a groove 4 is opened on the supporting arc plate 3 along its circumference, a connecting rod mechanism 5 is installed on the groove 4, and a head model 6 is arranged at the end of the connecting rod mechanism 5. The angle of the head model 6 is adjusted by controlling the connecting rod mechanism 5 to rotate along the groove 4 and the connecting rod mechanism 5 itself.

[0026] In a preferred embodiment, Figure 1 As shown in , the lifting platform also includes a lifting motor 7, a sprocket 8 is connected to the main shaft of the lifting motor 7, a chain 9 connected to the lifting plate 1 is arranged on the sprocket 8, and the lifting motor 7 controls the lifting plate 1 to move up and down through the sprocket 8 and the chain 9; Preferably, the lifting platform further comprises a longitudinal guide rail 10, and the lifting plate 1 is provided with a guide sleeve 11 sleeved on the outside of the longitudinal guide rail 10, and the cooperation between the longitudinal guide rail 10 and the guide sleeve 11 provides a limit for the lifting plate 1 to move up and down.

[0027] In a preferred embodiment, Figure 2 As shown in FIG. 1 , a clamp consisting of two clamping rods 12 is provided on the lifting plate 1. An impact plate 13 is connected above the hammer head 2, and an end head 14 is arranged above the impact plate 13. The clamp can open and close to clamp the end head 14. When the clamp releases the end head 14, the hammer head 2, the impact plate 13 and the end head 14 are synchronously freed, and the hammer head 2 impacts the head model 6.

[0028] Preferably, a steering gear 15 is provided on the lifting plate 1 , and a cam 16 is connected to the steering gear 15 . The cam 16 is provided between the two clamping rods 12 . The steering gear 15 drives the cam 16 to rotate to open the clamp, so that the clamp releases the end 14 .

[0029] Preferably, a spring is provided inside the impact plate 13 and outside the clamping rod 12 , and the clamping rod 12 is pressed inwardly by the spring so that the clamping rod 12 remains in an inwardly contracted state, thereby clamping the end 14 .

[0030] In a preferred embodiment, Figure 2 , Figure 3 , Figure 4 As shown in the figure, the impact plate 13 and the hammer head 2 are connected by a piezoelectric dynamic force sensor 17, the hammer head 2 can translate along the X-axis in the horizontal direction relative to the piezoelectric dynamic force sensor 17, and the piezoelectric dynamic force sensor 17 can translate along the Y-axis in the horizontal direction relative to the impact plate 13. In the present application, the X-axis direction and the Y-axis direction are both parallel to the horizontal plane, and the X-axis is perpendicular to the Y-axis.

[0031] The height distance between the impact plate 13 and the hammer 2 can be adjusted by rotating the piezoelectric dynamic force sensor 17 .

[0032] Preferably, a lower groove 18 with a T-shaped cross section is opened on the top of the hammer head 2 along the X-axis direction. The lower groove 18 is narrow at the top and wide at the bottom. A T-shaped nut 19 is installed in the lower groove 18. The T-shaped nut 19 can slide in the lower groove 18 along the X-axis direction. An upper groove 20 with a T-shaped cross-section is opened at the bottom of the impact plate 13 along the Y-axis direction. The upper groove 20 is wide at the top and narrow at the bottom. A square nut 21 is installed in the upper groove 20. The square nut 21 can slide in the upper groove 20 along the Y-axis direction; through the piezoelectric dynamic force sensor 17 and the corresponding horizontal moving mechanism, the hammer head 2 can be fine-tuned in the horizontal direction to correct the position deviation caused by the tooth meshing fixation of the lower supporting arc plate.

[0033] like Figure 3 , Figure 4 As shown in , an upper bolt 22 is arranged above the piezoelectric dynamic force sensor 17, and a lower bolt 23 is arranged below the piezoelectric dynamic force sensor 17. The upper bolt 22 and the lower bolt 23 are screwed in opposite directions; the upper bolt 22 is screwed into the square nut 21, and the lower bolt 23 is screwed into the T-shaped nut 19. Based on such a design, the distance between the hammer head and the impact head model 6 can be fine-tuned by screwing the piezoelectric dynamic force sensor 17, so as to correct the height error caused by the tooth meshing.

[0034] Preferably, if Figure 3 , Figure 4 and Figure 5 As shown in the figure, a through hole 24 is provided at the end of the impact plate 13, and the lifting platform also includes a vertically arranged falling wire 45, which passes through the through hole 24. The falling wire 45 cooperates with the through hole 24 to guide the impact plate to fall freely, ensuring that the hammer head 2 impacts vertically downward.

[0035] An optical displacement sensor 44 is provided near the bottom of the falling wire 45 to measure the displacement change during the impact process in real time.

[0036] In a preferred embodiment, Figure 5 , Figure 6 and Figure 7 As shown in , the impact table also includes an X-axis tooth surface bottom plate 25 located at the bottom, and the X-axis tooth surface bottom plate 25 is provided with densely arranged racks with triangular cross-sections and extending along the X-axis direction; horizontal guide rails 26 extending along the Y-axis direction are provided on both sides of the X-axis tooth surface bottom plate 25, and guide rail sliders 27 that can reciprocate along the horizontal guide rails 26 are provided on the horizontal guide rails 26; On the guide rail slider 27, a Y-axis tooth surface bottom plate 28 is arranged along the length direction of the guide rail slider 27, and the Y-axis tooth surface bottom plate 28 is provided with densely arranged racks with a triangular cross section and extending along the Y-axis direction; The guide rail slider 27 is also provided with an embedded slider 29 that can reciprocate along the length direction of the guide rail slider 27, and the support arc plate 3 is installed on the embedded slider 29, and the support arc plate 3 is driven to move in the horizontal direction by sliding the guide rail slider 27 and the embedded slider 29; Preferably, a fixed rod 30 capable of reciprocating in the vertical direction is also provided on the embedded slider 29; a horizontal fixed rotary lock knob 31 is provided above the fixed rod 30 and is screwed with the embedded slider 29, and a Y-axis toothed insert 32 and an X-axis toothed insert 33 are provided below the fixed rod 30; when the fixed rod 30 is pressed downward by the horizontal fixed rotary lock knob 31, the Y-axis toothed insert 32 meshes with the Y-axis toothed bottom plate 28, and the X-axis toothed insert 33 meshes with the X-axis toothed bottom plate 25, thereby locking the embedded slider 29 and the supporting arc plate 3 in the horizontal direction. The two meshing locking mechanisms of the Y-axis toothed insert 32 and the X-axis toothed insert 33 are controlled by a horizontal fixed rotary lock knob 31, and only one screwing is required to achieve the locking of two degrees of freedom in the horizontal direction, complete the fixing of the supporting arc plate, and improve the working efficiency and convenience of the experimental test.

[0037] In a preferred embodiment, Figure 8 and Fig. 9 As shown in , the connecting rod mechanism 5 includes a fixing bolt 34, the head model 6 is screwed and fixed to the end of the fixing bolt 34, and an arc fixing rotary lock button 35, an arc plate inner slider 36 and a fixing sleeve 37 are provided on the fixing bolt 34; the arc fixing rotary lock button 35 is integrated with the fixing bolt 34 and rotates synchronously, and the arc plate inner slider 36 is in an arc shape as a whole, and a rack with a triangular cross section is provided on it; In the supporting arc plate 3, a cavity 38 with an overall arc shape for accommodating the slider 36 in the arc plate is provided on both sides of the slot 4; a rack with a triangular cross section is provided on the arc-shaped top surface of the cavity 38, and the slider 36 in the arc plate can move in the cavity 38 to adjust the angle of the connecting rod mechanism 5 and the head model 6; The connecting rod mechanism 5 is fixed and locked to the supporting arc plate 3 by the engagement of the slider 36 in the arc plate with the arc-shaped top surface of the cavity 38 .

[0038] Preferably, the fixing bolt 34 and the circular arc fixing rotary lock knob 35 are an integral structure, and the fixing bolt 34 is controlled to rotate by externally twisting the circular arc fixing rotary lock knob 35. The circular arc plate inner slider 36 is provided with an internal thread, which cooperates with the fixing bolt 34. The circular arc plate inner slider 36 is controlled to move along the axial direction of the fixing bolt 34 by twisting the fixing bolt 34, so that the circular arc plate inner slider 36 can be engaged with the top surface of the cavity 38 and can move in the cavity 38; the fixing sleeve 37 is provided with an internal thread that cooperates with the fixing bolt 34, and can be twisted and moved on the fixing bolt 34, so that it can abut against the head model, and then the head model 6 is locked by the fixing bolt 34 to prevent the head model 6 from rotating by itself; the head model 6 also begins to have an internal thread, which cooperates with the fixing bolt 34, so that the angular direction and elongation of the head model 6 can be controlled by twisting the head model 6, so as to set the desired impact angle and position.

[0039] In a preferred embodiment, Figure 1 and Fig.10 As shown in the figure, a support frame 41 is arranged on the outside of the lifting platform and the impact platform, and a detachable baffle frame 39 is arranged on the outside of the support frame 41. A groove 40 for installing a gel ice and snow board is opened on the baffle frame 39, and the temperature near the head model 6 inside the support frame 41 is controlled by the gel ice and snow board.

[0040] In the present application, the gel ice and snow board has unique physical properties, and more than 90% of its composition is water. Therefore, it has almost the same refrigeration function as natural ice and snow, and it will not melt like ordinary ice cubes. By cooling it into an ice and snow state and then installing it on the baffle frame 39 and placing it around the sample to be tested, it can effectively simulate the impact under low temperature conditions. In traditional low-temperature impact experiments, it is usually necessary to freeze the samples in advance or use complex refrigeration equipment to maintain a low-temperature environment. The gel ice and snow board and baffle frame 39 in the present application perfectly solve these problems. There is no need to freeze the samples in advance, and a stable low-temperature environment can be provided for the experiment at the moment of impact, which greatly improves the efficiency and convenience of the experiment.

[0041] Preferably, if Figure 1 , Figure 5 and 10 As shown in the figure, the baffle frame 39 is provided with a plurality of pieces, which are distributed around the sample to be tested 6. An outwardly protruding mounting boss 42 is provided at the edge of the baffle frame 39, and accordingly, an inwardly recessed mounting groove 43 is provided on the support frame 41, and the baffle frame 39 is quickly and firmly mounted on the support frame 41 by embedding the mounting boss 42 into the mounting groove 43.

[0042] The present invention also provides a novel multi-angle head drop hammer impact test method, which is implemented by the novel multi-angle head drop hammer impact device described above.

[0043] Preferably, the method comprises the following steps: Step 1, control the steering gear 15 to rotate 90° to open the clamp; control the lifting plate 1 to descend through the lifting motor 7 so that the clamp can clamp the end 14; then control the steering gear 15 to rotate 90° so that the clamping rod 12 clamps the clamping end 14; Step 2, by moving the guide rail slider 27 and the embedded slider 29, the support arc plate 3 is moved to a predetermined position, and then the fixing rod 30 is controlled to move downward by the horizontal fixed rotary lock knob 31, the Y-axis tooth pattern insert 32 is engaged with the Y-axis tooth surface bottom plate 28, and the X-axis tooth pattern insert 33 is engaged with the X-axis tooth surface bottom plate 25, thereby locking the embedded slider 29 and the support arc plate 3 in the horizontal direction; Step 3, install the head model 6 on the fixing bolt 34 and lock it with the fixing sleeve 37; after the slider 36 in the arc plate slides to a predetermined position in the cavity 38, that is, after adjusting the installation angle of the connecting rod mechanism 5, tighten the slider 36 in the arc plate through the arc fixing locking knob 35, so that the slider 36 in the arc plate engages with the arc-shaped top surface of the cavity 38, and locks the connecting rod mechanism 5 to the supporting arc plate 3; Step 4, install the piezoelectric dynamic force sensor 17 and the hammer head 2 on the impact plate 13, fine-tune the position of the hammer head 2 in the horizontal direction to eliminate the error caused by the tooth meshing on the impact table; and fine-tune the height of the hammer head 2 by rotating the piezoelectric dynamic force sensor 17; Step 5, embed the gel ice and snow board into the groove 40 of the baffle frame 39, and then install the baffle frame 39 into the support frame 41, so that the gel ice and snow board surrounds the head model 6; 3-5 minutes after the installation is completed, the subsequent operation steps can be performed, that is, at this time, the temperature at the head model 6 can be reduced from room temperature to 5-8 degrees Celsius; Step 6, control the servo to rotate and open the clamp, and the impact plate falls freely along the falling wire, and impacts the head model 6 through the hammer head 2, and data information is obtained by measuring through the piezoelectric dynamic force sensor 17 and the optical displacement sensor 44.

[0044] After the first impact is completed, prepare for the second impact; during the second impact, the position of the nut on the punch and the impact plate can be adjusted, and the rotary lock knob on the impact table can also be adjusted to achieve a more accurate impact.

[0045] Choose Figures 1 to 10The new multi-angle head drop hammer impact device was used to perform impact tests on the bionic head model. The same impact force was used to perform five impact tests at different angles on the same part of the head model, so as to obtain the movement and force data of the head model when it was impacted at 6 degrees Celsius. The specific testing process is as follows: Step 1, control the steering gear 15 to rotate 90° to open the clamp; control the lifting plate 1 to descend through the lifting motor 7 so that the clamp can clamp the end 14; then control the steering gear 15 to rotate 90° so that the clamping rod 12 clamps the clamping end 14; Step 2, by moving the guide rail slider 27 and the embedded slider 29, the support arc plate 3 is moved to a predetermined position, and then the fixing rod 30 is controlled to move downward by the horizontal fixed rotary lock knob 31 to lock the embedded slider 29 and the support arc plate 3 in the horizontal direction; Step 3, install the head model 6 on the fixing bolt 34 and lock it with the fixing sleeve 37; after the slider 36 in the arc plate slides to a predetermined position in the cavity 38, that is, after adjusting the installation angle of the connecting rod mechanism 5, tighten the slider 36 in the arc plate through the arc fixing locking knob 35, so that the slider 36 in the arc plate engages with the arc-shaped top surface of the cavity 38, and locks the connecting rod mechanism 5 to the supporting arc plate 3; Step 4, install the piezoelectric dynamic force sensor 17 and the hammer head 2 on the impact plate 13, fine-tune the position of the hammer head 2 in the horizontal direction to eliminate the error caused by the tooth meshing on the impact table; and fine-tune the height of the hammer head 2 by rotating the piezoelectric dynamic force sensor 17; Step 5, embed the gel ice and snow board into the groove 40 of the baffle frame 39, and then install the baffle frame 39 into the support frame 41, so that the gel ice and snow board surrounds the head model 6; when the temperature at the head model 6 drops to 6 degrees Celsius, start the impact test; Step 6, control the servo to rotate and open the clamp, and the impact plate falls freely along the falling wire, and impacts the head model 6 through the hammer head 2, and data information is obtained by measuring through the piezoelectric dynamic force sensor 17 and the optical displacement sensor 44.

[0046] The specific data of the 5 impact tests are shown in Table 1 below: Table 1 5 times impact test data

[0047] The total time taken to complete the above five impact tests is 10 minutes; It can be seen from the above embodiments that the new multi-angle head-drop hammer impact device and testing method provided by the present application can accurately obtain key data in the impact test, and can quickly and efficiently give completely consistent impact force during multiple repeated tests, thereby improving the reliability of the test results; in addition, the new multi-angle head-drop hammer impact device and testing method can greatly improve the test efficiency, not only shortening the time interval between multiple tests, but also maintaining the ideal test temperature by itself, saving time in adjusting the test temperature.

[0048] The present invention has been described above in conjunction with preferred embodiments, but these embodiments are only exemplary and serve only as an illustration. On this basis, the present invention may be subjected to a variety of substitutions and improvements, all of which fall within the scope of protection of the present invention.

Claims

1. A new multi-angle head drop hammer impact device, characterized in that: The device includes a lifting table located at the top and an impact table located at the bottom; The lifting platform comprises a lifting plate (1) that can move up and down, a hammer head (2) that can fall freely is arranged on the lifting plate (1), and the falling starting height of the hammer head (2) can be adjusted; The impact table comprises a supporting circular arc plate (3), wherein the supporting circular arc plate (3) is movable in a horizontal direction; a slot (4) is provided on the supporting circular arc plate (3) along its circumference, a connecting rod mechanism (5) is mounted on the slot (4), a head model (6) is arranged at the end of the connecting rod mechanism (5), and the angle of the head model (6) is adjusted by controlling the connecting rod mechanism (5) to rotate along the slot (4) and the connecting rod mechanism (5) itself to rotate.

2. The novel multi-angle head drop hammer impact device according to claim 1 is characterized in that: The lifting platform further comprises a lifting motor (7), a main shaft of which is connected to a sprocket (8), a chain (9) connected to the lifting plate (1) is arranged on the sprocket (8), and the lifting motor (7) controls the lifting plate (1) to move up and down via the sprocket (8) and the chain (9); The lifting platform further comprises a longitudinal guide rail (10), and the lifting plate (1) is provided with a guide sleeve (11) sleeved on the outside of the longitudinal guide rail (10), and the cooperation between the longitudinal guide rail (10) and the guide sleeve (11) provides a limit for the lifting plate (1) to move up and down.

3. The novel multi-angle head drop hammer impact device according to claim 1 is characterized in that: A clamp consisting of two clamping rods (12) is provided on the lifting plate (1). An impact plate (13) is connected above the hammer head (2), and an end head (14) is arranged above the impact plate (13). The clamp can open and close to clamp the end head (14); when the clamp releases the end head (14), the hammer head (2), the impact plate (13) and the end head (14) are synchronously freed, and the hammer head (2) impacts the head model (6).

4. The novel multi-angle head drop hammer impact device according to claim 3 is characterized in that: A steering gear (15) is arranged on the lifting plate (1), and a cam (16) is connected to the steering gear (15). The cam (16) is arranged between two clamping rods (12). The steering gear (15) drives the cam (16) to rotate to open the clamp, so that the clamp releases the end head (14).

5. The novel multi-angle head drop hammer impact device according to claim 3 is characterized in that: The impact plate (13) and the hammer head (2) are connected via a piezoelectric dynamic force sensor (17); the hammer head (2) can translate along an X-axis in a horizontal direction relative to the piezoelectric dynamic force sensor (17); the piezoelectric dynamic force sensor (17) can translate along a Y-axis in a horizontal direction relative to the impact plate (13); the X-axis is perpendicular to the Y-axis; The height distance between the impact plate (13) and the hammer head (2) can be adjusted by rotating the piezoelectric dynamic force sensor (17).

6. The novel multi-angle head drop hammer impact device according to claim 5 is characterized in that: A lower groove (18) with a T-shaped cross section is provided on the top of the hammer head (2) along the X-axis direction, the lower groove (18) being narrow at the top and wide at the bottom, a T-shaped nut (19) being installed in the lower groove (18), and the T-shaped nut (19) being able to slide in the lower groove (18) along the X-axis direction; An upper groove (20) with a T-shaped cross section is provided at the bottom of the impact plate (13) along the Y-axis direction. The upper groove (20) is wide at the top and narrow at the bottom. A square nut (21) is installed in the upper groove (20). The square nut (21) can slide in the upper groove (20) along the Y-axis direction. An upper bolt (22) is arranged above the piezoelectric dynamic force sensor (17), and a lower bolt (23) is arranged below the piezoelectric dynamic force sensor (17), wherein the upper bolt (22) and the lower bolt (23) have opposite rotation directions; the upper bolt (22) is screwed into the square nut (21), and the lower bolt (23) is screwed into the T-shaped nut (19).

7. The novel multi-angle head drop hammer impact device according to claim 1 is characterized in that: The impact table further comprises an X-axis tooth surface bottom plate (25) located at the bottom, on which racks having a triangular cross section and extending along the X-axis direction are densely arranged; horizontal guide rails (26) extending along the Y-axis direction are arranged on both sides of the X-axis tooth surface bottom plate (25), and guide rail sliders (27) capable of reciprocatingly sliding along the horizontal guide rails (26) are arranged on the horizontal guide rails (26); A Y-axis tooth surface bottom plate (28) is arranged on the guide rail slider (27) along the length direction of the guide rail slider (27), and the Y-axis tooth surface bottom plate (28) is provided with densely arranged racks with triangular cross-sections and extending along the Y-axis direction; An embedded slider (29) capable of reciprocating along the length direction of the guide rail slider (27) is also provided on the guide rail slider (27); the support circular arc plate (3) is mounted on the embedded slider (29); and the support circular arc plate (3) is driven to move in the horizontal direction by sliding the guide rail slider (27) and the embedded slider (29); A fixed rod (30) capable of reciprocating in a vertical direction is also provided on the embedded slider (29); a horizontal fixed rotary lock knob (31) screwed together with the embedded slider (29) is provided above the fixed rod (30); a Y-axis toothed insert block (32) and an X-axis toothed insert block (33) are provided below the fixed rod (30); when the fixed rod (30) is pressed downward by the horizontal fixed rotary lock knob (31), the Y-axis toothed insert block (32) meshes with the Y-axis toothed bottom plate (28), and the X-axis toothed insert block (33) meshes with the X-axis toothed bottom plate (25), thereby locking the embedded slider (29) and the supporting arc plate (3) in the horizontal direction.

8. The novel multi-angle head drop hammer impact device according to claim 1 is characterized in that: The connecting rod mechanism (5) comprises a fixing bolt (34), the head model (6) is screwed and fixed to the end of the fixing bolt (34), and the fixing bolt (34) is provided with an arc fixing rotary lock button (35), an arc plate inner slider (36) and a fixing sleeve (37); the arc fixing rotary lock button (35) and the fixing bolt (34) are integrated and rotate synchronously, and the arc plate inner slider (36) is in an arc shape as a whole and is provided with a rack with a triangular cross section; In the supporting arc plate (3), a cavity (38) having an overall arc shape for accommodating an arc plate inner slider (36) is provided on both sides of the slot (4); a rack having a triangular cross section is provided on the arc-shaped top surface of the cavity (38); the arc plate inner slider (36) can move in the cavity (38) to facilitate adjustment of the angles of the connecting rod mechanism (5) and the head model (6); The connecting rod mechanism (5) is fixed and locked onto the supporting circular arc plate (3) by engaging the slider (36) in the circular arc plate with the arc-shaped top surface of the cavity (38).

9. A novel multi-angle head drop hammer impact test method, characterized in that: The method is implemented by the novel multi-angle head drop hammer impact device according to any one of claims 1 to 8; the method comprises the following steps: Step 1, control the steering engine (15) to rotate 90 degrees to open the clamp; control the lifting plate (1) to descend through the lifting motor (7) so that the clamp can clamp the end (14); and then control the steering engine (15) to rotate 90 degrees so that the clamping rod (12) clamps the clamping end (14); Step 2, by moving the guide rail slider (27) and the embedded slider (29), the support arc plate (3) is moved to a predetermined position, and then the fixing rod (30) is controlled to move downward by the horizontal fixing lock knob (31), so as to lock the embedded slider (29) and the support arc plate (3) in the horizontal direction; Step 3, the head model (6) is mounted on the fixing bolt (34) and locked by the fixing sleeve (37); the slider (36) in the arc plate slides to a predetermined position in the cavity (38), that is, after the installation angle of the connecting rod mechanism (5) is adjusted, the slider (36) in the arc plate is tightened by the arc fixing locking knob (35), so that the slider (36) in the arc plate is engaged with the arc-shaped top surface of the cavity (38), and the connecting rod mechanism (5) is locked to the supporting arc plate (3); Step 4, installing a piezoelectric dynamic force sensor (17) and a hammer head (2) on the impact plate (13), fine-adjusting the position of the hammer head (2) in the horizontal direction to eliminate the error caused by the tooth meshing on the impact table; and fine-adjusting the height of the hammer head (2) by rotating the piezoelectric dynamic force sensor (17); Step 5, embedding the gel ice snow board into the groove (40) of the baffle frame (39), and then installing the baffle frame (39) into the support frame (41), so that the gel ice snow board surrounds the head model (6); Step 6, control the steering gear to rotate and open the clamp, and the impact plate falls freely along the falling wire, and the hammer head (2) impacts the head model (6), and data information is obtained by measuring through the piezoelectric dynamic force sensor (17) and the optical displacement sensor (44).

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