A portable pneumatic low-speed impact testing machine and impact testing method

Abstract

The present invention relates to a portable pneumatic low-speed impact testing machine and an impact testing method, comprising an impact mechanism for performing low-speed impact at any angle on a fixed structural member; a pneumatic drive mechanism providing driving power for the impact mechanism; a speed measurement and data acquisition system for real-time acquisition of the displacement-time data of the hammer during the impact process, and converting it into the instantaneous speed during the impact, and realizing speed monitoring of the entire impact process; the mechanism is light and highly applicable, and is convenient for rapid installation at complex test sites and any locations. The hammer speed is realized by a hammer speed measuring device and a data acquisition system, and the punch that rebounds after the impact is captured to prevent the hammer from having a secondary impact on the test piece during the impact process; the instantaneous speed of the entire impact process can be accurately measured and the data can be collected in real time; the impact speed can be adjusted by controlling the pressure value of the air storage tank, and the magnitude of the impact energy can be continuously adjusted.

Description

Technical Field

[0001] The present invention relates to the technical field of impact testing, and in particular to a portable pneumatic low-speed impact testing machine and an impact testing method. Background Art

[0002] Composite materials are increasingly widely used in the fields of aviation and civil industry, and composite parts will inevitably be damaged by impact during manufacturing and use. Composite materials are sensitive to impact damage and are prone to defects such as delamination and cracking, thereby reducing the performance of materials and structures. Therefore, in structural design and engineering application research, performance tests are usually conducted after impact damage is introduced to materials or structures.

[0003] In the aviation field, there are usually two types of impact damage introduced: high-speed impact by a small-mass punch or low-speed impact by a large-mass hammer. Regarding low-speed impact by a large-mass hammer, a desktop impact tester is usually used to pre-create impact damage, but the test piece must be placed in the test space of the impact tester, and impact damage cannot be introduced at the structural test site. Currently available portable low-speed impact testers include drop hammer type or spring type, but there are some disadvantages: impact at any angle cannot be performed; due to structural limitations, it is not possible to easily pre-create damage at any position on the structural part; the impact energy range of a single hammer is small, and it is usually necessary to equip multiple hammers of different masses for replacement; the structure is complex and not light enough, etc.

[0004] Impact testing machines are usually equipped with speed measuring devices to evaluate the impact energy. The speed measuring device of existing impact testing machines usually measures the time t required for the hammer to pass a fixed distance s, and then calculates the average speed v m =s / t, assuming that the average speed v m That is, the average velocity v of the hammer when it hits the sample surface m Instead of instantaneous speed. Summary of the invention

[0005] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a portable pneumatic low-speed impact testing machine and impact testing method, which uses high-pressure gas as a power source, has a simple, light and easy-to-move overall structure, can impact any position of the test piece, can introduce low-speed impact at the structural test site, and test data can be collected in real time during the impact process.

[0006] To achieve the above object, the present invention adopts the following technical scheme: a portable pneumatic low-speed impact testing machine, including an impact mechanism, a pneumatic drive mechanism, and a speed measurement and data acquisition system;

[0007] The impact mechanism is used to perform low-speed impact at any angle on the fixed structural member;

[0008] The pneumatic drive mechanism provides driving power for the impact mechanism;

[0009] The speed measurement and data acquisition system is used to obtain the displacement-time data of the hammer when the impact mechanism impacts the test piece that needs to be subjected to impact damage during the test, and convert it into the instantaneous speed at the time of impact.

[0010] The impact mechanism includes a connecting tube, a holding handle fixedly connected to the connecting tube is provided at one end of the connecting tube, and the other end of the connecting tube is fixedly connected to mutually parallel guide rails, and the guide rails are perpendicular to the end surface of the connecting tube, a cylinder is fixedly provided in the connecting tube, and a pneumatic actuating rod of the cylinder extends in the direction of the guide rails and is located between the mutually parallel guide rails, a hammer body moving up and down along the guide rails is provided on the guide rails, a hammer head is fixedly provided at one end of the hammer body away from the cylinder, and a clamping column is fixedly provided at the other end of the hammer body, and the clamping column is hooked or separated from a clamping structure fixedly provided at the end of the pneumatic actuating rod, the cylinder is pneumatically connected to the pneumatic drive mechanism; the pneumatic drive mechanism drives the pneumatic actuating rod of the cylinder to extend and retract.

[0011] The other end of the connecting tube relative to the gripping handle is fixedly connected to a support base, and mutually parallel guide rails are fixedly connected to the support base. The end of the guide rail away from the support base is fixedly connected to a support top seat, and the support top seat is located below the hammer body of the impact hammer.

[0012] The connecting tube is provided with an end surface of one end of the guide rail, on which an electromagnet fixing base is fixedly connected; the end of the electromagnet fixing base away from the connecting tube is fixedly connected with a suction cup electromagnet, which is electrically connected to an electromagnet switch fixed on the connecting tube; when power is supplied to the suction cup electromagnet, the magnetic force generated by the electromagnet adsorbs the hammer body.

[0013] The buckle structure includes a connecting base fixedly connected to the end of the pneumatic actuating rod, hooks movably connected to the connecting base and symmetrically arranged, the symmetrically arranged hooks are connected by springs, and the ends of the clamping columns open the symmetrical hooks and hang upside down on the hooks to connect the hammer body of the ram with the pneumatic actuating rod.

[0014] The upper sleeve of the clamping column is provided with a sliding block, and the sliding block moves up and down along the clamping rod of the clamping column; the hammer body of the punching hammer is connected with the guide rail through a linear bearing.

[0015] The pneumatic drive structure includes a gas tank, an air compressor arranged on the gas tank, and the air compressor is connected to the gas tank, a pneumatic valve arranged on the gas tank and connected to the gas tank, the pneumatic valve is connected to the pneumatic switch provided on the cylinder through a pipeline, the pneumatic switch is provided with a pneumatic switch handle, the gas tank is also provided with a digital pressure gauge and a pressure relief valve for detecting pressure, and the air compressor is provided with a switch electrically connected to the air compressor.

[0016] The data acquisition system includes a linear displacement sensor arranged in a connecting tube, a linear displacement sensor pull rod having one end inserted in the linear displacement sensor and the other end extending to the outside of the connecting tube, and the linear displacement sensor pull rod moves in the linear displacement sensor, the linear displacement sensor is used to detect the displacement data of the linear displacement sensor pull rod, and a spare nut is provided at the end of the linear displacement sensor pull rod located outside the connecting tube, and the spare nut is in contact with the upper end surface of the hammer body of the hammer, the linear displacement sensor is electrically connected to a displacement signal converter, and the displacement signal converter is electrically connected to the processor through a data acquisition module, the data acquisition module converts the analog signal obtained by the displacement signal converter into a digital signal, and the processor collects the displacement data and time data collected by the data acquisition module and converts them into instantaneous speed.

[0017] The connecting tube is provided with a digital inclinometer for detecting angles.

[0018] An impact test method of a portable pneumatic low-speed impact tester is carried out according to the following steps:

[0019] Step 1: Hold the handle and place the impact mechanism against the fixed structure that needs to be tested, and fix the impact tester at the test site to ensure that the end of the guide rail of the impact mechanism is against the fixed structure;

[0020] The electromagnet switch is turned on, the suction cup electromagnet is energized to generate magnetism, and at the same time, the hammer body of the punch hammer moves to the uppermost end of the guide rail, the clamping column enters into the mutually symmetrical clamping hooks, and the slider opens the mutually symmetrical clamping hooks, and the suction cup electromagnet absorbs the hammer body of the punch hammer so that the hammer body of the punch hammer is fixed to the uppermost end of the guide rail;

[0021] The switch is turned on, the pneumatic valve is closed, and the air compressor works to inflate the gas tank. Make sure that the pressure detected by the digital pressure gauge is greater than the set pressure value. Turn off the switch and adjust the air pressure in the gas tank through the pressure relief valve to ensure that the air pressure is the same as the set pressure value.

[0022] Step 2: Open the pneumatic valve and pneumatic switch, and the pneumatic action rod of the cylinder pushes the hammer body downward. When the pneumatic action rod is at the limit position, the hammer body continues to move downward under the action of inertia, and the clamping column withdraws from the mutually symmetrical clamping hooks and separates from the pneumatic action rod. The hammer body continues to move downward, impacts the fixed structure to be tested, and rebounds. After the rebound, the hammer body moves upward, and the clamping column enters the mutually symmetrical clamping hooks and hangs upside down in the clamping hooks;

[0023] At the same time, during the downward movement of the hammer body, the linear displacement sensor rod moves downward along with the hammer body. The linear displacement sensor detects the displacement of the linear displacement sensor rod as the displacement of the hammer body, and converts the detected displacement data through a displacement signal converter and sends it to the data acquisition module. The data acquisition module sends the received data to the processor for processing and calculation to obtain the instantaneous speed.

[0024] The beneficial effects of the present invention are as follows: the impact testing machine includes an impact mechanism, a pneumatic drive mechanism and a data acquisition system, which can be quickly installed at any position. The drop hammer speed is achieved through a drop hammer speed measuring device and a data acquisition system, which can realize accurate measurement of the instantaneous impact speed and real-time collection of data of the entire impact process. The hammer moves along the guide column, and the direction in which the impact testing machine is installed determines the impact direction, so impacts at any angle can be achieved, and both upward and downward impacts are feasible. The inclinometer installed on the testing machine can conveniently display the impact angle; the impact speed is adjusted by controlling the pressure value of the gas storage tank, that is, the magnitude of the impact energy is adjusted. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of the present invention;

[0026] Figure 2 It is a structural schematic diagram of the impact mechanism in the present invention;

[0027] Figure 3 It is a schematic diagram of the matching structure of the clamping hook and the clamping column before the experiment in the present invention;

[0028] Figure 4 It is a schematic diagram of the matching structure when the clamping column and the clamping hook are separated in the present invention;

[0029] Figure 5 It is a schematic diagram of the structure when the hammer body rebounds after the hammer impacts and the clamping column enters the clamping hook in the present invention;

[0030] Figure 6 It is a schematic diagram of the structure in which the clamping column is hung upside down in the clamping hook in the present invention. DETAILED DESCRIPTION

[0031] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0032] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0033] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features; in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0034] Example

[0035] like Figure 1 A portable pneumatic low-speed impact testing machine comprises an impact mechanism 1, a pneumatic drive mechanism 2, and a speed measurement and data acquisition system 3;

[0036] The impact mechanism 1 is used to perform low-speed impact on a fixed structural member at any angle;

[0037] The pneumatic drive mechanism 2 provides driving power for the impact mechanism 1;

[0038] The speed measurement and data acquisition system 3 is used to obtain the displacement-time data of the hammer when the impact mechanism 1 impacts the test piece that needs to be subjected to impact damage during the test, and convert it into the instantaneous speed at the time of impact.

[0039] Specifically, when conducting the test, the impact tester is fixed on the detection fixture that needs to be tested according to the needs of the site, and then the pneumatic drive mechanism 2 and the data acquisition system 3 are assembled with the impact mechanism 1, and the pneumatic drive mechanism 2 is turned on. The pneumatic drive mechanism drives the impact mechanism to impact the structural member that needs to be impact tested. At the same time, during the impact process, the data acquisition system collects the displacement-time data of the impact mechanism 1 during the impact process, and processes the collected data to obtain the instantaneous speed of the impact mechanism when it impacts the component that needs to be tested.

[0040] Specifically, if Figure 1 and Figure 2The impact mechanism 1 includes a connecting tube 5, and a holding handle 4 fixedly connected to the connecting tube 5 is provided at one end of the connecting tube 5. The other end of the connecting tube 5 is fixedly connected to mutually parallel guide rails 7, and the guide rails are perpendicular to the end surface of the connecting tube 5. A cylinder 9 is fixedly provided in the connecting tube 5. The pneumatic actuating rod 12 of the cylinder 9 extends in the direction of the guide rails 7 and is located between the mutually parallel guide rails 7. A hammer body 13 that moves up and down along the guide rails 7 is provided on the guide rails 7. A hammer head 14 is fixedly provided at one end of the hammer body 13 away from the cylinder 9, and a clamping column 27 is fixedly provided at the other end of the hammer body 13. The clamping column 27 is hooked or separated with a buckle structure fixedly provided at the end of the pneumatic actuating rod 12. The cylinder 9 is pneumatically connected to the pneumatic drive mechanism 2; the pneumatic drive mechanism 2 drives the pneumatic actuating rod 12 of the cylinder 9 to retract and retract.

[0041] The gripping handle 4 is used for making it convenient for people to carry the device, and is also convenient for impact tests at different angles. The connecting tube serves as the basic device of the entire device. In order to facilitate the guide rail 7 to be fixed on the connecting tube, a support base 6 is fixedly connected to the other end of the connecting tube relative to the gripping handle, and then the guide rail 7 is fixedly connected to the support base 6 to ensure that the guide rail 7 can be stably installed on the connecting tube. In order to ensure that the mutually parallel guide rails 7 have better integrity when in use, a supporting top seat 8 is fixedly provided at one end of the guide rail away from the support base 6. The support base 8 connects the mutually parallel guide rails 7 and can effectively play a supporting role when in use. At the same time, in order for the support base 8 not to affect the falling of the hammer body 13 to impact the structural parts, the support base 8 is located below the hammer body, and the hammer head of the hammer can pass through the support base to impact the structural parts.

[0042] During operation, when an impact test is required, the clamping column is hooked on the buckle structure to ensure that the pneumatic actuating rod 12 of the cylinder 9 is in a shortened state, and the cylinder 9 is pneumatically driven to drive the pneumatic actuating rod 12 to extend. When the pneumatic actuating rod 12 reaches the limit position, the hammer body 13 continues to descend under the action of inertia, and the clamping column 27 is separated from the buckle structure, and the hammer head 14 performs an impact test on the fixed structural member being tested. After the impact occurs, the hammer body 13 rebounds upward, and the clamping column 27 is hung upside down on the buckle structure, which effectively prevents the possibility of a secondary impact.

[0043] Furthermore, in order to ensure that when the pneumatic action rod 12 reaches the limit position, the hammer body can be quickly separated from the buckle structure to ensure the impact speed, and at the same time ensure that during the rebound process, the clamping column can be stably hung upside down on the buckle structure to ensure that no secondary impact occurs,

[0044] like Figure 1 and Figure 2 As shown, the buckle structure includes a connection base 24 fixedly connected to the end of the pneumatic action rod 12, a hook 25 movably connected to the connection base 24 and symmetrically arranged, the symmetrically arranged hooks 25 are connected by a spring 26, and the end of the clamping column 27 opens the symmetrical hooks 25 and hangs upside down on the hooks 25, so as to connect the hammer body 13 with the pneumatic action rod 12. The symmetrical hooks 25 are movably connected to the connection base 24 and connected by the spring 26, which can ensure that the hook 25 is engaged and automatically separated, and at the same time, the barb on the hook 25 extends in the corresponding reverse direction, ensuring that the hammer-shaped column head at the upper end of the clamping column can be clamped, and at the same time, the column head of the clamping column can open the hook when rebounding, so that it hangs upside down on the hook.

[0045] At the same time, in order to further ensure that the clamping column and the hook can be separated quickly when separated, and not too much force is required to ensure their separation, specifically, a slider 28 is provided on the upper sleeve of the clamping column 27, and the slider 28 moves up and down along the clamping rod of the clamping column 27; the hammer body 13 of the impact hammer is connected to the guide rail 7 through a linear bearing 15.

[0046] When in use, the clamping column 27 is inserted into the mutually symmetrical clamping hooks and extends to the inner top of the clamping hooks. The slider 28 is located between the mutually symmetrical clamping hooks to open the symmetrically arranged clamping hooks. At the same time, the diameter of the slider is greater than or equal to the maximum diameter of the lower end of the clamping column 27. At the same time, when the hammer body and the buckle structure are not separated, Figure 3 The slider and the hook are relatively stationary. When the cylinder pushes the pneumatic actuating rod to the limit position, the pneumatic actuating rod stops, and the clamping column continues to move downward under the action of inertia. Figure 4 As shown in the figure, when the clamping head of the clamping column moves to the position of the slider, the slider and the clamping column are driven downward together, and the hammer body of the punch hammer is separated from the buckle structure and falls freely. The hammer head on the hammer body of the punch hammer performs an impact test on the structural member. After the impact is completed, the hammer body rebounds, and the clamping column on the hammer body of the punch hammer is as shown in the figure. Figure 5 Insert it into the hook as shown and Figure 6 The barb shown is in the hook to avoid secondary impact.

[0047] At the same time, in order to ensure that when the cylinder does not push the pneumatic actuating rod to move, the clamping column can be stably inserted into the mutually symmetrical clamping hooks, and the slider can open the mutually symmetrical clamping hooks, so as to ensure that the hammer body of the punch hammer and the pneumatic actuating rod are temporarily fixedly and stably connected, an electromagnet fixing base 20 is fixedly connected to the end surface of the end of the guide rail 7 provided on the connecting tube 5, and a suction cup type electromagnet 21 is fixedly connected to the end of the electromagnet fixing base 20 away from the connecting tube 5, and the suction cup type electromagnet 21 is electrically connected to the electromagnet switch 22 fixed on the connecting tube 5. When the suction cup type electromagnet 21 is energized, the magnetic force generated by the magnet attracts the hammer body 13. Specifically, the hammer body of the punch hammer is moved to the uppermost end, the clamping column is inserted into the clamping hook, and the slider opens the clamping hook at the same time. At this time, the electromagnet switch is turned on, the suction cup type electromagnet 21 is energized, generates magnetism, and adsorbs the punch hammer head, so as to ensure its stability, prevent the clamping column from sliding relative to the slider, and prevent the slider from being unable to open the clamping hook before the work starts.

[0048] When conducting the test, ensure that the extension and retraction speed of the pneumatic actuator driven by the cylinder meets the speed required for impact, such as Figure 1 The pneumatic drive structure 2 includes a gas tank 35, an air compressor 30 arranged on the gas tank 35, and the air compressor 30 is connected to the gas tank 35, and a pneumatic valve 34 is arranged on the gas tank 35 and connected to the gas tank 35, the pneumatic valve 34 is connected to the pneumatic switch 10 provided on the cylinder 9 through a pipeline, the pneumatic switch 10 is provided with a pneumatic switch handle 11, the gas tank 35 is also provided with a digital pressure gauge 32 and a pressure relief valve 33 for detecting pressure, and the air compressor 30 is provided with a switch 31 electrically connected to the air compressor 30. Before conducting the impact test, the air compressor is turned on through the switch 31, and the pneumatic valve is closed at the same time. The air compressor compresses the air and stores it in the gas tank. The pressure value of the gas tank is determined by the digital pressure gauge on the gas tank, and at the same time, it is ensured that the pressure value of the gas tank is greater than the pressure value of the cylinder action. Then, the pressure of the air in the gas tank is adjusted through the pressure relief valve. When the pressure value in the gas tank is equal to the pressure value used by the cylinder, the adjustment is stopped. When conducting the test, the pneumatic valve is opened, and the pneumatic switch is turned on through the pneumatic switch handle 11. The compressed air in the gas tank enters the cylinder to drive the pneumatic action rod of the cylinder to extend, thereby providing power for the impact device.

[0049] In order to facilitate the detection of the displacement of the hammer body during detection and facilitate data processing, the data acquisition system 3 includes a linear displacement sensor 16 arranged in the connecting tube 5, one end of which is inserted into the linear displacement sensor 16 and the other end of which extends to the outside of the connecting tube 5. The linear displacement sensor rod 17 moves in the linear displacement sensor 16. The linear displacement sensor 16 is used to detect the displacement data of the linear displacement sensor rod 17. The end of the linear displacement sensor rod 17 located outside the connecting tube 5 is provided with a spare nut 8, and the spare nut 8 is in contact with the upper end surface of the hammer body 13. The linear displacement sensor 16 is electrically connected to a displacement signal converter 19, and the displacement signal converter 19 is electrically connected to the processor 37 through the data acquisition module 36. The processor 37 converts the displacement data and time data collected by the data acquisition module 36 into instantaneous velocity. When conducting an impact test, since one end of the linear displacement sensor rod 17 is located in the linear displacement sensor 16 and can move relatively in the linear displacement sensor 16, when the hammer body is falling, due to the gravity (the tightening nut 8 can ensure that the linear displacement sensor rod 17 is in contact with the hammer push head), the linear displacement sensor rod 17 and the hammer body fall simultaneously, and the linear displacement sensor 16 detects the displacement of the linear displacement sensor rod 17, and the measured displacement is the displacement of the hammer head. Then the linear displacement sensor 16 converts the detected data through the displacement signal converter 19 and sends it to the data acquisition module. The data acquisition module sends the received data to the processor (computer terminal) for processing, and calculates the instantaneous speed of the hammer head at the time of impact. The formula used is the calculation formula in the background technology of this application, and the common knowledge in this technical field will not be described in detail here.

[0050] Furthermore, in order to ensure that the tilt angle can be measured when performing tilt impact, a digital inclinometer 29 for detecting the angle is provided on the connecting tube 5 .

[0051] An impact test method of a portable pneumatic low-speed impact tester is carried out according to the following steps:

[0052] Step 1: Hold the handle 4 and place the impact mechanism 1 against the fixed structure that needs to be tested for impact, and fix the impact tester at the test site to ensure that the end of the guide rail 7 of the impact mechanism 1 is against the fixed structure;

[0053] The electromagnet switch 21 is turned on, the suction cup electromagnet 21 is energized to generate magnetism, and at the same time, the hammer body 13 moves to the uppermost end of the guide rail 7, the clamping column 27 enters the mutually symmetrical clamping hooks 25, and the slider 28 opens the mutually symmetrical clamping hooks 25, and the suction cup electromagnet 21 absorbs the hammer body 13 so that the hammer body 13 is fixed to the uppermost end of the guide rail 7;

[0054] The switch 31 is turned on, the pneumatic valve 34 is closed, and the air compressor 30 works to inflate the gas tank 35, ensuring that the pressure of the gas tank detected by the digital pressure gauge 32 is greater than the set pressure value, and the switch 31 is closed, and the air pressure in the gas tank 35 is adjusted through the pressure relief valve 33 to ensure that the air pressure is the same as the set pressure value;

[0055] Step 2: Open the pneumatic valve 34, the pneumatic switch 10, and the pneumatic actuating rod 12 of the cylinder 9 pushes the hammer body 13 downward. When the pneumatic actuating rod 12 is at the limit position, the hammer body 13 continues to move downward under the action of inertia, and the clamping column 27 withdraws from the mutually symmetrical clamping hooks 25 and separates from the pneumatic actuating rod 12. The hammer body 13 continues to move downward, impacts the fixed structure to be tested, and rebounds. After the rebound, the hammer body 13 moves upward, and the clamping column 27 enters the mutually symmetrical clamping hooks 25 and hangs upside down in the clamping hooks 25;

[0056] At the same time, during the downward movement of the hammer body 13, the linear displacement sensor rod 17 moves downward along with the hammer body 13, and the linear displacement sensor 16 detects the displacement of the linear displacement sensor rod 17, which is the displacement of the hammer body 13, and converts the detected displacement data through the displacement signal converter 19 and sends it to the data acquisition module 36. The data acquisition module 36 sends the received data to the processor 37 for processing and calculation to obtain the instantaneous speed.

[0057] When conducting impact tests, it can be divided into preparatory work before the experiment, impact work and data collection work;

[0058] The preparation work before the test is to fix the impact mechanism 1 on the structural part to be tested, and adjust the angle of the impact mechanism 1 according to the requirement of the tilt angle to ensure that the angle displayed by the digital inclinometer 29 meets the required angle, and then drive the pneumatic mechanism and the data acquisition system to be associated with the components on the impact mechanism, including electrical connection and pipeline, mechanical connection. After the assembly is completed, the pneumatic valve is closed, the switch is turned on, the air compressor starts working, and the compressed air is stored in the gas tank. At the same time, according to the digital pressure gauge 32, it is detected that the pressure of the gas tank is greater than the set pressure value, the switch 31 is closed, and the air pressure in the gas tank 35 is adjusted through the pressure relief valve 33 to ensure that the air pressure is the same as the set pressure value.

[0059] At the same time, the hammer body is moved upward to insert the clamping column into the clamping hook, and the slider opens the clamping hook. At this time, the electromagnetic switch is turned on, and the suction cup electromagnet 21 is energized (the electromagnetic switch and the suction cup electromagnet are connected by a wire 23), generating magnetism, and the hammer body is adsorbed on the suction cup electromagnet 21 to ensure that the hammer body moves relatively. After completing all preparations, the impact test is carried out;

[0060] Impact test, open the pneumatic valve, preferably the last preparation work before the impact test, then turn on the pneumatic switch through the pneumatic switch handle, the compressed air in the gas tank enters the cylinder through the pipeline, driving the pneumatic actuating rod of the cylinder to extend, and the pneumatic actuating rod drives the hammer body downward during the extension process, and the hammer body is separated from the suction cup type electromagnet 21, and at the same time, ensure that the downward speed of the cylinder actuating rod is greater than the speed of free fall, ensure that the slider is relative to the hook static device, and ensure that the slider can open the hook. When the pneumatic actuating rod is extended to the limit position, the hammer body continues to fall under the action of inertia, and at the same time the card column falls outward from the hook. When the card head of the card column reaches the position of the slider, it drives the slider to fall together, avoiding the situation where the card hook is stuck to the main card column. When the hammer body is completely separated from the pneumatic actuating rod, it falls freely and impacts the structural parts to be tested. After the impact, the hammer body rebounds upward, the card column is inserted into the hook, and hangs upside down in the hook to avoid secondary impact. (The cylinder actuating rod 12 starts to move, causing the hammer to separate from the electromagnet 21 and move forward along the guide rail 7. When the cylinder actuating rod 12 extends to the limit position, Figure 4 As shown, the hammer continues to move forward under the action of inertia, the clamping column 27 is separated from the connection base 24 and the slider 28 is pulled out from the hook 25, as shown in FIG. Figure 5 As shown in FIG. 1 , the hammer rebounds after hitting the surface of the test piece, and the clamping column 27 moves into the clamping hook 25, as shown in FIG. Figure 6 As shown, at this time, the anti-secondary impact device completes the interception of the impact hammer).

[0061] While the impact test is being carried out, the linear displacement sensor rod 17 and the hammer body fall simultaneously, and the linear displacement sensor 16 detects the displacement of the linear displacement sensor rod 17, which is the displacement of the hammer head. The linear displacement sensor 16 then converts the detected data through a displacement signal converter 19 and sends it to a data acquisition module. The data acquisition module sends the received data to a processor (computer terminal) for processing, and calculates the instantaneous speed of the hammer head at the time of impact, thereby completing the entire impact test.

[0062] This test method ensures that the drop hammer speed is achieved through the drop hammer speed measuring device and data acquisition system, which can realize the accurate measurement of the instantaneous impact speed and the real-time collection of data during the entire impact process. The hammer moves along the guide column, and the direction in which the impact tester is installed determines the impact direction, so any angle of impact can be achieved, and both upward and downward impacts are feasible. The angle meter installed on the tester can conveniently display the impact angle; the impact speed is adjusted by controlling the pressure value of the gas storage tank, that is, the size of the impact energy is adjusted.

[0063] The above embodiments are merely examples of the present invention and do not limit the protection scope of the present invention. All designs that are the same or similar to the present invention fall within the protection scope of the present invention.

Claims

1. A portable pneumatic low-speed impact testing machine, characterized in that: It comprises an impact mechanism (1), a pneumatic drive mechanism (2), and a speed measurement and data acquisition system (3); The impact mechanism (1) is used to perform a low-speed impact at any angle on a fixed structural member; the pneumatic drive mechanism (2) provides driving power for the impact mechanism (1); The speed measurement and data acquisition system (3) is used to collect real-time displacement-time data of the hammer when the impact mechanism (1) impacts the detected object during the impact test, and convert it into instantaneous speed-time data of the entire impact process; The impact mechanism (1) comprises a connecting tube (5), the other end of the connecting tube (5) is fixedly connected to a mutually parallel guide rail (7), the guide rail (7) is provided with a hammer body (13) which moves up and down along the guide rail (7), and one end of the hammer body (13) is fixedly provided with a clamping column (27); The upper sleeve of the clamping column (27) is provided with a sliding block (28), and the sliding block (28) moves up and down along the clamping rod of the clamping column (27); the hammer body (13) of the punching hammer is connected to the guide rail (7) through a linear bearing (15); The connecting tube (5) is provided with a digital inclinometer (29) for detecting angles.

2. A portable pneumatic low-speed impact testing machine according to claim 1, characterized in that: A gripping handle (4) fixedly connected to the connecting tube (5) is provided at one end of the connecting tube (5), and the guide rail is perpendicular to the end surface of the connecting tube (5). A cylinder (9) is fixedly provided in the connecting tube (5), and a pneumatic actuating rod (12) of the cylinder (9) extends in the direction of the guide rail (7) and is located between the mutually parallel guide rails (7). A hammer head (14) is fixedly provided at one end of the hammer body (13) away from the cylinder (9), and the clamping column (27) is hooked or separated with a clamping structure fixed at the end of the pneumatic actuating rod (12), and the cylinder (9) is pneumatically connected to the pneumatic driving mechanism (2); the pneumatic driving mechanism (2) drives the pneumatic actuating rod (12) of the cylinder (9) to extend and retract.

3. A portable pneumatic low-speed impact testing machine according to claim 2, characterized in that: The other end of the connecting tube (5) opposite to the gripping handle (4) is fixedly connected to a support base (6), and mutually parallel guide rails (7) are fixedly connected to the support base (6). The end of the guide rail (7) away from the support base (6) is fixedly connected to a support top seat (8), and the hammer body (13) is located between the support top seat (8) and the support base (6).

4. A portable pneumatic low-speed impact testing machine according to claim 2, characterized in that: The connecting tube (5) is provided with an end surface of one end of the guide rail (7) on which an electromagnet fixing base (20) is fixedly connected, and the end of the electromagnet fixing base (20) away from the connecting tube (5) is fixedly connected with a suction cup type electromagnet (21), and the suction cup type electromagnet (21) is electrically connected to an electromagnet switch (22) fixedly arranged on the connecting tube (5). When the suction cup type electromagnet (21) is energized, it generates magnetic attraction to attract the hammer body (13).

5. A portable pneumatic low-speed impact testing machine according to claim 2, characterized in that: The buckle structure comprises a connecting base (24) fixedly connected to the end of the pneumatic actuating rod (12), hooks (25) movably connected to the connecting base (24) and symmetrically arranged, the symmetrically arranged hooks (25) are connected by springs (26), and the ends of the clamping columns (27) open the symmetrically arranged hooks (25) and hang upside down on the hooks (25), thereby connecting the hammer body (13) and the pneumatic actuating rod (12).

6. A portable pneumatic low-speed impact testing machine according to claim 2, characterized in that: The pneumatic drive mechanism (2) comprises a gas tank (35), an air compressor (30) arranged on the gas tank (35), the air compressor (30) being connected to the gas tank (35), a pneumatic valve (34) arranged on the gas tank (35) and connected to the gas tank (35), the pneumatic valve (34) being connected to a pneumatic switch (10) arranged on the cylinder (9) through a pipeline, the pneumatic switch (10) being provided with a pneumatic switch handle (11), the gas tank (35) being further provided with a digital pressure gauge (32) and a pressure relief valve (33) for detecting pressure, and the air compressor (30) being provided with a switch (31) electrically connected to the air compressor (30).

7. A portable pneumatic low-speed impact testing machine according to claim 2 or 6, characterized in that: The data acquisition system (3) comprises a linear displacement sensor (16) arranged in the connecting tube (5), a linear displacement sensor pull rod (17) having one end inserted in the linear displacement sensor (16) and the other end extending outside the connecting tube (5), and the linear displacement sensor pull rod (17) moves in the linear displacement sensor (16), the linear displacement sensor (16) is used to detect the displacement data of the linear displacement sensor pull rod (17), and the end of the linear displacement sensor pull rod (17) located outside the connecting tube (5) is provided with a reserve nut ( 18), the backup nut (18) contacts the upper end surface of the hammer body (13), the linear displacement sensor (16) is electrically connected to a displacement signal converter (19), the displacement signal converter (19) is electrically connected to a processor (37) through a data acquisition module (36), the data acquisition module (36) converts the analog signal obtained by the displacement signal converter (19) into a digital signal, and the processor (37) collects the displacement data and time data collected by the data acquisition module (36) and converts them into instantaneous speed.

8. An impact test method for a portable pneumatic low-speed impact tester, applied to the portable pneumatic low-speed impact tester according to claim 1, characterized in that: Follow these steps: Step 1: Hold the handle (4) and place the impact mechanism (1) against the fixed structure that needs to be impact tested, and fix the impact tester at the test site to ensure that the end of the guide rail (7) of the impact mechanism (1) is against the fixed structure; The electromagnet switch (22) is turned on, the suction cup electromagnet (21) is energized to generate magnetism, and at the same time, the hammer body (13) moves to the uppermost end of the guide rail (7), the clamping column (27) enters the mutually symmetrical clamping hooks (25), and the slider (28) opens the mutually symmetrical clamping hooks (25), and the suction cup electromagnet (21) absorbs the hammer body (13) so that the hammer body (13) is fixed to the uppermost end of the guide rail (7); The switch (31) is turned on, the pneumatic valve (34) is closed, and the air compressor (30) works to inflate the gas tank (35), ensuring that the pressure of the gas tank detected by the digital pressure gauge (32) is greater than the set pressure value, and the switch (31) is closed, and the air pressure in the gas tank (35) is adjusted through the pressure relief valve (33) to ensure that the air pressure is the same as the set pressure value; Step 2: Open the pneumatic valve (34), the pneumatic switch (10), and the pneumatic actuating rod (12) of the cylinder (9) pushes the hammer body (13) downward. When the pneumatic actuating rod (12) is at the limit position, the hammer body (13) continues to move downward under the action of inertia, and the clamping column (27) withdraws from the mutually symmetrical clamping hooks (25) and separates from the pneumatic actuating rod (12). The hammer body (13) continues to move downward, impacts the fixed structure to be tested, and rebounds. After the rebound, the hammer body (13) moves upward, and the clamping column (27) enters the mutually symmetrical clamping hooks (25) and hangs upside down in the clamping hooks (25); At the same time, during the downward movement of the hammer body (13), the linear displacement sensor rod (17) moves downward along with the hammer body (13), and the linear displacement sensor (16) detects the displacement of the linear displacement sensor rod (17), which is the displacement of the hammer body (13), and converts the detected displacement data through a displacement signal converter (19) and sends it to a data acquisition module (36). The data acquisition module (36) sends the received data to a processor (37) for processing and calculation to obtain an instantaneous speed.

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