Speed sensor calibration device of drop hammer impact testing machine

Abstract

The invention relates to a speed sensor calibration device of a drop hammer impact testing machine, which comprises a device frame, a vertically arranged vacuum tube is arranged on the device frame, a hammer body capable of moving up and down is arranged in the vacuum tube, and the hammer body comprises an outer hammer body with an inner hole and a cylindrical peripheral surface; the hammer body further comprises an inner hammer body which is assembled in an inner hole of the outer hammer body in a guiding and moving mode in the vertical direction, the inner hammer body and the outer hammer body are coaxially arranged, a big-end-up positioning conical head is arranged at the bottom of the inner hammer body, the height of the inner hammer body is smaller than that of an inner hole of the outer hammer body, and the inner hammer body is provided with a calibration station contained in the inner hole of the outer hammer body. And the inner hammer body is also provided with a collision station in which the positioning conical head is in positioning fit with the positioning conical groove and the upper end of the inner hammer body is in centering fit with the inner hole of the outer hammer body. The technical problem that in the prior art, after a hammer body collides with an impact buffering device, the posture of the hammer body is uncertain, and follow-up free falling motion of the hammer body is possibly affected is solved.

Description

Technical Field

[0001] The present invention relates to the field of verification and calibration, and particularly to a calibration device for a speed sensor of a drop hammer impact testing machine. Background Art

[0002] A drop hammer impact testing machine is a special device for applying an impact test force to a specimen and conducting an impact test. It is used to measure the impact resistance of materials or structures under dynamic loads, widely applied in the quality inspection of various products, and is also a testing instrument for research institutions to study new materials. Its working principle is to convert gravitational potential energy into impact energy through the free fall motion of the hammer body to conduct an impact test on the tested sample. The drop hammer impact testing machine has a speed measurement device, i.e., a speed measurement sensor, for detecting the falling speed of the drop hammer. Since the falling speed of the drop hammer is a key parameter characterizing the external impact force of the drop hammer, the current verification regulations in China require calibration through the speed measurement device.

[0003] The speed measurement sensor is usually a laser speed sensor. Its basic working principle is that when the drop hammer passes through the emitted laser of the laser speed sensor, the drop hammer will block the emitted laser, and based on the blocking time of the drop hammer, the falling speed of the drop hammer is calculated.

[0004] In order to achieve precise calibration of the speed sensor, the applicant designed a "standard device for the speed sensor used in the calibration of a drop hammer impact testing machine" and applied for a related patent. The application number of this patent is 2024220725258. In this patent, in order to avoid the influence of air friction on the drop hammer speed, a vertically arranged vacuum tube is provided, and there is a hammer body that can move up and down inside the vacuum tube.

[0005] During use, the hammer body is lifted to a certain height through an electromagnetic adsorption device, and then the power is cut off. The hammer body freely falls without the influence of air friction. When the hammer body passes through the emitted laser of the laser speed sensor, the laser speed sensor is calibrated by comparing the free fall speed of the hammer body with the reading of the laser speed sensor. After the hammer body passes through the laser speed sensor, the hammer body collides with the impact buffer device and waits for the next adsorption and lifting of the electromagnetic adsorption device. However, the problem in the existing technology is that after the hammer body collides with the impact buffer device, its posture cannot be determined, and it is possible that the hammer body tilts in the hammer body positioning groove, that is, the axis of the hammer body is not consistent with the axis of the hammer body positioning groove. In this way, when the electromagnetic adsorption device adsorbs the hammer body for the next use, the hammer body will be skewed with respect to the electromagnetic adsorption device, and when the hammer body falls again, it may contact and rub against the inner wall of the vacuum tube, affecting the free fall motion of the hammer body. Summary of the Invention

[0006] The object of the present invention is to provide a calibration device for the speed sensor of a drop hammer impact testing machine, so as to solve the technical problem in the prior art that after the hammer body collides with the impact buffer device, its attitude is uncertain and may affect the subsequent free fall motion of the hammer body.

[0007] To solve the above technical problems, the technical solution of a calibration device for the speed sensor of a drop hammer impact testing machine in the present invention is as follows: A calibration device for the speed sensor of a drop hammer impact testing machine includes a device frame. A vertically arranged vacuum tube is provided on the device frame. A hammer body that can move up and down is arranged in the vacuum tube. The outer periphery of the hammer body is arranged at an interval from the inner wall of the vacuum tube. A hammer body buffer structure is provided at the bottom of the vacuum tube. The hammer body includes an outer hammer body with a cylindrical outer surface having an inner hole. The hammer body further includes an inner hammer body that is guided and movably assembled in the inner hole of the outer hammer body in the up and down direction. The inner hammer body and the outer hammer body are coaxially arranged. The bottom of the inner hammer body has a positioning cone head that is larger at the top and smaller at the bottom. The hammer body buffer structure includes a vertically arranged buffer groove. The notch edge of the buffer groove is used to collide with the bottom of the outer hammer body when the hammer body falls. A collision head is guided and movably assembled in the buffer groove in the up and down direction. A positioning cone groove matching the positioning cone head is provided at the upper end of the collision head. The height of the inner hammer body is less than the height of the inner hole of the outer hammer body. The inner hammer body has a calibration station received in the inner hole of the outer hammer body. The inner hammer body also has a collision station where the positioning cone head and the positioning cone groove are in positioning cooperation, and the upper end of the inner hammer body is in centering cooperation with the inner hole of the outer hammer body. A sensor mounting plate is provided on the vacuum tube above the hammer body buffer structure.

[0008] Further, the sensor mounting plate includes a left mounting plate fixed to the left side of the vacuum tube and a right mounting plate fixed to the right side of the vacuum tube. The left mounting plate and the right mounting plate are horizontally arranged.

[0009] Further, a vertically arranged buffer spring is provided between the bottom of the collision head and the bottom of the buffer groove.

[0010] Further, an electromagnetic adsorption device for adsorbing the inner hammer body to lift the height of the hammer body is guided and movably assembled in the vacuum tube in the up and down direction. A lifting winch is provided on the upper side of the vacuum tube. The lifting winch is connected to the electromagnetic adsorption device through a pull rope.

[0011] Further, a lifting rod is fixed to the upper end of the inner hammer body and is in guiding and moving cooperation with the upper end of the outer hammer body in the vertical direction. A connecting plate for adsorbing and connecting with the lower end of the electromagnetic adsorption device is arranged at the upper end of the lifting cylinder. A plurality of track bars are arranged on the inner wall of the vacuum tube at intervals in the circumferential direction, and the track bars are arranged vertically. A track groove for guiding and moving cooperation with the track bars is arranged on the outer periphery of the electromagnetic adsorption device. The track bars include high-position track bars and low-position track bars located on both the upper and lower sides of the high-position track bars. The height of the low-position track bars is lower than that of the high-position track bars. The height of the track groove matches the height of the high-position track bars. The lower end of the high-position track bar is used for stop cooperation with the outer hammer body to limit the upward movement limit of the outer hammer body.

[0012] Further, the lifting rod includes a front-side lifting rod and a rear-side lifting rod. The connecting plate includes a front-side connecting plate fixed to the upper end of the front-side lifting rod and a rear-side connecting plate fixed to the upper end of the rear-side lifting rod. The laser emitted by the speed sensor to be measured passes through the gap between the front-side connecting plate and the rear-side connecting plate and the gap between the front-side lifting rod and the rear-side lifting rod.

[0013] The beneficial effects of the present invention are as follows: In the present invention, the hammer body includes an outer hammer body and an inner hammer body that is in guiding and moving cooperation with the inner hole of the outer hammer body. When the hammer body freely falls in the vacuum tube, the inner hammer body is in the calibration position received in the inner hole of the outer hammer body. The inner hammer body and the outer hammer body move downward in free fall synchronously. The falling speed of the hammer body is measured by the outer hammer body blocking the laser emitted by the laser speed sensor. Since the inner hammer body is received in the inner hole of the outer hammer body, the positioning cone head at the bottom of the inner hammer body will not affect the measurement of the falling speed of the hammer body. After the hammer body passes through the laser speed sensor, the outer hammer body collides and stops with the notch edge of the buffer groove, and the inner hammer body comes out from the lower end of the inner hole of the outer hammer body. The positioning cone head at the bottom of the inner hammer body is in positioning cooperation with the positioning cone groove, thereby positioning the position of the inner hammer body. The upper end of the inner hammer body and the inner hole of the outer hammer body are still in a guiding cooperation relationship. Therefore, the position of the outer hammer body can be positioned to ensure that the outer hammer body and the vacuum tube are in the same axis state, thereby avoiding friction and collision between the hammer body and the tube wall of the vacuum tube when the hammer body falls again for use. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] By reading the following detailed description with reference to the accompanying drawings, the above and other objects, features, and advantages of the exemplary embodiments of the present disclosure will become readily understood. In the drawings, several embodiments of the present disclosure are shown in an exemplary rather than restrictive manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein: Figure 1 is a schematic structural diagram of an embodiment of the speed sensor calibration device in the present invention; Figure 2 is Figure 1 the schematic diagram of the state when the hammer body passes through the laser speed sensor during the falling process in Figure 3It is a schematic diagram of the state when the electromagnetic adsorption device in the present invention adsorbs the inner hammer body again; Figure 4 It is Figure 3 In the top view direction of [[ID=]], the mating schematic diagram of the high - level track bar, the low - level track bar and the tube wall of the vacuum tube; Figure 5 It is Figure 3 In the top view direction of [[ID=]], the structural schematic diagram of the electromagnetic adsorption device; Figure 6 It is Figure 1 In [[ID=]], the structural schematic diagram of the hammer body; Figure 7 It is Figure 6 In [[ID=]], the side view of the hammer body; 1. Hoisting winch; 2. Pulling rope; 3. Vacuum tube; 4. Low - level track bar; 5. Electromagnetic adsorption device; 6. Track groove; 7. High - level track bar; 8. Inner hammer body; 9. Outer hammer body; 10. Hammer body; 11. Front - side lifting rod; 12. Left - side mounting plate; 13. Right - side mounting plate; 14. Laser speed sensor; 15. Reflective plate; 16. Device frame; 17. Buffer groove; 18. Collision head; 19. Positioning cone groove; 20. Buffer spring; 21. Positioning cone head; 22. Front - side connecting plate; 23. Vacuum pumping port; 24. Rear - side lifting rod; 25. Rear - side connecting plate. Specific embodiments

[0015] For the convenience of understanding the present invention, the present invention will be described in more detail below in conjunction with the accompanying drawings and specific embodiments. The preferred embodiments of the present invention are shown in the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure content of the present invention more thorough and comprehensive.

[0016] It should be noted that unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not used to limit the present invention.

[0017] An embodiment of the speed sensor of a drop - hammer impact testing machine in the present invention is as Figures 1 to 7 shown: It includes a device frame 16. A vertically arranged vacuum tube 3 is provided on the device frame 16. A hammer body 10 capable of moving up and down is arranged in the vacuum tube 3. The hammer body 10 includes an outer hammer body 9 with an inner hole. The outer peripheral surface of the outer hammer body 9 is a cylindrical surface with an axis extending in the up - down direction. An inner hammer body 8 is guided and movably assembled in the inner hole of the outer hammer body 9. The outer diameter of the outer hammer body 9 is smaller than the inner diameter of the vacuum tube 3. Therefore, there is an annular gap between the outer periphery of the outer hammer body and the inner wall of the vacuum tube. The inner hammer body includes a cylindrical section and a positioning cone head 21 with a large upper part and a small lower part arranged at the bottom of the cylindrical section.

[0018] A hammer body buffer structure is provided at the bottom of the vacuum tube. The hammer body buffer structure includes a vertically arranged buffer groove 17. The inner diameter of the buffer groove 17 matches the outer diameter of the cylindrical section of the inner hammer body. The notch edge of the buffer groove is used to collide with the bottom of the outer hammer body 9 when the hammer body falls. A collision head 18 is movably assembled in the buffer groove along the up-and-down direction. A vertically arranged buffer spring 20 is provided between the bottom of the collision head 18 and the bottom of the buffer groove. A positioning cone groove 19 matching the positioning cone head is provided at the upper end of the collision head. The positioning cone groove 19 is coaxially arranged with the vacuum tube 3. The height of the inner hammer body 8 is less than the inner hole height of the outer hammer body. The inner hammer body has a calibration station received in the inner hole of the outer hammer body. The inner hammer body also has a collision station where after the outer hammer body collides with the notch edge of the buffer groove, the positioning cone head is in positioning cooperation with the positioning cone groove, and the upper end of the inner hammer body is in centering cooperation with the inner hole of the outer hammer body. A sensor mounting plate is provided on the upper side of the vacuum tube at the hammer body buffer structure. The vacuum tube is made of a transparent material.

[0019] The sensor mounting plate includes a left mounting plate 12 fixed to the left side of the vacuum tube and a right mounting plate 13 fixed to the right side of the vacuum tube. The left mounting plate 12 and the right mounting plate 13 are horizontally arranged. During use, the laser emitting device and the laser receiving device of the laser distance measuring sensor 14 are mounted on the right mounting plate 13, and the reflector 15 is mounted on the left mounting plate. The laser emitted by the laser emitting device passes through the vacuum tube and then irradiates on the reflector, and then is reflected back to the laser receiving device by the reflector. The working principle of the laser distance measuring sensor belongs to the prior art and will not be elaborated here.

[0020] A vacuum tube top plate is provided at the top of the vacuum tube. An electromagnetic adsorption device 5 for adsorbing the inner hammer body to lift the height of the hammer body is movably assembled in the vacuum tube along the up-and-down direction. The electromagnetic adsorption device 5 is an electromagnet. A lifting winch 1 is provided on the upper side of the vacuum tube. The lifting winch is driven by a winch motor. The lifting winch is connected to the electromagnetic adsorption device 5 through a pull rope 2. The pull rope 2 is in guiding movement cooperation with the vacuum tube top plate. A vacuum pumping port 23 is provided at the bottom of the vacuum tube. During use, a vacuum pump is connected to the vacuum pumping port. When the vacuum degree in the vacuum tube is insufficient, the vacuum pump works to ensure the vacuum degree in the vacuum tube.

[0021] A lifting rod is fixed to the upper end of the inner hammer body and is in guiding movement cooperation with the upper end of the outer hammer body in the vertical direction. A connecting plate for adsorbing and connecting with the lower end of the electromagnetic adsorption device is arranged at the upper end of the lifting cylinder. The connecting plate is horizontally arranged and is used to increase the contact area with the electromagnetic adsorption device so as to ensure the adsorption force. A plurality of track bars are arranged on the inner wall of the vacuum tube at intervals in the circumferential direction. The track bars are vertically arranged. A track groove 6 for guiding movement cooperation with the track bars is arranged on the outer periphery of the electromagnetic adsorption device. The track bars include a high-position track bar 7 and low-position track bars 4 located on both the upper and lower sides of the high-position track bar. In this embodiment, the high-position track bar and the low-position track bar are relative. The height of the high-position track bar is higher than that of the low-position track bar, so it is called the high-position track bar. The height of the track groove matches the height of the high-position track bar. The lower end of the high-position track bar is used for blocking and cooperating with the outer hammer body to limit the upward movement limit of the outer hammer body. Through the guiding cooperation between the track bars and the electromagnetic adsorption device, the electromagnetic adsorption device can be restricted from rotating relative to the vacuum tube. At the same time, the high-position track bar can also limit the upward movement limit of the outer hammer body, ensuring that the inner hammer body can be received in the inner hole of the outer hammer body.

[0022] The lifting rod includes a front-side lifting rod 11 and a rear-side lifting rod 24. The connecting plate includes a front-side connecting plate 22 fixed to the upper end of the front-side lifting rod and a rear-side connecting plate 25 fixed to the upper end of the rear-side lifting rod. The laser emitted by the speed sensor to be calibrated passes through the gap between the front-side connecting plate and the rear-side connecting plate and the gap between the front-side lifting rod and the rear-side lifting rod. In this way, the front-side lifting rod, the rear-side lifting rod, the front-side connecting plate, and the rear-side connecting plate will not block the laser and avoid detection errors.

[0023] During use, first as Figure 1 shown, the electromagnetic adsorption device lifts the hammer body to a high position. At this time, the inner hammer body is hidden in the outer hammer body. Then the electromagnetic adsorption device is powered off, and the outer hammer body and the inner hammer body fall freely synchronously. By using the shielding of the outer hammer body on the laser, the speed of the outer hammer body is measured. According to the height of the outer hammer body, the calculated speed of the outer hammer body is compared with the measured speed to calibrate the speed sensor. After the hammer body passes through the laser speed measurement sensor from top to bottom, the outer hammer body collides with the notch edge of the buffer groove. Under the action of inertia, the positioning cone head at the lower end of the inner hammer body enters the positioning cone groove of the collision head, thereby realizing the positioning of the inner hammer body and ensuring that the inner hammer body is coaxially arranged with the vacuum tube. Since the upper end of the inner hammer body and the outer hammer body are still in a centering contact relationship, the coaxial arrangement relationship between the outer hammer body and the vacuum tube is ensured. When it needs to be used again, the electromagnetic adsorption device moves downward until it contacts the front-side connecting plate and the rear-side connecting plate. The electromagnetic adsorption device is powered on, and then the hammer body is lifted to the specified height by using the lifting winch.

[0024] In the above description of this specification, unless otherwise clearly defined and limited, terms such as "fixed", "installed", "connected" or "coupled" should be understood in a broad sense. For example, with respect to the term "connected", it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, or it can be the communication inside two components or the interaction relationship between two components. Therefore, unless otherwise clearly limited in this specification, those skilled in the art can understand the specific meanings of the above terms in the present invention according to specific circumstances.

[0025] According to the above description of this specification, those skilled in the art can also understand the terms used as follows. For example, terms indicating orientation or positional relationships such as "upper", "lower", "front", "rear", "left", "right", "length", "width", "thickness", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", "center", "longitudinal", "transverse", "clockwise" or "counterclockwise" are based on the orientation or positional relationships shown in the drawings of this specification. They are only for the purpose of facilitating the description of the solutions of the present invention and simplifying the description, rather than explicitly or implicitly indicating that the devices or components involved must have the specific orientation, be constructed and operated in the specific orientation. Therefore, the above terms of orientation or positional relationships cannot be understood or interpreted as limitations on the solutions of the present invention.

[0026] In addition, terms such as "first" or "second" used in this specification to refer to numbers or ordinals are only for descriptive purposes and cannot be understood as explicitly or implicitly indicating relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this specification, the meaning of "a plurality" is at least two, such as two, three or more, etc., unless otherwise clearly and specifically defined.

[0027] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A velocity sensor calibration device for a drop weight impact testing machine, comprising a device frame, characterized in that: A vertically arranged vacuum tube is arranged on the device frame, a hammer body capable of moving up and down is arranged in the vacuum tube, the outer periphery of the hammer body is arranged at intervals with the inner wall of the vacuum tube, a hammer body buffer structure is arranged at the bottom of the vacuum tube, the hammer body comprises an outer hammer body with an inner hole whose outer periphery surface is a cylindrical surface, the hammer body also comprises an inner hammer body guided and moved in the inner hole of the outer hammer body along the up and down directions, the inner hammer body and the outer hammer body are coaxially arranged, the bottom of the inner hammer body has a positioning cone head which is larger at the top and smaller at the bottom, the hammer body buffer structure comprises a vertically arranged buffer groove, the notch edge of the buffer groove is used to collide with the bottom of the outer hammer body when the hammer body falls, a collision head is guided and moved in the buffer groove along the up and down directions, a positioning cone groove matching the positioning cone head is arranged at the upper end of the collision head, the height of the inner hammer body is less than the height of the inner hole of the outer hammer body, the inner hammer body has a calibration station received in the inner hole of the outer hammer body, the inner hammer body also has a collision station in which the positioning cone head is positioned and matched with the positioning cone groove, and the upper end of the inner hammer body is matched with the inner hole of the outer hammer body for centering, and a sensor mounting plate is arranged on the vacuum tube at the upper side of the hammer body buffer structure.

2. The speed sensor calibration device according to claim 1, characterized in that: The sensor mounting plate comprises a left mounting plate fixed on the left side of the vacuum tube and a right mounting plate fixed on the right side of the vacuum tube, and the left mounting plate and the right mounting plate are arranged horizontally.

3. The speed sensor calibration device according to claim 1, characterized in that: A vertically arranged buffer spring is arranged between the bottom of the collision head and the groove bottom of the buffer groove.

4. The speed sensor calibration device according to any one of claims 1 to 3, characterized in that: An electromagnetic adsorption device for adsorbing the inner hammer body and raising the height of the hammer body is installed in the vacuum tube along the up-down direction. A lifting winch is arranged on the upper side of the vacuum tube, and the lifting winch is connected to the electromagnetic adsorption device through a pull rope.

5. The speed sensor calibration device according to claim 4, characterized in that: A lifting rod is fixed to the upper end of the inner hammer body and is coordinated with the upper end of the outer hammer body for guiding and moving in the up and down directions. A connecting plate for adsorption and connection with the lower end of the electromagnetic adsorption device is arranged at the upper end of the lifting cylinder. A plurality of track bars arranged at intervals along the circumferential direction are arranged on the inner wall of the vacuum tube. The track bars are arranged vertically. A track groove is arranged on the outer periphery of the electromagnetic adsorption device and is coordinated with the track bar for guiding and moving. The track bars include a high-position track bar and low-position track bars located on the upper and lower sides of the high-position track bar. The height of the low-position track bar is lower than that of the high-position track bar. The height of the track groove matches that of the high-position track bar. The lower end of the high-position track bar is used to cooperate with the outer hammer body to stop and limit the upward movement limit of the outer hammer body.

6. The speed sensor calibration device according to claim 5, characterized in that: The lifting rod includes a front lifting rod and a rear lifting rod, the connecting plate includes a front connecting plate fixed to the upper end of the front lifting rod and a rear connecting plate fixed to the upper end of the rear lifting rod, and the laser emitted by the speed sensor to be measured passes through the gap between the front connecting plate and the rear connecting plate and the gap between the front lifting rod and the rear lifting rod.

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