High temperature impact force calibration device and calibration method

Abstract

The present invention discloses a high-temperature impact force calibration device and calibration method, the device includes a temperature box, an infrared heating plate, a lifting device, a hammer head, an acceleration sensor, a hammer head position sensor, a waveform generator, an impact force sensor, a temperature sensor, a controller and an anvil; the infrared heating plate is used to perform radiation heating on the impact force sensor, the temperature sensor is used to measure the temperature of the impact force sensor; the impact force sensor is used to measure the impact force of the hammer head hitting the anvil; the acceleration sensor is used to measure the acceleration of the hammer head, and the impact force value is calculated according to the measured acceleration. The controller calibrates the impact force sensor by comparing the impact force value calculated by the acceleration sensor with the impact force value measured by the impact force sensor. The present invention uses infrared radiation heating to create a transient high-temperature dynamic thermal shock environment, completes high-temperature shock calibration in this environment, and improves the repeatability and accuracy of calibration data.

Description

Technical Field

[0001] The invention belongs to the technical field of impact measurement and testing equipment, and in particular relates to a high-temperature impact force calibration device and a calibration method. Background Art

[0002] The measurement of transient impact force is an extremely important branch in the field of dynamic measurement. It is widely used in aerospace, aviation, weapons, construction, transportation, ships, mining, geophysical exploration and environmental equipment testing. Therefore, the research on impact acceleration and transient impact force calibration technology has broad and far-reaching significance. Sensitivity is a basic characteristic parameter of the sensor. It not only reflects the application range of the sensor, but also characterizes the performance of the sensor. Accurately measuring this parameter plays a decisive role in studying the performance of the sensor and improving the quality of the product.

[0003] According to "GB / T37776-2019 Dynamic Force Sensor Calibration Method Impact Force Calibration", the current room temperature calibration methods for impact force sensors are mainly comparison method and absolute method. The calibration device is a drop hammer impact force generating device, and its working principle is: a rigid mass block that falls freely from a certain height in the plumb direction collides with the dynamic force sensor installed on the base. The impact motion generated during the impact is converted into impact force excitation and transmitted to the impact force sensor through the mass block. However, in actual use, the measurement error of the sensor due to changes in ambient temperature can be as high as 10% to 50%. Obviously, this cannot be ignored. Regarding the temperature effect of the sensitivity of the impact force sensor, the current domestic standard is "GB / T13823.16-1995 Vibration and shock sensor calibration method transient temperature sensitivity test method", which uses the same method as "IS05347-18-1993 Vibration and shock sensor calibration method Part 18: Transient temperature sensitivity test method", both of which use dry ice solution with alcohol to generate low temperature temperature shock and test sensitivity.

[0004] The above standards only propose verification methods for low-temperature impact force calibration, but do not mention high-temperature impact force calibration, which makes the calibration data unsuitable for impact force sensors used in high-temperature working conditions such as explosions. At the same time, the temperature change gradient of the dry ice solution immersion method is small, which does not match the temperature change in actual applications such as explosions. Therefore, the calibration results of impact force sensors used in such working conditions have great uncertainty, which can easily cause safety accidents. Summary of the invention

[0005] The purpose of the present invention is to provide a high temperature impact force calibration device and calibration method, which adopts infrared radiation heating to create a transient high temperature dynamic thermal shock environment, completes high temperature impact calibration in this environment, and improves the repeatability and accuracy of calibration data.

[0006] One aspect of the present invention provides a high temperature impact force calibration device, comprising a temperature box, an infrared heating plate, a lifting device, a hammer head, an acceleration sensor, a hammer head position sensor, a waveform generator, an impact force sensor, a temperature sensor, a controller and an anvil;

[0007] The temperature box is used to provide a stable thermal environment. The infrared heating plate and the impact force sensor to be calibrated are arranged in the temperature box. The infrared heating plate is used to radiate heating to the impact force sensor and provide a thermal shock environment for the impact force sensor. The temperature sensor is used to measure the temperature of the impact force sensor.

[0008] The lifting device can move up and down to drive the hammer head to move up and down, and can make the hammer head perform free fall motion by releasing the hammer head. The waveform generator is installed at the top of the impact hammer head to generate a semi-sine impact force with a certain pulse width range. The impact force sensor is installed on the anvil to measure the impact force of the hammer head hitting the anvil. The anvil and the hammer head are installed coaxially as an impact receptor of the hammer head.

[0009] The acceleration sensor is used to measure the acceleration of the hammer head, and the impact force value is calculated based on the measured acceleration. The hammer head position sensor is used to detect the position of the hammer head. The controller is used to control the heating of the infrared heating plate and the movement of the lifting device, and synchronously collect the measurement data of the hammer head position sensor, the impact force sensor, and the temperature sensor. The impact force sensor is calibrated by comparing the impact force value calculated by the acceleration sensor with the impact force value measured by the impact force sensor.

[0010] Preferably, the high temperature impact force calibration device further comprises a hammer disengaging device, a cage buffer, an air floating cage, a guide rail, and a gland plate;

[0011] The hammer head disengaging device is used to disengage the hammer head from the anvil, the retaining frame buffer is used for protective limiting and absorbing the residual energy after the hammer head impacts, the air floating retaining frame is used to support the upper part of the hammer head to ensure the overall straightness of the device, the guide rail is used to ensure the linear free fall motion of the hammer head, and the pressure cover plate is set on the top of the device as a counterweight to ensure the overall stability of the device.

[0012] Preferably, the hammer position sensor is also used to alarm and start the hammer disengagement device to move upward to intercept the lifting device when the hammer deviates from the safe position, thereby protecting the impact force sensor from being damaged by the impact.

[0013] Another aspect of the present invention provides a high temperature impact force calibration method, which uses the above-mentioned high temperature impact force calibration device to calibrate the impact force sensor, comprising:

[0014] Step 1: The controller sets the impact force value, and calculates the starting position of the hammer head according to the set impact force value;

[0015] Step 2: The controller identifies the current position of the hammer head through the hammer head position sensor, and determines whether the position is correct by comparing it with the starting position of the hammer head. If it is incorrect, the controller moves the hammer head up or down by moving the lifting device upward or downward until the current position of the hammer head is the same as the starting position of the hammer head.

[0016] Step 3: The controller sets the temperature range and temperature gradient of the high temperature shock, and sets the heating power of the infrared heating plate according to the set temperature range and temperature gradient;

[0017] Step 4: The infrared heating plate starts heating, and the temperature change of the impact force sensor is monitored by the temperature sensor. When the temperature gradient is less than the set value, positive feedback is applied to the set heating power to increase the heating power to achieve the set temperature gradient;

[0018] Step 5: The lifting device releases the hammer head to start free fall. When the hammer head falls to the specified position, the controller triggers the temperature sensor, impact force sensor and acceleration sensor to start synchronous collection;

[0019] Step 6: The acceleration sensor calculates the actual impact force value according to the measured acceleration. The controller compares the actual impact force value with the set impact force value, and adjusts the starting position of the hammer head by feedback. Steps 2 to 5 are repeated until the actual impact force value and the set impact force value meet the calibration requirements, thus completing the calibration of the current force value point.

[0020] Step 7: Repeat steps 1 to 6 for the next force point to be calibrated until the calibration of all force points of the impact force sensor is completed.

[0021] According to the high temperature impact force calibration device and calibration method of the above aspects of the present invention, infrared radiation heating is used to create a transient high temperature dynamic thermal shock environment, in which high temperature impact calibration is completed, thereby improving the repeatability and accuracy of the calibration data. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings used in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work:

[0023] Figure 1 It is a structural schematic diagram of a high temperature impact force calibration device according to an embodiment of the present invention;

[0024] Among them: 1-temperature box, 2-infrared heating plate, 3-hammer disengaging device, 4-cage buffer, 5-air floating cage, 6-guide rail, 7-pressure cover plate, 8-lifting device, 9-hammer, 10-acceleration sensor, 11-hammer position sensor, 12-waveform generator, 13-impact force sensor, 14-temperature sensor, 15-controller, 16-anvil. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] An embodiment of the present invention provides a high temperature impact force calibration device, Figure 1 FIG. 1 is a schematic diagram of the structure of a high temperature impact force calibration device according to an embodiment of the present invention. Figure 1 As shown, the high temperature impact force calibration device of the embodiment of the present invention includes a temperature box 1, an infrared heating plate 2, a hammer head disengaging device 3, a retaining frame buffer 4, an air floating retaining frame 5, a guide rail 6, a pressure cover plate 7, a lifting device 8, a hammer head 9, an acceleration sensor 10, a hammer head position sensor 11, a waveform generator 12, an impact force sensor 13, a temperature sensor 14, a controller 15 and an anvil 16.

[0027] The temperature box 1 , the infrared heating plate 2 , the impact force sensor 13 , and the temperature sensor 14 constitute an infrared radiation heating structure, which provides a thermal shock environment for the impact force sensor 13 .

[0028] The hammer disengaging device 3, the retaining frame buffer 4, the air-floating retaining frame 5, the guide rail 6, the pressure cover plate 7, the lifting device 8, the hammer 9, the acceleration sensor 10, the hammer position sensor 11, the waveform generator 12, the impact force sensor 13 and the anvil 16 constitute an impact generating structure, which can be controlled according to the set impact force value.

[0029] The acceleration sensor 10, the hammer position sensor 11, the impact force sensor 13, the temperature sensor 14, and the controller 15 constitute a data acquisition structure to achieve synchronous acquisition of temperature and impact force.

[0030] The hammer head 9, the acceleration sensor 10, the hammer head position sensor 11, the waveform generator 12, the impact force sensor 13, and the controller 15 constitute a calibration data acquisition structure.

[0031] The temperature box 1 adopts a heat insulation structure design, which is used to provide a stable thermal environment and improve the temperature control accuracy. The infrared heating plate 2 and the impact force sensor 13 to be calibrated are arranged in the temperature box 1. The infrared heating plate 2 is used as a heating source, and adopts the principle of thermal radiation for efficient heating, and can provide a transient temperature environment.

[0032] The hammer disengaging device 3 is used to disengage the impact hammer 9 and the impact anvil 16. The retaining frame buffer 4 mainly plays a protective limit role, absorbing the residual energy of the hammer 9 after the impact is completed. The air-floating retaining frame 5 is used to support the upper part of the hammer 9 to ensure the overall straightness of the device and produce a standard impact stroke. The guide rail 6 is the main component of the impact stroke to ensure the linear free fall motion of the hammer 9. The pressure cover plate 7 is set at the top of the device as the main counterweight to ensure the overall stability of the vertical device.

[0033] The lifting device 8 can move up and down, and is used to drive the hammer head 9 to move up and down, and can release the hammer head 9 to make the hammer head 9 perform free fall motion. The power source of the lifting device 8 is a motor, and the motor can rotate in both positive and negative directions to complete the up and down motion of the lifting device 8 during operation.

[0034] The hammer head 9 is the main impact motion generating device. It falls from a specified position and hits the impact force sensor with a certain initial velocity, providing an excitation signal for the impact force sensor. The acceleration sensor 10 is used to collect the acceleration of the hammer head 9. On the premise of determining the mass of the hammer head 9, according to Newton's second law, the impact force value is calculated as the standard data of the impact force sensor 13 to be calibrated.

[0035] The hammer position sensor 11 can detect the position of the hammer. Its main functions include two parts. One is to serve as a synchronous trigger signal. When the hammer 9 falls to the impact position, it is fed back to the controller 15 to start synchronously collecting the calibration data of the temperature sensor 14, the impact force sensor 13 and the acceleration sensor 10. The other is to serve as a safety limit. When the hammer deviates from the safe position, an alarm is issued and the hammer disengaging device 3 is started to move upward to intercept the lifting device 8 to protect the calibrated impact force sensor 13 from being damaged by the impact.

[0036] The waveform generator 12 is installed at the top of the impact hammer 9 to generate a semi-sine impact force with a certain pulse width range. The impact force sensor 13 is installed on the anvil 16 as the calibrated device to measure the semi-sine impact force of the hammer 9 hitting the anvil 16. The temperature sensor 14 is opposite to the impact force sensor 13 to measure the temperature value of the area near the impact force sensor 13. The anvil 16 is installed coaxially with the hammer 9 and acts as an impact receptor during operation to cooperate in completing the specified impact action.

[0037] The controller 15 is used to control the heating of the infrared heating plate 2 and the movement of the lifting device 8, and synchronously collects the measurement data of the hammer position sensor 11, the impact force sensor 13, and the temperature sensor 14, and calibrates the impact force sensor 13 by comparing the impact force value calculated by the acceleration sensor 10 and the impact force value measured by the impact force sensor 13.

[0038] In one embodiment, the controller 15 integrates a temperature control module, an impact control module and a synchronous trigger module, and adjusts the temperature condition loading, impact condition loading and the synchronous collection of mechanical parameters and temperature parameters of the impact process in a closed loop according to demand.

[0039] An embodiment of the present invention further provides a high temperature impact force calibration method, which uses the high temperature impact force calibration device of the above embodiment to perform high temperature impact force calibration, including the following steps:

[0040] Step 1: The controller 15 sets the impact force value. In one embodiment, the impact force value F=100N is set. According to the set impact force value, the starting position of the hammer head (impact height) h=160mm is calculated.

[0041] Step 2. The hammer position sensor 11 identifies the current position h0 of the hammer, and the controller 15 determines whether the position is correct by comparing the size relationship between h and h0. If the position is inappropriate, a movement command is issued to the lifting device. When h0<h, the controller 15 issues an ascending command, and the lifting device 8 starts to move upward, driving the hammer 9 to move upward together. When h0=h, the controller 15 issues a stop command, and the ascending movement terminates. When h0>h, the controller 15 issues a descending command, and the lifting device 8 starts to move downward, driving the hammer 9 to move downward together. When h0=h, the controller 15 issues a stop command, and the movement of the lifting device 8 terminates. The impact force value F is achieved by changing the height h, and the relationship between the two is:

[0042]

[0043] The collision process is:

[0044]

[0045] Where A is the introduced amplitude correction coefficient;

[0046] ω——angular velocity of the impact signal;

[0047] ——Initial phase.

[0048] Then the impact acceleration a monitored by the acceleration sensor is:

[0049]

[0050] The impact force F is:

[0051]

[0052] The maximum impact force is

[0053] Step 3: The controller 15 sets the temperature range T of the high temperature shock min ~T max and the temperature change rate (temperature gradient) k, the controller 15 sets the heating power P(t) that meets the test requirements according to the operating temperature range and the temperature change rate.

[0054] In one embodiment, the temperature gradient k=0.2°C / s, and the heating power of the infrared heating plate 2 is:

[0055]

[0056] The controller 15 issues a heating command to the infrared heating plate 2, and the infrared heating plate 2 starts to work and irradiates the impact force sensor 13. When the temperature of the impact force sensor 13 rises from room temperature to T min When the controller 15 performs power adjustment, the temperature of the impact force sensor is stabilized at T min . The temperature change rate k is:

[0057]

[0058] Where T t ——The temperature of the impact force sensor at time t;

[0059] T t+Δt ——The temperature of the impact force sensor at time t+Δt;

[0060] Δt——set temperature gradient.

[0061] Step 4: The controller 15 issues a command to the infrared heating plate 2, and the infrared heating plate 2 starts heating. The controller 15 monitors the temperature change of the impact force sensor 13. When the temperature change gradient is less than the set value k, the controller 15 applies positive feedback α(t) to P(t) to achieve the temperature gradient by increasing the working input of the infrared heating plate 2.

[0062]

[0063] After adjustment After k is satisfied, the controller 15 stably executes the heating scheme.

[0064] Step 5: After the measurement requirements are met, impact can be performed. The controller 15 issues an impact command, the lifting device 8 is released, the hammer head 9 is released and starts free fall, and the acceleration sensor 10 records the collected acceleration data. The hammer head position sensor 11 captures the real-time position of the hammer head 9 and waits for triggering. When the hammer head falls to the specified position, the controller 15 issues a collection trigger command to the temperature sensor 14, the impact force sensor 13 and the acceleration sensor 10 to start synchronous collection.

[0065] Step 6: The controller 15 processes the temperature signal, the impact force signal and the acceleration signal. The acceleration sensor collects the acceleration change during the impact process and calculates the actual impact force value F according to the hammer mass according to F=ma. 实际 , controller 15 compares F 实际 And set the force value F, feedback to adjust the hammer head starting position h until F 实际 Until the set force value F reaches the actual calibration requirement, the calibration of the current force value point is completed.

[0066] Step 7: Repeat steps 1 to 6 for the next force point to be calibrated until the calibration of all force points of the impact force sensor is completed.

[0067] The high temperature impact force calibration device and calibration method of the above-mentioned embodiment of the present invention have the following beneficial effects:

[0068] 1. The present invention adopts an infrared heating device, which can quickly heat the impact force sensor according to the set temperature conditions, realize the precise control of the temperature range and temperature gradient dual parameters, and create a controllable transient thermal shock environment;

[0069] 2. The present invention adopts temperature control closed-loop feedback control, which can automatically calculate and adjust the thermal power according to the set temperature gradient;

[0070] 3. The present invention adopts the hammer position signal as a trigger, and can synchronously collect signals from the temperature sensor, impact force sensor and acceleration sensor, and can effectively collect calibration data of the impact force sensor of real thermal shock, thereby improving the accuracy of the test data.

[0071] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A high temperature impact force calibration device, characterized in that: It includes a temperature box, an infrared heating plate, a lifting device, a hammer head, an acceleration sensor, a hammer head position sensor, a waveform generator, an impact force sensor, a temperature sensor, a controller and an anvil; The temperature box is used to provide a stable thermal environment. The infrared heating plate and the impact force sensor to be calibrated are arranged in the temperature box. The infrared heating plate is used to radiate heating to the impact force sensor and provide a thermal shock environment for the impact force sensor. The temperature sensor is used to measure the temperature of the impact force sensor. The lifting device can move up and down to drive the hammer head to move up and down, and can make the hammer head perform free fall motion by releasing the hammer head. The waveform generator is installed at the top of the impact hammer head to generate a semi-sine impact force with a certain pulse width range. The impact force sensor is installed on the anvil to measure the impact force of the hammer head hitting the anvil. The anvil and the hammer head are installed coaxially as an impact receptor of the hammer head. The acceleration sensor is used to measure the acceleration of the hammer head, and the impact force value is calculated based on the measured acceleration. The hammer head position sensor is used to detect the position of the hammer head. The controller is used to control the heating of the infrared heating plate and the movement of the lifting device, and synchronously collect the measurement data of the hammer head position sensor, the impact force sensor, and the temperature sensor. The impact force sensor is calibrated by comparing the impact force value calculated by the acceleration sensor with the impact force value measured by the impact force sensor. The controller is used to set the temperature range and temperature gradient of the high-temperature impact, set the heating power of the infrared heating plate according to the set temperature range and temperature gradient, and monitor the temperature change of the impact force sensor through the temperature sensor. When the temperature gradient is less than the set temperature gradient, positive feedback is applied to the set heating power to increase the heating power to achieve the set temperature gradient.

2. The high temperature impact force calibration device according to claim 1, characterized in that: It also includes a hammer head disengaging device, a cage buffer, an air-floating cage, a guide rail, and a gland plate; The hammer head disengaging device is used to disengage the hammer head from the anvil, the retaining frame buffer is used for protective limiting and absorbing the residual energy after the hammer head impacts, the air floating retaining frame is used to support the upper part of the hammer head to ensure the overall straightness of the device, the guide rail is used to ensure the linear free fall motion of the hammer head, and the pressure cover plate is set on the top of the device as a counterweight to ensure the overall stability of the device.

3. The high temperature impact force calibration device according to claim 2, characterized in that: The hammer position sensor is also used to alarm and start the hammer disengagement device to move upward to intercept the lifting device when the hammer deviates from the safe position, thereby protecting the impact force sensor from being damaged by the impact.

4. A high temperature impact force calibration method, using the high temperature impact force calibration device according to any one of claims 1 to 3 to calibrate an impact force sensor, characterized in that: include: Step 1: The controller sets the impact force value, and calculates the starting position of the hammer head according to the set impact force value; Step 2: The controller identifies the current position of the hammer head through the hammer head position sensor, and determines whether the position is correct by comparing it with the starting position of the hammer head. If it is incorrect, the controller moves the hammer head upward or downward through the lifting device until the current position of the hammer head is the same as the starting position of the hammer head. Step 3: The controller sets the temperature range and temperature gradient of the high temperature shock, and sets the heating power of the infrared heating plate according to the set temperature range and temperature gradient; Step 4: The infrared heating plate starts heating, and the temperature change of the impact force sensor is monitored by the temperature sensor. When the temperature gradient is less than the set value, positive feedback is applied to the set heating power to increase the heating power to achieve the set temperature gradient; Step 5: The lifting device releases the hammer head to start free fall. When the hammer head falls to the specified position, the controller triggers the temperature sensor, impact force sensor and acceleration sensor to start synchronous collection; Step 6: The acceleration sensor calculates the actual impact force value according to the measured acceleration. The controller compares the actual impact force value with the set impact force value, and adjusts the starting position of the hammer head by feedback. Steps 2 to 5 are repeated until the actual impact force value and the set impact force value meet the calibration requirements, thus completing the calibration of the current force value point. Step 7: Repeat steps 1 to 6 for the next force point to be calibrated until the calibration of all force points of the impact force sensor is completed.

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