An ice layer hardness testing device and system

Abstract

An ice layer hardness testing device and system, including a low temperature test chamber and its support assembly, cylinder, cylinder connecting piece and pneumatic system and control and measurement system outside the low temperature test chamber, the support assembly includes a base, a column and a sample support seat, the top of the column is provided with a cylinder mounting plate, the cylinder connecting piece includes a coaxial cylinder rod connecting piece, an S-shaped tension and compression sensor, a pressure head adapter and a steel ball, the pneumatic system includes a gas source, a filter pressure reducer and an electromagnetic reversing valve, and the control and measurement system includes a PLC and an upper computer. The utility model discloses in the testing process by the sample support seat of keeping stationary to support the ice layer sample, drives the spherical pressure head to move through the upper pneumatic loading chain, and the actual pressure head load is detected with the force sensor in series in the force transmission chain, the displacement sensor is detected with the movement end displacement, and the same sampling clock is established and adopted through the contact reference, and the data pair of effective penetration load and relative penetration depth is formed.

Description

Technical Field

[0001] This utility model belongs to the field of material mechanical property testing and low temperature environment testing technology, specifically relating to an ice layer hardness testing device and system. Background Technology

[0002] The mechanical response of ice is related to freezing temperature, hardening time, gas content, impurities, substrate interface state, and loading rate. For ice removal, low-temperature friction, and risk assessment of icing in rails or components, comparable indentation load and indentation depth data are needed under conditions where the environmental conditions of the ice layer remain essentially unchanged. The spherical indenter method can form local contact with a specified spherical diameter and loading process, making it suitable as a test basis for characterizing ice hardness.

[0003] Existing cryogenic ice hardness testing devices typically consist of a sample stage and hardness testing components inside a cryogenic chamber, with control and data acquisition devices located outside the chamber. Load and displacement are obtained using force and displacement sensors. One typical approach involves keeping the spherical indenter stationary while an electric lifting mechanism moves the sample stage and ice body upwards, establishing a zero point upon detection of contact. This type of solution has solved the fundamental problems of conducting ice indentation tests inside the cryogenic chamber and transmitting signals between the inside and outside of the chamber.

[0004] Existing general-purpose hardness testing equipment also discloses structures or control methods such as coaxial drive and indenter, independent force measuring element, linear displacement detection, adjustable sample support, and automatic loading after contact. Therefore, using only a low-temperature test chamber, a combination of force and displacement sensors, coaxial arrangement, adjustable support, or automatic contact determination is insufficient to solve the complete testing problem of specific ice layer samples in low-temperature environments.

[0005] When the sample stage is raised, the sample, support, and positioning structure all move with the raising mechanism. For guide rails, long components, irregularly shaped icing components, or icing components that need to maintain their original installation posture, moving the sample stage will increase the moving mass and installation space, and may cause changes in the sample support position, measurement point alignment, or ice layer condition during loading, which is not conducive to multi-point comparison under fixed load conditions.

[0006] Before the ice layer is pressed in, there is a free stroke, connection gap, and zero-load fluctuation when the steel ball approaches the surface. If the cylinder stroke, actuator command position, or air supply pressure is directly used to replace the actual pressing depth and actual pressure head load, factors such as approach stroke, connector deformation, sealing friction, and throttling pressure drop will be mixed into the test results. If the displacement sensor is connected in series with the force transmission chain or the installation reference moves with the loading chain, additional forces and reference drift may also be introduced.

[0007] Pneumatic loading is suitable for creating a long approach stroke inside a cryogenic chamber and placing the pressure regulating components outside the chamber. However, during the ice contact phase, it is necessary to control the approach speed and uniformly handle the indentation control command in case of termination or abnormal conditions. Judging contact solely by a single force threshold can easily lead to misidentifying vibrations, reversing impacts, or instantaneous fluctuations in electrical signals as genuine contact. Furthermore, if contact determination, displacement zeroing, and force-displacement sampling are triggered separately by different devices, it can also cause inconsistencies between the load and indentation depth timescales.

[0008] Furthermore, a clear interface and status relationship are required between the mechanical actuators inside the cryogenic chamber and the pneumatic, control, and data processing components outside the chamber. If test parameters, calibration coefficients, operating status, termination reasons, and raw data are stored separately, it becomes difficult to determine the valid data range when over-range, signal disconnection, or cylinder stoppage occurs. This also hinders the verification of ice layer test results at different hardening times or different measuring points.

[0009] Therefore, there is a need for an ice hardness testing device and system that is not simply a parallel arrangement of existing low-temperature chambers, hardness indenters, and sensors, but rather a system that integrates an upper-mounted pneumatic motion indenter, a series actual force measurement chain, an independent displacement installation reference, continuous sampling contact determination, simultaneous clock force-displacement pairing, and pneumatic anomaly interlocking, all while the sample is supported by a static support.

[0010] This invention addresses the problems of existing low-temperature ice testing devices, such as the difficulty in separating the sample stage movement from the near-empty stroke and the actual indentation displacement, the difficulty in matching the actual indentation load with the displacement sampling timescale, and the lack of a unified handling method for abnormal pneumatic loading conditions. It provides an ice hardness testing device and system. Utility Model Content

[0011] The purpose of this invention is to provide an ice hardness testing device and system.

[0012] This utility model is implemented according to the following technical solution.

[0013] An ice hardness testing device includes a low-temperature test chamber, a support assembly inside the low-temperature test chamber, a cylinder, a cylinder connector, and a pneumatic system and a control and measurement system outside the low-temperature test chamber, wherein: The support assembly includes a base, a column on the base, and a sample support base, with a cylinder mounting plate provided on the top of the column; The cylinder connector includes a cylinder rod connector, an S-shaped tension / compression sensor, a pressure head adapter, and a steel ball, all coaxially connected in sequence at the lower end of the cylinder piston rod. The cylinder connector is positioned vertically and vertically corresponding to the sample support base. A displacement sensor is installed on the cylinder housing. The pneumatic system includes an air source, a filter regulator, and an electromagnetic reversing valve. The air source, filter regulator, electromagnetic reversing valve, and cylinder are connected in sequence through an air path. An induced check valve and a direct-flow speed control valve are respectively installed on the parallel air path between the electromagnetic reversing valve and the cylinder. The control and measurement system includes a PLC and a host computer. The S-type tension / compression sensor is connected to the PLC and the host computer in sequence via a weighing transmitter. The displacement sensor, PLC, and solenoid directional valve are connected in sequence.

[0014] This utility model also provides an ice hardness testing system, which includes at least the ice hardness testing device described in any of the above solutions.

[0015] Furthermore, the sample support base is used to support the ice sample and remains stationary relative to the base during the test; the cylinder body is fixed to the cylinder mounting plate and located above the sample support base. The piston rod of the cylinder drives the steel ball downward through the cylinder rod connector, S-type tension / compression sensor, and pressure head adapter, forming a series axial force transmission chain for measuring the actual pressure head load; the housing of the displacement sensor is fixed to the cylinder body, and the displacement detection rod is connected to the moving end of the axial force transmission chain to detect the axial displacement of the moving end relative to the housing. The displacement sensor is not connected in series with the sample support base. The axial force transmission chain is described; the S-type tension / compression sensor is connected to the first analog input of the PLC via a weighing transmitter to form a force channel, and the displacement sensor is connected to the second analog input of the PLC to form a displacement channel; the PLC is used to control the steel ball to approach the ice sample at low speed, and to confirm contact based on the contact judgment condition that the load increment relative to the unloaded baseline continuously meets the preset number of sampling points. The displacement reading at the time of contact confirmation is used to establish a contact reference, and the axial displacement increment of the moving end after contact confirmation is used as the relative indentation depth h of the steel ball pressing into the ice layer. The load reading F of the force channel is used to determine the contact depth. m The effective pressing load F is determined by the difference between the effective pressing load F and the unloaded baseline F0 of the same diameter. The effective pressing load F is paired with the relative pressing depth h according to the same sampling clock and sent to the host computer. The PLC is also used to trigger abnormal interlocking when the force channel or displacement channel is abnormal, the cylinder stops abnormally or a manual emergency stop occurs, cancel the continue pressing control command, and output the return control signal to the solenoid directional valve.

[0016] Furthermore, the PLC is used to record the unloaded baseline F0 of the force channel before the steel ball contacts the ice sample, taking the direction of increasing indentation load as the positive load direction, and recording the current load reading, calibrated by the force channel and used for this baseline difference calculation, as F. m According to F=F m-F0 determines the effective indentation load F; when F reaches or exceeds the preset contact judgment threshold for N consecutive sampling points, contact is confirmed, and the reading of the displacement sensor at the time of contact confirmation is recorded as the contact displacement x0, where N is the preset number of consecutive sampling points and is a positive integer; taking the pressing direction of the steel ball as the positive displacement direction, the relative indentation depth h is determined according to the current displacement reading x after contact confirmation, according to h=x-x0, where h takes the contact confirmation position as the zero point and is used to characterize the relative depth of the steel ball pressed into the ice layer after contact confirmation, and is paired with the effective indentation load F at the corresponding sampling time.

[0017] Furthermore, the air source is connected to the cylinder via a filter pressure reducer and an electromagnetic reversing valve. An induced check valve and a direct-flow speed control valve are installed in the working air path between the electromagnetic reversing valve and the cylinder. The filter pressure reducer is used to adjust the air supply pressure, the electromagnetic reversing valve is used to switch the extension and return directions of the cylinder, and the direct-flow speed control valve is used to adjust the air flow rate to control the approach speed and return speed of the steel ball.

[0018] Furthermore, the weighing transmitter is used to convert the bridge output of the S-type tension / compression sensor into a standard voltage signal and transmit it to the first analog input of the PLC; the PLC exchanges test parameters, raw timing data, operating status and abnormal status with the host computer through an industrial communication interface.

[0019] Furthermore, the host computer is used to save the zero-point calibration and range calibration results of the force channel and the length reference calibration results of the displacement channel, associate the calibration coefficient, calibration date and equipment identification with the test task, and calculate the ice layer hardness characterization value based on the effective indentation load F and relative indentation depth h at the same sampling time; the PLC is used to cancel the continued indentation control command when the preset stop load or stop displacement is reached, and output the return control signal to the electromagnetic reversing valve, and is also used to send the original timing data, action status and abnormal cause before and after the abnormal interlock trigger to the host computer for storage.

[0020] The beneficial effects of this utility model are: This invention employs a loading method where the sample support remains stationary while the upper indenter moves downwards. During testing, an ice sample or a test component with an ice layer on its surface is placed on the sample support. This support is suitable for ice test objects of different shapes, sizes, carriers, and preparation methods. The load path and displacement detection path are separated by a series actual force chain and an independent displacement reference. Continuous N-point contact determination reduces the impact of instantaneous disturbances on contact identification. Simultaneous clock sampling strictly matches the actual load with the relative indentation depth after contact. Pressure regulation, speed regulation, and abnormal interlocking coordinate the loading action, preserving original timing data for traceability. These effects are achieved through the combined mechanical, pneumatic, and control features, rather than by any single general-purpose component. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the internal device of the low-temperature test chamber of this utility model; Figure 2 This is a schematic diagram of the combination of the base, column, and cylinder mounting plate; Figure 3 This is a schematic diagram of the sample support base; Figure 4 This is a schematic diagram of the cylinder rod connector; Figure 5 This is a schematic diagram of an S-type tension / compression sensor; Figure 6 This is a schematic diagram of the pressure head adapter; Figure 7 This is a schematic diagram of a steel ball; Figure 8 This is a schematic diagram of the combination of cylinder rod connector, S-type tension / compression sensor, pressure head adapter and steel ball; Figure 9 This is a schematic diagram of the displacement detection rod connector; Figure 10 This is a schematic diagram of the combination of the displacement sensor and the displacement detection rod connector; Figure 11 It is attached Figure 7 To be continued Figure 10 A schematic diagram of the combination; Figure 12 This is a schematic diagram of a pneumatic connection. Figure 13 This is a schematic diagram of the control and measurement connection. Figure 14 This is a schematic diagram of the force-displacement dual-channel decoupled measurement principle; Figure 15 This is a schematic diagram of the contact reference establishment and synchronous acquisition principle; Figure 16 This is a flowchart of the pneumatic loading state and abnormal interlock control.

[0022] Among them, 1-cylinder, 2-base, 3-column, 4-sample support, 411-base plate, 412-support plate, 413-connecting column, 414-adjusting elongated hole, 5-cylinder mounting plate, 6-cylinder rod connector, 7-S-type tension / compression sensor, 8-pressure head adapter, 9-steel ball, 10-displacement sensor, 101-housing, 102-displacement detection rod, 103-displacement detection rod connector, 11-air source, 12-filter pressure reducer, 13-electromagnetic reversing valve, 14-induction check valve, 15-straight-through speed control valve, 16-PLC, 17-host computer, 18-weighing transmitter. Detailed Implementation

[0023] The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments.

[0024] Example 1 like Figures 1-16 As shown, an ice hardness testing device includes a low-temperature test chamber, a support assembly inside the low-temperature test chamber, a cylinder 1, a cylinder connector, and a pneumatic system and a control and measurement system outside the low-temperature test chamber, wherein: The support assembly includes a base 2, a column 3 on the base 2 and a sample support 4, and a cylinder mounting plate 5 is provided on the top of the column 3; The cylinder connector includes a cylinder rod connector 6, an S-type tension / compression sensor 7, a pressure head adapter 8, and a steel ball 9, which are coaxially connected in sequence at the lower end of the cylinder piston rod. The cylinder connector is arranged vertically and vertically with the sample support 4. A displacement sensor 10 is installed on the outer shell of the cylinder 1. The pneumatic system includes an air source 11, a filter pressure reducer 12, and an electromagnetic reversing valve 13. The air source 11, the filter pressure reducer 12, the electromagnetic reversing valve 13, and the cylinder 1 are connected in sequence through an air path. An induction check valve 14 and a direct-flow speed control valve 15 are respectively installed on the parallel air path between the electromagnetic reversing valve 13 and the cylinder 1. The control and measurement system includes a PLC16 and a host computer 17. The S-type tension / compression sensor 7 is connected to the first analog input of the PLC16 via a weighing transmitter 18. The displacement sensor 10 is connected to the second analog input of the PLC16. The digital output of the PLC16 is connected to the solenoid directional valve 13. The PLC16 is communicatively connected to the host computer 17.

[0025] The ice hardness testing device has a sample support base 4 welded together from a base plate 411, a support plate 412, and a connecting column 413 between the base plate 411 and the support plate 412. The base plate 411 is provided with an adjustment elongated hole 414.

[0026] The cylinder 1, sample support 4, S-type tension / compression sensor 7, displacement sensor 10, and steel ball 9 are installed inside the low-temperature test chamber.

[0027] The gas source 11, filter pressure reducer 12, electromagnetic reversing valve 13, weighing transmitter 18, PLC 16 and host computer 17 are located outside the low temperature test chamber; the gas pipe and signal line pass through the test interface of the low temperature test chamber, and the test interface is equipped with a seal that is compatible with the low temperature test chamber.

[0028] The sample support 4 is connected to the base 2 by screws installed in the adjustment elongated hole 414, and remains stationary as the steel ball 9 approaches and presses into the ice sample.

[0029] One end of the cylinder rod connector 6 is connected to the piston rod of the cylinder 1, and the other end is connected to the S-type tension / compression sensor 7, so that the cylinder piston rod, cylinder rod connector 6, and S-type tension / compression sensor 7 are connected in series along the same loading axis to transmit axial loading force. The displacement sensor 10 does not participate in this series force transmission connection.

[0030] The steel ball 9 is a spherical indenter. In this embodiment, the diameter of the steel ball 9 is 3mm. The connecting part of the steel ball 9 is provided with an internal threaded hole, and it is threadedly connected to the indenter adapter 8 through the internal threaded hole. The pressing surface of the steel ball 9 faces the ice sample.

[0031] Example 2 like Figures 1-16 As shown, this utility model also provides an ice layer hardness testing system, which includes at least the ice layer hardness testing device described in Embodiment 1.

[0032] The ice hardness testing system described above has a sample support 4 for supporting the ice sample and remaining stationary relative to the base 2 during the test. The cylinder body of the cylinder 1 is fixed to the cylinder mounting plate 5 and located above the sample support 4. The piston rod of the cylinder 1 drives the steel ball 9 downward through the cylinder rod connector 6, the S-type tension / compression sensor 7, and the pressure head adapter 8, forming a series axial force transmission chain for measuring the actual pressure head load. The housing 101 of the displacement sensor 10 is fixed to the cylinder body of the cylinder 1, and the displacement detection rod 102 is connected to the moving end of the axial force transmission chain to detect the axial displacement of the moving end relative to the housing 101. Device 10 is not connected in series with the axial force transmission chain; the S-type tension / compression sensor 7 is connected to the first analog input of PLC 16 via weighing transmitter 18 to form a force channel, and the displacement sensor 10 is connected to the second analog input of PLC 16 to form a displacement channel; PLC 16 is used to control the steel ball 9 to approach the ice sample at low speed, and to confirm contact based on the contact judgment condition that the load increment relative to the unloaded baseline continuously meets the preset number of sampling points. The contact reference is established by the displacement reading at the time of contact confirmation, and the axial displacement increment of the moving end after contact confirmation is used as the relative indentation depth h of the steel ball 9 pressing into the ice layer. The load reading F of the force channel is used as the reference. m The effective pressing load F is determined by the difference between the effective pressing load F and the unloaded baseline F0 of the same diameter. The effective pressing load F is paired with the relative pressing depth h according to the same sampling clock and sent to the host computer 17. The PLC 16 is also used to trigger abnormal interlocking when the force channel or displacement channel is abnormal, the cylinder 1 stops abnormally or is manually stopped, cancel the continuing pressing control command, and output the return control signal to the electromagnetic reversing valve 13.

[0033] The ice hardness testing system described herein uses a PLC16 to record the unloaded baseline F0 of the force channel before the steel ball 9 contacts the ice sample. The direction of increasing indentation load is taken as the positive load direction. The current load reading, calibrated by the force channel and used for calculating the baseline difference, is recorded as F. m According to F=F m -F0 determines the effective indentation load F; when F reaches or exceeds the preset contact judgment threshold for N consecutive sampling points, contact is confirmed, and the reading of displacement sensor 10 at the time of contact confirmation is recorded as contact displacement x0, where N is the preset number of consecutive sampling points and is a positive integer; taking the pressing direction of steel ball 9 as the positive displacement direction, according to the current displacement reading x after contact confirmation, the relative indentation depth h is determined by h=x-x0, with the contact confirmation position as the zero point, which is used to characterize the relative depth of steel ball 9 pressed into the ice layer after contact confirmation, and is paired with the effective indentation load F at the corresponding sampling time.

[0034] The ice hardness testing system has an air source 11 connected to a cylinder 1 via a filter pressure reducer 12 and an electromagnetic reversing valve 13. An induction check valve 14 and a direct-flow speed regulating valve 15 are installed in the working air path between the electromagnetic reversing valve 13 and the cylinder 1. The filter pressure reducer 12 is used to adjust the air supply pressure, the electromagnetic reversing valve 13 is used to switch the extension and return directions of the cylinder 1, and the direct-flow speed regulating valve 15 is used to adjust the air flow rate to control the approach speed and return speed of the steel ball 9.

[0035] The ice hardness testing system described herein has a weighing transmitter 18 used to convert the bridge output of the S-type tension / compression sensor 7 into a standard voltage signal and transmit it to the first analog input of the PLC 16; the PLC 16 exchanges test parameters, raw timing data, operating status and abnormal status with the host computer 17 through an industrial communication interface.

[0036] The ice hardness testing system described herein includes a host computer 17 for storing the zero-point calibration and range calibration results of the force channel and the length reference calibration results of the displacement channel, associating the calibration coefficient, calibration date, and equipment identification with the test task, and calculating the ice hardness characterization value based on the effective indentation load F and relative indentation depth h at the same sampling time; the PLC 16 is used to cancel the continued indentation control command when the preset stop load or stop displacement is reached, and output a return control signal to the electromagnetic reversing valve 13, and is also used to send the original timing data, action status, and abnormal cause before and after the abnormal interlock trigger to the host computer 17 for storage.

[0037] The cylinder 1, cylinder rod connector 6, S-type tension / compression sensor 7, pressure head adapter 8, and 3mm diameter steel ball 9 are arranged along the same loading axis. The S-type tension / compression sensor 7 bears the tension and pressure transmitted by the axial force transmission chain. The steel ball 9 is located at the lower end of the pressure head adapter 8, and the trajectory of the center of the steel ball 9 coincides with the loading axis.

[0038] The cylinder 1 is a double-acting cylinder of model AirTAC SE32×250, with a cylinder diameter of 32mm, a stroke of 250mm, a working pressure of 0.1~1.0MPa, a working temperature of -20~80℃, a speed range of 30~800mm / s, an interface specification of PT1 / 8, and adjustable buffer; the cylinder mounting plate 5 and the cylinder connector are compatible with the mounting interface of this model.

[0039] The S-type tension / compression sensor 7 is a ZEMIC H3-C3-50kg-3B, with a rated range of 50kg, a rated output of 2.0±0.004mV / V, a comprehensive error of no more than ±0.020%FS, a safe overload of 150%FS, an IP67 protection rating, and an operating temperature of -35~65℃. This sensor is connected in series between the cylinder rod connector 6 and the pressure head adapter 8, with the force direction aligned with the cylinder piston rod axis to ensure that the measured value corresponds to the actual pressure head load.

[0040] The displacement sensor 10 is a rod-type linear displacement sensor, including a housing 101 and a displacement detection rod 102 that can move axially relative to the housing 101, used to convert axial displacement into a displacement detection signal.

[0041] The displacement sensor 10 is arranged parallel to the cylinder 1. The housing 101 is fixed to the side of the cylinder body of the cylinder 1 by a mounting buckle. The mounting buckle engages with the slot on the housing 101 and connects to the cylinder body of the cylinder 1. The housing 101 does not move with the cylinder piston rod, forming a fixed reference for displacement detection. The displacement detection rod 102 is connected to the moving end of the axial force transmission chain through the displacement detection rod connector 103 and moves axially with the moving end. The displacement detection rod connector 103 is used for displacement transmission at the moving end, and the housing 101 is fixed by the mounting buckle. The displacement sensor 10 is not connected in series with the axial force transmission chain composed of the cylinder 1, the S-type tension / compression sensor 7, and the steel ball 9. The force channel and the displacement channel are separated on the mechanical path and paired at the control end according to the same sampling clock.

[0042] The pneumatic system includes an AirTAC GFR200-08 filter regulator 12, an AirTAC 4V210-08 DC24V five-port two-position solenoid directional valve 13, an AirTAC PCV06 induced check valve 14, and an AirTAC PSL8-01A straight-through speed control valve 15. The solenoid directional valve 13 has an operating pressure of 0.15–0.8 MPa, a PT1 / 4 port, and a coil voltage of DC24V.

[0043] The air source 11 is connected to the cylinder 1 via a filter pressure reducer 12 and a solenoid directional valve 13. The working air path between the solenoid directional valve 13 and the cylinder 1 is equipped with an induction check valve 14 and a direct-flow speed control valve 15. The filter pressure reducer 12 is used to regulate the air supply pressure, the solenoid directional valve 13 is used to switch the extension and return directions, the opening and closing of the induction check valve 14 is determined by the pressure of its branch and the pilot control state, and the direct-flow speed control valve 15 is used to regulate the gas flow rate of its branch to control the cylinder's movement speed. Termination and abnormal state control are achieved by the PLC 16 in conjunction with the solenoid directional valve 13.

[0044] The PLC16 uses a SIMATIC S7-1200 CPU 1212C DC / DC / DC converter, featuring 8 digital inputs, 6 digital outputs, and two 0-10V analog inputs, with a rated power supply range of DC 20.4-28.8V. The two analog inputs receive actual load and displacement signals respectively, while the digital outputs control the solenoid directional valves. The host computer 17 inputs sample identification, ambient temperature, contact threshold, number of continuous sampling points, stop load, stop displacement, sampling period, and storage path.

[0045] The weighing transmitter 18 is a ZEMIC HC510 configured with a 0-10V output. It converts the bridge millivolt signal from the S-type tension / compression sensor 7 into a 0-10V standard voltage signal, which is then connected to the first analog input of the PLC 16. The displacement sensor 10 provides a 0-10V standard voltage signal corresponding to the displacement, which is connected to the second analog input of the PLC 16. The range of the displacement sensor 10 covers the actual detection stroke, and its housing fixing method and detection rod connection method are adapted to the installation relationship of this embodiment.

[0046] The force channel, consisting of the S-type tension / compression sensor 7, the weighing transmitter 18, and the first analog input of the PLC 16, is used as a complete measurement chain for zero-point and range calibration. The displacement channel, consisting of the displacement sensor 10 and the second analog input of the PLC 16, is calibrated using a traceable length reference. The host computer 17 associates the calibration coefficient, calibration date, and equipment identification with the test task, and uses the effective indentation load F and relative indentation depth h at the same sampling time to calculate the hardness characterization value. The original time series data is not overwritten due to changes in processing parameters.

[0047] In other words, the weighing transmitter 18 converts the bridge output of the S-type tension / compression sensor 7 into a standard voltage signal and transmits it to the first analog input of the PLC 16. The displacement signal of the displacement sensor 10 is transmitted to the second analog input of the PLC 16. The PLC 16 controls the electromagnetic reversing valve 13 through digital output and exchanges test parameters, raw timing data, operating status and abnormal status with the host computer 17 through the industrial communication interface. The air pipes and signal lines pass through the same test interface area or separate test interface areas of the low temperature environment test chamber and are sealed at the interface.

[0048] The PLC16 is used to control the cylinder 1 to bring the steel ball 9 close at a low speed to the ice sample supported by the sample support 4, based on the calibrated force channel load reading F. m Subtract the unloaded baseline F0 of the same diameter to obtain the effective indentation load F; confirm contact according to the contact judgment condition that F continuously meets the preset number of sampling points, establish the contact displacement x0 based on the reading of displacement sensor 10 when contact is confirmed, and form a data pair of F and relative indentation depth h according to the same sampling clock after contact is confirmed.

[0049] The F m The current load reading obtained according to the force channel calibration relationship and used for this baseline difference calculation; F0 is the load reading when steel ball 9 is not in contact with the ice layer, and F m Unloaded baseline recorded under the same load diameter; effective indentation load F is calculated as F=F m -F0 is determined. If the force channel has been tare along the same unloaded baseline, then F0 in this calculation is 0, and F = F m The unloaded baseline before tare is no longer deducted. The indentation direction is taken as the positive displacement direction, and the relative indentation depth h is determined by h = x - x0; h is characterized by the axial displacement increment of the moving end after contact confirmation, excluding the approach stroke before contact confirmation. Contact threshold, continuous sampling confirmation, and the stress and deformation of the loaded structure may cause a difference between h and the true geometric indentation depth calculated from the undeformed ice surface.

[0050] The PLC16 executes test tasks in the following sequence: standby, self-test, low-speed approach, contact determination, synchronous acquisition, termination, and return. An abnormal interlock can be triggered during the test, switching to a fault handling state. In the contact determination state, if the effective applied load F reaches the contact determination threshold but is not continuously maintained for N sampling points, the contact displacement x0 is not established, and low-speed approach control continues. In the synchronous acquisition state, the load readings F at the same sampling time are... m The effective indentation load F, displacement reading x, relative indentation depth h, and action status are associated and saved, and the corresponding F0 and x0 are retained.

[0051] When the preset stop load or stop displacement is reached, PLC16 cancels the continue pressing control command and outputs a return control signal to the solenoid directional valve 13. If a disconnection occurs in the force or displacement channel, the sensor exceeds its range, the cylinder stops abnormally, or a manual emergency stop is performed, PLC16 triggers an abnormal interlock, cancels the continue pressing control command, outputs a return control signal, and sends the original timing data, action status, and cause of the abnormality before and after the trigger to the host computer 17 for storage. The abnormal interlock maintains the fault state until it is manually reset and passes a self-test before the test can be restarted.

[0052] The host computer 17 sends test parameters to the PLC 16, including at least the sample identification, ambient temperature, contact judgment threshold, number of continuous sampling points N, stop load, stop displacement, and sampling period. The PLC 16 does not output the effective relative indentation depth when the contact displacement x0 is not established, and does not generate an effective hardness characterization value when the force signal or displacement signal does not meet the validity conditions, but retains the original timing data and records the abnormal flag. After manual reset, the PLC 16 returns to the standby state after self-test.

[0053] During testing, after the sample support 4 is aligned with the measuring point, it is locked relative to the base 2 and remains stationary. The cylinder 1, located on the upper part of the column 3, drives the steel ball 9 to move downward. The cylinder piston rod, cylinder rod connector 6, S-type tension / compression sensor 7, pressure head adapter 8, and steel ball 9 are connected in series along the loading axis, so that the S-type tension / compression sensor 7 is located in the actual motion transmission chain. This is different from the method of moving the ice body towards the fixed pressure head by the sample stage or calculating the pressure head load by the air supply pressure.

[0054] The PLC16 records the no-load baseline F0 of the force channel before the steel ball 9 contacts the ice layer; when the effective indentation load F=F m Contact is confirmed when F0 reaches or exceeds the contact determination threshold and is maintained at N sampling points continuously. The displacement reading at that moment is recorded as x0. The relative indentation depth h after contact is calculated as x - x0, and is paired with the effective indentation load F at the same sampling moment. For instantaneous exceedances, x0 is not established. The contact reference establishment and synchronous acquisition process is as follows: Figure 15 As shown.

[0055] The force channel and displacement channel are calibrated as a complete measurement chain, and the calibration coefficients and versions are associated with the test task. When using the spherical indenter penetration depth method, the host computer 17 can calculate the ice layer hardness characterization value according to H=F / (πDh), and the calculation object is the effective indentation data where F is greater than zero and h is greater than zero. Where F is the effective indentation load after deducting the unloaded baseline; D is the diameter of the steel ball 9; and h is the relative indentation depth obtained after contact confirmation. When F is in N and D and h are in mm, the unit of H is N / mm. 2 (MPa).

[0056] Installation process: like Figure 1 , Figure 12 and Figure 13 As shown, in this embodiment, the mechanical execution and detection components are placed inside the low-temperature test chamber, while the air source 11, filter pressure reducer 12, electromagnetic reversing valve 13, weighing transmitter 18, PLC 16, and host computer 17 are placed outside the chamber in the ambient temperature area. Air pipes and signal lines pass through the test chamber's testing interface, and the interface uses a seal compatible with the test chamber, eliminating the need to open the door to adjust air pressure, control the program, or save data during the test.

[0057] Air source 11 is a laboratory compressed air pipeline or a matching air supply unit. Compressed air passes sequentially through filter and pressure reducer 12 and enters solenoid directional valve 13. The two working ports of solenoid directional valve 13 are connected to the two chambers of cylinder 1 through air passages. Induction check valve 14 and direct-flow speed control valve 15 are located at... Figure 12 The corresponding branch is shown. Filter pressure reducer 12 regulates the supply air pressure, and direct-flow speed control valve 15 regulates the gas flow rate of its branch; solenoid directional valve 13 receives control signals from PLC 16 to switch the extension and return directions of cylinder 1. Piping and joints avoid the loading range.

[0058] The S-type tension / compression sensor 7 is connected to the weighing transmitter 18, and the standard voltage output of the weighing transmitter 18 is connected to the first analog input of the PLC 16; the standard voltage output of the displacement sensor 10 is connected to the second analog input. The PLC 16 drives the solenoid directional valve 13 through digital output and exchanges task parameters, time-stamped sampling data, action status and abnormal status with the host computer 17 through the industrial communication interface.

[0059] like Figure 1 As shown, the base 2 is located at the bottom of the device, and the column 3 is fastened to the base 2. The cylinder mounting plate 5 spans the top of the column 3. The overall assembly envelope is approximately 600mm × 1016mm × 1000mm. During manufacturing, the profile length can be adjusted according to the space of the low-temperature test chamber and the sample size, but the relative reference relationship between the cylinder 1, the sample support 4, the displacement sensor 10 and the loading axis remains unchanged.

[0060] The sample support 4 is mounted on the base 2. The adjusting elongated hole 414 is used to move the base plate 411 before testing so that the test point of the ice sample is located on the loading axis of the steel ball 9. After the position is adjusted, the fasteners are tightened so that the sample support 4 remains stationary relative to the base 2 during the approach, contact and pressing of the steel ball 9.

[0061] The cylinder body of cylinder 1 is fixed on cylinder mounting plate 5. The piston rod faces the sample support 4 and is connected in sequence to cylinder rod connector 6, S-type tension / compression sensor 7, pressure head adapter 8, and steel ball 9. Using the motion trajectory of the center of steel ball 9 as the loading reference, cylinder mounting plate 5 and sample support 4 are adjusted so that the trajectory is consistent with the surface normal at the point to be measured in the ice layer. The sensor cable is stress-released at the column to avoid cable pulling and forming additional load.

[0062] like Figures 9 to 11 and Figure 14 As shown, the housing 101 of the displacement sensor 10 is fixed to the side of the cylinder body of the cylinder 1 by a mounting clip. The displacement detection rod 102 is connected to the moving end driven by the cylinder 1 through the displacement detection rod connector 103. The displacement detection rod 102 follows the displacement of the moving end, and the displacement detection rod connector 103 moves with the moving end; the housing 101 and its mounting clip remain stationary. The displacement sensor 10 is not located in the series force transmission chain composed of the cylinder 1, the S-type tension / compression sensor 7, and the steel ball 9, and is used to detect the axial displacement of the moving end relative to the fixed reference of the cylinder body.

[0063] The theoretical extension force of cylinder 1 can be calculated as F c =pπd 2 / 4 verification, where p is the effective working pressure and d is the cylinder diameter. The theoretical extension force is only used for the selection of air source, cylinder and safety upper limit. The test load is based on the effective indentation load F after the force channel reading of the S-type tension and compression sensor 7 connected in series in the force transmission chain is calibrated and the no-load baseline is subtracted. The actual pressure head load is not replaced by the converted value of air supply pressure.

[0064] During force channel calibration, the S-type tension / compression sensor 7, weighing transmitter 18, and the first analog input of PLC 16 are used as a complete link for zero-point and range verification. During displacement channel calibration, the correspondence between displacement sensor 10 and the second analog input of PLC 16 within the usage range is checked using a traceable length reference. Calibration coefficients, calibration dates, and equipment identification are written into the test task. Before loading, the no-load values ​​and full-scale protection status of both channels are checked respectively.

[0065] Debugging process: During assembly and debugging, first, without a sample, cylinder 1 is extended and returned at low speed to check the trajectory of the steel ball 9, the parallelism of the displacement detection rod 102, and whether the cylinder connecting parts are stuck. Then, a rigid calibration piece is used to check the direction of load increase and displacement increase. The control program records a segment of non-contact no-load data to form the load no-load baseline F0 and allowable fluctuation range for the current task.

[0066] Place the ice sample or icing component on the sample support 4, ensuring the test area is below the steel ball 9. After adjusting the support position, tighten the fasteners between the support and base 2 to keep the sample support 4 stationary during loading. The test object is supported by the support; the installation and locking of the support does not constitute clamping of the test object. After the sample reaches stability at the specified low temperature, the steel ball 9 stops above the ice layer. If it is necessary to change the measuring point, first return the cylinder 1, then adjust the placement of the test object or the installation position of the support, and retighten the support. Do not search for the measuring point by having the steel ball 9 slide on the ice surface.

[0067] Testing process: After the test begins, the host computer 17 sends task parameters to the PLC 16, which then causes cylinder 1 to drive the axial transmission chain downwards at a low speed. During the approach phase, the airflow in the air path is maintained under controlled pressure, and the force channel continuously provides calibrated load readings F. m The displacement sensor 10 outputs the displacement reading x of the moving end relative to the fixed reference of the cylinder body; x before contact confirmation is not directly used as the relative indentation depth of the ice layer.

[0068] like Figure 15 As shown, when the effective indentation load F = F m When F0 reaches or exceeds the contact determination threshold and remains at N sampling points, PLC16 confirms that the steel ball 9 is in contact with the ice layer and records the displacement reading at the confirmation moment as x0. If F only exceeds the threshold within fewer than N sampling points and then falls back, the contact determination condition is not met, x0 is not established, and low-speed proximity control continues. After confirming contact, the relative indentation depth is calculated according to h=x-x0.

[0069] PLC16 reads the load reading F using the same sampling clock. m And displacement reading x, according to F=F m -F0 calculates the effective indentation load and assigns the same task identifier, sampling sequence number, and action status to each sampling point; the host computer saves F... m The correspondence between F0, F, x, x0, and h is established. Thus, the approach stroke before contact confirmation and the relative indentation process after confirmation are separated in the data, and any effective indentation load can be traced back to the relative indentation depth at the same sampling time.

[0070] like Figure 16As shown, PLC16 executes the test in the following sequence: standby, self-test, low-speed approach, contact determination, synchronous acquisition, termination, and return. When the preset stop load or stop displacement is reached, PLC16 cancels the continue pressing control command and outputs a return control signal to the solenoid directional valve 13. In the event of signal disconnection, sensor over-range, abnormal cylinder stoppage, or manual emergency stop, the abnormal interlock is immediately triggered, the continue pressing control command is canceled, a return control signal is output, the abnormal state and cause are recorded, and the original timing data is saved.

[0071] The host computer 17 calculates the ice hardness characterization value of the valid sampling points according to H=F / (πDh), where the meanings and units of F, D, and h are consistent with the aforementioned definitions. Valid hardness characterization values ​​are not generated for sampling points where x0 is not established, F is not greater than zero, h is not greater than zero, the signal is disconnected, the sensor is out of range, the sampling timescales of the two channels are inconsistent, or the sampling points are in an abnormal state. The original time series data, processed data, status codes, and reasons for abnormalities are saved separately, and the original records are not overwritten during recalculation.

[0072] After the test is completed, return cylinder 1 to a safe position and check the condition of steel ball 9, indenter adapter 8, and ice indentation. Clean and maintain the indenter assembly and sample support 4, and calibrate the measurement channel according to usage. For different cylinder diameters, strokes, ball diameters, support profiles, or sampling parameters, as long as the test still maintains the coordinated relationship of the sample being supported by a stationary sample support, the upper indenter moving, the actual force measured in series, the independent displacement reference, continuous sampling contact zeroing, and the simultaneous clock force-displacement pairing, all are implementations of this utility model concept.

[0073] This article uses specific examples to illustrate the principles and implementation methods of this utility model. The above examples are only for the purpose of helping to understand the method and core ideas of this utility model. The above description is only a preferred embodiment of this utility model. It should be noted that due to the limitations of written expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this utility model, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the concept and technical solution of this utility model to other occasions without modification, should all be considered within the protection scope of this utility model.

Claims

1. An ice hardness testing device, characterized in that, Includes a low-temperature test chamber, supporting components inside the low-temperature test chamber, cylinder (1), cylinder connectors, and a pneumatic system and control and measurement system outside the low-temperature test chamber, wherein: The support assembly includes a base (2), a column (3) on the base (2) and a sample support seat (4), and a cylinder mounting plate (5) is provided on the top of the column (3). The cylinder connector includes a cylinder rod connector (6), an S-type tension / compression sensor (7), a pressure head adapter (8), and a steel ball (9) that are coaxially connected in sequence at the lower end of the cylinder piston rod. The cylinder connector is arranged vertically and vertically with the sample support seat (4). The cylinder (1) housing is equipped with a displacement sensor (10). The pneumatic system includes an air source (11), a filter pressure reducer (12), and an electromagnetic reversing valve (13). The air source (11), the filter pressure reducer (12), the electromagnetic reversing valve (13), and the cylinder (1) are connected in sequence through an air path. An induced check valve (14) and a direct-flow speed control valve (15) are respectively installed on the parallel air path between the electromagnetic reversing valve (13) and the cylinder (1). The control and measurement system includes a PLC (16) and a host computer (17). The S-type tension and compression sensor (7) is connected to the first analog input of the PLC (16) via a weighing transmitter (18). The displacement sensor (10) is connected to the second analog input of the PLC (16). The digital output of the PLC (16) is connected to the electromagnetic reversing valve (13). The PLC (16) is communicatively connected to the host computer (17).

2. The ice hardness testing device according to claim 1, characterized in that, The sample support base (4) is welded together from a base plate (411), a support plate (412) and a connecting column (413) between the base plate (411) and the support plate (412). An adjustment elongated hole (414) is provided on the base plate (411).

3. An ice hardness testing system, characterized in that, The ice hardness testing system includes at least the ice hardness testing device as described in any one of claims 1 to 2.

4. The ice hardness testing system according to claim 3, characterized in that, The sample support (4) is used to support the ice sample and remains stationary relative to the base (2) during the test. The cylinder body of the cylinder (1) is fixed to the cylinder mounting plate (5) and located above the sample support (4). The piston rod of the cylinder (1) drives the steel ball (9) to move downward through the cylinder rod connector (6), the S-type tension and compression sensor (7), and the pressure head adapter (8), forming a series axial force transmission chain for measuring the actual pressure head load. The housing (101) of the displacement sensor (10) is fixed to the cylinder body of the cylinder (1). The displacement detection rod (102) is connected to the moving end of the axial force transmission chain and is used to detect the axial displacement of the moving end relative to the housing (101). The sensor (10) is not connected in series with the axial force transmission chain; the S-type tension / compression sensor (7) is connected to the first analog input of the PLC (16) via the weighing transmitter (18) to form a force channel, and the displacement sensor (10) is connected to the second analog input of the PLC (16) to form a displacement channel; the PLC (16) is used to control the steel ball (9) to approach the ice sample at low speed, and to confirm contact based on the contact judgment condition that the load increment relative to the unloaded baseline continuously meets the preset number of sampling points. The contact reference is established by the displacement reading when the contact is confirmed, and the axial displacement increment of the moving end after the contact is confirmed is used as the relative indentation depth h of the steel ball (9) pressing into the ice layer. The load reading F of the force channel is used to determine the contact. m The difference between the effective press load F and the unloaded baseline F0 of the same diameter is used to determine the effective press load F. The effective press load F is paired with the relative press depth h according to the same sampling clock and sent to the host computer (17). The PLC (16) is also used to trigger abnormal interlocking when the force channel or displacement channel is abnormal, the cylinder (1) stops abnormally or is manually stopped, cancel the continued press control command, and output the return control signal to the electromagnetic reversing valve (13).

5. The ice hardness testing system according to claim 4, characterized in that, The PLC (16) is used to record the unloaded baseline F0 of the force channel before the steel ball (9) contacts the ice sample. Taking the direction of the increase in the indentation load as the positive direction of the load, the current load reading, which is calibrated by the force channel and used for the calculation of the baseline difference, is recorded as F. m According to F=F m -F0 determines the effective indentation load F; when F reaches or exceeds the preset contact judgment threshold for N consecutive sampling points, contact is confirmed, and the reading of the displacement sensor (10) at the time of contact confirmation is recorded as the contact displacement x0, where N is the preset number of consecutive sampling points and is a positive integer; taking the pressing direction of the steel ball (9) as the positive displacement direction, according to the current displacement reading x after contact confirmation, the relative indentation depth h is determined by h=x-x0, with the contact confirmation position as the zero point, which is used to characterize the relative depth of the steel ball (9) pressed into the ice layer after contact confirmation, and is paired with the effective indentation load F at the corresponding sampling time.

6. The ice hardness testing system according to claim 3, characterized in that, The air source (11) is connected to the cylinder (1) via a filter pressure reducer (12) and an electromagnetic reversing valve (13). An induction check valve (14) and a direct-flow speed regulating valve (15) are provided in the working air path between the electromagnetic reversing valve (13) and the cylinder (1). The filter pressure reducer (12) is used to adjust the air supply pressure. The electromagnetic reversing valve (13) is used to switch the extension and return directions of the cylinder (1). The direct-flow speed regulating valve (15) is used to adjust the air flow rate to control the approach speed and return speed of the steel ball (9).

7. The ice hardness testing system according to claim 3, characterized in that, The weighing transmitter (18) is used to convert the bridge output of the S-type tension and compression sensor (7) into a standard voltage signal and transmit it to the first analog input of the PLC (16); the PLC (16) exchanges test parameters, raw timing data, action status and abnormal status with the host computer (17) through the industrial communication interface.

8. The ice hardness testing system according to claim 4, characterized in that, The host computer (17) is used to save the zero-point verification and range verification results of the force channel and the length reference verification results of the displacement channel, associate the calibration coefficient, calibration date and equipment identification with the test task, and calculate the ice layer hardness characterization value according to the effective pressing load F and relative pressing depth h at the same sampling time; the PLC (16) is used to cancel the continued pressing control command when the preset stop load or stop displacement is reached, and output the return control signal to the electromagnetic reversing valve (13), and is also used to send the original timing data, action status and abnormal cause before and after the abnormal interlock trigger to the host computer (17) for storage.

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