An automatic vicat apparatus

Abstract

The application discloses an automatic Vicat apparatus, which comprises a rack, a sample bearing module arranged on the rack, a probe module, a resistivity testing module and a controller. The resistivity testing module comprises an electrode assembly in contact with a sample to be tested and a resistivity acquisition unit electrically connected with the electrode assembly; the controller acquires resistivity data collected by the resistivity acquisition unit, calculates a resistivity change rate, and dynamically adjusts a probe frequency according to the resistivity change rate. The application can monitor the resistivity change in the hydration process of the material in real time, automatically increase the probe frequency in the stage where the resistivity changes obviously, capture the condensation characteristic point, and significantly improve the accuracy and reliability of the condensation time test. Meanwhile, the application realizes automatic operation and multi-station parallel measurement, eliminates human errors, and improves the test efficiency.

Description

Technical Field

[0001] This invention relates to the field of building material performance testing equipment, and in particular to an automatic Vicat apparatus. Background Technology

[0002] The Vicat apparatus is a commonly used instrument for determining parameters such as standard consistency water requirement and setting time in cement. Traditional Vicat apparatuses rely on manual operation: the tester manually releases the probe, visually reads the scale data, and repeats the measurement at fixed time intervals. This method has several drawbacks: manual readings are easily influenced by subjective factors, resulting in low accuracy; it is difficult to precisely control the time interval during long-term testing, easily missing initial and final setting characteristic points; the single-station design leads to low testing efficiency and prevents simultaneous comparative testing of multiple samples. Furthermore, traditional Vicat apparatuses are limited in function, only measuring setting time and unable to simultaneously acquire information on the microstructural evolution during the material's hydration process.

[0003] Some automated Vicat apparatuses have emerged in the existing technology. For example, CN200947100Y discloses a fully automated Vicat apparatus that achieves automatic needle raising and lowering and automatic reading. However, these existing automated Vicat apparatuses still have significant shortcomings. Their setting time testing still adopts a fixed time interval probing mode, without taking into account the microscopic changes in the hydration process inside the material. The testing frequency is not increased in time when approaching the initial and final setting stages, which may miss characteristic points and lead to insufficient measurement accuracy. Secondly, most existing automated Vicat apparatuses only focus on the single indicator of setting time and have not achieved the coordinated testing of multiple indicators related to the microscopic properties of the material. Summary of the Invention

[0004] Objective of this invention: The objective of this invention is to provide an automated Vicat apparatus capable of real-time monitoring of material hydration processes and dynamically adjusting testing strategies. This invention also provides a testing method using the automated Vicat apparatus.

[0005] Technical Solution: The present invention provides an automatic Vicat apparatus, comprising a frame, a sample carrying module mounted on the frame for carrying the sample to be tested, a probing module mounted on the frame for inserting a probe into the sample to obtain the sample state, a resistivity testing module for real-time acquisition of resistivity data of the sample during the condensation process, and a controller communicatively connected to the resistivity testing module and the probing module. The resistivity testing module includes an electrode assembly in contact with the sample to be tested and a resistivity acquisition unit electrically connected to the electrode assembly. The controller acquires the resistivity data acquired by the resistivity acquisition unit, calculates the resistivity change rate, and dynamically adjusts the probe probing frequency based on the resistivity change rate.

[0006] Furthermore, the controller divides the testing process into an initial setting test stage and a final setting test stage;

[0007] During the initial coagulation test, when the resistivity change rate reaches or exceeds the preset initial coagulation threshold, the probe frequency is increased from the normal initial coagulation frequency to the initial coagulation densification frequency; when the resistivity change rate is lower than the initial coagulation threshold, it is restored to the normal initial coagulation frequency.

[0008] During the final coagulation test, when the resistivity change rate reaches or exceeds the preset final coagulation threshold, the probe frequency is increased from the normal final coagulation frequency to the final coagulation encryption frequency; when the resistivity change rate is lower than the final coagulation threshold, it is restored to the normal final coagulation frequency.

[0009] The initial coagulation encryption frequency is greater than the initial coagulation normal frequency, and the final coagulation encryption frequency is greater than the final coagulation normal frequency.

[0010] Furthermore, before the probe penetrates the sample to be tested, the data acquisition of the resistivity testing module is paused; after the penetration action is completed, the data acquisition of the resistivity testing module is resumed.

[0011] Furthermore, the probing module includes a liftable probe, a displacement sensor for detecting the depth of the probe into the sample to be tested, and a first motor for driving the probe to rise and fall. The controller determines the initial and final solidification states of the sample to be tested based on the data from the displacement sensor.

[0012] Furthermore, the test needles include a primary solidification test needle and a final solidification test needle. After the controller determines that the sample to be tested has reached the primary solidification state, it controls the probing module to switch to the final solidification test needle for testing.

[0013] Furthermore, the sample carrying module includes a rotatable mold plate with multiple stations for placing sample boxes. The controller controls the rotation of the mold plate, moving the sample boxes at different stations sequentially to the underside of the probe. Each sample box has an electrode assembly extending vertically along its generatrix on its inner wall.

[0014] Furthermore, the electrode assembly includes multiple electrodes vertically embedded along the inner wall busbar of the sample container, extending from the bottom to the top of the sample container. The two outer sets of electrodes serve as current electrodes, and the two inner sets serve as voltage electrodes, forming a four-terminal measurement circuit.

[0015] Furthermore, the resistivity acquisition unit includes an AC voltage output unit and a current acquisition unit, used to apply an AC excitation signal to the electrode assembly and acquire the response current signal.

[0016] The present invention also provides a testing method for an automated Vicat apparatus, applicable to any of the automated Vicat apparatuses described above, comprising the following steps:

[0017] Place the sample to be tested on the sample carrier module;

[0018] The resistivity test module collects resistivity data of the sample under test in real time during the condensation process. The resistivity change rate is the derivative of resistivity with respect to time. The controller calculates the instantaneous rate of change of resistivity per unit time based on the real-time resistivity data.

[0019] The probing frequency is dynamically adjusted based on the resistivity change rate: During the initial setting test, when the resistivity change rate reaches or exceeds the initial setting threshold, the probing frequency is increased from the initial setting normal frequency to the initial setting densification frequency; otherwise, the probing is performed at the initial setting normal frequency. During the final setting test, when the resistivity change rate reaches or exceeds the final setting threshold, the probing frequency is increased from the final setting normal frequency to the final setting densification frequency; otherwise, the probing is performed at the final setting normal frequency.

[0020] The controller controls the probing module to probe the sample at an adjusted probing frequency, and obtains the depth data of the probe penetrating the sample to determine the coagulation state of the sample.

[0021] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:

[0022] (1) By monitoring the resistivity change in real time, the key stage of material hydration can be perceived, the detection frequency can be automatically increased, and the omission of feature points caused by fixed interval detection can be avoided, which significantly reduces the measurement error of condensation time. This does not increase manpower output and can greatly improve the test accuracy.

[0023] (2) Multiple samples can be measured at the same time. The manual staff only needs to load and clean the samples. The subsequent measurement, judgment, recording, and summarization steps are all completed automatically by the equipment, which significantly improves the testing efficiency. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 This is the left view of the present invention;

[0026] Figure 3 This is a front view of the present invention;

[0027] Figure 4 This is a schematic diagram of the frame structure in this invention;

[0028] Figure 5 This is a side view of the frame in this invention;

[0029] Figure 6 This is a schematic diagram of the structure of the pilot-scale mold disk of the present invention. Detailed Implementation

[0030] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0031] As shown in the figure, this invention discloses an automatic Vicat apparatus, including a frame 1, a sample carrying module 2, a probe module 3, a controller 4, and a resistivity testing module. The entire Vicat apparatus is placed on a load-bearing base 6. The frame 1 is vertically mounted on the load-bearing base 6. The sample carrying module 2 is located below the frame 1 and above the load-bearing base 6. The probe module 3 is located between the frame and the sample carrying module. The controller 4 serves as both a control mechanism and a display function, and is located on the load-bearing base 6 on the side opposite to the sample carrying module 2 and the frame 1. The resistivity testing module is located inside the sample carrying module 2.

[0032] The frame 1 includes a support 11 connected to a load-bearing base, a column 12 vertically positioned behind the support 11, and a crossbeam 13 positioned on top of the column 12. A probe module 3 is located below the crossbeam 13 and is used to insert a test needle into the sample to determine its state. The probe module includes a test needle 31, a displacement sensor 32, a first motor 33, a linear guide rail 34, a slider 35, and a mounting plate 36. The lead screw is vertically oriented, with its upper end mounted on the crossbeam 13 via a bearing, and its lower end being free. A driven synchronous pulley is fixedly mounted on the upper end of the lead screw. The first motor 33 is mounted on the support 11, and its output shaft is connected to a driving synchronous pulley. The driving and driven synchronous pulleys are connected via a synchronous belt drive. A linear guide rail 34 is located on one side of the column 12, and the slider 35 slides within the linear guide rail 34. A mounting plate 36 is connected to the slider 35, and the mounting plate 36 has a nut seat that threads with the lead screw. When the first motor rotates, it drives the lead screw to rotate via the synchronous belt. Since the nut seat is fixed to the mounting plate, and the mounting plate is guided by the linear guide rail via the slider, the nut seat cannot rotate with the lead screw but moves up and down along the lead screw, causing the mounting plate and test needle to rise and fall. The test needle 31 includes a primary solidification test needle 311 and a final solidification test needle 312, which are arranged side-by-side on the front side of the mounting plate 36 and are detachably fixed by their respective holders. The dimensions of the primary and final solidification test needles conform to the requirements of GB / T1346-2011 standard. The displacement sensor 32 is a laser displacement sensor or a grating ruler displacement sensor, fixedly mounted on the mounting plate 36 with its detection end facing downwards. It is used to detect the displacement of the test needle 31 relative to the bottom of the sample box 22 in real time and transmit the displacement signal to the controller 4 in real time. The controller 4 determines the penetration depth of the test needle 31 based on the displacement data fed back by the displacement sensor 32, and thus determines the primary and final solidification states of the sample to be tested.

[0033] To assist in determining the condensation state, a camera 7 is installed on the outward-extending part of the top of the frame 1. The camera 7 faces the test mold plate 21. When the test needle is pulled out of the sample, the camera takes an image around the needle hole to determine whether the needle hole is closed and whether there are water droplets on the surface. This serves as an auxiliary basis for determining the condensation state and is cross-verified with the data from the displacement sensor to improve the reliability of the determination.

[0034] The sample carrying module 2 is disc-shaped and used to carry the sample to be tested. The sample carrying module 2 includes a test mold plate 21, a sample box 22, a base coupling 23, and a second motor 24. The test mold plate 21 has a circular disc structure with multiple circular positioning grooves evenly spaced along its upper surface for placing the sample boxes 22. The sample boxes 22 are truncated cones, and their dimensions conform to the requirements of GB / T1346-2011 standard. In this embodiment, there are four sample boxes 22. Each positioning groove has a through hole at its bottom for the electrode assembly 5 to pass through. The lower end of the base coupling 23 is fixedly connected to the load-bearing base 6, and the upper end of the base coupling 23 is connected to the center bottom of the test mold plate 21, used to rotatably support the test mold plate 21 above the load-bearing base 6. The output shaft of the second motor 24 outputs power to the base coupling 23 via gear transmission. The second motor is electrically connected to the controller 4. The controller 4 drives the test mold plate to rotate by controlling the rotation angle of the second motor, so that the sample boxes 22 at different stations move sequentially to directly below the test needle 31.

[0035] The resistivity testing module includes an electrode assembly 5 and a resistivity acquisition unit. The electrode assembly 5 comprises multiple electrodes vertically arranged along the inner wall of the sample container 22, extending from the bottom to the top of the container. In this embodiment, the electrode assembly 5 consists of four sets of miniature stainless steel electrodes, spaced apart from adjacent electrodes. The four sets of electrodes are electrically connected to an AC voltage output unit and a current acquisition unit via wires, forming a four-terminal measurement circuit: the two outer sets of electrodes act as current electrodes, connected in series with the current acquisition unit to apply a test current to the sample; the two inner sets of electrodes act as voltage electrodes, connected in parallel with the AC voltage output unit to acquire the voltage drop across the test segment of the sample. The AC voltage output unit applies an AC excitation signal of a set frequency and amplitude to the electrode assembly 5. The resistivity testing module also includes a signal processing unit with built-in impedance analysis and resistivity calculation algorithms, capable of calculating the resistivity value of the sample in real time based on the acquired voltage and current signals. The resistivity change rate is the differential of resistivity with respect to time, i.e., the instantaneous rate of change of resistivity per unit time. The signal processing unit or controller calculates the resistivity difference between adjacent time points by dividing the time interval using the resistivity data acquired in real time, thus obtaining the resistivity change rate. The signal processing unit is also communicatively connected to the controller 4, transmitting the resistivity data and resistivity change rate to the controller 4 in real time.

[0036] Controller 4, a PLC controller or microcontroller, is mounted on the support base 6. It includes a display screen, operation buttons, and a USB interface on one side of the frame, allowing for parameter setting, data display, and data export. The probing frequency refers to the time interval between two probing actions; a shorter interval indicates a higher frequency. The controller's control logic is as follows:

[0037] Acquire resistivity data transmitted by the signal processing unit and calculate the resistivity change rate;

[0038] The testing process is divided into an initial setting test stage and a final setting test stage. In the initial setting test stage: probes are performed at the normal initial setting frequency, i.e., once every 5 minutes. When the resistivity change rate reaches or exceeds the preset initial setting threshold, the probe frequency is increased to the initial setting densification frequency, i.e., once every 1 minute. When the resistivity change rate is lower than the initial setting threshold, the frequency is restored to the normal initial setting frequency (5 min / time).

[0039] During the final setting test: Probing is performed at the normal final setting frequency, i.e., once every 15 minutes; when the resistivity change rate reaches or exceeds the preset final setting threshold, the probing frequency is increased to the final setting intensified frequency, i.e., once every 5 minutes; when the resistivity change rate is lower than the final setting threshold, it reverts to the normal final setting frequency (15 minutes / test). The GB / T 1346-2011 standard specifies the probing frequencies for the initial setting and final setting stages; this invention provides an accelerated frequency for each of the two stages.

[0040] Before the first motor drives the test needle to perform the piercing action, a pause command is sent to the signal processing unit to pause the data acquisition of the resistivity test module; after the piercing action is completed and the test needle is reset, a resume command is sent to the signal processing unit to resume the data acquisition of the resistivity test module.

[0041] Based on the displacement data fed back by the displacement sensor, the initial and final solidification states of the sample under test are determined.

[0042] After determining that the sample to be tested has reached the initial solidification state, the first motor is controlled to raise the initial solidification needle and move the final solidification needle to the test position for subsequent testing.

[0043] The second motor is controlled to drive the test mold plate to rotate, moving the sample boxes at different stations sequentially to the underside of the test needle, thus achieving multi-station cyclic testing.

[0044] This invention also discloses an automatic Vicat apparatus testing method, comprising the following steps:

[0045] Place the sample to be tested on the sample carrier module;

[0046] The resistivity data of the sample under test during the condensation process is collected in real time by the resistivity testing module, and the resistivity change rate is calculated. The resistivity change rate is the derivative of resistivity with respect to time, that is, the instantaneous rate of change of resistivity per unit time.

[0047] The probing frequency is dynamically adjusted based on the resistivity change rate: During the initial setting test, when the resistivity change rate reaches or exceeds the initial setting threshold, the probing frequency is increased from the initial setting normal frequency (5 min / time) to the initial setting densification frequency (1 min / time); otherwise, the probing is performed at the initial setting normal frequency. During the final setting test, when the resistivity change rate reaches or exceeds the final setting threshold, the probing frequency is increased from the final setting normal frequency (15 min / time) to the final setting densification frequency (5 min / time); otherwise, the probing is performed at the final setting normal frequency.

[0048] The controller controls the probing module to probe the sample under test at an adjusted probing frequency, and obtains the depth data of the probe penetrating the sample under test to determine the coagulation state of the sample under test.

[0049] After determining that the sample to be tested has reached the initial solidification state, the first motor is controlled to raise the initial solidification needle and move the final solidification needle to the test position for subsequent testing.

[0050] The second motor is controlled to drive the test mold plate to rotate, moving the sample boxes at different stations sequentially to the underside of the test needle, thus achieving multi-station cyclic testing.

Claims

1. An automatic Vicat apparatus, comprising a frame (1), a sample carrying module (2) disposed on the frame (1) and used to carry a sample to be tested, and a probing module (3) disposed on the frame (1) and used to insert a probe (31) into the sample to be tested to obtain the sample state, characterized in that, It also includes a resistivity testing module for real-time acquisition of resistivity data of the sample under test during the condensation process, and a controller (4) that is communicatively connected to the resistivity testing module and the probe module (3). The resistivity testing module includes an electrode assembly (5) that contacts the sample under test and a resistivity acquisition unit that is electrically connected to the electrode assembly. The controller (4) acquires the resistivity data acquired by the resistivity acquisition unit, calculates the resistivity change rate, and dynamically adjusts the probe frequency of the probe according to the resistivity change rate.

2. The automatic Vicat apparatus according to claim 1, characterized in that, The controller divides the testing process into an initial solidification test stage and a final solidification test stage. During the initial coagulation test, when the resistivity change rate reaches or exceeds the preset initial coagulation threshold, the probing frequency of the test needle (31) is increased from the initial coagulation normal frequency to the initial coagulation encryption frequency; when the resistivity change rate is lower than the initial coagulation threshold, it is restored to the initial coagulation normal frequency. During the final coagulation test, when the resistivity change rate reaches or exceeds the preset final coagulation threshold, the probing frequency of the probe (31) is increased from the normal final coagulation frequency to the final coagulation encryption frequency; when the resistivity change rate is lower than the final coagulation threshold, it is restored to the normal final coagulation frequency. The initial coagulation encryption frequency is greater than the initial coagulation normal frequency, and the final coagulation encryption frequency is greater than the final coagulation normal frequency.

3. The automatic Vicat apparatus according to claim 1, characterized in that, Before the test needle (31) performs the action of piercing into the sample to be tested, the data acquisition of the resistivity test module is paused; after the piercing action is completed, the data acquisition of the resistivity test module is resumed.

4. The automatic Vicat apparatus according to claim 1, characterized in that, The probing module (3) includes a liftable test needle (31), a displacement sensor (32) for detecting the depth of the test needle into the sample to be tested, and a first motor (33) for driving the test needle (31) to rise and fall. The controller (4) determines the initial solidification state and final solidification state of the sample to be tested based on the data from the displacement sensor (32).

5. The automatic Vicat apparatus according to claim 1, characterized in that, The test needle (31) includes a primary solidification test needle (311) and a final solidification test needle (312). After the controller determines that the sample to be tested has reached the primary solidification state, it controls the probe module (3) to switch to the final solidification test needle (312) for testing.

6. The automatic Vicat apparatus according to claim 1, characterized in that, The sample carrying module (2) includes a rotatable test mold plate (21), which has multiple stations for placing sample boxes (22). The controller controls the rotation of the test mold plate to move the sample boxes at different stations to the underside of the test needle (31) in sequence.

7. The automatic Vicat apparatus according to claim 6, characterized in that, The electrode assembly (5) includes a plurality of electrodes arranged vertically along the generatrix of the inner wall of the sample box (22), the plurality of electrodes extending from the bottom to the top of the sample box (22).

8. The automatic Vicat apparatus according to claim 1, characterized in that, The resistivity acquisition unit includes an AC voltage output unit and a current acquisition unit, which are used to apply an AC excitation signal to the electrode assembly (5) and acquire the response current signal.

9. The automatic Vicat apparatus according to claim 1, characterized in that, The frame (1) is equipped with a camera (7) for acquiring image information of the sample to be tested, and the camera (7) is communicatively connected to the controller (4).

10. A testing method for an automated Vicat apparatus, applied to the automated Vicat apparatus according to any one of claims 1-9, characterized in that, Includes the following steps: Place the sample to be tested on the sample carrier module (2); The resistivity test module collects resistivity data of the sample under test in real time during the condensation process. The resistivity change rate is the derivative of resistivity with respect to time. The controller calculates the instantaneous rate of change of resistivity per unit time based on the real-time collected resistivity data. The probe frequency of the probe module (3) is dynamically adjusted according to the resistivity change rate. In the initial solidification test stage, when the resistivity change rate reaches or exceeds the initial solidification threshold, the probe frequency is increased from the initial solidification normal frequency to the initial solidification encryption frequency; otherwise, the probe is performed at the initial solidification normal frequency. In the final solidification test stage, when the resistivity change rate reaches or exceeds the final solidification threshold, the probe frequency is increased from the final solidification normal frequency to the final solidification encryption frequency; otherwise, the probe is performed at the final solidification normal frequency. The controller (4) controls the probing module (3) to pierce the sample under test at the adjusted probing frequency, and obtains the depth data of the needle (31) piercing the sample under test to determine the coagulation state of the sample under test.

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