Automatic inspection device and method for sand under sand supply tank of high-pressure water jet cleaning equipment

Abstract

The application discloses a sand feeding tank sand discharging automatic inspection device and method of high-pressure water jet cleaning equipment, which comprises a plurality of sensors, a measurement bridge and an inspection device, wherein the plurality of sensors are arranged at each sand discharging port of the sand feeding tank; the measurement bridge is used for being communicated with the corresponding sensor according to the gating control of the inspection device to obtain the instantaneous inductance value of the corresponding sensor; the inspection device is used for controlling the measurement bridge to automatically and cyclically measure the gated sand discharging port in sequence and obtain the instantaneous inductance value of the corresponding sensor; and the instantaneous inductance value is compared with the initial inductance value of the corresponding pipe port which is calibrated in advance, whether the change value of the instantaneous inductance value of the sensor exceeds the threshold value is determined, whether the corresponding sand discharging port is blocked is determined, and if the sand discharging port is blocked, the corresponding alarm signal point of the sand discharging port is lightened. The application realizes automatic inspection of multiple sand discharging ports.

Description

Technical Field

[0001] This invention relates to the field of metal surface cleaning technology, and in particular to a device and method for real-time detection of blockage at the sand inlet of a sand supply tank in an abrasive high-pressure water jet metal surface cleaning equipment. Background Technology

[0002] High-pressure water jet cleaning of metal surfaces is a green, pollution-free, purely physical surface cleaning technology. Its principle is to use a mixture of high-pressure water and metal abrasive to impact the metal surface, thereby removing impurities such as oxide scale.

[0003] The sand supply tank is a crucial component of waterjet cleaning equipment. It contains abrasive metal particles that are mixed with high-pressure water through the inlet. Due to factors such as abrasive caking, rust, and abnormal system pressure, the inlet of the sand supply tank is prone to blockage. During high-pressure waterjet metal surface cleaning, the flow rate of the abrasive in the mixture is strictly controlled; a decrease in abrasive concentration will severely impact cleaning quality. Therefore, real-time monitoring of the blockage status at the inlet of the sand supply tank is essential.

[0004] See Figure 1 The number of abrasive outlets on a single abrasive tank (grit tank) in a water jet cleaning system ranges from 8 to 48, while the number of abrasive tanks in the entire system ranges from 8 to 20, resulting in hundreds of inspection points at the outlets. Currently, there is no device on the market suitable for automatically detecting metal abrasive blockage at the outlets. Manual inspection is currently the primary method. The abrasive tanks are stored in sealed metal cabinets, and each individual outlet of each abrasive tank can only be manually inspected when the equipment is shut down. This visual comparison is extremely labor-intensive, prone to misjudgment, and lacks accuracy and real-time reliability. Furthermore, the information from manual inspections is delayed, which is detrimental to equipment control and quality assurance. In addition, to ensure continuous production, the equipment cannot be frequently shut down. Summary of the Invention

[0005] This invention provides an automatic inspection device and method for sand supply tanks in high-pressure water jet cleaning equipment, which solves the technical problems of huge workload and difficulty in ensuring accuracy and real-time performance of manual inspection.

[0006] To solve the above-mentioned technical problems, the technical solution proposed by this invention is as follows:

[0007] An automatic sand discharge inspection device for a high-pressure water jet cleaning equipment's sand supply tank includes:

[0008] Multiple sensors are installed at each sand outlet of the sand supply tank;

[0009] A measuring bridge is used to connect with the corresponding sensor according to the gating control of the inspection device in order to obtain the instantaneous inductance value of the corresponding sensor.

[0010] The inspection device is used to control the measuring bridge to automatically and cyclically measure the selected sand outlets in sequence; and obtain the instantaneous inductance value of the corresponding sensor; compare the instantaneous inductance value with the initial inductance value of the corresponding pipe outlet that has been calibrated in advance; and determine whether the corresponding sand outlet is blocked based on whether the change value of the instantaneous inductance value of the sensor exceeds the threshold. If it is blocked, the alarm signal corresponding to the sand outlet will be lit.

[0011] Preferably, the change in the instantaneous inductance of the sensor is calculated using the following formula:

[0012] r=(L-Ls) / Ls (1)

[0013] Where Ls represents the initial inductance value of the coil, L represents the instantaneous inductance value, and r is the change in the instantaneous inductance value. When r exceeds the threshold, it is determined that the sand outlet where the sensor is located is blocked.

[0014] Preferably, the sensor is a coil sensor, comprising a single-layer tightly wound coil of enameled wire wound at the sand outlet of the sand supply tank, with the enameled wires arranged closely together, and the outer enamel removed from both ends of the coil to serve as terminals for connection to the normally open measuring bridge.

[0015] Preferably, the inspection device includes:

[0016] The main control unit is used to generate multiple inspection signals to control the measuring bridge to automatically and cyclically measure the selected sand outlets in sequence; store the initial inductance value of the coil sensor of the pipe outlet; obtain the instantaneous inductance value of the corresponding selected sensor; compare the instantaneous inductance value with the pre-calibrated initial inductance value of the corresponding pipe outlet, and determine whether the change value of the instantaneous inductance value of the sensor exceeds the threshold, thereby determining whether the corresponding sand outlet is blocked. If blocked, an alarm signal is output to the channel of the corresponding sand outlet.

[0017] The switching circuit includes a normally open digital switch composed of multiple relays; the two terminals of the coil sensor are respectively connected to a pair of normally open contacts of the relays; when the multi-channel inspection signal issued by the main control unit selects the channel corresponding to the lower sand port, the normally open contacts of the two relays are connected to obtain the instantaneous inductance value of the corresponding coil.

[0018] The alarm circuit is used to display an alarm based on the alarm signal from the corresponding sand outlet channel.

[0019] Preferably, the inspection device further includes:

[0020] The digital decoding unit, connected to the main control unit, is used to expand the main control unit's four I / O interfaces into 16 addressable I / O interfaces through cascading.

[0021] The level conversion circuit is connected to the 16 addressable I / O interface of the digital decoding unit. It is used to convert the low level output by the digital decoding unit to a high level, and drive the corresponding switch group circuit through the high level to enable the corresponding normally open contact.

[0022] This invention also discloses an automatic inspection method for sand supply tank of a high-pressure water jet cleaning equipment, comprising the following steps:

[0023] By installing sensors at each sand outlet of the sand supply tank, and by automatically cycling through each sand outlet of the sand supply tank one by one, the instantaneous inductance value of the coil on the selected sand outlet is automatically acquired. Based on the comparison and analysis with the coil characteristic value when the pipe is blocked, the system determines whether the corresponding sand outlet is blocked based on whether the change value of the instantaneous inductance of the sensor exceeds the threshold. If it is blocked, the alarm signal corresponding to the sand outlet is lit.

[0024] Preferably, the change in the instantaneous inductance of the sensor is calculated using the following formula:

[0025] r=(L-Ls) / Ls (1)

[0026] Where Ls represents the initial inductance value of the coil, L represents the instantaneous inductance value, and r is the change in the instantaneous inductance value. When r exceeds the threshold, it is determined that the sand outlet where the sensor is located is blocked.

[0027] The present invention has the following beneficial effects:

[0028] The automatic inspection device and method for the sand supply tank of the high-pressure water jet cleaning equipment of the present invention can detect in real time whether the sand supply port of the abrasive tank is blocked; it can automatically complete the inspection of multiple sand supply ports and give corresponding alarm indications, which greatly reduces the intensity of manual inspection and ensures the surface cleaning effect.

[0029] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0030] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0031] Figure 1 This is a schematic diagram of the structure of the lower sand inlet of a high-pressure water jet sand supply tank in existing technology;

[0032] Figure 2 This is a schematic diagram of the automatic sand supply tank inspection device of the high-pressure water jet cleaning equipment according to a preferred embodiment of the present invention;

[0033] Figure 3 This is a circuit diagram of the main control unit of the inspection device according to a preferred embodiment of the present invention;

[0034] Figure 4 This is a circuit diagram of the digital decoding unit and level conversion unit of the inspection device according to a preferred embodiment of the present invention;

[0035] Figure 5 This is the data channel of the main control circuit of the inspection device in a preferred embodiment of the present invention;

[0036] Figure 6 This is a circuit diagram of the switch group circuit according to a preferred embodiment of the present invention;

[0037] Figure 7 This is a circuit diagram of the alarm circuit of a preferred embodiment of the present invention;

[0038] Figure 8 This is a flowchart of the automatic inspection method for sand supply tank of the high-pressure water jet cleaning equipment according to a preferred embodiment of the present invention. Detailed Implementation

[0039] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0040] See Figure 2 The automatic inspection device for sand discharge from the sand supply tank of the high-pressure water jet cleaning equipment of the present invention includes: multiple sensors, a measuring bridge (LCR), and an inspection device, wherein the multiple sensors are correspondingly arranged at each sand discharge port of the sand supply tank; the measuring bridge is used to connect with the corresponding sensor according to the selection control of the inspection device to obtain the instantaneous inductance value of the corresponding sensor; the inspection device is used to control the measuring bridge to automatically and cyclically measure the selected sand discharge ports in sequence; and obtain the instantaneous inductance value of the corresponding sensor; compare the instantaneous inductance value with the initial inductance value of the corresponding pipe port that has been pre-calibrated, and determine whether the corresponding sand discharge port is blocked based on whether the change value of the instantaneous inductance value of the sensor exceeds a threshold; if blocked, the alarm signal corresponding to the sand discharge port is lit.

[0041] In some implementations, the change in the instantaneous inductance of the sensor is calculated using the following formula:

[0042] r=(L-Ls) / Ls (1)

[0043] Where Ls represents the initial inductance value of the coil, L represents the instantaneous inductance value, and r is the change in the instantaneous inductance value. When r exceeds the threshold, it is determined that the sand outlet where the sensor is located is blocked.

[0044] In some implementations, the sensor is a coil sensor, comprising a single-layer tightly wound coil of enameled wire wound at the sand inlet of the sand supply tank, with a length controlled to be approximately 2.5 cm; the enameled wires are tightly arranged to obtain a high quality factor, and the outer enamel is removed from both ends of the coil to serve as terminals that are normally open and connected to the measuring bridge. The terminals are controlled by the device's monitoring circuit and are connected to the measuring bridge in a time-sharing manner, thereby enabling the device to obtain the inductance change value of the coil.

[0045] In some embodiments, the inspection device includes:

[0046] The main control unit generates multiple inspection signals to control the measuring bridge to automatically and sequentially select the sand outlet; stores the initial inductance value of the coil sensor at the pipe outlet; acquires the instantaneous inductance value of the selected corresponding sensor; compares the instantaneous inductance value with the pre-calibrated initial inductance value of the corresponding pipe outlet, and determines whether the change in the instantaneous inductance value exceeds a threshold, thereby determining whether the corresponding sand outlet is blocked. If blocked, an alarm signal is output to the corresponding sand outlet channel (the alarm signal is cleared after the blockage problem is resolved). For implementation, see [link to implementation details]. Figure 3 , Figure 5 The main control unit can be a 51 microcontroller.

[0047] The digital decoding unit, connected to the main control unit, is used to cascade the main control unit's four I / O interfaces into a 16-channel addressable I / O interface; for implementation, see [link to implementation details]. Figure 4 This section mainly consists of two 74LS138 digital decoders, which are cascaded to extend addressing from 3-8 to 4-16, allowing the processor to control a large number of external devices with limited I / O resources. In this setup, the microcontroller uses four output interfaces to gain control of 16 external addresses, thus enabling addressing operations for 16 external ports.

[0048] The level conversion circuit, connected to the 16 addressable I / O interface of the digital decoding unit, converts the low-level output of the digital decoding unit to a high-level output. This high-level output drives the corresponding switch group circuit, enabling the corresponding normally open contact to be activated. In implementation, NAND logic is used; when activated, a low-level signal is output. See also... Figure 4 This part of the circuit uses an inverter 74ls04d to boost the low level signal to a high level signal and improve the load-driving capability so as to drive the subsequent switching circuit.

[0049] For the switch group circuit, see [link / reference] Figure 6The system includes a normally open digital switch consisting of 16 relays; the two terminals of the coil sensor are connected to a pair of normally open contacts of the relays; when the multi-channel inspection signal from the main control unit selects the corresponding channel of the lower sand port, the normally open contacts of the two relays are connected to obtain the instantaneous inductance value of the corresponding coil. When the device is not powered on, the coils are not connected to the inspection device, and the inductance value read on the LCR instrument is invalid. When any group of coils is selected by the decoding circuit, it is equivalent to being directly connected to the LCR, and the LCR data at this time is the instantaneous inductance value of that coil.

[0050] The alarm circuit is used to display an alarm based on the alarm signal from the corresponding sand outlet channel. For implementation, please refer to... Figure 7 The alarm circuit can be composed of an IO expansion module 74HC164 and light-emitting diodes. Since the IO resources of the main control part are precious, the output method corresponding to the alarm signal one by one cannot be adopted. Therefore, the 74HC164 is used to implement the serial input-parallel output control method. Two IO ports are used to control 16 alarm signals. The control logic is generated by the main control circuit.

[0051] This invention also discloses an automatic inspection method for sand discharge from a sand supply tank in a high-pressure water jet cleaning equipment, comprising the following steps: setting a sensor at each sand discharge port of the sand supply tank; automatically cyclically selecting each sand discharge port of the sand supply tank one by one, automatically acquiring the instantaneous inductance value of the coil on the selected sand discharge port, comparing and analyzing it with the coil characteristic value when the pipe is blocked according to a pre-calibrated standard, and determining whether the corresponding sand discharge port is blocked based on whether the change value of the instantaneous inductance of the sensor exceeds a threshold; if blocked, illuminating the alarm signal corresponding to the sand discharge port.

[0052] See Figure 8 The inspection method of this invention is used to detect whether the sand inlet of the sand supply tank of a high-pressure water jet metal surface cleaning equipment is blocked. The device automatically completes the cyclic detection of 16 sand inlets and gives an alarm signal for the blocked inlet. The specific steps are as follows:

[0053] Initialization: A single-layer coil, approximately 2.5 cm in length, is wound using insulated wire at the sand inlet of the sand supply tank. A clean water test is then conducted to obtain the corresponding coil inductance value L. S A total of 16 such L's can be obtained. S These values ​​are stored by the device's main control circuit. Initialization only needs to be done once; subsequent steps are executed automatically by the program.

[0054] Step 1: The main control program stores the L in the ROM SLoad it into memory for later use, and start a permanent loop to perform a cyclic detection task. The first one to be detected is the No. 1 lower sand port coil. Therefore, the main control circuit sets the corresponding IO output port to the binary value "0000" and enables the No. 1 timer for 2 seconds.

[0055] Step 2: The "0000" signal output by the main control IO is captured by the 74LS138 decoder chip. At this time, the high-order decoder is blocked, and the low-order decoder decodes "0000", resulting in a decimal "0". Therefore, the Y0 output of the low-order decoder 74LS138 is low level, around 0V, representing a valid signal. Other outputs are blocked as invalid signals.

[0056] Step 3: The decoder output level enters the inverter 74LS04D. It can be seen that the inverter inputs 6A to 1A are binary values ​​"111110" in sequence. Therefore, the inverter output is "000001", that is, the 1A port outputs a valid level signal, and the 2A to 6A ports output invalid voltage.

[0057] Step 4: Because the inverter 1A port outputs a valid high level, relay group 1 jumps, and its normally open contact closes, while relay groups 2 through 16 remain unchanged. Therefore, the two ends of coil 1 are connected to the measurement ports of the LCR bridge.

[0058] Step 5: The main control program receives the LCR data through the serial port and filters it using software to obtain the reliable inductance value L of coil 1. The inductance value is then calculated using formula (1) with the stored corresponding Ls value. If r <= 43%, it indicates that the abrasive flow rate at the bottom of the abrasive outlet is normal; if r >= 60%, it indicates that the abrasive outlet is blocked and an alarm signal needs to be given.

[0059] Step 6: If an alarm was determined to be needed in Step 5, the main control program writes an 8-bit binary number, "00000001", into the IO expander 74HC164. The QA output pin of the 74HC164 will then show a high-level signal, while other outputs remain low. The QA signal enables the alarm light to operate, thus triggering the abrasive blockage alarm. If no alarm is needed in Step 5, QA will remain low, and the alarm signal will remain off.

[0060] Step 7: Repeat steps 1 to 6. At this time, the main control circuit outputs "0010" to the decoding circuit, and starts the detection of coil No. 2. This process is repeated to achieve automatic inspection.

[0061] Based on the working principle of the abrasive waterjet cleaning device, when the abrasive outlet of the abrasive tank is blocked, only a small amount of clean water can pass through the outlet, while the abrasive stops flowing, which will seriously affect the quality of surface cleaning. The automatic inspection device of this invention can automatically inspect 16 abrasive outlets. By sequentially connecting to the LCR (Liquid Crystal Reflector), it automatically acquires the inductance value of the coil on the outlet. Based on comparison and analysis with the coil characteristic value when the outlet is blocked (as per pre-calibrated values), it determines whether the corresponding outlet is blocked. If blocked, the alarm signal corresponding to that outlet is activated. Then, the next round of automatic inspection begins, achieving the purpose of automatic detection and alarm for outlet blockage, greatly reducing the workload of manual inspection, and improving the accuracy and real-time performance of the judgment.

[0062] In summary, this invention achieves automatic measurement and comparison of 16 sand outlets by directly binding a single-layer coil to the sand outlet for judgment, and through the cooperation between the automatic inspection device, the automatic inspection program and the integrated circuit, it can monitor the blockage in real time and give alarm prompts, which greatly improves the detection accuracy and real-time performance and improves the automation level of the production process.

[0063] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An automatic inspection device for sand supply tank of a high-pressure water jet cleaning equipment, characterized in that, include: Multiple sensors are correspondingly installed at each sand outlet of the sand supply tank; the sensor is a coil sensor, which includes a single-layer tightly wound coil of enameled wire at the sand outlet of the sand supply tank, with the enameled wires arranged tightly between them, and the outer enamel removed from both ends of the coil to serve as terminals that are normally open and connected to the measuring bridge. A measuring bridge is used to connect to the corresponding sensor according to the gating control of the inspection device, in order to obtain the instantaneous inductance value of the corresponding sensor; the change in the instantaneous inductance value of the sensor is calculated by the following formula: r = (L - Ls) / Ls(1) Where Ls represents the initial inductance value of the coil, L represents the instantaneous inductance value, and r is the change in the instantaneous inductance value. When r exceeds the threshold, it is determined that the sand outlet where the sensor is located is blocked. The inspection device is used to control the measuring bridge to automatically and cyclically measure the selected sand outlets in sequence; and obtain the instantaneous inductance value of the corresponding sensor; compare the instantaneous inductance value with the initial inductance value of the corresponding pipe outlet that has been pre-calibrated; and determine whether the corresponding sand outlet is blocked based on whether the change value of the instantaneous inductance value of the sensor exceeds the threshold. If it is blocked, the alarm signal corresponding to the sand outlet is lit. When the sand inlet of the sand supply tank is blocked, only a small amount of clean water can pass through the sand inlet, while the abrasive stops flowing.

2. The automatic sand supply tank inspection device of the high-pressure water jet cleaning equipment according to claim 1, characterized in that, The inspection device includes: The main control unit is used to generate multiple inspection signals to control the measuring bridge to automatically and cyclically measure the selected sand outlets in sequence; store the initial inductance value of the coil sensor of the pipe outlet; obtain the instantaneous inductance value of the corresponding selected sensor; compare the instantaneous inductance value with the pre-calibrated initial inductance value of the corresponding pipe outlet, and determine whether the change value of the instantaneous inductance value of the sensor exceeds the threshold, thereby determining whether the corresponding sand outlet is blocked. If blocked, an alarm signal is output to the channel of the corresponding sand outlet. The switching circuit includes a normally open digital switch composed of multiple sets of relays; the two terminals of the coil sensor are respectively connected to a pair of normally open contacts of the relays; when the multi-channel inspection signal issued by the main control unit selects the channel corresponding to the lower sand port, the normally open contacts of the two relays are connected to obtain the instantaneous inductance value of the corresponding coil. The alarm circuit is used to display an alarm based on the alarm signal from the corresponding sand outlet channel.

3. The automatic sand supply tank inspection device of the high-pressure water jet cleaning equipment according to claim 2, characterized in that, The inspection device also includes: A digital decoding unit, connected to the main control unit, is used to cascade the four I / O interfaces of the main control unit into 16 addressable I / O interfaces. The level conversion circuit is connected to the 16 addressable I / O interface of the digital decoding unit. It is used to convert the low level output by the digital decoding unit to a high level, and drive the corresponding switch group circuit through the high level to enable the corresponding normally open contact.

4. An automatic inspection method for sand supply tank discharge in a high-pressure water jet cleaning equipment, characterized in that, Includes the following steps: A sensor is installed at each sand outlet of the sand supply tank. The sensor is a coil sensor, which includes a single-layer tightly wound coil of enameled wire at the sand outlet of the sand supply tank. The enameled wires are tightly arranged, and the outer paint is removed at both ends of the coil to serve as terminals connected to the normally open measuring bridge. Each sand outlet of the sand supply tank is selected sequentially in an automatic cycle. The instantaneous inductance value of the coil at the selected sand outlet is automatically acquired. Based on the comparison and analysis with the coil characteristic value when the outlet is blocked, the change in the instantaneous inductance of the sensor is determined to see if it exceeds a threshold. If it is blocked, the alarm signal corresponding to the sand outlet is lit. The change in the instantaneous inductance value of the sensor is calculated using the following formula: r = (L - Ls) / Ls(1) Where Ls represents the initial inductance value of the coil, L represents the instantaneous inductance value, and r is the change in the instantaneous inductance value. When r exceeds the threshold, it is determined that the sand outlet where the sensor is located is blocked.

Images