A sand blasting device based on upper and lower sand blasting pressure cooperative control and a control method thereof

Abstract

The present application relates to plate surface sand blasting treatment equipment technical field, specifically is a kind of sand blasting equipment and control method based on upper and lower sand blasting pressure collaborative control.The equipment includes sand blasting machine body, stirring device, upper sand blasting pump, lower sand blasting pump, pressure detection component and control component;Sand blasting machine body is equipped with conveying mechanism and the upper sand blasting component and lower sand blasting component located in the upper and lower sides of conveying channel.Control component respectively obtains upper and lower sand blasting liquid supply pressure, compares with corresponding preset pressure target, and according to the pressure regulation state of each branch, respectively or synchronously adjusts the output of two sand blasting pumps, so that upper and lower sand blasting pressure is maintained in corresponding allowable range.The present application can adapt to the structure and flow resistance difference of upper and lower sand blasting branch, improve the consistency and equipment operation stability of plate double-sided sand blasting.

Description

Technical Field

[0001] This invention relates to the technical field of sandblasting equipment for sheet metal surfaces, specifically a sandblasting device and its control method based on coordinated control of upper and lower sandblasting pressure. Background Technology

[0002] Sandblasting typically uses pressurized fluid to carry abrasive particles through nozzles and propel them onto the surface of a material to remove oxides, residues, or create a surface with a predetermined roughness. To improve processing efficiency, existing sandblasting equipment usually has sandblasting components on both the top and bottom sides of the material, allowing for simultaneous double-sided treatment during transport. The sandblasting pressure directly affects the abrasive's ejection speed and impact strength; whether the pressure of the top and bottom blasts can be maintained within their respective set ranges determines whether the treatment level on both surfaces of the material is consistent.

[0003] CN115401616A discloses a high-pressure abrasive slurry descaling device for steel plates. It includes two lower high-pressure abrasive slurry descaling devices below the steel plate and two corresponding upper high-pressure abrasive slurry descaling devices above the steel plate. This device can treat both the upper and lower surfaces of the steel plate and allows for adjustment of the nozzle angle and the working height of the upper descaling devices. This solution primarily improves the treatment coverage by adjusting the spatial arrangement of the upper and lower descaling devices and the nozzle position, but does not further address adjusting the corresponding liquid supply power based on the actual pressure of each of the upper and lower sandblasting branches.

[0004] CN110103151A discloses a cleaning system and method for descaling metal sheets using high-pressure water jet blasting. The system includes descaling nozzles on both the upper and lower sides of the sheet, and a high-pressure pump supplies pressurized water to these nozzles. A frequency converter regulates the pump's speed to adjust its output pressure. While this method enables double-sided blasting and adjustable supply pressure, the upper and lower nozzles are powered by a high-pressure supply system. The disclosure does not specify pressure feedback or independent pump control for the upper and lower blasting branches. When the number of nozzles, pipe lengths, or flow resistance differ, adjusting the same supply pressure makes it difficult to correct pressure deviations on both sides separately.

[0005] CN115826496A discloses a control system and method for a high-pressure water jet sandblasting production line for cleaning metal strips. The system includes a high-pressure pump frequency conversion control unit within the main control system, and a pressure detection unit to collect the pressure value of the high-pressure pump output pipeline. The high-pressure pump starts at a preset frequency, and enters a start-up ready state when the detected pressure exceeds the lower limit of normal operation. In case of high or low pressure, the system executes alarms, shutdowns, or state switching. This solution improves the automation level and operational protection capabilities of the sandblasting production line. However, its pressure signal is mainly used for start-up condition judgment, abnormal alarms, and interlocking protection, and does not address the issue of separately changing the output of the two sandblasting pumps according to the upper and lower sandblasting pressures, ensuring that the upper and lower pressures simultaneously meet their respective pressure ranges and predetermined pressure relationships.

[0006] Therefore, existing technologies can achieve synchronous sandblasting of the upper and lower surfaces of the sheet metal, frequency conversion regulation of the sandblasting pump, and detection of sandblasting pressure. However, these functions are mainly manifested in the sandblasting structure arrangement, single liquid supply pressure regulation, or pressure threshold monitoring. For sandblasting equipment with different numbers of nozzles, spray pipes, and pipeline resistance in the upper and lower sandblasting components, the upper and lower sandblasting branches may generate different actual pressures under the same pump frequency or the same liquid supply conditions. Adjusting only the common pressure or only monitoring the pressure is insufficient to promptly eliminate pressure deviations in one branch, easily leading to situations where the pressure on one side meets the process requirements while the pressure on the other side remains too high or too low. Furthermore, nozzle wear, partial blockage, and changes in pipeline resistance can also alter the pressure change corresponding to the fixed frequency adjustment, causing repeated frequency adjustments or pressure fluctuations. Summary of the Invention

[0007] The purpose of this invention is to provide a sandblasting device and its control method based on coordinated control of upper and lower sandblasting pressure, so as to solve the technical problems mentioned in the background art.

[0008] Based on the above ideas, the present invention provides the following technical solution: A sandblasting device based on coordinated control of upper and lower sandblasting pressure, comprising: It includes the sandblasting machine body (1), the mixing device (4), the sandblasting pump (5), the pressure detection component, and the control component; The sandblasting machine body (1) includes a conveying mechanism, an upper sandblasting assembly and a lower sandblasting assembly. The conveying mechanism forms a conveying channel for the plate to be processed to pass through. The upper sandblasting assembly and the lower sandblasting assembly are respectively arranged on the upper and lower sides of the conveying channel. The sandblasting pump (5) includes an upper sandblasting pump and a lower sandblasting pump. The upper sandblasting pump is connected between the stirring device (4) and the upper sandblasting assembly, and the lower sandblasting pump is connected between the stirring device (4) and the lower sandblasting assembly. The pressure detection assembly includes an upper pressure detection component for detecting the hydraulic pressure of the upper sandblasting supply and a lower pressure detection component for detecting the hydraulic pressure of the lower sandblasting supply. The control component is connected to the upper pressure detection element, the lower pressure detection element, the upper sandblasting pump, and the lower sandblasting pump, respectively, for acquiring the upper sandblasting pressure detection results and the lower sandblasting pressure detection results, comparing the upper sandblasting pressure detection results and the lower sandblasting pressure detection results with the corresponding preset pressure targets, determining the pressure regulation state of the upper sandblasting branch and the lower sandblasting branch, and controlling the output of the upper sandblasting pump and the lower sandblasting pump respectively according to the pressure regulation state, so that the upper sandblasting pressure and the lower sandblasting pressure are maintained within the corresponding allowable range.

[0009] Preferably, the control component is located in the electrical control cabinet (2). The control component includes a controller, a human-machine interface unit, a first frequency converter connected to the upper sandblasting pump, and a second frequency converter connected to the lower sandblasting pump. The human-machine interface unit is used to set the pressure targets of the upper sandblasting branch and the lower sandblasting branch respectively. The controller adjusts the operating status of the upper sandblasting pump and the lower sandblasting pump respectively through the first frequency converter and the second frequency converter.

[0010] Preferably, the upper pressure detection element is disposed on the upper sandblasting liquid supply pipeline between the upper sandblasting pump and the upper sandblasting assembly, and the lower pressure detection element is disposed on the lower sandblasting liquid supply pipeline between the lower sandblasting pump and the lower sandblasting assembly; both the upper pressure detection element and the lower pressure detection element have a pressure signal output terminal, and the output pressure detection signal includes a signal characterizing the actual pressure value or a status signal characterizing the relationship between the actual pressure and the preset pressure limit.

[0011] Preferably, both the upper sandblasting assembly and the lower sandblasting assembly include at least one spray disc, the spray disc including a liquid supply main pipe, multiple spray pipes communicating with the liquid supply main pipe, and multiple nozzles spaced apart along the spray pipes.

[0012] Preferably, the multiple spray pipes are arranged at intervals along the conveying direction of the plate and extend along the width direction of the conveying channel, and the multiple nozzles are distributed along the length direction of the corresponding spray pipes; the nozzles of the upper sandblasting assembly face the upper surface of the plate to be treated, and the nozzles of the lower sandblasting assembly face the lower surface of the plate to be treated, so that the spraying area formed by the nozzles covers the effective processing width of the plate to be treated.

[0013] Preferably, the mixing device (4) includes a mixing cylinder, a mixing drive and a mixing component disposed in the mixing cylinder, the mixing drive being used to drive the mixing component to mix sand and water to form a sandblasting liquid; the control component is also connected to the mixing drive and is configured to allow the upper sandblasting pump and the lower sandblasting pump to start after the mixing drive is in operation.

[0014] Preferably, it also includes a separation pump (3), a sedimentation tank (6) and a sand-water separator. The sedimentation tank (6) is connected to the return end of the sandblasting machine body (1). The inlet end of the separation pump (3) is connected to the sedimentation tank (6). The outlet end of the separation pump (3) is connected to the sand-water separator. The sand recovery end of the sand-water separator is connected to the stirring device (4).

[0015] A control method for a sandblasting device based on coordinated control of upper and lower sandblasting pressures, applied to the aforementioned sandblasting device, the method comprising: S1. Start the mixing device to mix the sand and water to form a sandblasting liquid, and determine the upper sandblasting pressure target and lower sandblasting pressure target according to the sandblasting process requirements of the board to be treated. S2. After the stirring device is in operation, start the upper sandblasting pump and the lower sandblasting pump to deliver the sandblasting liquid to the upper sandblasting assembly and the lower sandblasting assembly respectively. S3. The plate to be processed is conveyed through the upper sandblasting assembly and the lower sandblasting assembly, and the upper and lower surfaces of the plate to be processed are sandblasted respectively. S4. Obtain the upper sandblasting pressure detection result and the lower sandblasting pressure detection result, and compare the upper sandblasting pressure detection result and the lower sandblasting pressure detection result with the corresponding sandblasting pressure target respectively; S5. Based on the upper sandblasting pressure detection results and the lower sandblasting pressure detection results, determine the pressure regulation status of the upper sandblasting branch and the lower sandblasting branch respectively, and adjust the output of the upper sandblasting pump and the lower sandblasting pump respectively so that the upper sandblasting pressure and the lower sandblasting pressure are maintained within the corresponding allowable range.

[0016] Preferably, in step S5: When the pressure of any sandblasting branch is lower than the corresponding allowable range, increase the output of the sandblasting pump corresponding to that sandblasting branch. When the pressure in any sandblasting branch exceeds the corresponding allowable range, reduce the output of the sandblasting pump corresponding to that sandblasting branch. When the pressure of any sandblasting branch is within the corresponding allowable range, maintain the current output of the sandblasting pump corresponding to that sandblasting branch; When both the upper sandblasting branch and the lower sandblasting branch require pressure adjustment, the upper sandblasting pump and the lower sandblasting pump are adjusted respectively within the same control cycle.

[0017] Preferably, after step S5, the method further includes: S6. The sand-water mixture returned after sandblasting is introduced into a sedimentation tank, and the sand-water mixture is transported to a sand-water separator by a separation pump. The sand obtained by the sand-water separator is then transported back to the stirring device.

[0018] The technical solution of the present invention may include the following beneficial effects: This invention, by setting up independent upper and lower sandblasting pumps and corresponding pressure detection devices, enables the controller to adjust the output of the two sandblasting pumps separately based on the upper and lower sandblasting pressures. Unlike methods that only display or alarm the sandblasting pressure or adjust the upper and lower sandblasting components as a whole through a single liquid supply pressure, this invention establishes a direct control relationship between the upper and lower pressure detection results and the corresponding sandblasting pumps, ensuring that the upper and lower sandblasting pressures are maintained within their respective allowable ranges.

[0019] This invention allows for the selective adjustment of one or both sandblasting pumps based on varying upper and lower sandblasting pressures. It maintains the current output while ensuring both upper and lower sandblasting pressures meet set conditions. This adapts to pressure differences arising from variations in the number of nozzles, spray pipes, and pipeline resistance between the upper and lower sandblasting components, preventing pressure deviations on one side from process requirements when adjusting the pressure on the other. This reduces the difference in sandblasting action between the upper and lower surfaces of the material, minimizing the possibility of insufficient or excessive sandblasting, and improving the consistency of double-sided sandblasting and the stability of continuous equipment operation.

[0020] Furthermore, this invention can also determine the pressure response characteristics of each sandblasting branch by utilizing the upper and lower sandblasting pressures and the operating frequencies of the two sandblasting pumps, and determine the frequency adjustment amount by combining the pressure change trend and the pressure difference between the upper and lower branches, so that the adjustment range of the sandblasting pumps is adapted to the current state of the branch. This method can reduce pressure overshoot and frequent frequency increases and decreases when there is nozzle wear, partial blockage, or changes in pipeline resistance, and limit further frequency increases when the pressure response is continuously abnormal or the operating frequency reaches its upper limit, providing a basis for equipment maintenance. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the sandblasting equipment of the present invention; Figure 2 This is a front view structural diagram of the sandblasting equipment of the present invention; Figure 3 This is a top view of the sandblasting equipment of the present invention. Figure 4This is a schematic diagram showing the arrangement of the spray disc, spray pipe and nozzle in the sandblasting assembly of the present invention; Figure 5 This is a flowchart of the sandblasting equipment control method of the present invention.

[0022] Explanation of reference numerals in the attached drawings: 1. Sandblasting machine body; 2. Electrical control cabinet; 3. Separation pump; 4. Agitator; 5. Sandblasting pump; 6. Sedimentation tank. Detailed Implementation

[0023] Example 1 This embodiment provides a sandblasting device and its control method based on coordinated control of upper and lower sandblasting pressure, used to simultaneously perform sandblasting roughening treatment on the upper and lower surfaces of printed circuit boards and other materials. Figure 1 The diagram shown is a schematic representation of the overall structure of the sandblasting equipment. Figure 2 The image shown is a front view structural diagram of the sandblasting machine body, as follows: Figure 3 The diagram shown is a top view of the sandblasting machine body, mixing device, and sandblasting pump. Figure 4 The diagram shows the arrangement of the spray pipes and nozzles in the spray disc. Figure 5 The diagram shows a flowchart of the coordinated control method for upper and lower sandblasting pressure.

[0024] like Figure 1 As shown, the sandblasting equipment includes a sandblasting machine body 1, an electrical control cabinet 2, a separation pump 3, a stirring device 4, a sandblasting pump 5, and a sedimentation tank 6. The sandblasting pump 5 includes an upper sandblasting pump and a lower sandblasting pump, which are independently configured. The upper sandblasting pump supplies sandblasting fluid to the upper sandblasting assembly within the sandblasting machine body 1, and the lower sandblasting pump supplies sandblasting fluid to the lower sandblasting assembly within the sandblasting machine body 1. The upper and lower sandblasting pumps are each driven by an independent drive motor, and their operating frequencies are adjusted by independent frequency converters.

[0025] The sandblasting machine body 1 includes a frame, a sandblasting chamber, a conveying mechanism, an upper sandblasting assembly, and a lower sandblasting assembly. The conveying mechanism is mounted on the frame and includes a conveying drive motor and multiple conveying rollers arranged sequentially along the conveying direction of the sheet metal. These multiple conveying rollers together form a conveying channel penetrating the sandblasting chamber. Figure 2 As shown, the material to be treated enters through the inlet end of the sandblasting machine body 1, passes through the sandblasting chamber along the inlet direction, and is discharged from the outlet end. The upper sandblasting assembly is located above the conveying channel, and the lower sandblasting assembly is located below the conveying channel, so as to spray sandblasting liquid toward the upper and lower surfaces of the material to be treated, respectively.

[0026] In this embodiment, the sandblasting equipment has external dimensions of 2769mm × 2800mm × 1400mm, a conveyor surface height of 1200mm, and allows for a 25mm installation adjustment. The conveyor surface width is 700mm, and the effective processing width is 620mm. The conveying speed of the conveying mechanism can be adjusted within the range of 0.5 to 5.0m / min, and can be set to 2.5m / min during normal production. The maximum applicable plate size is 510mm × 610mm, the minimum size is 300mm × 300mm, and the plate thickness ranges from 0.1 to 1.6mm. The above dimensions and operating parameters are used to illustrate the specific configuration of this embodiment. Those skilled in the art can adjust the corresponding parameters according to the specifications of the plate to be processed.

[0027] like Figure 2 and Figure 4 As shown, the upper sandblasting assembly includes two upper spray plates arranged along the material conveying direction. Each upper spray plate is equipped with seven upper spray pipes and fifty-six upper nozzles, and the two upper spray plates together have fourteen upper spray pipes and one hundred and twelve upper nozzles. The lower sandblasting assembly includes two lower spray plates arranged along the material conveying direction. Each lower spray plate is equipped with six lower spray pipes and forty-eight lower nozzles, and the two lower spray plates together have twelve lower spray pipes and ninety-six lower nozzles.

[0028] like Figure 4 As shown, taking one of the spray discs as an example, the spray disc includes a main liquid supply pipe and multiple spray nozzles connected to the main liquid supply pipe. The main liquid supply pipe is arranged along the periphery of the spray disc, and the multiple spray nozzles are parallel to each other and extend along the effective width of the conveying channel. Multiple nozzles are spaced apart along the length of each spray nozzle, so that the spray area formed by each nozzle covers the effective processing width of the material to be treated.

[0029] The nozzle can be made of wear-resistant and corrosion-resistant UPVC material. The nozzle includes a nozzle seat and a ceramic nozzle core detachably installed within the nozzle seat. The nozzle core can be a T-015 type ceramic nozzle core, and the nozzle and nozzle can be connected via a G1 / 4 thread. The spray direction of each nozzle is consistent, and the nozzle is offset by approximately 10° relative to the installation direction of its corresponding nozzle, ensuring seamless connection between the spray areas of adjacent nozzles and reducing the possibility of blank spray areas on the board surface. The quantity, materials, and installation angles described are specific configurations used in this embodiment and do not constitute a limitation on the quantity and form of the spray disc, nozzle, and nozzles.

[0030] The mixing device 4 includes a mixing tank, a mixing motor, a mixing shaft, and mixing components mounted on the mixing shaft. The mixing motor is mounted on the mixing tank and is connected to the mixing shaft for driving the mixing components to rotate, ensuring that the diamond abrasive and water added to the mixing tank are thoroughly mixed to form a blasting fluid. During the blasting process, the mixing motor continues to run to reduce changes in the concentration of the blasting fluid caused by the settling of the diamond abrasive.

[0031] like Figure 1and Figure 3 As shown, the upper and lower sandblasting pumps are arranged side-by-side on one side of the stirring device 4. The inlet ends of both pumps are connected to the stirring cylinder via suction pipes. The outlet end of the upper sandblasting pump is connected to the upper sandblasting assembly via an upper sandblasting supply pipe, and the outlet end of the lower sandblasting pump is connected to the lower sandblasting assembly via a lower sandblasting supply pipe. The upper and lower sandblasting supply pipes are independent of each other, allowing for separate adjustment of the upper and lower sandblasting pressures.

[0032] In this embodiment, the upper and lower sandblasting pumps are each driven by a fully enclosed external fan motor with a power of 11kW. The impellers, pump covers, and other components in contact with the sandblasting fluid within the pump body are made of ultra-high molecular weight polyethylene to improve wear resistance when pumping sand-containing liquids. Each of the upper and lower sandblasting pumps is connected to a frequency converter. The controller adjusts the output frequency of the corresponding frequency converter to change the rotational speed and sandblasting fluid delivery rate of the respective sandblasting pump.

[0033] An upper pressure sensor is installed on the upper sandblasting supply line, and a lower pressure sensor is installed on the lower sandblasting supply line. In this embodiment, both the upper and lower pressure sensors are diaphragm pressure gauges with upper and lower limit contacts. The gauge dial diameter is 75mm, and the detection range is 0–0.4MPa. The pressure gauges are used to display the actual pressure in the corresponding supply line on-site and output pressure status signals to the controller in electrical control cabinet 2 via the upper and lower limit contacts.

[0034] In other implementations, a pressure sensor capable of continuously outputting analog or digital pressure signals can be used, allowing the controller to directly obtain the actual pressure value of the corresponding sandblasting branch. Regardless of whether a pressure gauge or a pressure sensor is used, it should be installed between the outlet of the corresponding sandblasting pump and the inlet of the sandblasting assembly to reflect the supply pressure of the sandblasting assembly during operation.

[0035] The electrical control cabinet 2 contains a controller, a human-machine interface unit, a first frequency converter, a second frequency converter, a contactor, and a motor protector. The first frequency converter is connected to the upper sandblasting pump, and the second frequency converter is connected to the lower sandblasting pump. The controller is electrically connected to the upper pressure detection device, the lower pressure detection device, the first frequency converter, the second frequency converter, the stirring motor, and the conveying drive motor.

[0036] Operators can set the upper and lower sandblasting pressure targets separately through the human-machine interface unit. The pressure targets can be expressed as target pressure values ​​or as an allowable pressure range with upper and lower limits. The upper and lower sandblasting pressure targets can be set according to the type of sheet material, sheet thickness, surface roughening requirements, and sandblasting fluid concentration; they can be the same or different. In this embodiment, the sandblasting pressure is set within the range of 0.10–0.30 MPa, and the specific setting value is determined based on the sheet material processing requirements.

[0037] The controller also implements a start-up interlock between the stirring device 4 and the sandblasting pump 5. When the stirring motor is not running, the controller prohibits the upper and lower sandblasting pumps from starting; only after the stirring motor starts and the sandblasting liquid reaches a uniform state will the controller allow the upper and lower sandblasting pumps to operate. This reduces the possibility of diamond abrasive settling, the sandblasting pump running dry, or drawing in sandblasting liquid with uneven concentration.

[0038] The bottom of the sandblasting machine body 1 is equipped with a return liquid structure. After the sandblasting liquid is sprayed onto the plate, it flows into the return liquid structure under gravity and enters the sedimentation tank 6. The sedimentation tank 6 is used to collect the sand-water mixture returned from the sandblasting machine body 1. The inlet end of the separation pump 3 is connected to the sedimentation tank 6, and the outlet end of the separation pump 3 is connected to the sand-water separator. The sand-water separator separates the recovered sand-water mixture. The usable corundum is returned to the stirring device 4 through the sand recovery end, and the separated water is sent to the water treatment equipment through the drainage end.

[0039] The equipment can also be equipped with a sand guide cylinder. During cleaning of the mixing tank, the sand-water mixture inside the mixing tank can be switched via a valve to be transported to the sand guide cylinder by the separator pump 3 for sedimentation and filtration, thus facilitating the cleaning of the mixing tank and related pipelines. The sand guide cylinder is mainly used for sand replacement and maintenance and does not participate in the adjustment of the upper and lower sandblasting pressure under normal production conditions.

[0040] like Figure 5 As shown, the control method in this embodiment includes the following steps S1 to S6.

[0041] S1. Stir to form a sandblasting fluid and set the upper and lower sandblasting pressure targets.

[0042] Add water and corundum to the mixing tank, and start the stirring motor to continuously stir the corundum and water. In this embodiment, 75 kg of corundum can be added first, stirred evenly, and then the concentration of the sandblasting fluid can be measured. Corundum can then be gradually added according to the test results until the volume concentration of corundum in the sandblasting fluid reaches 18% to 20%. The actual amount of corundum added can be adjusted according to the amount of water in the mixing tank, the mesh size of the corundum, and the process requirements. In this embodiment, the amount added to achieve the target concentration is approximately 80 kg.

[0043] The stirring device 4 runs for about 15 minutes to ensure that the corundum is evenly dispersed in the water. The operator, according to the process requirements of the material to be treated, inputs the upper and lower sandblasting pressure targets through the human-machine interface unit, and adjusts the upper and lower limit contacts of the diaphragm pressure gauge to positions that match the corresponding allowable pressure ranges.

[0044] S2. Start the upper and lower sandblasting pumps and supply liquid to the upper and lower sandblasting components.

[0045] After the controller confirms that the stirring motor is running, it releases the start interlock of the upper and lower sandblasting pumps and controls the first and second frequency converters to start respectively. The upper sandblasting pump draws sandblasting liquid from the stirring tank and delivers it to the upper sandblasting assembly through the upper sandblasting liquid supply pipeline; the lower sandblasting pump draws sandblasting liquid from the stirring tank and delivers it to the lower sandblasting assembly through the lower sandblasting liquid supply pipeline.

[0046] In the initial startup phase, the first and second frequency converters drive the corresponding sandblasting pumps according to the preset initial frequency. After the upper and lower sandblasting liquid supply lines are filled with liquid and pressure is established, the controller enters the pressure regulation state.

[0047] S3. Convey the sheet material and simultaneously sandblast the upper and lower surfaces.

[0048] The conveyor mechanism is activated, and the sheet material to be processed is transported by... Figure 2 The plate enters the conveying channel at the feed end shown. In this embodiment, the conveying speed is set to 2.5 m / min. After the plate enters the sandblasting chamber, the upper sandblasting component sprays sandblasting liquid onto the upper surface of the plate, and the lower sandblasting component sprays sandblasting liquid onto the lower surface of the plate, so that the upper and lower surfaces of the plate are sandblasted and roughened in the same conveying process.

[0049] The upper and lower sandblasting assemblies are supplied with liquid by the upper sandblasting pump and the lower sandblasting pump, respectively. Therefore, even if the upper and lower sandblasting assemblies have different flow resistances due to differences in the number of nozzles, pipe lengths, or nozzle wear, they can be adjusted individually by the corresponding sandblasting pumps.

[0050] S4. Collect the upper and lower sandblasting pressures and compare them with the corresponding pressure targets.

[0051] During the sandblasting process, the upper pressure sensor continuously monitors the pressure in the upper sandblasting liquid supply line, and the lower pressure sensor continuously monitors the pressure in the lower sandblasting liquid supply line, and outputs detection signals to the controller respectively.

[0052] When using a diaphragm pressure gauge with upper and lower limit contacts, the controller determines whether the actual sandblasting pressure is below, within, or above the allowable pressure range based on the on / off state of the corresponding lower and upper limit contacts. When using a pressure sensor, the controller directly compares the obtained actual pressure value with the corresponding pressure target.

[0053] The controller determines the pressure status of the upper and lower sandblasting branches within the same control cycle, thereby determining whether the upper and lower sandblasting pumps need to be adjusted.

[0054] S5. Coordinate the output of the upper and lower sandblasting pumps to stabilize the sandblasting pressure.

[0055] When the sandblasting pressure is lower than the allowable range, the controller increases the output frequency of the first frequency converter, thereby increasing the speed of the sandblasting pump and the delivery volume of the sandblasting liquid; when the sandblasting pressure is higher than the allowable range, the controller decreases the output frequency of the first frequency converter; when the sandblasting pressure is within the allowable range, the controller maintains the current output frequency of the first frequency converter.

[0056] When the current sandblasting pressure is lower than the allowable range of the lower sandblasting pressure, the controller increases the output frequency of the second frequency converter, thereby increasing the speed of the lower sandblasting pump and the delivery volume of the lower sandblasting fluid; when the current sandblasting pressure is higher than the allowable range of the lower sandblasting pressure, the controller decreases the output frequency of the second frequency converter; when the current sandblasting pressure is within the allowable range, the controller maintains the current output frequency of the second frequency converter.

[0057] When the pressure of only one sandblasting branch deviates from the corresponding allowable range, the controller only adjusts the sandblasting pump corresponding to that sandblasting branch and maintains the current output of the other sandblasting pump. When both the upper and lower sandblasting pressures deviate from the corresponding allowable ranges, the controller adjusts the first and second frequency converters respectively within the same control cycle. The controller cyclically performs pressure acquisition, pressure comparison, and frequency conversion adjustment until both the upper and lower sandblasting pressures are within their respective allowable ranges.

[0058] During equipment debugging or manual operation, operators can also adjust the first and second frequency converters respectively using pressure increase and pressure decrease commands on the human-machine interface unit. The same independent frequency converter adjustment path for upper and lower sandblasting is used in both automatic and manual control modes.

[0059] As nozzles age, their orifice diameter may increase due to wear, leading to a decrease in pressure in the corresponding supply line. In this case, the operating frequency of the corresponding sandblasting pump can be increased within the inverter's rated frequency range to increase the sandblasting fluid delivery and maintain the set pressure. In this embodiment, the upper limit of the inverter's output frequency is set to 60Hz. If the pressure cannot be restored to the allowable range after the inverter reaches this upper limit, nozzle wear, missing nozzles, pipeline leaks, or blockage of the suction filter structure should be checked, and the corresponding components should be cleaned or replaced based on the inspection results. When the pressure rises abnormally, the nozzle should be checked for blockage.

[0060] S6. Recover and separate the sand-water mixture and return the sand to the mixing device.

[0061] After the sandblasting fluid is sprayed onto the upper and lower surfaces of the board, the return liquid carrying the sand enters the settling tank 6. The separation pump 3 transports the sand-water mixture in the settling tank 6 to the sand-water separator, which separates the usable corundum from the water. The separated corundum is returned to the mixing device 4 and remixed with the sandblasting fluid in the mixing tank; the separated water is transported to the water treatment equipment.

[0062] During continuous sandblasting, step S6 can be performed synchronously with steps S3 to S5, and does not necessarily have to be started only after the upper and lower sandblasting pressures have been adjusted. Figure 5 Step S6 is arranged after step S5 to represent the complete flow path of the sandblasting fluid from spraying, recirculation, separation to reuse.

[0063] Through the aforementioned structure and control method, the upper and lower sandblasting pumps employ independent liquid supply pipelines and frequency conversion adjustment paths. The controller simultaneously determines the upper and lower sandblasting pressure status within the same control cycle and adjusts the corresponding sandblasting pumps accordingly, ensuring that both upper and lower sandblasting pressures remain within their respective process requirements. This approach can accommodate differences in the number of nozzles, spray pipes, and flow resistance between the upper and lower sandblasting components. Furthermore, it allows for independent adjustment of the corresponding sandblasting branches when pressure changes occur due to nozzle wear or partial blockage, thereby improving the consistency of sandblasting treatment on the upper and lower surfaces of the sheet metal.

[0064] Example 2 This embodiment further improves the coordinated adjustment process of upper and lower sandblasting pressure in step S5. Utilizing the existing upper and lower sandblasting pressures and the operating frequencies of the two sandblasting pumps 5, the pressure response characteristics of each of the upper and lower sandblasting branches are determined online, and the frequency adjustment amount of the two sandblasting pumps 5 is determined based on the upper and lower pressure deviation and the upper and lower pressure difference deviation.

[0065] The control method for a sandblasting device based on coordinated control of upper and lower sandblasting pressure provided in this embodiment includes the following steps S1 to S6.

[0066] S1, control the operation of the stirring device 4 to mix the abrasive and water to form a sandblasting fluid, and set the upper sandblasting target pressure and the lower sandblasting target pressure respectively.

[0067] S2, after the stirring device 4 meets the preset stirring conditions, the sandblasting pump 5 connected to the upper sandblasting assembly and the sandblasting pump 5 connected to the lower sandblasting assembly are started to deliver sandblasting liquid to the upper sandblasting assembly and the lower sandblasting assembly respectively.

[0068] S3, the plate to be treated is conveyed by the conveying mechanism in the sandblasting machine body 1, and the upper sandblasting component and the lower sandblasting component spray sandblasting liquid onto the upper and lower surfaces of the plate respectively.

[0069] S4: Collect the upper sandblasting pressure and the lower sandblasting pressure respectively, compare the upper sandblasting pressure with the upper sandblasting target pressure, and compare the lower sandblasting pressure with the lower sandblasting target pressure.

[0070] S5, based on the upper sandblasting pressure, lower sandblasting pressure and the operating frequency of the two sandblasting pumps 5, the pressure response characteristics of the upper and lower sandblasting branches are determined online, the predicted compensation requirements of the upper and lower sandblasting pressures are formed, and the frequency adjustment amount of the two sandblasting pumps 5 is determined collaboratively based on the pressure response characteristics and the predicted compensation requirements; step S5 includes the following steps S51 to S53.

[0071] S51, obtain the upper sandblasting pressure sequence, lower sandblasting pressure sequence, upper sandblasting pump operating frequency sequence, and lower sandblasting pump operating frequency sequence according to the sampling time sequence. Time-align the corresponding pressure sequence and operating frequency sequence according to the pressure response lag of each sandblasting branch, and determine the pressure response coefficients of the upper and lower sandblasting branches respectively, formula (1):

[0072] In the formula, i=u represents the upper sandblasting branch, i=l represents the lower sandblasting branch; k represents the sampling point number corresponding to the current control calculation time; n represents the sampling point traversal sequence number within the pressure response recognition time window; M represents the number of valid sampling points within the pressure response recognition time window; P i (n) represents the sandblasting pressure of the i-th sandblasting branch at the n-th sampling point, in MPa; f i (n i ) indicates that the i-th sandblasting branch is in the n-th... i The operating frequency of the sandblasting pump at each sampling point is expressed in Hz. i n represents the number of pressure response hysteresis points in the i-th sandblasting branch, which is a non-negative integer; i Indicates the frequency sampling point number that is time-aligned with the nth pressure sample value; This represents the arithmetic mean of the operating frequencies of the i-th sandblasting branch within the current pressure response identification time window, after time alignment, in Hz. K represents the arithmetic mean of the sandblasting pressure of the i-th sandblasting branch within the current pressure response identification time window, in MPa. i (k) represents the pressure response coefficient of the i-th sandblasting branch determined at the current control operation time, with units of MPa / Hz, used to characterize the sandblasting pressure change caused by the unit frequency change of the corresponding sandblasting pump.

[0073] S52, based on the target pressure of upper sandblasting, the target pressure of lower sandblasting, the current upper and lower sandblasting pressures, and the recent trends in the changes of upper and lower sandblasting pressures, determine the pressure coordination demand vector composed of the upper pressure prediction compensation, the lower pressure prediction compensation, and the upper and lower pressure difference prediction compensation, formula (2):

[0074] D(k) represents the pressure coordination demand vector at the current control operation moment; Indicates the target pressure for sandblasting. This indicates the target pressure for sandblasting, with units of MPa. Indicates setting a target value; P u (k) and P l (k) represents the upper and lower sandblasting pressures at the current sampling point, respectively, in MPa; P u (k q) and P l (k q) represents the upper and lower sandblasting pressures at the q-th sampling point before the current sampling point, respectively, in MPa; T s The pressure sampling period is represented in seconds (s); q represents the number of sampling intervals used to determine the pressure change trend, and is a positive integer; qT s T represents the time interval corresponding to the trend of pressure change, in seconds (s). h This represents the time domain for pressure prediction, in seconds; D u (k) represents the predicted compensation amount for the upper pressure after considering the current pressure change trend; D l (k) represents the predicted downpressure compensation amount after considering the current pressure change trend; D Δ (k) represents the predicted compensation amount for the pressure difference after considering the trend of pressure change. The unit of all three is MPa.

[0075] S53, based on the pressure response coefficients and pressure coordination demand vectors of the upper and lower sandblasting branches, and under the constraints of the allowable operating frequency of sandblasting pump 5, the allowable frequency change in a single control cycle, and the pressure adjustment direction, the target frequency adjustment amount of the upper and lower sandblasting pumps is determined, formula (3):

[0076] Δf u and Δf l These represent the candidate frequency adjustment amounts for the upper and lower sandblasting pumps used in the solution process, respectively, in Hz; and These represent the optimal frequency adjustment values ​​for the upper and lower sandblasting pumps, respectively, obtained at the current control operation moment, in Hz. Δ represents the optimal result that minimizes the objective function; Δ represents the increment relative to the current operating frequency of the sandblasting pump, with a positive value indicating an increase in the operating frequency and a negative value indicating a decrease in the operating frequency; Ω(k) represents the set of candidate frequency adjustment quantities allowed at the current control operation moment, which is jointly limited by the minimum effective operating frequency, the maximum allowable operating frequency, the allowable frequency change in a single control cycle, and the direction of frequency adjustment of the sandblasting pump; η represents the upper and lower pressure difference coordination coefficient, which is a dimensionless non-negative parameter; argmin represents the combination of frequency adjustment quantities selected from the candidate frequency adjustment quantity set Ω(k) that minimizes the subsequent objective function; the quantities in the square brackets in formula (3) are all predicted pressure deviations, in MPa, and the units of all terms in the objective function are MPa. 2 .

[0077] S6: The sand-water mixture discharged from the sandblasting machine body 1 is collected and transported to the sand-water separation position by the separation pump 3. The usable abrasive is returned to the stirring device 4, and the separated water is discharged into the water treatment equipment. Step S6 can be performed continuously during the execution of steps S3 to S5.

[0078] In this embodiment, the controller in the electrical control cabinet 2 is connected to the upper sandblasting pressure detection device, the lower sandblasting pressure detection device, and the frequency converters corresponding to the two sandblasting pumps 5. The upper and lower sandblasting pressure detection devices are designed to output pressure values ​​to the controller, and their pressure detection range is 0 to 0.4 MPa.

[0079] The controller obtains the upper and lower sandblasting pressures through an analog input interface or a communication interface, acquires the actual operating frequency of the two sandblasting pumps 5 through the inverter's operating status register, and outputs frequency commands to the two inverters respectively through the communication interface or frequency setting interface. The human-machine interface is used to input the upper sandblasting target pressure, lower sandblasting target pressure, allowable pressure deviation, allowable pressure difference deviation, upper frequency limit, and single-cycle frequency change.

[0080] The controller is equipped with data acquisition, data preprocessing, online pressure response identification, pressure coordination demand calculation, frequency regulation calculation, and pressure response anomaly detection functions. All of these functions are implemented through the controller program, eliminating the need for additional independent computing equipment.

[0081] This embodiment employs two independent branch pressure response models. The input data forms a data matrix of size M×4 within an identification time window, where the four fields are, in order, the upper sandblasting pressure, the lower sandblasting pressure, the upper sandblasting pump operating frequency, and the lower sandblasting pump operating frequency; the online identification result is two-dimensional data composed of two pressure response coefficients; the pressure coordination requirement is three-dimensional data; and the final output is the two-dimensional frequency adjustment of the two sandblasting pumps 5.

[0082] In one specific setting of this embodiment, the pressure sampling frequency is 10Hz, and the pressure data resolution is 0.001MPa; the operating frequency sampling frequency is 10Hz, and the operating frequency data resolution is 0.1Hz. The controller executes complete steps S51 to S53 once every 1 second.

[0083] The target pressures for upper and lower sandblasting are set within the range of 0.10–0.30 MPa, depending on the process requirements of the material to be treated. The two target pressures can be the same or different. Therefore, the pressure difference between the upper and lower targets is not limited to zero.

[0084] During the sampling process, the controller handles abnormal data in the following manner: Pressure data exceeding 0–0.4 MPa and frequency data exceeding the inverter's allowable range are marked as invalid data; When the change in adjacent pressure sampling values ​​exceeds 0.02 MPa, and the trend is not confirmed in the next two consecutive sampling values, the corresponding sampling value will be removed as an isolated outlier. Five-point median processing is performed on the pressure data to reduce sandblasting fluid pulsation and electrical signal interference; When no more than two consecutive sampling points are missing, the most recent valid sampling value is used to fill in the missing points; when more than three consecutive sampling points are missing, the pressure response coefficient of the corresponding branch is paused from being updated. When the time stamp deviation between the upper and lower pressure data and the frequency data exceeds 50ms, resampling and alignment are performed according to the time stamp. Within the first 3 seconds after the sandblasting pump 5 starts, online identification is not performed, and the initial pressure build-up is completed using the pressure range control method of Example 1.

[0085] Preferably, the identification time window includes 40 to 100 sampling points. This embodiment uses 60 sampling points, corresponding to an identification time of 6 seconds. The pressure response coefficient is updated only when there are at least three different effective operating frequencies within the identification time window, and the difference between the maximum and minimum operating frequencies is not less than 0.5 Hz. This directly eliminates time windows where the operating frequency does not change, and there is no need to artificially add a constant to the denominator of formula (1).

[0086] After the stirring device 4 is started and runs for about 15 minutes to stabilize the sandblasting liquid concentration at 18% to 20%, the two sandblasting pumps 5 start running respectively. The controller acquires the upper and lower sandblasting pressures and corresponding operating frequencies, and aligns the pressure data with the frequency data according to the pressure response hysteresis of each sandblasting branch.

[0087] The pressure response hysteresis can be determined during the equipment commissioning phase. Specifically, a frequency change of 0.5–1.0 Hz is applied to a sandblasting pump 5, and the time elapsed from the change in frequency command to the pressure change reaching 10% of the final pressure change is recorded. This time is then converted into the number of sampling points. The pressure response hysteresis is determined separately for the upper and lower sandblasting branches, and they do not need to be the same.

[0088] The sandblasting pump 5 is a centrifugal conveying device, and its head changes nonlinearly with the rotational speed. However, within the local working range formed by adjacent operating frequencies, the pressure change caused by the frequency change can be represented by the local response slope of pressure to frequency. Formula (1) obtains the current pressure response coefficient of the corresponding sandblasting branch by identifying the correlation between frequency change and hysteretic pressure change within the time window.

[0089] When nozzles wear down, pipelines leak, or inlet filtration resistance increases, the effective pressure increment generated by the same frequency increment usually decreases, and the identified pressure response coefficient decreases accordingly. When some nozzles become clogged, leading to increased flow resistance in the branch, the pressure response coefficient, or the pressure value corresponding to the same operating frequency, may increase. Therefore, the pressure response coefficient can reflect the current comprehensive hydraulic response state of the sandblasting branch.

[0090] The corresponding branch model will only be updated if the calculated pressure response coefficient is positive, falls within the effective range determined during the equipment commissioning phase, and the direction of pressure change obtained using this pressure response coefficient is consistent with the actual direction of pressure change. Otherwise, the previous effective pressure response coefficient will be retained, and the current identification status will be marked as invalid.

[0091] The controller forms a pressure coordination demand vector using formula (2) based on the current upper and lower sandblasting pressures obtained in step S4, the upper and lower sandblasting target pressures set in step S1, and the recent pressure change trend.

[0092] Among them, the upper pressure prediction compensation amount is used to represent the pressure that the upper sandblasting branch still needs to compensate at the end of the prediction time domain after considering the current upper sandblasting pressure change trend; the lower pressure prediction compensation amount is used to represent the pressure that the lower sandblasting branch still needs to compensate; the upper and lower pressure difference prediction compensation amount is used to represent the difference that still needs to be corrected between the upper and lower sandblasting pressures after considering the pressure change trends of the two branches.

[0093] When the sandblasting pressure on one side is rapidly approaching the corresponding target pressure, the pressure trend term reduces the predictive compensation on that side, causing the controller to reduce the frequency rise before the pressure reaches the target value, thereby suppressing pressure overshoot. When the sandblasting pressure on one side is moving away from the corresponding target pressure, the pressure trend term increases the predictive compensation, thereby improving the adjustment speed of the corresponding branch.

[0094] In this embodiment, the pressure change trend interval is 0.5–2 s, and the pressure prediction time domain is 0.5–1.5 s. Preferably, both the pressure change trend interval and the pressure prediction time domain are set to 1 s.

[0095] Optionally, the allowable deviations of the upper and lower sandblasting pressures are set to ±0.003 to ±0.005 MPa, and the allowable deviation of the upper and lower sandblasting pressure difference is set to ±0.003 to ±0.005 MPa. When both the upper and lower sandblasting pressures and the pressure difference are within their respective allowable ranges, the pressure coordination requirement for this control cycle is set to a hold state, and no new frequency adjustment is generated.

[0096] The controller uses the two pressure response coefficients obtained in step S51 as the current pressure conversion parameters of the sandblasting branch, and the three pressure compensation quantities obtained in step S52 as the current control targets. The target frequency adjustment of the two sandblasting pumps 5 is obtained by formula (3).

[0097] The first two terms of formula (3) are used to make the predicted pressure changes of the upper and lower sandblasting branches close to their respective predicted compensation amounts, and the third term is used to make the difference in the predicted pressure changes of the two branches close to the predicted compensation amount of the upper and lower pressure difference. The upper and lower pressure difference coordination coefficient is preferably set to 0.5 to 2.0. In this embodiment, it is set to 1.0. Only one coordination coefficient is used to avoid multiple empirical weights from having an unclear impact on the control results.

[0098] The set of allowed frequency adjustment values ​​must include at least the following constraints: The adjusted operating frequency shall not be lower than the minimum effective operating frequency determined during equipment commissioning; The adjusted operating frequency shall not exceed the allowable frequency of the sandblasting pump 5 and the corresponding strain gauge, wherein the highest operating frequency shall not exceed 60Hz. The frequency variation in a single control cycle shall not exceed 0.5–2.0 Hz; Under normal adjustment conditions, the direction of frequency change is consistent with the predicted compensation direction of the corresponding branch, preventing the branch that has reached the target pressure from deviating from its target pressure in the opposite direction in order to correct the pressure difference. When the corresponding sandblasting branch is within the allowable pressure range and does not cause the pressure difference to exceed the limit, the frequency adjustment of the branch remains zero.

[0099] In an implementation method that is easy for PLC controllers to execute, the allowed frequency adjustment is discretized with a resolution of 0.1Hz. If the allowable adjustment range per cycle is -2.0 to 2.0Hz, then each sandblasting branch has 41 candidate frequency adjustment values. The controller calculates the result of each candidate combination in formula (3) in turn, and selects the candidate combination with the smallest result as the target frequency adjustment value. When there are multiple identical results, the combination with the smaller sum of the absolute values ​​of the two frequency adjustment values ​​is selected first. This method compares a maximum of 1681 combinations per control cycle, which can be completed by an existing controller within a 1s control cycle.

[0100] After the target frequency adjustment is sent to the two frequency converters, the frequency converters correspondingly change the operating frequency of the sandblasting pump 5, thereby changing the liquid supply pressure of the upper and lower sandblasting components. The controller re-executes steps S4 and S51 to S53 in the next control cycle. When the upper and lower sandblasting pressures and the pressure difference between them are within the allowable range for three consecutive control cycles, the current operating frequency is maintained.

[0101] This embodiment uses a deterministic online identification model. After the equipment is first debugged, the nozzle is replaced, or the pipeline is cleaned, the upper and lower sandblasting branches are initially calibrated.

[0102] During initial calibration, run the stirring device 4 for about 15 minutes and maintain the sandblasting fluid concentration at 18%–20%. Within the safe operating range of the sandblasting pump 5, set five frequency points sequentially: 35Hz, 40Hz, 45Hz, 50Hz, and 55Hz. Hold each frequency point for 8 seconds, discarding the transition data of the first 3 seconds and retaining the pressure data of the last 5 seconds.

[0103] Preferably, three sets of calibration processes are performed consecutively. The first two sets of data are used to determine the initial pressure response coefficient, pressure response hysteresis, and effective coefficient range, while the third set of data is used for verification. Using the pressure detection value as the verification benchmark, when the relative deviation between the predicted pressure change and the actual pressure change does not exceed 10%, the initial pressure response coefficient, pressure response hysteresis, and effective coefficient range are written into the controller's non-volatile storage area; when the verification deviation exceeds 10%, the nozzle, filter position, pipeline seal, and pressure detection status are checked before recalibration.

[0104] After the equipment is running normally, step S51 updates the pressure response coefficient using the most recent valid data in the identification time window, so that the model can adapt to the slow wear of the nozzle and changes in the state of the sandblasting fluid. If there is no valid frequency change in the identification time window, the most recent valid pressure response coefficient is retained, and no frequency disturbance for identification is actively added to the sandblasting pump 5.

[0105] The controller compares the pressure change predicted by formula (3) with the actual pressure change detected after frequency modulation. When the single effective frequency change is not less than 0.5 Hz, and the actual pressure change is less than 30% of the predicted pressure change for three consecutive control cycles, or the actual pressure change direction is opposite to the predicted direction for three consecutive control cycles, the corresponding sandblasting branch is marked as having an abnormal pressure response.

[0106] The frequency increase will be paused and a maintenance prompt will be displayed if any of the following occurs: The optimal frequency adjustment given by formula (3) is constrained by the upper limit of 60Hz frequency for three consecutive control cycles, and the corresponding sandblasting pressure is still below the allowable range. After the frequency of the sandblasting pump 5 was increased, the corresponding pressure response coefficient continued to decrease, and the sandblasting pressure could not be restored. The actual pressure changes and the predicted pressure changes were inconsistent for several consecutive control cycles. Pressure or frequency data is missing for more than the set time.

[0107] When the pressure response coefficient decreases and the sandblasting pressure is low, the controller prompts to check for nozzle wear, missing nozzles, pipeline leaks, or blockage at the inlet filter. When the pressure response coefficient increases significantly and the sandblasting pressure is high, the controller prompts to check for blockage in the nozzle or spray pipe. These prompts are intended to narrow down the scope of maintenance checks, preventing pressure abnormalities from being solely attributed to a single fault.

[0108] When the pressure response coefficient of one branch is invalid, that branch temporarily adopts the independent pressure range adjustment method of Example 1, while the other branch can still be adjusted according to its effective pressure response coefficient, and the pressure difference coordination term is suspended. When the pressure data on both sides is invalid, the most recent safe operating frequency is maintained; if the pressure data is continuously invalid for more than 1 second, a pressure detection abnormality information is output, and the conveying of the plate can be optionally suspended.

Claims

1. A sandblasting device based on coordinated control of upper and lower sandblasting pressure, characterized in that, include: It includes the sandblasting machine body (1), the mixing device (4), the sandblasting pump (5), the pressure detection component, and the control component; The sandblasting machine body (1) includes a conveying mechanism, an upper sandblasting assembly and a lower sandblasting assembly. The conveying mechanism forms a conveying channel for the plate to be processed to pass through. The upper sandblasting assembly and the lower sandblasting assembly are respectively arranged on the upper and lower sides of the conveying channel. The sandblasting pump (5) includes an upper sandblasting pump and a lower sandblasting pump. The upper sandblasting pump is connected between the stirring device (4) and the upper sandblasting assembly, and the lower sandblasting pump is connected between the stirring device (4) and the lower sandblasting assembly. The pressure detection assembly includes an upper pressure detection component for detecting the hydraulic pressure of the upper sandblasting supply and a lower pressure detection component for detecting the hydraulic pressure of the lower sandblasting supply. The control component is connected to the upper pressure detection element, the lower pressure detection element, the upper sandblasting pump, and the lower sandblasting pump, respectively, for acquiring the upper sandblasting pressure detection results and the lower sandblasting pressure detection results, comparing the upper sandblasting pressure detection results and the lower sandblasting pressure detection results with the corresponding preset pressure targets, determining the pressure regulation state of the upper sandblasting branch and the lower sandblasting branch, and controlling the output of the upper sandblasting pump and the lower sandblasting pump respectively according to the pressure regulation state, so that the upper sandblasting pressure and the lower sandblasting pressure are maintained within the corresponding allowable range.

2. A sandblasting device based on coordinated control of upper and lower sandblasting pressure according to claim 1, characterized in that, The control component is located in the electrical control cabinet (2). The control component includes a controller, a human-machine interface unit, a first frequency converter connected to the upper sandblasting pump, and a second frequency converter connected to the lower sandblasting pump. The human-machine interface unit is used to set the pressure targets of the upper sandblasting branch and the lower sandblasting branch respectively. The controller adjusts the operating status of the upper sandblasting pump and the lower sandblasting pump respectively through the first frequency converter and the second frequency converter.

3. A sandblasting device based on coordinated control of upper and lower sandblasting pressure according to claim 2, characterized in that, The upper pressure detection device is installed on the upper sandblasting liquid supply pipeline between the upper sandblasting pump and the upper sandblasting assembly, and the lower pressure detection device is installed on the lower sandblasting liquid supply pipeline between the lower sandblasting pump and the lower sandblasting assembly; both the upper pressure detection device and the lower pressure detection device have a pressure signal output terminal, and the output pressure detection signal includes a signal representing the actual pressure value or a status signal representing the relationship between the actual pressure and the preset pressure limit.

4. A sandblasting device based on coordinated control of upper and lower sandblasting pressure according to claim 3, characterized in that, Both the upper sandblasting assembly and the lower sandblasting assembly include at least one spray disc. The spray disc includes a liquid supply main pipe, multiple spray pipes connected to the liquid supply main pipe, and multiple nozzles spaced apart along the spray pipes.

5. A sandblasting device based on coordinated control of upper and lower sandblasting pressure according to claim 4, characterized in that, Multiple spray pipes are arranged at intervals along the conveying direction of the plate and extend along the width direction of the conveying channel, and multiple nozzles are distributed along the length direction of the corresponding spray pipes; the nozzles of the upper sandblasting assembly face the upper surface of the plate to be treated, and the nozzles of the lower sandblasting assembly face the lower surface of the plate to be treated, so that the spraying area formed by the nozzles covers the effective processing width of the plate to be treated.

6. A sandblasting device based on coordinated control of upper and lower sandblasting pressure according to claim 5, characterized in that, The mixing device (4) includes a mixing cylinder, a mixing drive and a mixing component disposed in the mixing cylinder. The mixing drive is used to drive the mixing component to mix sand and water to form a sandblasting liquid. The control component is also connected to the stirring drive and is configured to allow the upper and lower sandblasting pumps to start after the stirring drive is in operation.

7. A sandblasting device based on coordinated control of upper and lower sandblasting pressure according to claim 6, characterized in that, It also includes a separation pump (3), a sedimentation tank (6) and a sand-water separator. The sedimentation tank (6) is connected to the return end of the sandblasting machine body (1). The inlet end of the separation pump (3) is connected to the sedimentation tank (6). The outlet end of the separation pump (3) is connected to the sand-water separator. The sand recovery end of the sand-water separator is connected to the stirring device (4).

8. A control method for a sandblasting equipment based on coordinated control of upper and lower sandblasting pressure, characterized in that, The method, applied to the sandblasting equipment based on coordinated control of upper and lower sandblasting pressure as described in any one of claims 1 to 7, comprises: S1. Start the mixing device to mix the sand and water to form a sandblasting liquid, and determine the upper sandblasting pressure target and lower sandblasting pressure target according to the sandblasting process requirements of the board to be treated. S2. After the stirring device is in operation, start the upper sandblasting pump and the lower sandblasting pump to deliver the sandblasting liquid to the upper sandblasting assembly and the lower sandblasting assembly respectively. S3. The plate to be processed is conveyed through the upper sandblasting assembly and the lower sandblasting assembly, and the upper and lower surfaces of the plate to be processed are sandblasted respectively. S4. Obtain the upper sandblasting pressure detection result and the lower sandblasting pressure detection result, and compare the upper sandblasting pressure detection result and the lower sandblasting pressure detection result with the corresponding sandblasting pressure target respectively; S5. Based on the upper sandblasting pressure detection results and the lower sandblasting pressure detection results, determine the pressure regulation status of the upper sandblasting branch and the lower sandblasting branch respectively, and adjust the output of the upper sandblasting pump and the lower sandblasting pump respectively so that the upper sandblasting pressure and the lower sandblasting pressure are maintained within the corresponding allowable range.

9. A control method for a sandblasting equipment based on coordinated control of upper and lower sandblasting pressure according to claim 8, characterized in that, In step S5: When the pressure of any sandblasting branch is lower than the corresponding allowable range, increase the output of the sandblasting pump corresponding to that sandblasting branch. When the pressure in any sandblasting branch exceeds the corresponding allowable range, reduce the output of the sandblasting pump corresponding to that sandblasting branch. When the pressure of any sandblasting branch is within the corresponding allowable range, maintain the current output of the sandblasting pump corresponding to that sandblasting branch; When both the upper sandblasting branch and the lower sandblasting branch require pressure adjustment, the upper sandblasting pump and the lower sandblasting pump are adjusted respectively within the same control cycle.

10. A control method for a sandblasting equipment based on coordinated control of upper and lower sandblasting pressure according to claim 9, characterized in that, The process after step S5 also includes: S6. The sand-water mixture returned after sandblasting is introduced into a sedimentation tank, and the sand-water mixture is transported to a sand-water separator by a separation pump. The sand obtained by the sand-water separator is then transported back to the stirring device.

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