A piezoelectric injection valve, a piezoelectric injection valve device and a self-cleaning control method thereof

Abstract

The application provides a piezoelectric jet valve, a piezoelectric jet valve device and a self-cleaning control method thereof, which comprises a jet valve body, a drop detection assembly and a lifting mechanism, the jet valve body comprises a nozzle, the drop detection assembly is movably arranged on one side of the nozzle through the lifting mechanism; the drop detection assembly comprises a first mounting seat and a detection sensor, the first mounting seat is provided with a detection through slot for the jet fluid of the nozzle to pass through, the detection sensor is installed on the side wall of the detection through slot and is used for detecting the jet drop state of the nozzle; the lifting mechanism is fixed on one side surface of the jet valve body and is used for adjusting the relative position of the drop detection assembly and the nozzle along the jet direction of the nozzle. The application provides a novel piezoelectric jet valve, a piezoelectric jet valve device and a self-cleaning control method thereof, realizes real-time and accurate monitoring of the jet state of the nozzle, intelligent identification of abnormal working conditions and automatic cleaning closed-loop control of the nozzle based on the detection result.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of piezoelectric jet valves, in particular to a piezoelectric jet valve, a piezoelectric jet valve device and a self-cleaning control method thereof. BACKGROUND

[0002] As a high-precision fluid control device, piezoelectric jet valves are widely used in microelectronic packaging, LED manufacturing, biomedical treatment, precision dispensing and other fields. The core advantage is that it can realize non-contact, high-frequency and high-precision micro-fluid jetting, meeting the growing demand for precision manufacturing in modern industry.

[0003] However, the existing piezoelectric jet valve device still faces some technical challenges in actual application. For example, patent No. CN214599895U discloses a piezoelectric jet valve convenient to adjust. Although the position of the nozzle is adjusted by motor-driven gear transmission, the structure design does not include nozzle state monitoring and active cleaning module, and it cannot cope with the problem of nozzle function decay after long-term work. For another example, patent No. CN219273530U discloses a side dispensing and wiping device. Although an automatic wiping mechanism composed of a cloth feeding reel, a cloth collecting reel and a wiping wheel is adopted, the cleaning trigger depends on a preset program, and lacks dynamic linkage with the real-time state of the nozzle, making it difficult to achieve targeted cleaning.

[0004] Specifically, the current technical problems are concentrated in three dimensions: first, nozzle clogging risk. When working at high frequency or for a long time, the nozzle port may be blocked by solidified fluid or dust adsorption, causing jetting precision to decay or even product defects; second, jetting abnormal phenomenon. Influenced by fluid characteristics, environment and parameter fluctuations, the nozzle may produce unexpected droplets and filaments, polluting the workpiece and interfering with subsequent processes; third, the monitoring and cleaning system is disconnected. Traditional detection methods have poor real-time performance, and even if there is an automatic cleaning function, the lack of closed-loop linkage leads to delayed response and low efficiency, making it difficult to meet the continuous operation needs of the automatic production line. SUMMARY

[0005] The purpose of the present application is to provide a piezoelectric jet valve, a piezoelectric jet valve device and a self-cleaning control method thereof to solve the above technical problems.

[0006] The first aspect provides a piezoelectric jet valve, which comprises a jet valve body, a droplet detection assembly and a lifting mechanism, wherein:

[0007] The jet valve body comprises a nozzle;

[0008] The drop detection assembly is movably arranged on one side of the nozzle by a lifting mechanism, and includes a first mounting seat and a detection sensor.

[0009] The lifting mechanism is fixed to one side of the injection valve body and is used to adjust the relative position of the drop detection assembly and the nozzle along the injection direction of the nozzle.

[0010] In the above technical solution, the drop detection assembly is integrated with the piezoelectric injection valve body, and the relative position is adjusted by the lifting mechanism, which solves the problems of low detection precision and inability to provide real-time feedback in the traditional drop detection, and provides position adjustment capability for subsequent automatic cleaning.

[0011] Further, the detection sensor is an optical fiber sensor or a laser sensor. By using high-precision optical fiber sensors or laser sensors, the detection sensitivity and reliability are improved, and the product failure rate caused by delayed detection is reduced.

[0012] Further, the optical fiber sensor is provided with a plurality of optical fibers arranged in an array. The array of optical fibers expands the detection range, reduces the detection blind area, and improves the capture ability of irregular drops or filaments.

[0013] Further, the first mounting seat is provided with a detection channel, and the side wall of the detection channel is provided with a detection port for mounting the detection sensor. A glass sheet is mounted in front of the detection port. The glass sheet effectively isolates the detection sensor from the injected glue or liquid, preventing the sensor from being contaminated, thereby prolonging its service life, reducing maintenance costs, and ensuring long-term stability and accuracy of detection.

[0014] Further, the housing of the first mounting seat is made of aluminum, and the cavity around the detection sensor is filled with thermal insulation material. The lightweight aluminum housing reduces the load of the device, and the thermal insulation material reduces the influence of environmental temperature on the sensor, ensuring detection stability.

[0015] Further, the lifting mechanism includes a sliding block mounting seat, a guide column, a spring, a stroke adjuster and a second mounting seat. The sliding block mounting seat and the spring are sleeved on the guide column, the guide column and the stroke adjuster are respectively mounted on the upper and lower ends of the second mounting seat, the spring is located on the side of the sliding block mounting seat away from the stroke adjuster, and the acting forces of the spring and the stroke adjuster are parallel to the moving direction of the sliding block mounting seat. The cooperation of the guide column and the spring realizes the stable movement of the sliding block mounting seat, realizes the passive or automatic adjustment of the lifting mechanism, the stroke adjuster ensures the accuracy of position adjustment, and improves the position adaptability of the drop detection assembly.

[0016] Further, the second mounting seat is fixed with a sliding rail, and the sliding block mounting seat is provided with a protrusion matched with the sliding rail. The cooperation of the sliding rail and the protrusion effectively limits the lateral shaking of the sliding block mounting seat, ensures the stability and vertical precision of the droplet detection assembly during lifting, and avoids false detection caused by shaking.

[0017] Further, the stroke adjuster includes an adjusting column and a locking nut, and the adjusting column is movably fixed to the lower end of the second mounting seat through the locking nut. The stroke adjuster structure can manually or automatically accurately set the lower limit position of the droplet detection assembly by adjusting the relative position of the locking nut and the adjusting column, and provides flexible and high-precision position calibration capability.

[0018] Further, the droplet detection assembly further includes a microcontroller arranged in the first mounting seat, and an indicator lamp and a communication line electrically connected with the microcontroller, and the microcontroller is electrically connected with the detection sensor. Integrating the microcontroller into the droplet detection assembly realizes local processing and preliminary judgment of the optical signal, reduces the burden of the main control system, and improves the response speed and reliability of the system.

[0019] The second aspect provides a piezoelectric jet valve device, which includes a wiping mechanism, a control system, a three-axis displacement platform, and the piezoelectric jet valve described in the first aspect, and the control system is in communication connection with the piezoelectric jet valve, the wiping mechanism and the three-axis displacement platform, wherein:

[0020] The wiping mechanism includes a driving wheel, a driven wheel, a wiping block and a wiping cloth, both ends of the wiping cloth are wound around the outer periphery of the driven wheel and the driving wheel, and the middle section of the wiping cloth passes through the wiping block, and the wiping block is higher than the wiping port.

[0021] In the above technical solution, the cooperation of multiple components realizes integrated control from droplet detection to automatic cleaning, and improves the rapid response capability of the device to jetting abnormalities.

[0022] Further, guide shafts are installed on both sides of the wiping block, and the guide shafts are used to make the wiping cloth move in a "W" type trajectory in the wiping port. The "W" type trajectory makes the protruding wiping cloth contact the nozzle, and realizes automatic cleaning operation of the nozzle.

[0023] The third aspect provides a self-cleaning control method of a piezoelectric jet valve device, which uses the piezoelectric jet valve device described in the second aspect to realize self-cleaning of the nozzle of the piezoelectric jet valve, and the control method comprises the following steps:

[0024] S1, in response to the control system obtaining an abnormal alarm signal sent from the droplet detection assembly, the three-axis displacement platform is controlled to move the piezoelectric jet valve to a corresponding cleaning station of the wiping mechanism;

[0025] S2, control the wiping mechanism to start the cleaning operation, drive the wiping cloth to circulate through the driving wheel, and use the wiping block to cooperate with the wiping cloth to perform the cleaning operation on the nozzle;

[0026] S3, after the cleaning operation is completed, the three-axis displacement platform is controlled to reset the piezoelectric jet valve to the working station, and the cleaning state information is updated.

[0027] In the above technical solution, the whole process automation from abnormality detection to automatic cleaning is realized through the closed-loop control process, manual intervention is reduced, and production continuity is improved.

[0028] Further, the abnormal alarm signal is generated by the microcontroller of the drop detection assembly, and the microcontroller distinguishes the jetting state of the nozzle by setting different time thresholds:

[0029] When the nozzle is normally jetted, the duration of the light signal blocked by the detection sensor is between the first threshold and the second threshold; when the nozzle has a drop or a string phenomenon, the duration of the light signal blocked is less than the first threshold; when the nozzle is blocked, the duration of the light signal blocked is greater than the second threshold, wherein the first threshold is less than the second threshold.

[0030] In the above technical solution, different jetting states are distinguished by time thresholds, accurate judgment of abnormal types is realized, basis for targeted cleaning is provided, and the accuracy of abnormal processing is improved.

[0031] Compared with the prior art, the beneficial results of the present application are:

[0032] (1) The present application uses an optical fiber sensor or a laser sensor as a detection core, which has high sensitivity and high speed response characteristics to accurately capture micron-level drop or string phenomena, and performs real-time data analysis and state judgment through a microcontroller. This integrated detection scheme fundamentally solves the shortcomings of traditional detection methods, realizes all-weather and high-reliability monitoring during the jetting operation, and significantly improves the product yield.

[0033] (2) The present application constructs an integrated detection and adjustment system. By movably configuring the drop detection assembly on one side of the nozzle through the lifting mechanism, combining the design of the detection groove and the array sensor, real-time and accurate monitoring of the jetting drop state of the nozzle is realized, solving the problems of large detection blind area and insufficient sensitivity of traditional equipment; at the same time, the lifting mechanism realizes fine adjustment of the detection position through guide columns, stroke adjusters and other structures, which can adapt to different viscosity fluids and different jetting frequency working conditions, significantly improving the working condition adaptability of the equipment.

[0034] (3), the application controls the piezoelectric jet valve, the three-axis displacement platform and the wiping mechanism through the control system, when the droplet detection assembly identifies that the nozzle is abnormal (such as droplet, wire drawing, blockage), the automatic cleaning process can be triggered, the nozzle is moved to the wiping mechanism by the three-axis displacement platform, the wiping cloth and the soft wiping block are matched to complete the targeted cleaning through the "W" type movement, the defects that the detection and cleaning are disconnected and rely on manual intervention in the prior art are overcome, and the automation level and production continuity of the equipment are greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0035] The accompanying drawings are included to provide a further understanding of embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and serve to explain principles of the present application. Many of the anticipated advantages of the embodiments and other embodiments will be readily appreciated as the same become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts.

[0036] Figure 1 is a structural schematic diagram of a piezoelectric jet valve according to an embodiment of the present application;

[0037] Figure 2 is an assembly diagram of a droplet detection assembly and a lifting mechanism according to an embodiment of the present application;

[0038] Figure 3 is a structural schematic diagram of a droplet detection assembly without a lower cover plate according to an embodiment of the present application;

[0039] Figure 4 is a structural schematic diagram of an optical fiber sensor according to an embodiment of the present application;

[0040] Figure 5a is a structural schematic diagram of a lifting mechanism according to an embodiment of the present application;

[0041] Figure 5b is a partial enlarged view of A of a lifting mechanism according to an embodiment of the present application;

[0042] Figure 6 is a structural schematic diagram of a piezoelectric jet valve device according to an embodiment of the present application;

[0043] Figure 7a is a perspective view of a wiping mechanism according to an embodiment of the present application;

[0044] Figure 7b is a partial enlarged view of C of a wiping mechanism according to an embodiment of the present application;

[0045] Figure 7c is a top view of a wiping mechanism according to an embodiment of the present application;

[0046] Figure 7d is a sectional view of the wiping mechanism in the direction of B-B according to an embodiment of the present application;

[0047] The meanings of the numbers in the figure are as follows: 100 - injection valve body, 200 - drop detection assembly, 300 - lifting mechanism, 400 - wiping mechanism, 101 - nozzle, 201 - first mounting seat, 202 - detection sensor, 203 - indicator light, 204 - connecting block, 205 - communication line, 206 - MCU, 2011 - detection slot, 2012 - cavity, 2013 - glass sheet, 2021 - optical fiber, 301 - slider mounting seat, 302 - guide column, 303 - spring, 304 - stroke adjuster, 305 - second mounting seat, 306 - slide rail, 3011 - convex strip, 401 - wiping block, 402 - wiping cloth, 403 - guide shaft, 404 - observation hole, 405 - driving wheel, 406 - driven wheel, 407 - tension wheel, 408 - encoder, 409 - photoelectric sensor, 410 - wiping port, 3041 - locking nut, 3042 - adjusting column. DETAILED DESCRIPTION

[0048] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the scope of the present application.

[0049] Reference Figure 1 , Figure 1 A structural schematic diagram of a piezoelectric injection valve according to an embodiment of the present application is shown. As shown in the figure, the piezoelectric injection valve comprises an injection valve body 100, a drop detection assembly 200 and a lifting mechanism 300. The injection valve body 100 is provided below with a nozzle 101 for accurately injecting liquid or glue. The drop detection assembly 200 is movably mounted on one side of the injection valve body 100 through the lifting mechanism 300. The lifting mechanism 300 enables the drop detection assembly 200 to move along the injection direction of the nozzle 101, thereby adjusting the relative position between the drop detection assembly 200 and the nozzle 101. This structural design realizes the integration of the drop detection function and the injection valve body, and realizes the real-time monitoring of the nozzle drop under the premise of not affecting the normal work of the injection valve. The setting position of the drop detection assembly 200 enables it to continuously monitor the nozzle 101, and when abnormal drops occur in the working process of the injection valve body 100, the drop detection assembly 200 can timely capture the drop signal and perform corresponding processing through the control system.

[0050] Further reference is made to Figure 2 and Figure 3 , Figure 2 and Figure 3 respectively show the assembly view of the drop detection assembly and the lifting mechanism, and the structural schematic view of the drop detection assembly without the lower cover plate according to the embodiments of the present application. As shown in the figures, the drop detection assembly 200 comprises a first mounting seat 201 and a detection sensor 202. The shell of the first mounting seat 201 is preferably made of aluminum material, and a cavity 2012 is arranged inside for mounting the detection sensor 202. A detection through slot 2011 is formed on the first mounting seat 201, the side wall of the detection through slot 2011 is provided with a detection port for mounting the detection sensor 202, and a glass sheet 2013 is mounted in front of the detection port. The function of the glass sheet 2013 is to protect the detection sensor 202 from being contaminated by the sprayed liquid or glue, while not affecting the normal operation of the detection sensor. The detection sensor 202 is fixed in the first mounting seat 201, and an optical fiber or a laser emitting and receiving element is integrated inside for detecting the drop liquid passing through the detection through slot 2011. In order to ensure the stability and long-term reliability of the detection sensor 202, a heat insulation material is filled around the detection sensor 202 to prevent the heat generated by the spray valve body 100 in a high temperature working environment from damaging the detection sensor 202. The drop detection assembly 200 is connected with the lifting mechanism 300 through a connecting block 204, for realizing the relative position adjustment with the nozzle 101 under the driving of the lifting mechanism 300, so that it can be accurately located below the nozzle 101 to perform effective drop detection.

[0051] In some specific embodiments, the drop detection assembly 200 further comprises a microcontroller (MCU) 206 arranged in the first mounting seat 201, and an indicator light 203 and a communication line 205 electrically connected with the MCU 206, and the MCU 206 is electrically connected with the detection sensor 200. The MCU 206 is connected with the detection sensor 202 for real-time processing and analysis of the optical signal collected by the detection sensor 202. According to the change mode, duration and other parameters of the optical signal, the MCU 206 accurately judges the current working state of the nozzle 101, such as normal spraying, abnormal drop, wire drawing or blockage. When an abnormal condition is detected, the MCU 206 will control the indicator light 203 to emit a specific mode of warning signal (for example, flashing or changing color) to intuitively indicate the nozzle state to the operator or external equipment. At the same time, the MCU 206 sends state data or alarm signal to the external control system through the communication line 205 to trigger the subsequent automatic processing process. Preferably, the MCU 206 adopts an STM32 series microcontroller.

[0052] In some specific embodiments, the MCU 206 distinguishes different ejection states by setting different time thresholds. For example, when the nozzle is normally ejecting, the light signal is blocked for a duration between a first threshold and a second threshold; when there is dripping or stringing, the light signal is blocked for a duration less than the first threshold; and when the nozzle is clogged, the light signal is blocked for a duration greater than the second threshold. By setting different time thresholds, accurate judgment and classification of the nozzle state are achieved, so that the control system can take different measures. The first threshold is less than the second threshold, where the first threshold can be set to 100 microseconds and the second threshold can be set to 300 microseconds.

[0053] Further, with reference to Figure 4 , Figure 4 A structural schematic diagram of the optical fiber sensor according to an embodiment of the present application is shown. As shown, the detection sensor 202 is preferably an optical fiber sensor, which is internally provided with an array of several optical fibers 2021. The optical fibers 2021 generally include transmitting optical fibers and receiving optical fibers, which form an optical path in a specific spacing and arrangement, for forming a detection light beam. When the nozzle 101 is normally working, the optical path is unobstructed, and the receiving optical fibers receive complete light signals. When the nozzle 101 has abnormal conditions such as dripping, stringing or clogging, the dripped droplets or string-shaped gel will pass through the light beam, blocking or scattering part of the light, causing the light signal received by the receiving optical fibers to change. By analyzing the changes in the intensity and duration of the light signal, it can be accurately determined whether the nozzle 101 has dripping, stringing or clogging. The array of several optical fibers 2021 forms a wide-area detection range, improving the sensitivity and reliability of the dripping detection and avoiding the problem of missed detection due to the detection blind area of a single optical fiber. Preferably, the two side walls of the detection slot 2011 are respectively provided with optical fiber sensors, and a glass sheet with a thickness of 0.5 cm is assembled as a protective component at the optical fiber sensor mounting port. The optical fiber sensor adopts a multi-row array type reflection optical fiber structure with specifications of 2×9×0.25 mm (length×width×thickness).

[0054] In combination with Figure 2 and Figures 5a-5b , Figure 5a and Figure 5bThe structure schematic diagram of the lifting mechanism and the local enlarged view at A according to the embodiment of the present application are shown respectively. As shown in the figure, the lifting mechanism 300 comprises a slider mounting seat 301, a guide column 302, a spring 303, a stroke adjuster 304 and a second mounting seat 305. The second mounting seat 305 is fixed to a side wall of the piezoelectric jet valve body 100, providing a stable mounting base for the whole lifting mechanism. The slider mounting seat 301 is used to connect the drop detection assembly 200 and can move in the vertical direction (Y direction) on the second mounting seat 305. In order to ensure the smoothness and accuracy of the movement, the second mounting seat 305 is fixed with a slide rail 306, and the slider mounting seat 301 is provided with a protrusion 3011 matched with the slide rail 306. The matching structure of the slide rail and the protrusion effectively limits the lateral (X direction) deviation of the slider mounting seat 301, ensuring that it can only move vertically. The guide column 302 is vertically installed on the second mounting seat 305, and the slider mounting seat 301 and the spring 303 are sleeved on the guide column 302. The spring 303 is arranged above the slider mounting seat 301, and the stroke adjuster 304 is arranged below the slider mounting seat 301. The force directions of the spring 303 and the stroke adjuster 304 are parallel to the moving direction of the slider mounting seat 301. The spring 303 cooperates with the stroke adjuster 304 to adjust the vertical sliding position of the slider mounting seat 301. The stroke adjuster 304 is installed at the lower end of the guide column 302 and is used to adjust the moving stroke of the slider mounting seat 301. The stroke adjuster 304 comprises a locking nut 3041 and an adjusting column 3042. By rotating the adjusting column 3042, the lower limit position of the slider mounting seat 301 can be accurately controlled, so as to realize the accurate height adjustment of the drop detection assembly 200 relative to the nozzle 101. When the stroke adjuster 304 adjusts the slider mounting seat 301 to move up and down by an external driving force (the adjusting rod is connected with a servo motor or a stepping motor), the drop detection assembly 200 is driven to move smoothly along the slide rail 306, realizing the accurate adjustment of the relative distance between the nozzle 101 and the drop detection assembly 200.

[0055] With reference to the foregoing Figure 6 , the present application also provides a piezoelectric jet valve device, as shown in Figure 6 , which comprises a piezoelectric jet valve, a wiping mechanism 400, a control system and a three-axis displacement platform. The control system is in communication connection with the piezoelectric jet valve, the wiping mechanism 400 and the three-axis displacement platform respectively. The piezoelectric jet valve is composed of a jet valve body 100, a drop detection assembly 200 and a lifting mechanism 300, and the detailed structure and working principle have been described in the foregoing. The three-axis displacement platform is used to drive the piezoelectric jet valve to move above the wiping mechanism 400 when the control system detects that the piezoelectric jet valve needs to be cleaned, so as to realize the cleaning action of the nozzle of the piezoelectric jet valve.

[0056] With further reference to the foregoing Figures 7a-7d, Figures 7a-7d A perspective view, a local enlarged view at C, a top view and a sectional view in the direction of B-B of a wiping mechanism according to an embodiment of the present application are shown respectively. As shown in the figure, the wiping mechanism 400 comprises a housing and a wiping cloth 402, the housing is rotatably equipped with a driving wheel 405 and a driven wheel 406 on one side, a wiping opening 410 is formed on the top of the housing, a wiping block 401 and a guide shaft 403 are arranged at the wiping opening 410, and the height of the wiping block 401 is higher than that of the wiping opening 410; the two ends of the wiping cloth 402 are wound around the outer periphery of the driven wheel 406 and the driving wheel 405 respectively, and the middle part is wound around the wiping block 401 and the guide shaft 403, and the cooperation of the guide shaft 403 and the wiping block 401 makes the wiping cloth 402 form a "W" type movement track at the wiping opening 410. Preferably, the wiping block 401 is made of soft rubber or silicone material. A plurality of tensioning wheels 407 are arranged between the driving wheel 405 and the driven wheel 406, and the wiping cloth 402 between the driving wheel 405 and the driven wheel 406 is wound around the tensioning wheels 407; the tensioning wheels 407 are used to maintain the tensioning state of the wiping cloth 402, which can effectively prevent the wiping cloth 402 from relaxing or falling off during the movement process, thereby ensuring the cleaning effect of the nozzle to have good consistency and reliability.

[0057] In some specific embodiments, the wiping mechanism 400 further comprises a photoelectric sensor 409 and an encoder 408, which are respectively installed on one side of the driving wheel and / or the driven wheel, and are both used to detect the use state of the wiping cloth 402. The photoelectric sensor 409 is located on the side of the unused wiping cloth 402, which can detect the remaining amount of the wiping cloth 402 in real time, and when the wiping cloth 402 is about to be used up, the user can be reminded to replace the new wiping cloth 402 in time, so as to avoid the cleaning failure caused by the exhaustion of the wiping cloth 402.

[0058] In some specific embodiments, an observation hole 404 is formed on the cover plate on one side of the driving wheel 405 and the driven wheel 406, and the observation hole 404 is used to observe the wiping cloth 402 on the driving wheel 405 and the driven wheel 406 respectively. The observation hole 404 formed on the cover plate on one side of the driving wheel 405 and the driven wheel 406 facilitates the user to intuitively observe the working state of the wiping cloth 402, so as to ensure the normal operation of the wiping cloth 402.

[0059] The present application also provides a piezoelectric jet valve device self-cleaning control method, which uses the above piezoelectric jet valve device to realize the self-cleaning of the nozzle of the piezoelectric jet valve, and the control method comprises the following steps:

[0060] S1, in response to the control system obtaining an abnormal alarm signal sent from the drop detection assembly, the three-axis displacement platform moves the piezoelectric jet valve to the corresponding cleaning station of the wiping mechanism;

[0061] S2, control the wiping mechanism to start the cleaning operation, drive the wiping cloth to circulate by the driving wheel, and perform the cleaning operation on the nozzle by the wiping block cooperating with the wiping cloth;

[0062] S3, after the cleaning operation is completed, control the three-axis displacement platform to reset the piezoelectric jet valve to the working position, and update the cleaning state information.

[0063] In some specific embodiments, the abnormal alarm signal is generated by a microcontroller of the droplet detection assembly, which distinguishes the jetting state of the nozzle by setting different time thresholds:

[0064] When the nozzle is normally jetting, the duration of the light signal of the detection sensor being blocked is between the first threshold and the second threshold; when the nozzle has a droplet or string phenomenon, the duration of the light signal being blocked is less than the first threshold; when the nozzle is blocked, the duration of the light signal being blocked is greater than the second threshold, wherein the first threshold is less than the second threshold.

[0065] In some specific embodiments, when the control system receives the abnormal alarm signal sent by the MCU of the droplet detection assembly 200, the control system will start the automatic processing flow. The control system first sends a pause jetting instruction to the piezoelectric jet valve body 100, and sends a displacement control signal to the three-axis displacement platform to drive the piezoelectric jet valve to move along the X, Y, and Z axes to the upper side of the wiping mechanism 400, so that the nozzle 101 and the wiping port 410 are in a preset alignment position; then, the control system sends a cleaning start instruction to the wiping mechanism 400 to drive the driving wheel 405 to rotate to drive the wiping cloth 402 to circulate along the guide shaft 403, and perform the wiping operation on the nozzle by the cooperation of the wiping block 401 and the wiping cloth 402, and the tensioning wheel 407 maintains the constant tension of the wiping cloth 402; during the cleaning process, the encoder 408 monitors the running length of the wiping cloth 402 in real time, and the photoelectric sensor 409 synchronously detects the remaining amount of unused wiping cloth and feeds back to the control system; when the cleaning operation is completed or reaches the preset cleaning time, the control system instructs the three-axis displacement platform to reset the piezoelectric jet valve to the working position, and sends a resume jetting instruction to the jet valve body 100, and updates the cumulative consumption of the wiping cloth 402 by the counting data of the encoder 408.

[0066] In some specific embodiments, based on the size adaptation relationship between the wiping block and the detection channel of the droplet detection assembly, the nozzle self-cleaning is realized through the coordinated action of the three-axis displacement platform and the lifting mechanism: when the size of the wiping block is smaller than the size of the detection channel, the three-axis displacement platform drives the piezoelectric jet valve to move, so that the wiping block extends into the detection channel, and the cleaning action of the nozzle is performed through the cyclic movement of the wiping cloth in cooperation with the wiping block; when the size of the wiping block is larger than the size of the detection channel, under the transfer action of the three-axis displacement platform, the wiping block abuts against the droplet detection assembly, the spring in the lifting mechanism is used to move the droplet detection assembly upward to avoid the nozzle, and then the cleaning work of the nozzle is completed through the coordinated action of the wiping cloth and the wiping block.

[0067] Although the principles of the present application have been described in detail above with reference to the preferred embodiments thereof, it is to be understood that the above-described embodiments are merely illustrative of the present application and are not intended to limit the scope of the present application. The details in the embodiments do not constitute a limitation on the scope of the present application, and any equivalent changes, simple replacements, etc. based on the technical solutions of the present application, which do not depart from the spirit and scope of the present application, fall within the protection scope of the present application.

Claims

1. A piezoelectric injection valve device, characterized in that, The device includes a wiping mechanism, a control system, a three-axis displacement platform, and a piezoelectric jet valve. The control system is communicatively connected to the piezoelectric jet valve, the wiping mechanism, and the three-axis displacement platform, respectively. The wiping mechanism includes a driving wheel, a driven wheel, a wiping block, and a wiping cloth. The two ends of the wiping cloth are respectively wrapped around the outer periphery of the driven wheel and the driving wheel, and the middle section of the wiping cloth is wrapped around the wiping block. The wiping block is set higher than the wiping opening. The piezoelectric injection valve includes an injection valve body, a droplet detection component, and a lifting mechanism, wherein: The injection valve body includes a nozzle; The drip detection assembly is movably mounted on one side of the nozzle via the lifting mechanism. It includes a first mounting base and a detection sensor. The first mounting base has a detection channel for the fluid ejected from the nozzle to pass through. The detection sensor is mounted on the side wall of the detection channel and is used to detect the dripping state of the nozzle. The lifting mechanism is fixed to one side of the injection valve body and is used to adjust the relative position of the drip detection component and the nozzle along the injection direction of the nozzle. The lifting mechanism includes a slider mounting base, a guide column, a spring, a stroke adjuster, and a second mounting base. The slider mounting base and the spring are sleeved on the guide column. The guide column and the stroke adjuster are respectively installed at the upper and lower ends of the second mounting base. The spring is located on the side of the slider mounting base away from the stroke adjuster, and the force direction of the spring and the stroke adjuster is parallel to the movement direction of the slider mounting base. When the size of the wiping block is larger than the size of the detection channel, under the conveying action of the three-axis displacement platform, the wiping block abuts against the drip detection component, and the elastic force of the spring in the lifting mechanism causes the drip detection component to move upward to avoid the nozzle.

2. The piezoelectric injection valve device according to claim 1, characterized in that, The detection sensor is either a fiber optic sensor or a laser sensor.

3. The piezoelectric injection valve device according to claim 2, characterized in that, The fiber optic sensor contains several optical fibers arranged in an array.

4. The piezoelectric injection valve device according to claim 1, characterized in that, The side wall of the detection channel is provided with a detection port for installing the detection sensor, and a glass plate is installed in front of the detection port.

5. The piezoelectric injection valve device according to claim 1, characterized in that, The housing of the first mounting base is made of aluminum, and the cavity around the detection sensor is filled with heat-insulating material.

6. The piezoelectric injection valve device according to claim 1, characterized in that, The second mounting base is fixed with a slide rail, and the slider mounting base is provided with a protrusion that cooperates with the slide rail. The slider mounting base is connected to the first mounting base through a connecting block.

7. The piezoelectric injection valve device according to claim 1, characterized in that, The stroke adjuster includes an adjusting column and a nut, the adjusting column being movably fixed to the lower end of the second mounting base by the nut.

8. The piezoelectric injection valve device according to claim 1, characterized in that, The droplet detection assembly also includes a microcontroller disposed in the first mounting base, as well as an indicator light and a communication line electrically connected to the microcontroller, and the microcontroller is electrically connected to the detection sensor.

9. The piezoelectric injection valve device according to claim 1, characterized in that, The wiping block is equipped with guide shafts on both sides, and the guide shafts are used to make the wiping cloth move in a "W" shaped trajectory at the wiping opening.

10. A self-cleaning control method for a piezoelectric injection valve device, characterized in that, The piezoelectric injection valve device according to any one of claims 1-9 is used to achieve self-cleaning of the nozzle of the piezoelectric injection valve, wherein the control method is as follows: S1, in response to the control system receiving an abnormal alarm signal from the drip detection component, the control system controls the three-axis displacement platform to move the piezoelectric jet valve to the corresponding cleaning station of the wiping mechanism; S2, control the wiping mechanism to start the cleaning operation, drive the wiping cloth to move in a cycle through the drive wheel, and use the wiping block in conjunction with the wiping cloth to perform the cleaning action on the nozzle; S3, after the cleaning operation is completed, control the three-axis displacement platform to reset the piezoelectric jet valve to the working position and update the cleaning status information.

11. The self-cleaning control method for the piezoelectric injection valve device according to claim 10, characterized in that, The abnormal alarm signal is generated by the microcontroller of the droplet detection component. The microcontroller distinguishes the spraying state of the nozzle by setting different time thresholds. When the nozzle is spraying normally, the duration of the light signal being blocked by the detection sensor is between a first threshold and a second threshold; when the nozzle is dripping or stringing, the duration of the light signal being blocked is less than the first threshold; when the nozzle is clogged, the duration of the light signal being blocked is greater than the second threshold, wherein the first threshold is less than the second threshold.

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