Automatic water replenishing system based on overflow detection and water replenishing control method

Abstract

The invention relates to an automatic water replenishing system based on overflow detection and a water replenishing control method. The automatic water replenishing system and the water replenishing control method are used for carrying out automatic water replenishing control on a liquid containing tank containing a hot bath medium. The system comprises a liquid level detection unit, an overflow detection unit, a water replenishing execution unit and a control unit which are respectively used for monitoring the liquid level height in the container in real time and adjusting the working state of the water replenishing execution unit according to a detection result. When the liquid level is lower than the set lowest liquid level height, water replenishing is started, and if the liquid level does not rise again after water replenishing exceeds the minimum water replenishing time, the water replenishing flow is increased; when the liquid level reaches or exceeds the highest liquid level height, water replenishing is stopped immediately, closing is kept within the minimum water replenishing time, and if the liquid level is still high after the minimum water replenishing time is over, water replenishing continues to be stopped, and the follow-up water replenishing flow is reduced. Through the control logic, the system can effectively avoid excessive or insufficient water replenishing under the dynamic conditions of large liquid level fluctuation and non-uniform water consumption, and self-adaptive adjustment of the water replenishing amount is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hot bath stamping, in particular to an automatic water replenishment system and a water replenishment control method based on water overflow detection. BACKGROUND

[0002] In the hot bath stamping forming process of zinc-based plated sheet, the workpiece needs to complete the preheating and stamping process in a high-temperature liquid medium. The water level in the mold box has a direct impact on the uniformity of workpiece heat absorption, mold heat exchange efficiency and forming stability. In order to ensure product quality and process stable operation, the hot bath stamping forming process of zinc-based plated sheet puts forward higher requirements for water level control.

[0003] However, due to the production rhythm, the hot bath mold frequently opens and closes during operation, and the workpiece periodically immerses and separates from the liquid surface, causing significant fluctuations in the liquid in the box. The single-cycle water level oscillation amplitude can reach ±20mm. In addition, the process liquid is in a high-temperature state of 80℃ to 95℃, and the water surface evaporates rapidly, and the evaporation rate is closely related to temperature, environmental humidity and clamping frequency, which has high nonlinearity and uncertainty. Some product structures also cause liquid adhesion or carry-out, further increasing the risk of liquid level drop.

[0004] Most of the currently widely used water replenishment systems are passive structures controlled by float ball valves. The water replenishment system relies on the position of the float ball to control the opening or closing of the valve. After the liquid level changes, the float ball often cannot immediately reach the valve trigger position due to its own inertia and liquid disturbance, resulting in a lag in water replenishment. During the stamping forming process, the mold is frequently opened and closed, and the workpiece repeatedly enters and exits the liquid surface, causing violent fluctuations in the water surface, and the float ball is prone to shaking or even short-term floating abnormalities, thereby causing misjudgment.

[0005] Another common water replenishment scheme at present is an automatic water replenishment system based on a PID (proportional-integral-derivative) regulation algorithm. The system usually collects parameters such as liquid level height or liquid pressure in real time through a liquid level sensor or a pressure sensor, compares them with a preset target value, and then calculates the adjustment instruction of the water replenishment valve through a PID controller to realize continuous adjustment of the water replenishment amount and relative stability of the liquid level.

[0006] This type of system can achieve relatively accurate liquid level control under conditions of gentle liquid level changes and stable working conditions. However, in dynamic process scenarios such as hot bath stamping, the liquid level will fluctuate greatly for a short time due to factors such as frequent opening and closing of the mold, immersion and carry-out of the workpiece, which will cause frequent fluctuations in the sensor feedback value, misjudgment of the liquid level deviation by the system, and thus frequent start-stop or abnormal water replenishment instruction output of the water replenishment system.

[0007] Therefore, it is urgent to provide a water replenishment scheme suitable for hot bath stamping dynamic conditions to realize stable regulation of the liquid level of the hot bath mold and timely compensation of the evaporation amount. SUMMARY

[0008] To this end, the technical problem to be solved by the present application is to overcome the technical problem that the water replenishment system in the prior art cannot adapt to the complex working conditions of frequent water level fluctuations and evaporation loss superposition.

[0009] To solve the above technical problems, the present application provides an automatic water replenishment system based on overflow detection, comprising: A liquid receiving tank for containing a hot bath medium, the hot bath medium being used for heating treatment of workpieces in a hot bath stamping process; A liquid level detection unit arranged in the liquid receiving tank for detecting whether the real-time liquid level in the liquid receiving tank is lower than a set minimum liquid level height; An overflow detection unit arranged in an overflow groove on the liquid receiving tank for detecting whether the real-time liquid level in the liquid receiving tank reaches or exceeds a set maximum liquid level height, and the set maximum liquid level height corresponds to an overflow line of the overflow area; A water replenishment execution unit in communication with the liquid receiving tank for replenishing the hot bath medium into the liquid receiving tank; and A control unit electrically connected with the liquid level detection unit, the overflow detection unit and the water replenishment execution unit, respectively, for: When the liquid level is lower than the set minimum liquid level height, controlling the water replenishment execution unit to start water replenishment at an originally set water replenishment flow rate V0 at the first water replenishment, and continue for at least a set minimum water replenishment time If the liquid level is still lower than the set minimum liquid level height after the minimum water replenishment time , the water replenishment flow rate is increased to an incremental water replenishment flow rate V1 higher than the water replenishment flow rate V0, and the water replenishment continues until the liquid level reaches the set minimum liquid level height; When the liquid level reaches or exceeds the set maximum liquid level height, controlling the water replenishment execution unit to stop water replenishment and maintain the stop state for a set stop water replenishment period T 停 If the liquid level is still higher than the set maximum liquid level height after the end of the stop water replenishment period T 停 , the water replenishment is continued to be closed, and the initial flow rate at the next water replenishment start is set to a decremental water replenishment flow rate V2 lower than V0.

[0010] In an embodiment of the present application, the liquid receiving tank is provided with one or more overflow grooves, and the overflow grooves are in communication with the liquid receiving tank through a backflow pipe for recycling the overflow hot bath medium.

[0011] In an embodiment of the present application, an adjustable height baffle is arranged at the overflow port of the overflow groove for adjusting the overflow height of the overflow groove, thereby controlling the maximum liquid level height.

[0012] In one embodiment of the present application, the liquid level detection unit comprises a liquid level sensor. In one embodiment of the present application, the overflow detection unit comprises any one or a combination of more than two of a pressure sensor, a resistance sensor, and a temperature sensor.

[0013] In one embodiment of the present application, the water replenishment execution unit comprises an electrically controlled valve for controlling the on-off state of water replenishment of the hot bath medium and a flow meter for monitoring the actual water replenishment flow and feeding back flow information to the control unit.

[0014] The present application also provides an automatic water replenishment control method based on overflow detection, applied to a hot bath stamping die, characterized in that it comprises the following steps: S1. During the hot bath stamping stage using the hot bath stamping die, the overflow detection unit and the liquid level detection unit are used to detect whether the liquid surface in the liquid receiving container reaches the set maximum liquid level height or is lower than the set minimum liquid level height, and output an overflow simulation signal or a water replenishment simulation signal to the signal processing unit when detecting an abnormal liquid surface; S2. After the signal processing unit receives and processes the simulation signal, a control signal is output to the control unit, and the control unit generates a water replenishment control instruction according to the following rules: when the liquid surface is lower than the set minimum liquid level height, the control unit controls the water replenishment execution unit to start water replenishment at the originally set water replenishment flow V0 at the first water replenishment, and continues for at least a set minimum water replenishment time ; if the liquid surface is still lower than the set minimum liquid level height after the minimum water replenishment time , the water replenishment flow is increased to an incremental water replenishment flow V1 higher than the water replenishment flow V0, and the water replenishment continues until the liquid surface reaches the set minimum liquid level height; When the liquid surface reaches or exceeds the set maximum liquid level height, the control unit controls the water replenishment execution unit to stop water replenishment and maintain the stop state for a set stop water replenishment period T 停 ; if the liquid surface is still higher than the set maximum liquid level height after the stop water replenishment period T 停 ends, the water replenishment is continuously maintained in the closed state, and the initial flow at the next water replenishment start is set to a decremental water replenishment flow V2 lower than V0.

[0015] In one embodiment of the present application, V1 is 7 / 6-4 / 3V0.

[0016] In one embodiment of the present application, V2 is 1 / 3-2 / 3V0.

[0017] In one embodiment of the present application, the water replenishment execution unit is always open, and the open degree of the always open mode corresponds to the original set water replenishment amount V0, which is calculated by the change of static liquid level height after the stamping process is set with the stamping frequency K, and the specific formula is as follows: , Wherein, S 承液容箱 is the bottom area of the liquid container, K is the set stamping frequency, ΔH is the total height of the liquid level drop in the liquid container after the stamping K times by the hot bath stamping die, and t is the production beat time of a single product.

[0018] In one embodiment of the present application, the stop water replenishment period T 停 =K×t 零件生产节拍 , K is the set stamping frequency, and t is the production beat time of a single product; K has different values due to different products, wherein, for the first type of simple product, the value of K is 80-100, and for the second type of complex product, the value of K is 30-50.

[0019] In one embodiment of the present application, due to different products, the values are different, wherein, for the first type of simple product, ; for the second type of complex product, .

[0020] In one embodiment of the present application, the set minimum liquid level height is defined as , and the set maximum liquid level height is defined as , , wherein, h1 is 2-5 mm; , wherein, h2 is 2-5 mm.

[0021] In one embodiment of the present application, the control unit is further configured with an automatic static water replenishment mode and a manual mode, wherein, in the automatic static water replenishment mode, whether the real-time liquid level height is lower than the set minimum liquid level height or exceeds the set maximum liquid level height is detected by the liquid level detection unit at the same time, and the control unit generates corresponding water replenishment opening or closing instructions according to the detection result, so as to realize stable control of the liquid level within the set range; in the manual water replenishment mode, the liquid level detection unit and the overflow detection unit do not participate in the liquid level judgment, and the control unit controls the water replenishment execution unit to perform quantitative water replenishment or continuous water replenishment according to the water replenishment execution unit opening degree parameter or water replenishment instruction input by the user.

[0022] The above technical solution of the present invention has the following beneficial effects compared with the prior art: The automatic water replenishment system and method based on overflow detection provided by the present invention is provided with a liquid level detection unit and an overflow detection unit, which are used to monitor whether the liquid level is lower than the minimum liquid level or reaches the maximum liquid level respectively, so that the system can obtain the dynamic state of the liquid level in the tank in real time, and then realize the timely start or stop of water replenishment. Stop water replenishment cycle T 停 When the liquid level is continuously low, the water replenishment system can automatically increase the water replenishment amount if the initial water replenishment is ineffective, thereby speeding up the liquid level recovery; when the liquid level is continuously high, the water outage time can be extended and the subsequent water replenishment flow rate can be reduced to prevent excessive water replenishment and repeated overflow, so that the system can respond to liquid level changes more sensitively.

[0023] Furthermore, after detecting a water replenishment or overflow signal, the signal processing unit transmits it to the control unit, which issues specific adjustment instructions to the water replenishment execution unit, thereby implementing the water replenishment action. Compared with traditional static water replenishment solutions based on single-point liquid level switches, this invention can operate stably under actual working conditions where the water level is subject to dynamic fluctuations and the water replenishment amount is affected by multiple factors. It is suitable for hot bath stamping of zinc-coated parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings, wherein Figure 1 Schematic diagram of the structure of an automatic water replenishment system based on overflow detection in a preferred embodiment of the present invention; Figure 2 This is a schematic diagram of the liquid level status during the actual production process in a preferred embodiment of the present invention; Figure 3 It is a structural diagram of the material drag rack; Figure 4 This is a schematic diagram of an automatic water replenishment control method based on overflow detection in a preferred embodiment of the present invention.

[0025] Explanation of the reference numerals in the accompanying drawings in the specification: 001, upper mold; 002, hot-pressed blank; 003, material drag rack; 004, control panel; 005, liquid container; 006, electric control valve; 007, flow meter; 008, reflux pipe; 009, overflow detector; 010, overflow reflux tank; 011, lower mold; 012, liquid level detector; 013, hot bath medium; 014, lower mold base. DETAILED DESCRIPTION

[0026] The application will be further described below in conjunction with the drawings and specific embodiments so that those skilled in the art can better understand the application and implement it, but the embodiments are not limiting to the application.

[0027] Referring to Figures 1-3 As shown in the drawings, the embodiment of the application provides an automatic water replenishment system based on water overflow detection, which is suitable for zinc-based plated sheet hot bath stamping process, and is used for dynamic water replenishment control of the liquid receiving container 005 in the continuous production process of the hot bath stamping die, so as to maintain the stability of the hot bath liquid level and guarantee the process continuity and product quality.

[0028] The specific application scenario of the automatic water replenishment system based on water overflow detection in the embodiment of the application is the hot bath stamping die, which comprises an upper die 001, a lower die 011, a hot pressing blank 002 and a material dragging frame 003. The lower die 011 is arranged in a liquid receiving container 005 containing hot bath medium 013, and the material dragging frame 003 is arranged in two groups and oppositely arranged in the liquid receiving container 005, which is used for carrying the two side edge regions of the hot pressing blank 002. In the continuous hot bath stamping production, the upper die 001 periodically (t=hot pressing beat) presses the hot pressing blank 002 placed on the material dragging frame 003 into the lower die 011, and the liquid level of the hot bath medium 013 in the liquid receiving container 005 is in a highly fluctuating state.

[0029] The automatic water replenishment system based on water overflow detection comprises a liquid receiving container 005, a liquid level detection unit 012, a water overflow detection unit 009, a water replenishment execution unit and a control unit 004.

[0030] The liquid receiving container 005 is used for containing the hot bath medium 013, and the hot bath medium 013 is used for heating treatment of workpieces in the hot bath stamping process.

[0031] In order to monitor the lower limit of the liquid level, the liquid level detection unit 012 is arranged in the liquid receiving container 005 and is used for detecting whether the real-time liquid level height in the liquid receiving container 005 is lower than the set minimum liquid level height.

[0032] In order to monitor the upper limit of the liquid level, the water overflow detection unit 009 is arranged in the overflow groove 010 on the liquid receiving container 005, and is specifically arranged to detect whether the real-time liquid level height reaches or exceeds the set maximum liquid level height, and the set maximum liquid level height corresponds to the overflow line of the overflow region.

[0033] The water replenishment execution unit is in communication with the liquid receiving container 005 and is used for replenishing the hot bath medium 013 in the liquid receiving container 005.

[0034] The control unit 004 is electrically connected with the liquid level detection unit 012, the water overflow detection unit 009 and the water replenishment execution unit respectively, and the control unit 004 is used for: When the liquid level is below the set minimum liquid level height, the water replenishment executing unit is controlled to start water replenishment at the originally set water replenishment flow rate V0 at the first water replenishment, and continues for at least a set minimum water replenishment time If the liquid level is still below the set minimum liquid level height after the minimum water replenishment time , the water replenishment flow rate is increased to an increased water replenishment flow rate V1 higher than the water replenishment flow rate V0, and the water replenishment continues. When the liquid level reaches or exceeds the set maximum liquid level height, the water replenishment executing unit is controlled to stop water replenishment, and remains in the stopped state for a set water replenishment stopping period T 停 If the liquid level is still above the set maximum liquid level height after the water replenishment stopping period T 停 ends, the water replenishment remains closed, and the initial flow rate at the next water replenishment start is set to a decreased water replenishment flow rate V2 lower than the water replenishment flow rate V0. Of course, if the liquid level is not above the set maximum liquid level height after the water replenishment stopping period T 停 ends, the water replenishment at the next water replenishment start is still at the water replenishment flow rate V0.

[0035] The maximum height of the lower mold forming public is the key position that must be completely immersed in the hot bath medium 013 in the mold. If the liquid level is below this height, the workpiece heating is insufficient, which affects the forming effect and product quality. Therefore, to ensure the accuracy of water replenishment control, the maximum height of the lower mold forming public below the set minimum liquid level height is used as the reference, and a safety margin is appropriately set. To avoid the hot bath medium overflow or interfere with the normal operation of the material dragging frame caused by the liquid level being too high, the material dragging height of the material dragging frame below the set maximum liquid level height is used as the reference, and a safety margin is appropriately set.

[0036] Specifically, the set minimum liquid level height is defined as , and the set maximum liquid level height is defined as . , wherein h1 is 2-5 mm, and specifically h1 is 3 mm; , wherein h2 is 2-5 mm, and specifically h2 is 3 mm. The heights of h1 and h2 are measured from the upper surface of the lower mold base 014 as the unified measurement reference. The heights of h1 and h2 are measured from the upper surface of the lower mold base 014 as the unified measurement reference.

[0037] ​​In addition, the lowest liquid level detection signal output by the liquid level detection unit 012 is used not only to determine whether to start the water replenishment operation, but also as an interlock condition for the heating unit that heats the thermal bath medium 013. Specifically, when the liquid level in the liquid receiving tank 005 is lower than the set lowest liquid level, the control unit 004 will instruct the heating unit to suspend power output, so as to prevent dry burning or component damage caused by continued heating in the case of insufficient thermal bath medium 013. This design helps to interrupt the heating process in time when the liquid level is abnormal, avoids the risk of equipment operation, and enhances the safety of the thermal bath process.

[0038] Since the highest point of the lower mold forming male is the key position that must be completely immersed in the thermal bath medium 013 in the mold, the liquid level detection unit 012 is preferably arranged near the reference point (the highest point of the lower mold forming male) for real-time detection of whether the liquid level is lower than the set lowest liquid level.

[0039] The liquid level detection unit 012 is preferably a liquid level sensor for detecting whether the liquid level in the liquid receiving tank 005 is lower than the set lowest liquid level. The liquid level sensor can include but is not limited to a continuous capacitive liquid level sensor and an ultrasonic liquid level sensor. The continuous capacitive liquid level sensor realizes continuous monitoring of the liquid level through the change of the dielectric constant of the liquid; the ultrasonic liquid level sensor calculates the liquid level height by measuring the time difference between the emission and reflection of ultrasonic waves from the probe.

[0040] In an embodiment of the present application, the overflow detection unit 009 is preferably any one or a combination of a pressure sensor, a resistance sensor, or a temperature sensor for detecting whether the liquid level in the tank reaches or exceeds the set highest liquid level.

[0041] When the liquid level rises to the height of the overflow port of the overflow tank 010 and the thermal bath medium starts to flow into the overflow tank 010, the presence of liquid in the overflow tank will be sensed by the overflow detection unit 009, and a corresponding overflow signal will be output. Specifically: When the overflow detection unit 009 is a pressure sensor, the presence of liquid in the overflow tank can be determined by detecting the slight change in pressure in the tank after the thermal bath medium flows into the tank; When the overflow detection unit 009 is a resistance sensor, based on the electrical conductivity of the thermal bath liquid, a sudden change in resistance between the electrodes will occur when the liquid contacts the electrodes, thereby determining whether liquid has entered the overflow tank; When the overflow detection unit 009 is a temperature sensor, the temperature difference between the thermal bath medium and the surrounding air can be used as a basis for overflow determination, and the temperature change caused by the liquid contacting the sensor can be used as a basis for overflow determination.

[0042] In a specific embodiment of the present application, the upper part of the liquid receiving tank 005 is provided with one or more overflow grooves 010, and each overflow groove 010 is in communication with the liquid receiving tank 005 through a backflow pipe 008. When the hot bath liquid level rises above the overflow port height of the overflow groove 010, the excess hot bath medium 013 flows into the backflow pipe 008 through the overflow groove 010 and returns to the liquid receiving tank 005, thereby realizing the recovery of the overflowing hot bath medium 013, avoiding waste of the medium and reducing external pollution.

[0043] Further, the overflow port position of each overflow groove 010 is provided with a baffle, and the height of the baffle can be adjusted. By adjusting the height of the baffle, the overflow height of the overflow groove 010 can be changed, thereby flexibly setting the preset maximum liquid level height of the liquid receiving tank 005. In this way, the maximum liquid level of the system can be flexibly adjusted according to the requirements of the mold structure or different working conditions for the liquid level height, thereby better controlling the liquid level and avoiding unnecessary interference caused by frequent overflow or excessively high liquid level.

[0044] In an embodiment of the present application, one liquid level detection unit 012 and one overflow detection unit 009 are respectively arranged for monitoring whether the liquid level in the liquid receiving tank 005 is lower than the set minimum liquid level height or reaches the set maximum liquid level height. The water replenishment system controls the opening or closing of the water replenishment execution unit according to the feedback signal of the detection unit, thereby realizing the basic control of the water replenishment process.

[0045] In other embodiments, for some hot bath stamping systems with complex mold structure and large overall size, multiple liquid level detection units 012 can be arranged in the tank. These liquid level detection units 012 are respectively arranged near different key positions for synchronous detection of the liquid level at each position, thereby ensuring that each region can be maintained within a reasonable liquid level range. By arranging multiple liquid level detection units 012, even if the liquid level is unevenly distributed inside the tank, the mold can be uniformly heated, thereby avoiding the problem of insufficient heating of the product caused by excessively low local liquid level.

[0046] In an embodiment of the present application, as shown in FIG. 1, the water replenishment execution unit includes an electric control valve 006 arranged outside the liquid receiving tank 005 and a flow meter 007 connected thereto. The electric control valve 006 is used to control the opening and closing state of the water replenishment channel, thereby realizing the start-stop adjustment of the hot bath medium 013 replenishment process; the flow meter 007 is used to monitor the flow of the hot bath medium 013 through the water replenishment channel in real time, and feed back the flow information to the control unit 004, thereby realizing the closed-loop regulation and control of the system water replenishment strategy. The electric control valve 006 includes but is not limited to an electric ball valve, an electric proportional valve, and an electric balance valve.

[0047] Referring to Figures 1-4As shown, the embodiment of the present application also provides an automatic water replenishment control method based on water overflow detection, which is suitable for the water replenishment control process in the hot bath stamping die. The water replenishment method detects the real-time height of the liquid level of the hot bath medium 013, and dynamically controls the water replenishment amount and the water replenishment time according to the set minimum and maximum liquid level thresholds, so as to ensure the stability of the hot bath process and the safety of the equipment operation.

[0048] Specifically, first, in the hot bath stamping stage using the hot bath stamping die, the real-time liquid level in the liquid receiving container 005 is detected by the water overflow detection unit 009 and the liquid level detection unit 012 whether it reaches the set maximum liquid level height or is lower than the set minimum liquid level height, and when the liquid level is detected to be abnormal, the water overflow simulation signal or the water replenishment simulation signal is respectively output to the signal processing unit; Then, after receiving and processing the analog signal, the signal processing unit outputs a control signal to the control unit 004, and the control unit 004 generates a water replenishment control instruction according to the following rules: When the liquid level is lower than the set minimum liquid level height, the control unit controls the water replenishment execution unit to start water replenishment at the originally set water replenishment flow rate V0 at the first water replenishment, and continues for at least a set minimum water replenishment time If the liquid level is still lower than the set minimum liquid level height after the minimum water replenishment time , the water replenishment flow rate is increased to an incremental water replenishment flow rate V1 higher than the water replenishment flow rate V0, and the water replenishment continues until the liquid level reaches the set minimum liquid level height; When the liquid level reaches or exceeds the set maximum liquid level height, the control unit controls the water replenishment execution unit to stop water replenishment, and maintains the stop state for a set stop water replenishment period T 停 If the liquid level is still higher than the set maximum liquid level height after the stop water replenishment period T 停 ends, the water replenishment is continuously maintained in the closed state, and the initial flow rate when the next water replenishment is started is set to a decremental water replenishment flow rate V2 lower than V0.

[0049] Wherein, the set minimum liquid level height is defined as , and the set maximum liquid level height is defined as ; , wherein, h1 is 2-5 mm, and specifically h1 is 3 mm; , wherein, h2 is 2-5 mm, and specifically h2 is 3 mm.

[0050] Specifically, if the water replenishment is started and maintained for a set minimum water replenishment time If the water supply signal is still received after the end, the water supply continues with an incremental water supply flow V1, which is 1 / 6-1 / 3 higher than the original water supply flow V0; more specifically, the incremental water supply flow V1 is 1 / 3 higher than the original water supply flow V0.

[0051] Specifically, if the water supply signal is still received after the stop water supply period T 停 If the water overflow signal is still received after the end, the water supply continues to be closed, and the initial flow when the next water supply is opened is a reduced water supply flow V2, which is 1 / 3-2 / 3 of the water supply flow V0, and more specifically, the reduced water supply flow V2 is 2 / 3 of the original water supply flow V0.

[0052] In the embodiment of the application, the water supply execution unit (solenoid valve) is always open, and the always open mode opening degree corresponds to an original water supply flow V0. In order to set a suitable original water supply flow V0, a simulation test is first performed, that is, the stamping die is continuously stamped K times, and then the average consumption of the volume of hot bath medium per unit time is calculated through the change of the liquid level. The specific calculation formula is:

[0053] Among them, S 承液容箱 is the bottom area of the liquid receiving container 005, K is the set stamping number, ΔH is the total height of the liquid level drop in the liquid receiving container 005 after the hot bath stamping die is stamped K times, and t is the production beat time of a single product.

[0054] In order to offset the liquid level drop (i.e. liquid loss) caused by K times of stamping, the system needs to supplement the corresponding volume of hot bath medium. The water supply flow V0 represents the liquid volume that the water supply execution unit (such as an electric control valve) should deliver to the liquid receiving container in unit time during water supply operation. According to the water supply flow V0, the system can set the water supply duration, so as to make up the total water supply amount required at one time. At the same time, in actual operation, dynamic water supply adjustment can also be made with reference to the water supply flow V0, for example, increasing to the incremental water supply flow V1 or decreasing to the reduced water supply flow V2, so as to cope with different working conditions of the continuously low or continuously high liquid level.

[0055] In the embodiment of the application, the stop water supply period T 停 =K×t 零件生产节拍 , wherein K represents the set stamping number, and t is the production beat time of a single product (unit: second). During the stop water supply period, even if the liquid level detection unit or the water overflow detection unit feeds back the liquid level fluctuation signal, the system will not immediately re-execute the water supply judgment, so as to avoid the misjudgment and frequent start-stop caused by the short-time fluctuation of the liquid level, and ensure the stability of the water supply control.

[0056] ​In addition, after one replenishment is completed, the replenishment system must wait until K times of stamping are completed, that is, wait for a stop replenishment period T 停 , to re-determine whether the liquid level needs to be replenished again, which helps to avoid unnecessary replenishment behavior in a dynamic working condition in which the hot bath liquid level fluctuates greatly, improves the stability of the hot bath process, and is more energy-saving.

[0057] The specific value of K can be adjusted according to the product type: For the first type of simple product, the structure is relatively simple, the workpiece surface area is small, and the hot bath medium mass adsorbed per unit stamping is small, and it is recommended that the value of K is in the range of 80-100; For the second type of complex product, the structure is complex, the surface area is large, and the hot bath medium mass carried away per unit stamping is relatively large, and it is recommended that the value of K is in the range of 30-50.

[0058] It should be noted that: T 停 =K×t 零件生产节拍 and K has the same meaning, that is, the set number of stampings. The benefit of such a setting is that the system can replenish the liquid based on the replenishment flow rate V0 after every K times of stamping (that is, a T 停 period of time), which corresponds to the amount of liquid consumed due to stamping in this period of time. In this way, the frequency of replenishment (T 停 ) and the size of the replenishment flow rate (V0) can match each other, making the liquid level control more accurate and stable, and avoiding over-replenishment or under-replenishment as much as possible.

[0059] In the embodiments of the present application, the value of K is different due to different products; Among them, for the first type of simple product: , preferably, ; for the second type of complex product: , preferably, .

[0060] In one specific embodiment of the present application, to adapt to the liquid level control requirements of the hot bath stamping die in different production states, the control unit 004 is pre-set with multiple operating modes, including an automatic dynamic replenishment mode, an automatic static replenishment mode, and a manual mode. Users can select the corresponding mode according to the current working condition to achieve the best replenishment strategy.

[0061] In the automatic dynamic water replenishment mode, the water replenishment system defaults to use the overflow detection unit 009 to detect and control the maximum liquid level, and uses the liquid level detection unit 012 to detect and control the minimum liquid level. When the liquid level is lower than the set minimum liquid level, the liquid level detection unit 012 outputs a corresponding signal to the control unit, triggering the water replenishment execution unit (solenoid valve) to start the water replenishment operation. When the liquid level reaches or exceeds the set maximum liquid level, the overflow detection unit 009 outputs a corresponding signal to the control unit, triggering the water replenishment execution unit to stop the water replenishment operation and enter the stop water replenishment period control logic. The above-mentioned automatic dynamic water replenishment control scheme realized by the overflow detection unit 009 and the liquid level detection unit 012 has been described in detail in the foregoing embodiments, and will not be repeated here.

[0062] In the automatic static water replenishment mode, the liquid level detection unit 012 is used to detect whether the real-time liquid level is lower than the set minimum liquid level or exceeds the set maximum liquid level, and the control unit 004 generates a corresponding water replenishment start or stop instruction according to the detection result, realizing stable control of the liquid level within the set range. In the manual water replenishment mode, the liquid level detection unit 012 and the overflow detection unit 009 do not participate in liquid level judgment, and the control unit 004 controls the water replenishment execution unit to perform quantitative water replenishment or continuous water replenishment according to the water replenishment execution unit opening degree parameter or water replenishment instruction input by the user.

[0063] Through the above-mentioned setting of multiple water replenishment operation modes, the present application can realize automatic water replenishment control in dynamic working conditions, and can switch to automatic static water replenishment mode or manual control mode in special working conditions (such as fault shutdown) or debugging stage, enhancing the adaptability and operation flexibility of the system in different application scenarios.

[0064] To verify the adaptability and control performance advantages of the automatic water replenishment control system proposed by the present application in dynamic liquid level fluctuation working conditions, a traditional floating ball valve water replenishment system (referred to as Comparative Example 1) and a water replenishment system based on PID regulation (referred to as Comparative Example 2) are selected as comparative objects, and performance comparison is carried out in multiple dimensions such as water replenishment triggering mechanism, liquid level feedback mode, water replenishment adjustment capacity, system response capacity, control precision, liquid waste control, adaptability and control flexibility. The specific results are shown in Tables 1 and 2.

[0065] Table 1: Comparative analysis of the present application and Comparative Example 1 Comparison dimension Comparative Example 1 Invention scheme Effect or difference explanation Water replenishment trigger mechanism Passive mechanical floating ball control Multi-signal fusion active control Improve response speed and accuracy Liquid level feedback method Floating ball / contact probe Upper and lower limit dual sensor (liquid level + overflow) Improve identification ability and accuracy Water replenishment adjustment mechanism Single switch water replenishment, unable to adjust flow Adjustable water replenishment flow, with flow increase / decrease control Avoid overshoot / deficiency, improve stability System adaptability Unable to adapt to liquid level fluctuations and evaporation superposition Support ±20mm liquid level dynamic deviation Stable control, strong adaptability Control response method Delayed response, water level prone to repeated overflow Real-time response, with "minimum water replenishment time" and "water stop period" judgment logic Intelligent adjustment, reduce false water replenishment Liquid waste control Easy over-replenishment or repeated overflow Automatic replenishment and stop, reduce waste Reduce medium waste, improve efficiency Adapt to mold products Unable to adapt to product changes Support K value and beat flexible configuration Intelligent adaptation to different molds Control mode flexibility Single automatic control Support automatic, static, and manual modes Three modes switch flexibly, adapt to different scenarios Table 2: Comparative analysis of the present application and Comparative Example 2 Comparison dimension Comparative Example 2 Invention scheme Effect or difference explanation Water replenishment trigger mechanism Triggered based on pressure change (requires stable water level data) Multi-signal fusion active judgment Improve response speed, avoid false action Liquid level feedback method Single-point liquid level / pressure collection Liquid level + overflow dual detection Higher accuracy, stronger reliability Water replenishment adjustment mechanism Fixed PID proportional adjustment Flexible adjustment of water replenishment flow / frequency Avoid overshoot / deficiency, improve stability System adaptability Only applicable to stable liquid level Applicable to dynamic working conditions with fluctuations above ±20mm Control is more stable, scenarios are more extensive Control response method PID delayed response, prone to repeated water level Real-time response, with "minimum water replenishment time" and "water stop period" judgment logic Adjustment is accurate, avoid false water replenishment Liquid waste control PID over-adjustment may overflow Timely water stop, dynamic control Reduce hot bath medium waste Adapt to mold products PID parameters are fixed Flexible adaptation of K value and beat t Intelligent adaptation to diversified production Control mode flexibility Single PID automatic mode Support three control mode switching Three modes switch flexibly, adapt to different scenarios Obviously, the above embodiments are merely example for clearly illustrating, and are not limitation to the embodiments. For ordinary skilled in the art, other different forms of changes or variations can be made on the basis of the above description. Here, all the embodiments need not and can not be exhausted. The obvious changes or variations derived therefrom are still within the scope of the present invention.

Claims

1. An automatic water replenishment system based on overflow detection, characterized in that: include: A liquid container for containing a hot bath medium, which is used to heat the workpiece during the hot bath stamping process; a liquid level detection unit, disposed in the liquid holding tank, for detecting whether the real-time liquid level in the liquid holding tank is lower than a set minimum liquid level; an overflow detection unit, disposed in the overflow trough of the liquid holding tank, for detecting whether the real-time liquid level in the liquid holding tank reaches or exceeds a set maximum liquid level, wherein the set maximum liquid level corresponds to the overflow line of the overflow trough; a water replenishment execution unit, connected to the liquid holding tank, for replenishing the hot bath medium into the liquid holding tank; and The control unit is electrically connected to the liquid level detection unit, the overflow detection unit and the water replenishment execution unit, and is used to: When the liquid level is lower than the set minimum liquid level, the water replenishment execution unit is controlled to start water replenishment at the original set water replenishment flow rate V0 during the initial water replenishment, and continue for at least a set minimum water replenishment time. ; If after the minimum water filling time After the filling, if the liquid level is still lower than the set minimum liquid level, the water supply flow rate is increased to an incremental water supply flow rate V1 higher than the water supply flow rate V0, and water supply is continued until the liquid level reaches the set minimum liquid level; When the liquid level reaches or exceeds the set maximum liquid level, the water replenishment execution unit is controlled to stop replenishing water and maintain the stopped state for a set stop replenishment period T 停 If the water replenishment cycle T is stopped 停 After the end, if the liquid level is still higher than the set maximum liquid level, the water replenishment closed state will continue to be maintained, and the initial flow rate when the next water replenishment is turned on will be set to a reduced water replenishment flow rate V2 lower than V0.

2. The automatic water replenishment system based on overflow detection according to claim 1, characterized in that: The liquid holding tank is provided with one or more overflow troughs, and the overflow troughs are connected to the liquid holding tank via a reflux pipe for recovering overflowed hot bath medium.

3. The automatic water replenishment system based on overflow detection according to claim 2, characterized in that: A baffle with adjustable height is provided at the overflow port of the overflow trough, which is used to adjust the overflow height of the overflow trough, thereby controlling the set maximum liquid level height.

4. The automatic water replenishment system based on overflow detection according to claim 1, characterized in that: The liquid level detection unit includes a liquid level sensor; And / or, the overflow detection unit includes any one of a pressure sensor, a resistance sensor, and a temperature sensor, or a combination of two or more thereof.

5. The automatic water replenishment system based on overflow detection according to claim 1, characterized in that: The water replenishment execution unit includes an electric control valve and a flow meter. The electric control valve is used to control the water replenishment switch state of the hot bath medium. The flow meter is used to monitor the actual water replenishment flow and feed back flow information to the control unit.

6. An automatic water replenishment control method based on overflow detection, applied to hot bath stamping dies, characterized in that: The steps include: S1. During the hot bath stamping stage using the hot bath stamping die, the overflow detection unit and the liquid level detection unit respectively detect whether the liquid level in the liquid holding tank has reached a set maximum liquid level or is lower than a set minimum liquid level, and output an overflow simulation signal or a water replenishment simulation signal to the signal processing unit when an abnormal liquid level is detected; S2. After receiving and processing the analog signal, the signal processing unit outputs a control signal to the control unit, which generates a water replenishment control instruction according to the following rules: When the liquid level is lower than the set minimum liquid level, the control unit controls the water replenishment execution unit to start water replenishment at the original set water replenishment flow rate V0 during the initial water replenishment, and continues for at least a set minimum water replenishment time. ; If after the minimum water filling time After the filling, if the liquid level is still lower than the set minimum liquid level, the water supply flow rate is increased to an incremental water supply flow rate V1 higher than the water supply flow rate V0, and water supply is continued until the liquid level reaches the set minimum liquid level; When the liquid level reaches or exceeds the set maximum liquid level, the control unit controls the water replenishment execution unit to stop replenishing water and maintain the stopped state for a set stop replenishment period T 停 If the water replenishment cycle T is stopped 停 After the end, if the liquid level is still higher than the set maximum liquid level, the water replenishment closed state will continue to be maintained, and the initial flow rate when the next water replenishment is turned on will be set to a reduced water replenishment flow rate V2 lower than V0.

7. The automatic water replenishment control method based on overflow detection according to claim 6, characterized in that: The water replenishment execution unit is normally open. The opening degree of the normally open mode corresponds to the originally set water replenishment volume V0. The original water replenishment volume V0 is calculated by statistically analyzing the change in static liquid level after the stamping trial is set to the number of stampings K. The specific formula is as follows: ， Among them, S 承液容箱 is the bottom area of ​​the liquid holding tank, K is the set number of stamping times, ΔH is the total height of the liquid level in the liquid holding tank dropped after the hot bath stamping die stamps K times, and t is the production cycle time of a single product.

8. The automatic water replenishment control method based on overflow detection according to claim 7, characterized in that: The water replenishment stop period T 停 =K×t 零件生产节拍 , K is the set number of stamping times, t is the production cycle time of a single product; the value of K varies depending on the product. For the first type of simple products, the value of K is 80-100, and for the second type of complex products, the value of K is 30-50; and / or, depending on the product, The values ​​are different. For the first type of simple products, ; For the second type of complex products, .

9. The automatic water replenishment control method based on overflow detection according to claim 6, characterized in that: The minimum liquid level height is defined as , the maximum liquid level height is defined as , ,in, The height of the highest point of the lower die forming process, h1 is 2 to 5 mm; ,in, The drag height of the drag rack is h2, which is 2 to 5 mm.

10. The automatic water replenishment control method based on overflow detection according to any one of claims 6 to 9, characterized in that: The control unit is also configured with an automatic static water replenishment mode and a manual mode, wherein: In the automatic static water replenishment mode, the liquid level detection unit is used to simultaneously detect whether the real-time liquid level is lower than the set minimum liquid level or exceeds the set maximum liquid level. The control unit generates a corresponding water replenishment on or off instruction based on the detection result to achieve stable control of the liquid level within the set range; In the manual water replenishment mode, the liquid level detection unit and the overflow detection unit do not participate in liquid level judgment. The control unit controls the water replenishment execution unit to perform quantitative water replenishment or continuous water replenishment according to the water replenishment execution unit opening parameter or water replenishment instruction input by the user.

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