Precise and quantitative hot melt adhesive supply device and method

Abstract

The invention discloses a hot melt adhesive precise quantitative supply device and method. The hot melt adhesive precise quantitative supply device comprises a rack, and a melting and conveying module, an intelligent temperature control system, a precise quantitative and adhesive discharging module and a main control system are arranged on the rack; the melting and conveying module comprises a melt glue tank used for melting solid hot melt glue and a fluid conveying pipeline used for conveying the molten hot melt glue, the fluid conveying pipeline comprises a main conveying pipe communicated with the melt glue tank and a glue supply pipe communicated with the main conveying pipe, and positive and negative spiral blades are arranged in the main conveying pipe; a conveying spiral blade is arranged in the glue supply pipe; the melting and conveying module further comprises a driving mechanism for driving the positive and negative spiral blade and the conveying spiral blade; through multi-module collaborative design and precise control, the quantitative precision, the response speed, the operation consistency and the material adaptability are all improved, and the requirements of precision and high speed in modern production can be met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fluid coating equipment, in particular to a hot melt adhesive precise quantitative feeding device and method. BACKGROUND

[0002] As an environmentally friendly adhesive, hot melt adhesive is widely used in product packaging, automobile manufacturing, medical and health care, electronic product assembly and many other fields due to its fast curing speed, no solvent volatilization, high bonding strength and other advantages. In these application scenarios, precise quantitative feeding of hot melt adhesive is often required, such as bottom filling of chips in microelectronic packaging, and coating of small glue points or thin glue lines in precision assembly. These processes require highly precise and consistent glue feeding, and any slight deviation may result in performance degradation or direct scrap.

[0003] Traditional hot melt adhesive feeding methods have many technical deficiencies and cannot meet the modern production requirements of precision and high speed. In terms of quantitative accuracy, it is difficult to achieve precise quantification when conveying milligram or microliter level of hot melt adhesive due to pulsation, lag or "dripping" problems. In terms of response speed, it is difficult to adapt to high-speed production rhythm due to slow start and stop speed of the equipment in scenarios such as electronic packaging and precision assembly that require rapid dispensing or on-demand spraying. In terms of consistency guarantee, it is difficult to maintain long-term and multi-batch operation stability due to the extreme sensitivity of hot melt adhesive viscosity to temperature, and small temperature fluctuations will cause glue output to change. In terms of equipment and material compatibility, hot melt adhesive is prone to carbonization, degradation and clogging of precision flow channels when it stays in the equipment for too long or is subjected to inappropriate shear heat, and the range of suitable materials is narrow. For new high-performance hot melt adhesives such as reaction type polyurethane (PUR) that require strict moisture and residence time, it is difficult to meet their process requirements.

[0004] Therefore, a hot melt adhesive precise quantitative feeding device and method are proposed to solve the problems mentioned above. SUMMARY

[0005] The present application aims to provide a hot melt adhesive precise quantitative feeding device and method to solve the problems of low quantitative accuracy, slow response speed, poor stability and limited material compatibility of traditional hot melt adhesive feeding methods, which cannot meet the modern production requirements of precision and high speed.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solution: a hot melt adhesive precise quantitative feeding device and method, comprising a rack, The rack is provided with a melting and conveying module, an intelligent temperature control system, a precise quantitative and glue discharging module, and a main control system. The melting and conveying module comprises a glue melting tank for melting solid hot melt adhesive and a fluid conveying pipeline for conveying the melted hot melt adhesive, the fluid conveying pipeline comprises a main conveying pipe in communication with the glue melting tank and a glue supply pipe in communication with the main conveying pipe, the main conveying pipe is provided with positive and negative helical blades, and the glue supply pipe is provided with conveying helical blades, the melting and conveying module further comprises a driving mechanism for driving the positive and negative helical blades and the conveying helical blades; The precise metering and glue discharging module comprises a metering cylinder, a metering driving motor drivingly connected to the metering cylinder, and a precise metering screw rod arranged in the metering cylinder, the inlet end of the metering cylinder is in fluid communication with the outlet end of the glue supply pipe through a glue conveying pipe, and the outlet end of the metering cylinder is provided with a glue dispensing nozzle. The intelligent temperature control system comprises a controller and temperature sensors arranged at multiple positions of the melting and conveying module and the precise metering and glue discharging module, the controller is configured to adjust the power output of the associated heating elements based on the signals of the temperature sensors to maintain the viscosity of the hot melt adhesive flowing through each position within a set range. The main control system is electrically connected with the driving mechanism, the intelligent temperature control system and the metering driving motor, and is configured to coordinate the control of the glue dispensing operation of the melting and conveying module, the intelligent temperature control system and the precise metering and glue discharging module.

[0007] Preferably, the driving mechanism comprises a conveying driving motor and a melting driving motor, the conveying driving motor is connected with the conveying helical blades through a conveying transmission assembly, and the melting driving motor is connected with the positive and negative helical blades through a transmission mechanism.

[0008] Preferably, the melting and conveying module further comprises a stirrer arranged at the bottom of the glue melting tank, and one end of the positive and negative helical blades is drivingly connected with the stirrer through a stirring transmission assembly.

[0009] Preferably, the fluid conveying pipeline further comprises a backflow storage cavity and a backflow pipe, the backflow storage cavity is in communication with the end of the main conveying pipe away from the glue melting tank, one end of the backflow pipe is in communication with the backflow storage cavity, and the other end of the backflow pipe is in communication with the glue supply pipe to form a backflow path of the hot melt adhesive.

[0010] Preferably, the intelligent temperature control system adopts a multi-stage PID temperature control strategy, and the temperature sensors are arranged at at least two of the glue melting tank, the main conveying pipe, the backflow storage cavity, the glue supply pipe, the glue conveying pipe, the metering cylinder and the glue dispensing nozzle.

[0011] Preferably, the main control system is configured to dynamically adjust the waveform, frequency or amplitude of the control signal sent to the metering driving motor according to the preset glue dispensing parameters and / or real-time feedback signals from the intelligent temperature control system to compensate for the glue dispensing amount online.

[0012] Preferably, the inside of the glue dispensing nozzle is provided with an anti-dripping structure configured to perform a back suction action or a mechanical shut-off action after the end of the discharge phase of glue dispensing to prevent glue from dripping or stringing at the end of the nozzle.

[0013] Preferably, the precise metering and glue dispensing module integrates and fixes the metering cylinder and the metering drive motor through the mounting base.

[0014] The application also includes a method for using the hot melt adhesive precise metering and dispensing device according to any one of claims 1-8, comprising the following steps: S1: heating and melting solid hot melt adhesive into liquid state in the hot melt glue tank; S2: driving the forward and reverse helical blade to rotate, conveying and uniformly mixing the melted hot melt adhesive from the hot melt glue tank through the main conveying pipe, and maintaining the temperature and viscosity of the hot melt adhesive stable during the conveying process through the intelligent temperature control system; S3: driving the conveying helical blade to rotate, pumping the hot melt adhesive from the glue supply pipe to the metering cylinder through the glue conveying pipe; S4: controlling the metering drive motor to drive the precise metering screw to rotate through the main control system, and discharging a predetermined amount of hot melt adhesive from the glue dispensing nozzle; S5: after the glue dispensing nozzle completes glue dispensing, triggering the anti-dripping structure inside the glue dispensing nozzle to perform a back suction or mechanical shut-off action.

[0015] Preferably, in the S4, the main control system dynamically adjusts the control of the metering drive motor according to the preset glue dispensing parameters and / or real-time feedback signals from the intelligent temperature control system to compensate for the glue dispensing amount in real time.

[0016] Compared with the prior art, the application has the following advantages: the hot melt adhesive precise metering and dispensing device and method improve the quantitative precision, response speed, operation consistency and material adaptability through multi-module collaborative design and precise control, and can meet the needs of precision and high speed in modern production, and the specific contents are as follows: Firstly, the precise metering and glue dispensing module adopts a metering cylinder and precise metering screw cooperation structure, which can accurately control the hot melt adhesive discharge amount under the drive of the metering drive motor, especially suitable for micro-supply scenarios of milligram or microliter level; the main control system can dynamically adjust the control signal (waveform, frequency or amplitude) of the metering drive motor according to the preset parameters and real-time feedback of the intelligent temperature control system, realize online compensation of the glue dispensing amount, effectively avoid the conveying pulsation and lag problem in the traditional way; at the same time, the anti-dripping structure built-in the glue dispensing nozzle can completely solve the dripping and stringing phenomenon after glue dispensing through back suction or mechanical shut-off action, further guaranteeing the quantitative precision.

[0017] Secondly, the coordination control of the main control system to each module, especially the dynamic regulation and control of the metering drive motor, can realize the rapid start and stop of the equipment, improve the response efficiency of the glue dispensing instruction; combined with the efficient transmission of the precision metering screw, it can meet the demand of fast glue dispensing or on-demand injection in electronic packaging, precision assembly and other scenes, and adapt to the rhythm requirements of modern high-speed production.

[0018] At the same time, the intelligent temperature control system adopts multi-section PID temperature control strategy, which monitors the temperature in real time through temperature sensors arranged in the glue melting tank, main conveying pipe, metering cylinder, glue dispensing nozzle and other key positions, and accurately adjusts the power of the heating elements of each part to ensure the temperature stability of the hot melt adhesive in the whole process of melting, conveying and glue dispensing, and then maintains its viscosity within the set range; At the same time, the forward and reverse helical blades in the melting and conveying module can fully mix the hot melt adhesive, and the bottom agitator can assist to improve the melting uniformity, reduce the glue output difference caused by uneven material or temperature fluctuation, and effectively ensure the consistency of long-time and multi-batch operation.

[0019] Finally, the backflow storage cavity and liquid return pipe arranged in the melting and conveying module constitute the hot melt adhesive backflow path, which can reduce the residence time of hot melt adhesive in the equipment, avoid carbonization and degradation caused by long-term residence or improper shear heat, and effectively reduce the thermal damage to hot melt adhesive. It is not only suitable for conventional hot melt adhesive, but also can meet the process requirements of new high-performance hot melt adhesive such as reaction type polyurethane PUR which has strict requirements on moisture and residence time, and broaden the application material range of the equipment. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a whole structure schematic diagram of the present application; Figure 2 It is another perspective structure schematic diagram of the present application Figure 1 ; Figure 3 It is a cross-sectional structure schematic diagram of the melting and conveying module in the present application; Figure 4 It is another perspective structure schematic diagram of the present application Figure 3 ; Figure 5 It is a cross-sectional structure schematic diagram of the metering cylinder in the present application.

[0021] In the figure: 1, rack; 2, melting and conveying module; 201, glue melting tank; 202, stirrer; 203, main conveying pipe; 204, forward and reverse helical blade; 205, backflow storage cavity; 206, glue supply pipe; 207, conveying drive motor; 208, conveying transmission assembly; 209, conveying helical blade; 210, melting drive motor; 211, stirring transmission assembly; 212, glue conveying pipe; 213, backflow pipe; 3, intelligent temperature control system; 4, precise metering and glue dispensing module; 401, mounting base; 402, metering cylinder; 403, metering drive motor; 404, precise metering screw; 405, glue dispensing nozzle; 5, main control system. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only 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 work fall within the scope of protection of the present application.

[0023] Please refer to Figures 1-5 The present application provides a technical solution: a hot melt adhesive precise metering and feeding device and method, aiming to realize automatic melting, stable conveying, precise metering and controllable glue dispensing of hot melt adhesive, and is suitable for scenarios with high requirements for glue quantity precision, such as electronic packaging, medical device assembly, packaging and printing. The device is integrated on the rack 1, mainly including four core modules: melting and conveying module 2, intelligent temperature control system 3, precise metering and glue dispensing module 4, and main control system 5. Each module works cooperatively through mechanical connection or electrical signal interaction to form a complete closed-loop control process from solid-state glue melting to quantitative glue dispensing.

[0024] Melting and conveying module 2: This module is responsible for converting solid hot melt adhesive into liquid and conveying it to the subsequent metering link. The core components include a glue melting tank 201, a fluid conveying pipeline, and a driving mechanism.

[0025] Glue melting tank 201: As the initial melting container for hot melt adhesive, it is internally provided with a heating element for heating the input solid hot melt adhesive (such as glue particles or blocks) to a molten state. The bottom of the glue melting tank 201 is provided with a stirrer 202 to preliminarily stir the molten glue liquid to avoid local overheating or precipitation and ensure the uniformity of the glue liquid.

[0026] Fluid conveying pipeline: used for conveying the molten glue liquid in the glue melting tank 201 to the precise metering and glue dispensing module 4, specifically including: Main conveying pipe 203: one end is in communication with the discharge port of the glue melting tank 201, and the inside is provided with positive and negative helical blades 204. The positive and negative helical blades 204 push the glue liquid at both ends forward by forward rotation, and can realize local reflux mixing by reverse rotation, effectively solve the problem of stratification or uneven viscosity of the glue liquid in the conveying process, and at the same time enhance the shearing action of the glue liquid to reduce the viscosity fluctuation.

[0027] Reflux storage cavity 205: in communication with the end of the main conveying pipe 203 away from the glue melting tank 201, as a buffer storage space for glue liquid, can balance the pressure fluctuation in the pipeline.

[0028] Glue supply pipe 206: one end is in communication with the reflux storage cavity 205 through the liquid return pipe 213, and the other end is connected with the precise metering and glue discharging module 4 through the glue conveying pipe 212. The inside of the glue supply pipe 206 is provided with conveying helical blades 209, which stably pump the glue liquid to the downstream through the rotation of the helical blades. The pitch of the conveying helical blades 209 is designed to adapt to the viscosity characteristics of the glue liquid, and the conveying flow is stable.

[0029] Liquid return pipe 213: both ends are connected with the reflux storage cavity 205 and the glue supply pipe 206 respectively, forming a circulating reflux path of hot melt adhesive. When the pressure of the glue liquid in the glue supply pipe 206 is too high, part of the glue liquid can flow back to the reflux storage cavity 205 through the liquid return pipe 213, avoiding the pressure of the pipeline, causing the flow fluctuation, and at the same time maintaining the dynamic circulation of the glue liquid in the pipeline, preventing local cooling and solidification.

[0030] Driving mechanism: providing power for the helical blades and the stirrer, including: Melting driving motor 210: connected with the positive and negative helical blades 204 in the main conveying pipe 203 through a transmission mechanism (belt transmission), driving the positive and negative helical blades 204 to rotate forward and backward. At the same time, one end of the positive and negative helical blades 204 is connected with the stirrer 202 at the bottom of the glue melting tank 201 through the stirring transmission assembly 211 (chain transmission), realizing the linkage of the stirrer and the positive and negative helical blades, simplifying the driving structure and reducing the energy consumption.

[0031] Conveying driving motor 207: connected with the conveying helical blades 209 in the glue supply pipe 206 through a conveying transmission assembly 208 (such as synchronous pulley set), driving the conveying helical blades 209 to rotate, and the rotating speed can be adjusted by the main control system 5 to adapt to different glue supply flow requirements.

[0032] Intelligent temperature control system 3: the system is used for real-time monitoring and adjusting the temperature of hot melt adhesive in the melting, conveying and metering process, ensuring that the viscosity of the glue liquid is stable within the set range, and the core includes a controller (such as PLC or special temperature control chip), multiple temperature sensors and associated heating elements.

[0033] Temperature sensor arrangement: Multi-point distributed monitoring, sensors are embedded or attached to the inner wall of the glue tank 201, the outer wall of the main conveying pipe 203, the bottom of the backflow storage cavity 205, the middle section of the glue supply pipe 206, the interface of the glue conveying pipe 212, the outer wall of the metering cylinder 402, and the end of the glue dispensing nozzle 405, etc. (covering at least 2 or more positions), real-time collection of glue temperature data at each link.

[0034] Temperature control strategy: Multi-section PID (Proportional-Integral-Derivative) temperature control algorithm is adopted. The controller receives real-time signals from each temperature sensor, compares them with the preset temperature threshold (set according to the type of hot melt adhesive, usually 100-200°C), and adjusts the power output of the heating elements (such as the glue tank heating rod, the conveying pipe heating tape, the metering cylinder heating sleeve, etc.) at the corresponding positions to achieve independent closed-loop control of the temperature at each link. For example, when the glue temperature in the main conveying pipe 203 is lower than the set value, the controller increases the power of the heating tape; when the temperature of the glue dispensing nozzle 405 is too high, it reduces the heating power, finally controls the viscosity fluctuation of the glue at each position within ±5%.

[0035] Precise dosing and glue dispensing module 4: This module is responsible for accurately metering and controlling the dispensing of the conveyed glue. The core components are integrated on the installation base 401, including the metering cylinder 402, the metering drive motor 403, the precision metering screw 404, and the glue dispensing nozzle 405.

[0036] Metering cylinder 402: As the cavity for glue metering, its inlet end is in fluid communication with the outlet end of the glue supply pipe 206 through the glue conveying pipe 212, and the inside is provided with a precision metering screw 404. The pitch and tooth type of the metering screw 404 are precisely machined (with a precision of 0.01 mm), forming a small gap (0.02-0.05 mm) with the inner wall of the metering cylinder 402. The volume of the pushed glue is accurately controlled by the number of rotations of the screw.

[0037] Metering drive motor 403: A servo motor (such as a permanent magnet synchronous servo motor) is used, which is drivingly connected to the precision metering screw 404 through a shaft coupling. Its rotation angle can be accurately controlled (with a control precision of 0.01°) by the main control system 5, thereby realizing the quantitative output of the glue amount, and the single glue dispensing amount can be controlled within ±0.001 ml.

[0038] Glue dispensing nozzle 405: Installed at the outlet end of the metering cylinder 402, its inner diameter is designed according to the glue dispensing amount requirement (usually 0.2-2 mm). The nozzle is provided with an anti-dripping structure, which can be implemented in the following two ways: Back suction type: After the metering drive motor 403 completes the glue dispensing action, the main control system 5 controls the motor to reverse a small angle, driving the precision metering screw 404 to rotate in the opposite direction, generating negative pressure to suck the glue at the end of the nozzle back, avoiding dripping.

[0039] Mechanical shut-off: built-in micro electromagnetic valve or needle valve, valve closes quickly after glue dispensing (response time <5ms), cutting off the glue liquid path, preventing stringing or dripping.

[0040] Mounting base 401: made of high-strength aluminum alloy material, the metering cylinder 402, metering drive motor 403 and related connecting parts are fixed as a whole through bolts, ensuring coaxiality and stability during transmission, reducing the influence of mechanical vibration on the accuracy of measurement.

[0041] Master control system 5: as the control core of the device, industrial-grade PLC or embedded controller is used, which is electrically connected with the melting drive motor 210, the conveying drive motor 207, the controller of the intelligent temperature control system 3 and the metering drive motor 403 through data lines, realizing the cooperative control of each module.

[0042] Core control function: receiving the dispensing parameters (such as single glue dispensing amount, glue dispensing speed, dispensing frequency, etc.) input by the user through the human-machine interface, and storing the preset parameter library.

[0043] Real-time acquisition of temperature and viscosity related signals (derived through temperature-viscosity conversion model) feedback by the intelligent temperature control system 3, when the glue viscosity deviates from the set range, dynamically adjusting the control signal (such as pulse waveform, frequency or voltage amplitude) of the metering drive motor 403, for example, appropriately increasing the motor speed to compensate for the flow loss when the viscosity increases, realizing online real-time compensation of the glue dispensing amount.

[0044] Coordinating the start-stop and speed of the melting and conveying module 2 to ensure that the glue supply matches the metering glue dispensing amount, avoiding glue accumulation or interruption in the pipeline.

[0045] The working principle of the device: solid hot melt adhesive is heated and melted in the glue melting tank 201, after preliminary mixing by the stirrer 202, it is pushed to the main conveying pipe 203 by the forward and reverse helical blade 204, and further mixed under the action of the forward and reverse helical blade; After the glue enters the reflux storage cavity 205, it enters the glue supply pipe 206 through the return pipe 213, and is stably pumped to the metering cylinder 402 by the conveying helical blade 209; The intelligent temperature control system 3 controls the temperature of each link in real time to ensure the stability of the glue viscosity; The master control system 5 controls the metering drive motor 403 to drive the precision metering screw 404 according to the preset parameters and temperature control feedback, and the quantitative glue is discharged from the dispensing nozzle 405, and the anti-dripping structure is started after glue dispensing, completing a dispensing cycle.

[0046] Based on the above device, the embodiment provides a hot melt adhesive precise quantitative supply method, comprising the following steps: S1: hot melt adhesive melting The solid hot melt adhesive (such as EVA particles) is put into the glue melting tank 201, and the main control system 5 starts the heating element of the glue melting tank. The controller of the intelligent temperature control system 3 controls the temperature in the tank to be at the melting temperature of the hot melt adhesive (such as 150°C) according to the signal of the temperature sensor in the tank, so that the solid adhesive gradually melts into a uniform liquid state.

[0047] S2: glue liquid conveying and mixing The main control system 5 starts the melting drive motor 210, and drives the forward and reverse helical blade 204 in the main conveying pipe 203 to rotate (the forward rotation speed is set to 50-100 r / min) through the transmission mechanism, and at the same time, the stir transmission assembly 211 drives the stirrer 202 at the bottom of the glue melting tank 201 to rotate synchronously (the rotation speed is 30-60 r / min).

[0048] The forward and reverse helical blade 204 pushes the molten glue liquid in the glue melting tank 201 to the main conveying pipe 203, and realizes local reflux of the glue liquid by periodic reverse rotation (such as 1-2 turns every 30 seconds), which enhances the mixing effect; the intelligent temperature control system 3 monitors the temperature of the main conveying pipe 203 and the reflux storage cavity 205 in real time, adjusts the power of the corresponding heating element, and maintains the glue liquid temperature at 145-155°C, ensuring the viscosity stability (such as 2000-3000 cP).

[0049] S3: Glue liquid pumping The main control system 5 starts the conveying drive motor 207, and drives the conveying helical blade 209 in the glue supply pipe 206 to rotate (the rotation speed is set to 80-150 r / min according to the glue supply requirement) through the conveying transmission assembly 208, pumps the glue liquid in the reflux storage cavity 205 into the glue supply pipe 206 through the liquid return pipe 213, and stably conveys it to the inlet end of the metering cylinder 402 through the glue conveying pipe 212; the intelligent temperature control system 3 synchronously controls the temperature of the glue supply pipe 206 and the glue conveying pipe 212, to ensure that the viscosity of the glue liquid does not fluctuate significantly during conveying.

[0050] S4: Precise quantitative glue discharging The main control system 5 receives the preset dispensing parameters (such as single glue discharging amount 0.01 ml, glue discharging speed 5 mm / s), combines the real-time viscosity data (such as current viscosity 2500 cP, higher than standard value by 5%) fed back by the intelligent temperature control system 3, dynamically adjusts the control signal of the metering drive motor 403: increases the original set rotation angle (such as 36°) by 2% to 36.72°, and optimizes the pulse frequency to match the viscosity change.

[0051] The metering drive motor 403 drives the precision metering screw 404 to rotate according to the adjusted signal, pushes the predetermined amount of hot melt adhesive in the metering cylinder 402 to the dispensing nozzle 405, and discharges it from the end of the nozzle to the surface of the workpiece to be dispensed.

[0052] S5: Anti-dripping control At the moment when the glue dispensing nozzle 405 finishes the glue dispensing action (judged by the motor encoder signal), the main control system 5 triggers the anti-dripping structure: if it is a back-suction type, the metering drive motor 403 is controlled to rotate reversely by 0.5° to generate negative pressure to suck the glue at the end of the nozzle; if it is a mechanical shut-off type, the electromagnetic valve is controlled to close quickly (response time 3 ms) to cut off the glue passage to prevent dripping or stringing phenomenon.

[0053] Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can make modifications to the technical solutions recorded in the foregoing embodiments, or make equivalent replacements to some of the technical features, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A precision metering device for hot melt adhesive, comprising a frame (1), characterized in that: The frame (1) is equipped with a melting and conveying module (2), an intelligent temperature control system (3), a precision quantitative dispensing module (4), and a main control system (5). The melting and conveying module (2) includes a melting tank (201) for melting solid hot melt adhesive and a fluid conveying pipeline for conveying the melted hot melt adhesive. The fluid conveying pipeline includes a main conveying pipe (203) connected to the melting tank (201) and a glue supply pipe (206) connected to the main conveying pipe (203). The main conveying pipe (203) is provided with a forward and reverse spiral blade (204), and the glue supply pipe (206) is provided with a conveying spiral blade (209). The melting and conveying module (2) also includes a driving mechanism for driving the forward and reverse spiral blade (204) and the conveying spiral blade (209). The precision metering and dispensing module (4) includes a metering cylinder (402), a metering drive motor (403) connected to the metering cylinder (402), and a precision metering screw (404) disposed in the metering cylinder (402). The inlet end of the metering cylinder (402) is fluidly connected to the outlet end of the glue supply pipe (206) through the glue delivery pipe (212). The outlet end of the metering cylinder (402) is provided with a dispensing nozzle (405). The intelligent temperature control system (3) includes a controller and temperature sensors arranged in multiple locations in the melting and conveying module (2) and the precision metering and dispensing module (4); the controller is configured to adjust the power output of the associated heating element based on the signal from the temperature sensor in order to maintain the viscosity of the hot melt adhesive flowing through each location within a set range. The main control system (5) is electrically connected to the drive mechanism, the intelligent temperature control system (3) and the metering drive motor (403), and is configured to coordinate and control the dispensing operation of the melting and conveying module (2), the intelligent temperature control system (3) and the precision metering and dispensing module (4).

2. The hot melt adhesive precision metering device according to claim 1, characterized in that: The driving mechanism includes a conveying drive motor (207) and a melting drive motor (210). The conveying drive motor (207) is connected to the conveying spiral blade (209) through a conveying transmission assembly (208), and the melting drive motor (210) is connected to the forward and reverse spiral blades (204) through a transmission mechanism.

3. The hot melt adhesive precision metering device according to claim 2, characterized in that: The melting and conveying module (2) also includes a stirrer (202) disposed at the bottom of the melt tank (201), and one end of the positive and negative spiral blades (204) is connected to the stirrer (202) via a stirring transmission assembly (211).

4. The hot melt adhesive precision metering device according to claim 1, characterized in that: The fluid delivery pipeline also includes a reflux storage chamber (205) and a return pipe (213). The reflux storage chamber (205) is connected to the end of the main delivery pipe (203) away from the melt tank (201). One end of the return pipe (213) is connected to the reflux storage chamber (205), and the other end is connected to the glue supply pipe (206) to form a reflux path for hot melt adhesive.

5. The hot melt adhesive precision metering device according to claim 1, characterized in that: The intelligent temperature control system (3) adopts a multi-segment PID temperature control strategy. The temperature sensor is arranged in at least two of the following locations: the melt tank (201), the main delivery pipe (203), the return storage chamber (205), the glue supply pipe (206), the glue delivery pipe (212), the metering cylinder (402), and the glue dispensing nozzle (405).

6. The hot melt adhesive precision metering device according to claim 1, characterized in that: The main control system (5) is configured to dynamically adjust the waveform, frequency or amplitude of the control signal sent to the metering drive motor (403) according to the preset dispensing parameters and / or the real-time feedback signal from the intelligent temperature control system (3) in order to compensate the dispensing amount online.

7. The hot melt adhesive precision metering device according to claim 1, characterized in that: The dispensing nozzle (405) is provided with an anti-drip structure inside. The anti-drip structure is configured to perform a back suction action or a mechanical shut-off action after the dispensing discharge stage is completed, so as to prevent the adhesive from dripping or stringing at the end of the nozzle.

8. The hot melt adhesive precision metering device according to claim 1, characterized in that: The precision metering and dispensing module (4) integrates and fixes the metering cylinder (402) and the metering drive motor (403) through the mounting base (401).

9. A method using the hot melt adhesive precision metering device as described in any one of claims 1-8, characterized in that, Includes the following steps: S1: The solid hot melt adhesive is heated and melted into a liquid state in the melt tank (201); S2: Drive the forward and reverse spiral blades (204) to rotate, and transport the molten hot melt adhesive from the melt tank (201) through the main conveying pipe (203) and mix it. At the same time, the intelligent temperature control system (3) maintains the temperature and viscosity of the hot melt adhesive during the conveying process. S3: Drive the conveying spiral blade (209) to rotate, and pump the hot melt adhesive from the glue supply pipe (206) to the metering cylinder (402) via the glue delivery pipe (212). S4: The main control system (5) controls the metering drive motor (403) to drive the precision metering screw (404) to rotate, and discharges a predetermined amount of hot melt adhesive from the dispensing nozzle (405); S5: After the dispensing nozzle (405) completes dispensing, it triggers the internal anti-drip structure to perform a back suction or mechanical shut-off action.

10. The method according to claim 9, characterized in that, In S4, the main control system (5) dynamically adjusts the control of the metering drive motor (403) according to the preset dispensing parameters and / or the real-time feedback signal from the intelligent temperature control system (3) to compensate for the dispensing amount in real time.

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