Glue quantity control structure of glue dispenser

Abstract

The glue amount control structure comprises a glue dispensing barrel, a glue outlet head is arranged at the front end of the glue dispensing barrel, the rear end of the glue dispensing barrel is communicated with a glue inlet pipe, and a first adjusting barrel with the lower end open and the upper end closed is fixed in the glue dispensing barrel; a second adjusting cylinder with an open lower end and a closed upper end is fixed in the first adjusting cylinder; the diameter of the first adjusting cylinder is smaller than that of the dispensing cylinder; the diameter of the second adjusting cylinder is smaller than that of the first adjusting cylinder; the rear end of the second adjusting cylinder backwards penetrates through the upper end of the first adjusting cylinder in a sealed mode. A sealing sliding piston body is arranged in the second adjusting cylinder, and the sliding piston body divides the second adjusting cylinder into an upper air cavity and a lower adjusting cavity up and down; the rear end of the second adjusting cylinder is communicated with a pulse exhaust pipe; the technical performance of the dispensing device in precision, adaptability, efficiency and quality is remarkably improved, and particularly through collaborative optimization of negative pressure driving and back suction, many bottleneck problems in a traditional positive pressure technology and an existing negative pressure back suction technology are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of glue dispensing equipment, in particular to a glue quantity control structure of a glue dispensing machine. Background Art

[0002] Glue dispensing technology is widely used in electronic packaging, automobile manufacturing, biomedical equipment, precision machining and other fields. The main function of the glue dispensing device is to accurately apply the glue liquid to the target position in a set amount to meet the production process requirements. Traditional glue dispensing devices mainly use positive pressure to promote the flow of glue liquid to achieve glue discharge control, but this technology has many limitations in practical applications: 1. Limitations of positive pressure propulsion technology 1.1 The amount of glue output is difficult to accurately control When positive pressure pushes the glue, the amount of glue discharged is affected by many factors such as the cross-sectional area of ​​the dispensing tube, the pressure, and the viscosity of the glue. Especially when dispensing a small amount of glue, the accuracy of positive pressure pushing is difficult to meet high-demand application scenarios, such as microelectronics packaging, biomedicine and other fields, which need to control the dispensing volume to the μL level. The pressure fluctuation in traditional positive pressure technology can easily lead to uneven flow of glue or uncontrolled flow, affecting the dispensing quality.

[0003] 1.2 Poor adaptability to high viscosity glue When high-viscosity glue is pushed by positive pressure, due to the large flow resistance, higher pressure is required to promote flow. However, high pressure can easily lead to the phenomenon of "jetting" of glue, making it difficult to achieve stable and linear flow, especially when the dispensing path is long or complex. The problem is particularly serious. High pressure push will also cause greater mechanical stress on the dispensing device itself, shortening the service life of the device.

[0004] 1.3 The glue dripping phenomenon is difficult to completely solve After the glue is dispensed, due to inertia, excess glue often remains at the glue dispensing head, causing glue dripping or overflowing. Although some technologies use suction devices (such as reverse pressure or mechanical valves) to alleviate this problem, the glue dripping problem is still difficult to completely solve, especially in high-frequency or micro-dispensing operations, residual glue will significantly affect the dispensing accuracy.

[0005] 1.4 High energy consumption and low efficiency Traditional positive pressure dispensing devices need to continuously provide high pressure to drive the glue to flow, especially for high-viscosity glue, which requires a higher-power air pump, resulting in high energy consumption and low operating efficiency.

[0006] 2. Application and shortcomings of negative pressure suction technology In order to prevent glue dripping, some existing technologies have introduced a negative pressure suction mechanism, which generates negative pressure after dispensing to suck back the residual glue to avoid dripping. However, this technology is mostly passive design and has the following problems: Single function: Negative pressure suction is usually only used to prevent glue dripping, but does not play a role in glue flow control, and cannot accurately control the amount of glue dispensed.

[0007] Low suction efficiency: The existing suction design is mostly limited by the response speed of the air pump, which can easily lead to insufficient or excessive suction, and the residual glue cannot be completely removed, affecting the next dispensing.

[0008] Poor synergy with positive pressure control: Negative pressure suction is only an additional function, lacking organic combination with positive pressure propulsion technology, and the overall control efficiency and adaptability are low.

[0009] 3. Challenges to the inertial thinking of existing technologies Traditional dispensing devices generally use positive pressure to drive the glue flow, and on this basis superimpose back suction or other auxiliary functions. This technical route is limited by inertial thinking and fails to break through the following bottlenecks: The dispensing volume control and anti-drip functions are usually designed separately, making it difficult to achieve coordinated optimization.

[0010] The idea of ​​solving the problem of dispensing quantity control by improving the positive pressure accuracy is restricted by many factors such as device complexity, energy consumption, and adaptability, and the optimization space is limited.

[0011] The improvement of dispensing performance of high-viscosity glue is still at the level of pressure enhancement, and no breakthrough has been made in flow path optimization and glue control mechanism.

[0012] 4. Technical issues that need to be resolved Based on the above analysis, there are the following core problems to be solved in the prior art: How to accurately control the amount of glue discharged: A dispensing technology is needed that can adapt to different glue viscosities and achieve μL-level precision control, especially to solve the problem that the flow rate in positive pressure push is affected by the cross-sectional area and pressure fluctuations.

[0013] How to effectively prevent glue dripping: A technology is needed that can completely eliminate the residual glue from the glue head after dispensing is completed, while ensuring the stability and accuracy of the next dispensing operation.

[0014] How to improve the dispensing performance of high-viscosity glue: It is necessary to break through the bottleneck of existing positive pressure push and solve the problems of flow loss control and turbulence in the dispensing of high-viscosity glue from the perspective of flow path optimization and pressure mechanism improvement.

[0015] How to reduce energy consumption and improve efficiency: A dispensing device with lower energy consumption and higher efficiency is needed, especially in high-frequency dispensing and long-term operation scenarios, to solve the high energy consumption problem of the positive pressure push system.

[0016] How to overcome the limitations of inertial thinking: It is necessary to break through the limitations of traditional positive pressure technology and propose a new dispensing control mode to enable glue output control and glue drip prevention to work together and expand the scope of application of dispensing technology. Summary of the invention

[0017] The purpose of the present invention is to provide a glue quantity control structure for a glue dispensing machine. Through innovative design, the present invention significantly improves the technical performance of the glue dispensing device in terms of accuracy, adaptability, efficiency and quality. In particular, through the coordinated optimization of negative pressure drive and back suction, many bottleneck problems in traditional positive pressure technology and existing negative pressure back suction technology are solved, and the present invention has broad application value and promotion prospects.

[0018] The technical solution adopted by the present invention is as follows: The glue quantity control structure of the glue dispensing machine includes a glue dispensing cylinder, a glue outlet head is arranged at the front end of the glue dispensing cylinder, and a glue inlet pipe is connected to the rear end. A first adjustment cylinder with an open lower end and a closed upper end is fixed in the dispensing cylinder; a second adjustment cylinder with an open lower end and a closed upper end is fixed in the first adjustment cylinder; The diameter of the first adjustment cylinder is smaller than that of the dispensing cylinder, and the diameter of the second adjustment cylinder is smaller than that of the first adjustment cylinder; The rear end of the second adjusting cylinder is sealed backward and passes through the upper end of the first adjusting cylinder; A sealed sliding piston body is arranged in the second adjusting cylinder, and the sliding piston body divides the second adjusting cylinder into an upper air chamber and a lower adjusting chamber; The rear end of the second regulating cylinder is connected to a pulse exhaust pipe.

[0019] Wherein, a reducing ring is arranged at the lower end of the first adjusting cylinder; the reducing ring has an outwardly convex arc surface from the outside to the inside, so as to guide the flow of the glue liquid by utilizing the surface effect of the glue liquid.

[0020] The first adjusting cylinder is fixedly connected to the glue dispensing cylinder through a plurality of connecting rods, and the connecting rods are distributed at equal intervals to ensure the stability of the first adjusting cylinder and the smooth flow path of the glue liquid.

[0021] The sliding piston body is designed to be sealable and slideable, and its moving position is driven by the pressure difference in the upper air cavity, and the pressure difference is generated by an external precise pulse air pump through a pulse suction pipe.

[0022] Wherein, the sliding piston body is provided with an elastic sealing ring in the second adjusting cylinder, so as to improve the sealing performance and wear resistance of the sliding piston body in high-frequency operation.

[0023] Wherein, the pulse exhaust pipe is connected to an external precise pulse air pump, and the precise pulse air pump can instantly extract a certain amount of gas to form a negative pressure in the upper air cavity, thereby driving the sliding piston body to move upward.

[0024] The pumping rate of the pulse pumping tube is adjustable within a rate adjustment range of 0.01 to 0.5 liters per second to meet the dispensing requirements of glues with different viscosities.

[0025] A method for controlling the amount of glue of a glue dispensing machine comprises the following steps: S1. Use an external precise pulse air pump to instantly extract a certain amount of gas through the pulse air extraction pipe to form a negative pressure in the upper air cavity; S2. The negative pressure in the upper air chamber drives the sliding piston body to move upward, thereby forming a negative pressure in the lower regulating chamber; S3. The negative pressure in the lower regulating chamber attracts the external glue liquid into the regulating chamber, and at the same time attracts two parts of glue liquid: The glue between the first regulating cylinder and the second regulating cylinder moves downward, so that negative pressure is generated in the upper space of the first regulating cylinder, and the negative pressure takes effect after the dispensing is completed; The glue liquid near the reduced diameter ring arc surface in the glue dispensing cylinder moves downward, generating downward pressure, squeezing the glue liquid near the glue dispensing head to flow out, thus achieving glue dispensing; S4. After dispensing is completed, disconnect the pulse air pump from the external air pump to connect the upper air cavity to the outside world and restore atmospheric pressure; S5. The sliding piston body gradually falls back downward. During the falling process, the glue liquid in the first regulating cylinder is sucked back and moved upward under the action of negative pressure, thereby alleviating the pressure caused by the downward movement of the sliding piston body, avoiding the glue liquid from overflowing or dripping due to the pressure, and finally restoring the sliding piston body to its initial position, preparing for the next dispensing operation.

[0026] The convex arc surface of the reducing ring forms a surface effect during the flow of the glue liquid, and the surface effect can guide the glue liquid to flow stably along the arc surface and squeeze the glue liquid close to the glue outlet head out through the negative pressure effect.

[0027] The present invention provides a glue quantity control structure for a glue dispenser that realizes glue output control through negative pressure drive and dynamic back suction mechanism, which combines a multi-stage adjustment cylinder structure, a sliding piston body negative pressure drive, a liquid seal and an optimized design of the surface effect, overcomes many shortcomings of traditional positive pressure technology and existing negative pressure back suction technology, and can not only realize accurate control of glue output, but also effectively prevent glue dripping, with significant technical advantages and innovation. The following are the beneficial effects of the present invention: 1. Achieve precise control of glue output (1) Negative pressure drive control to improve glue dispensing accuracy The present invention adopts negative pressure drive instead of traditional positive pressure drive, and instantly extracts a certain amount of gas through the pulse suction pipe to form negative pressure in the upper air cavity, thereby driving the sliding piston body to move, and indirectly and accurately controlling the flow of the glue liquid. The accuracy of negative pressure control is directly related to the amount of air pumped, avoiding the phenomenon of uncontrolled glue output caused by the cross-sectional area of ​​the cylinder and pressure fluctuations in traditional positive pressure technology, and is particularly suitable for μL-level micro-dispensing needs.

[0028] (2) Multi-stage regulating cylinder structure optimizes flow The present invention manages the flow path of the glue liquid in sections through the multi-stage design of the first regulating cylinder and the second regulating cylinder: The lower regulating chamber of the second regulating cylinder directly controls the flow rate of the glue liquid accurately through negative pressure.

[0029] The liquid seal design of the first regulating cylinder and the surface effect of the reducing ring optimize the flow path of the glue liquid to ensure uniform and stable glue discharge.

[0030] The multi-stage adjustment cylinder structure significantly improves the accuracy of glue output and flow stability, and is suitable for high-precision dispensing scenarios.

[0031] (3) Surface effect further optimizes flow performance The reducing ring at the lower end of the first adjusting cylinder uses an outer convex arc surface design to guide the adhesive liquid to adhere to the flow through the surface effect, avoiding turbulence and bubble problems in the flow path. The combination of surface effect and negative pressure drive not only improves the linear stability of the adhesive liquid flow, but also significantly optimizes the dispensing performance of high-viscosity adhesive liquid.

[0032] 2. Effectively prevent glue dripping (1) Liquid seal design achieves dynamic balance The present invention uses the liquid seal structure in the first regulating cylinder to seal the upper space with the glue liquid, thereby preventing air from entering the flow path and ensuring the flow stability of the glue liquid. After the glue dispensing is completed, the liquid seal structure sucks back the residual glue liquid under the action of negative pressure, dynamically neutralizes the pressure generated by the downward movement of the sliding piston body, and avoids glue liquid residue and dripping at the glue outlet.

[0033] (2) Linked suction of the sliding piston body When the sliding piston moves downward, the negative pressure draws the glue back to the upper part of the regulating cylinder, effectively eliminating the residual glue in the glue dispensing path. The pulse suction volume can be adjusted to ensure appropriate suction, which can prevent glue dripping due to insufficient suction and avoid excessive suction affecting the next dispensing.

[0034] 3. High viscosity glue has strong applicability (1) Flow path optimization The present invention manages the flow path of high-viscosity glue in sections through negative pressure drive and multi-stage regulating cylinders, avoiding the problem of uncontrolled glue flow due to insufficient or excessive pressure in traditional positive pressure technology. The surface effect of the reduction ring optimizes the flow performance of high-viscosity glue, allowing it to flow smoothly and reduce flow resistance.

[0035] (2) No need for high pressure, reducing system stress High-viscosity glue needs to be applied with high pressure in traditional positive pressure technology, which easily generates large mechanical stress on the glue dispensing tube and glue dispensing head, affecting the life of the device. The present invention gradually attracts the high-viscosity glue to flow through negative pressure, which not only achieves stable flow control, but also avoids the loss of device components caused by high pressure, and has wider applicability.

[0036] 4. Reduce energy consumption and improve system efficiency (1) Energy-saving design of instantaneous air extraction The present invention only forms negative pressure through pulsed air extraction, without the need to continuously provide high pressure, which significantly reduces the energy consumption in the dispensing operation. Compared with the traditional positive pressure technology, the negative pressure drive mechanism is more efficient and is particularly suitable for long-term and high-frequency dispensing scenarios, while avoiding abnormal increase in the glue liquid temperature due to frequent application of large positive pressure.

[0037] (2) Simplify the device structure and reduce maintenance costs Negative pressure control combined with sliding piston body design eliminates the need for complex pressure regulating devices or mechanical valves, simplifies the system structure, and reduces the difficulty and cost of device maintenance.

[0038] 5. High frequency dispensing and micro dispensing support (1) Fast response to adapt to high frequency dispensing The sliding piston body has a fast response capability under negative pressure drive, and can quickly complete the glue dispensing and suction operations, which is suitable for high-frequency dispensing scenarios. The combination of negative pressure and surface effect maintains the stability and uniformity of the flow rate in high-frequency operations, significantly improving production efficiency.

[0039] (2) Precise adaptation for micro dispensing By adjusting the pulsed air pumping volume, the present invention can achieve μL-level precise dispensing, and is suitable for application scenarios requiring extremely high precision, such as microelectronic packaging and biomedical device manufacturing.

[0040] 6. Technological innovation and breakthrough of conventional thinking (1) Overcoming the limitations of traditional positive pressure technology The present invention breaks the idea of ​​positive pressure driving in traditional dispensing technology and realizes high precision and high adaptability of glue dispensing amount control by introducing negative pressure driving. Negative pressure driving not only optimizes the glue flow control, but also effectively solves the glue dripping problem that is difficult to avoid in positive pressure technology through dynamic back suction.

[0041] (2) From passive resuscitation to active drive and resuscitation coordination Traditional negative pressure technology is mostly used to prevent passive back suction of glue drops. The present invention expands negative pressure into a core driving mode, realizes the coordinated optimization of glue dispensing quantity control and dripping prevention, and creates a new glue dispensing control mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of the appearance of the glue quantity control structure of the glue dispensing machine of the present invention; Figure 2 It is a cross-sectional schematic diagram of the glue quantity control structure of the glue dispensing machine of the present invention; Figure 3 It is a schematic diagram of the glue quantity control structure of the glue dispensing machine of the present invention in a normal state; Figure 4 It is a schematic diagram of the glue quantity control structure of the glue dispensing machine of the present invention during glue dispensing; Figure 5 It is a schematic diagram of the glue quantity control structure of the glue dispensing machine of the present invention when glue dispensing is finished.

[0043] Markings in the figure: 1, glue dispensing cylinder; 2, glue outlet head; 3, glue inlet hose; 4, first adjusting cylinder; 41, reducing ring; 42, connecting rod; 5, second adjusting cylinder; 51, sliding piston body; 52, upper air chamber; 53, lower adjusting chamber; 54, pulse exhaust pipe. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0045] See also Figures 1 to 5 This invention relates to a glue quantity control structure of a glue dispenser, and the overall structure is as follows: Dispensing cartridge 1: The glue dispensing cylinder 1 is the main body of the device and is used to store glue liquid.

[0046] The front end of the glue dispensing cylinder 1 is provided with a glue dispensing head 2 for accurately releasing the glue liquid.

[0047] The rear end of the glue dispensing cylinder 1 is connected to an external glue supply source through a glue inlet pipe 3 to facilitate continuous material supply.

[0048] First adjustment cylinder 4: The first adjustment cylinder 4 is fixedly installed inside the glue dispensing cylinder 1 , with its lower end open and upper end closed, and is located in the middle position inside the glue dispensing cylinder 1 .

[0049] The diameter of the first regulating cylinder 4 is smaller than that of the dispensing cylinder 1 , and a secondary flow path of the glue is formed by size restriction.

[0050] A reducing ring 41 is provided at the lower end of the first adjusting cylinder 4. The reducing ring 41 has a convex arc surface design from outside to inside to guide the flow of the glue liquid by utilizing the surface effect, avoid turbulence, and ensure that the glue liquid flows to the glue outlet head 2 in a stable manner.

[0051] Second adjustment cylinder 5: The second adjusting cylinder 5 is installed in the first adjusting cylinder 4 , with its lower end open and upper end closed, and its diameter is smaller than the first adjusting cylinder 4 .

[0052] The rear end of the second regulating cylinder 5 seals and passes through the upper end of the first regulating cylinder 4 , and is connected to the pulse exhaust pipe 54 through the rear end thereof.

[0053] A sliding piston body 51 is disposed in the second regulating cylinder 5 , dividing the second regulating cylinder 5 into an upper air chamber 52 and a lower regulating chamber 53 .

[0054] Sliding piston body 51: The sliding piston body 51 is designed to be sealable and slidable, and its moving position is driven by the pressure difference of the upper air chamber 52 .

[0055] An elastic sealing ring is arranged around the sliding piston body 51 to improve the sliding sealing performance and ensure that the device does not have sealing failure during high-frequency operation.

[0056] The upward and downward movement of the sliding piston body 51 is driven by the negative pressure provided by the pulse suction pipe 54 .

[0057] Pulse exhaust pipe 54: The pulse exhaust pipe 54 is connected to an external precise pulse air pump, and can instantly extract a certain amount of gas to form a negative pressure in the upper air cavity 52 .

[0058] The suction rate of the pulse suction tube 54 is adjustable, and the rate range is 0.01 to 0.5 liters per second to meet the dispensing requirements of glues with different viscosities.

[0059] Fixing of the first adjusting cylinder 4: The first adjustment cylinder 4 is fixed by a plurality of equally spaced connecting rods 42 or an elastically stretched frame and detachably fixed inside the dispensing cylinder 1 to ensure its installation stability.

[0060] The design of the connecting rod 42 or the elastically expanded frame not only increases the structural strength, but also ensures that the flow path of the glue is unobstructed.

[0061] Glue dispensing method of glue quantity control structure of glue dispensing machine: In order to achieve precise control of the glue flow and dispensing amount, this device is operated through the following steps: S1: Negative pressure The external precise pulse air pump is started to instantly extract a certain amount of gas through the pulse air extraction pipe 54 , so that negative pressure is formed in the upper air cavity 52 .

[0062] The negative pressure of the upper air chamber 52 acts on the lower regulating chamber 53 through the sliding piston body 51, forming a downward attractive force.

[0063] S2: Movement of the sliding piston body Under the action of negative pressure, the sliding piston body 51 moves upward to expand the volume of the lower regulating chamber 53 , thereby forming negative pressure in the lower regulating chamber 53 .

[0064] At this time, the negative pressure attracts the external glue liquid into the lower regulating chamber 53.

[0065] S3: Attraction and flow of two parts of glue The first part of the glue liquid: The glue liquid between the first regulating cylinder 4 and the second regulating cylinder 5 is sucked under the negative pressure, and the upper space in the first regulating cylinder 4 generates negative pressure. This negative pressure can suck back the glue liquid after the glue dispensing is completed to prevent dripping or overflowing of glue.

[0066] The second part of the glue: The glue near the arc surface of the reduction ring 41 in the dispensing cylinder 1 is driven to move downward, generating downward pressure during the flow. The outer convex arc surface of the reduction ring 41 guides the glue to flow through the surface effect, and finally squeezes the glue near the dispensing head 2 to flow out, completing the dispensing action.

[0067] S4: Pressure recovery after dispensing After the dispensing is completed, the pulse suction pipe 54 is disconnected from the external air pump, so that the upper air cavity 52 is connected to the outside and the atmospheric pressure is restored.

[0068] As the pressure is restored, the sliding piston body 51 gradually falls back downward.

[0069] S5: Suction and reset When the sliding piston body 51 moves downward, the glue liquid in the first regulating cylinder 4 is sucked back to the upper space of the first regulating cylinder 4 under the action of negative pressure to neutralize the pressure caused by the downward movement of the sliding piston body 51 and prevent excess glue liquid from dripping from the glue outlet 2.

[0070] Finally, the sliding piston body 51 returns to its initial position, ready for the next dispensing operation.

[0071] This device is suitable for the field of precision dispensing, such as microelectronics packaging, medical device manufacturing, automotive parts gluing, etc. It is particularly suitable for precise dispensing of high-viscosity glue, with good adaptability, repeatability and efficiency.

[0072] This embodiment achieves precise control of the flow rate and dispensing amount of glue by optimizing the dispensing device structure and dispensing method, and has the characteristics of high precision, low loss and high adaptability. It is particularly suitable for scenarios requiring micro-dispensing or high-viscosity glue application. The device of the present invention can be combined with most of the existing, especially small dispensing mechanisms, to achieve significant optimization, as shown below: Case 1: Micro dispensing in the field of electronic packaging In electronic packaging, processes such as chip bonding and solder joint protection require precise coating of μL-level glue (such as conductive glue, epoxy resin glue, etc.) at the target location. The glue dispensing amount must be extremely precise, and there must be no overflow or dripping of glue, so as not to affect the circuit performance.

[0073] Disadvantages of traditional technology: Positive pressure dispensing is difficult to achieve precise control at the μL level, and the amount of glue discharged can easily be too much or too little due to pressure fluctuations.

[0074] High-viscosity conductive adhesives are easily "sprayed" under positive pressure, resulting in uneven dispensing or excessive dispensing.

[0075] After dispensing is completed, glue often remains at the dispensing head, causing glue dripping and contaminating the circuit board.

[0076] Application of the present invention: The present invention drives the sliding piston body 51 by negative pressure, and combines the precise control of the pulse exhaust pipe 54 to achieve precise μL-level flow control of the glue liquid.

[0077] The surface effect of the reducing ring 41 ensures the stable flow of the adhesive liquid, and even the high-viscosity conductive adhesive can be dispensed evenly.

[0078] After dispensing is completed, the dynamic suction mechanism sucks back the residual glue to completely prevent glue dripping or overflowing.

[0079] In actual tests, through precise control of pulsed air extraction, the present invention can achieve a glue dispensing volume accurate to 1.5 μL each time, and the glue dispensing error is controlled within ±0.1 μL.

[0080] After dispensing, there is no dripping from the glue head, and the workbench and circuit board remain clean.

[0081] Compared with the traditional positive pressure technology, the present invention has significant advantages in precise control and anti-drip capability.

[0082] Case 2: High viscosity glue coating in automotive parts processing During the automobile manufacturing process, the gluing of door sealing strips requires the use of high-viscosity sealant, which is evenly applied over a long path. At the same time, the amount of glue needs to be precisely controlled to avoid glue overflow and affect the sealing performance.

[0083] Disadvantages of traditional technology: High-viscosity sealants require high pressure to drive flow, but positive pressure can easily lead to uneven coating of the glue, resulting in glue accumulation in multiple places or intermittent flow.

[0084] After the positive pressure push ends, the inertia of the glue liquid often causes glue dripping or residue at the glue dispensing head, affecting subsequent operations.

[0085] Application of the present invention: The negative pressure drive combined with the multi-stage regulating cylinder structure allows the high-viscosity glue to gradually and smoothly transition in the flow path, avoiding flow loss or accumulation.

[0086] The arc surface design of the reducing ring 41 guides the flow of the adhesive liquid by utilizing the surface effect, thereby improving the coating uniformity of the adhesive liquid on a long path.

[0087] The dynamic suction mechanism prevents dripping after glue application and keeps the workbench clean.

[0088] In the door seal glue coating test, the present invention can control the glue to be evenly coated on a 20-meter path, and the glue thickness error is less than ±0.05mm.

[0089] After gluing is completed, there is no residual glue on the gluing head and no additional cleaning is required, which significantly improves production efficiency.

[0090] Case 3: Precision dispensing of biomedical devices In the manufacturing of medical devices, such as the assembly of insulin injection devices or test kits, biocompatible glue needs to be applied between tiny parts. The dispensing volume is usually required to be 2-5μL, and no overflow of glue should occur to avoid affecting the accuracy of the device or contaminating the reagents.

[0091] Disadvantages of traditional technology: Positive pressure technology cannot achieve μL-level dispensing accuracy and is easily affected by air pressure fluctuations.

[0092] Glue dripping or residual glue may contaminate precision medical devices and affect product quality.

[0093] Application of the present invention: Negative pressure drive combined with pulse suction volume adjustment can achieve precise control of the glue flow rate, which is particularly suitable for micro-dispensing of low-viscosity biocompatible glue.

[0094] After dispensing is completed, the dynamic suction mechanism sucks back the residual glue to ensure that the glue tip is clean and avoid secondary contamination.

[0095] The liquid seal design prevents air from entering the glue path, ensuring consistent dispensing quality.

[0096] In the assembly of the test kit, the present invention can stably control the dispensing volume at 3 μL each time, the dispensing error is less than ±0.05 μL, and the product qualification rate is improved to 99.8%.

[0097] After dispensing, there is no residual glue on the glue head, which fully meets the high cleanliness requirements of medical devices.

[0098] Case 4: Multi-frequency dispensing in precision machining In precision machining, such as bonding of mobile phone parts or waterproof sealing gluing, it is necessary to quickly complete the dispensing under high-frequency operation, which requires high dispensing accuracy and high efficiency.

[0099] Disadvantages of traditional technology: Positive pressure technology is prone to cause unstable glue liquid due to pressure fluctuations in high-frequency dispensing, and the dispensing amount cannot be kept consistent.

[0100] In high-frequency dispensing, glue dripping is more prominent, affecting processing efficiency and product quality.

[0101] Application of the present invention: The fast response capability of the sliding piston body 51 combined with the negative pressure driving mechanism enables the device to maintain the stability of the glue flow rate during high-frequency operation.

[0102] The dynamic suction mechanism ensures that there is no dripping after each dispensing, reducing the pollution to the processing environment.

[0103] The pulse air extraction volume can be adjusted to achieve precise matching of different dispensing volumes and frequencies.

[0104] In the test, the present invention can complete the dispensing operation at a high frequency of 1 second / time, and the dispensing amount error is less than ±0.1μL, which meets the requirements of precision machining.

[0105] The glue dripping phenomenon is completely eliminated, the glue dispensing efficiency is increased by 30%, and the production cost is significantly reduced.

[0106] Through the above practical cases, the present invention has demonstrated significant technical effects and practical application value in multiple fields: Precise control of glue output: Through negative pressure drive and multi-stage adjustment cylinder design, the present invention can achieve precise control from micro-dispensing to high-viscosity glue coating.

[0107] Glue dripping phenomenon is completely eliminated: Dynamic back suction and liquid seal design effectively solves the glue dripping problem in traditional technology and significantly improves the dispensing quality.

[0108] High efficiency and energy saving: The present invention is suitable for high-frequency dispensing and complex gluing scenarios, with high operating efficiency and low energy consumption.

[0109] Wide applicability: The present invention is applicable to dispensing needs in multiple fields such as electronics, automobiles, biomedicine, precision machinery, etc., showing extremely high technical adaptability and promotion value.

[0110] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A glue quantity control structure for a glue dispensing machine, comprising a glue dispensing cylinder (1), wherein a glue outlet head (2) is arranged at the front end of the glue dispensing cylinder (1), and a glue inlet pipe (3) is connected to the rear end of the glue dispensing cylinder (1), characterized in that: A first adjustment cylinder (4) with an open lower end and a closed upper end is fixed inside the dispensing cylinder (1); a second adjustment cylinder (5) with an open lower end and a closed upper end is fixed inside the first adjustment cylinder (4); The diameter of the first adjustment cylinder (4) is smaller than that of the dispensing cylinder (1), and the diameter of the second adjustment cylinder (5) is smaller than that of the first adjustment cylinder (4); The rear end of the second adjusting cylinder (5) is sealed backwards and passes through the upper end of the first adjusting cylinder (4); A sealed sliding piston body (51) is arranged in the second regulating cylinder (5), and the sliding piston body (51) divides the second regulating cylinder (5) into an upper air chamber (52) and a lower regulating chamber (53) at the upper and lower parts. The rear end of the second regulating cylinder (5) is connected to a pulse exhaust pipe (54).

2. The glue quantity control structure of the glue dispensing machine according to claim 1 is characterized in that: A reducing ring (41) is provided at the lower end of the first adjusting cylinder (4); the reducing ring (41) has an outwardly convex arc surface from the outside to the inside, so as to guide the flow of the glue liquid by utilizing the surface effect of the glue liquid.

3. The glue quantity control structure of the glue dispensing machine according to claim 2 is characterized in that: The first regulating cylinder (4) is fixedly connected to the glue dispensing cylinder (1) via a plurality of connecting rods (42), wherein the connecting rods (42) are distributed at equal intervals, thereby ensuring the stability of the first regulating cylinder (4) and a smooth flow path of the glue liquid.

4. The glue quantity control structure of the glue dispenser according to claim 1, characterized in that: The sliding piston body (51) is of a sealable sliding design, and its moving position is driven by the pressure difference in the upper air chamber (52), wherein the pressure difference is generated by an external precise pulse air pump through a pulse air extraction pipe (54).

5. The glue quantity control structure of the glue dispenser according to claim 4 is characterized in that: The sliding piston body (51) is provided with an elastic sealing ring in the second adjustment cylinder (5), which is used to improve the sealing performance and wear resistance of the sliding piston body (51) during high-frequency operation.

6. The glue quantity control structure of the glue dispenser according to claim 1, characterized in that: The pulse air extraction pipe (54) is connected to an external precision pulse air pump, and the precision pulse air pump can instantly extract a certain amount of gas, so that negative pressure is formed in the upper air chamber (52), thereby driving the sliding piston body (51) to move upward.

7. The glue quantity control structure of the glue dispenser according to claim 6, characterized in that: The pumping rate of the pulse pumping tube (54) is adjustable, and the rate adjustment range is 0.01 to 0.5 liters per second to meet the dispensing requirements of glue liquids with different viscosities.

8. A method for controlling the amount of glue in a glue dispensing machine, characterized in that: The following steps are involved: S1. A certain amount of gas is instantaneously extracted through the pulse exhaust pipe (54) by an external precise pulse air pump, so that a negative pressure is formed in the upper air cavity (52); S2. The negative pressure in the upper air chamber (52) drives the sliding piston body (51) to move upward, thereby forming a negative pressure in the lower regulating chamber (53); S3. The negative pressure in the lower regulating chamber (53) attracts the external glue liquid into the regulating chamber, and simultaneously attracts two parts of glue liquid: The glue liquid between the first regulating cylinder (4) and the second regulating cylinder (5) moves downward, so that negative pressure is generated in the upper space of the first regulating cylinder (4), and the negative pressure takes effect after the glue dispensing is completed; The glue liquid near the arc surface of the reducing ring (41) in the glue dispensing cylinder (1) is driven to move downward, thereby generating downward pressure, squeezing the glue liquid near the glue dispensing head (2) to flow out, thereby achieving glue dispensing; S4. After the dispensing is completed, the pulse exhaust pipe (54) is disconnected from the external air pump, so that the upper air cavity (52) is connected to the outside world and the atmospheric pressure is restored; S5. The sliding piston body (51) gradually falls back downward. During the falling process, the glue liquid in the first regulating cylinder (4) is sucked back upward under the action of negative pressure, thereby alleviating the pressure caused by the downward movement of the sliding piston body (51) and preventing the glue liquid from overflowing or dripping due to the pressure. Finally, the sliding piston body (51) is restored to the initial position to prepare for the next dispensing operation.

9. The method for controlling the amount of glue in a glue dispensing machine according to claim 8, characterized in that: The convex arc surface of the reducing ring (41) forms a surface effect during the flow of the glue liquid. The surface effect can guide the glue liquid to flow stably along the arc surface and squeeze the glue liquid close to the glue outlet head (2) to flow out through the negative pressure effect.

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