Quantitative dropper and quantitative dropper

Abstract

The quantitative water dropper comprises an assembly part and a water dropper suction head located at the top of the assembly part, a liquid outlet is formed in one end of the water dropper suction head, and a liquid channel communicated with the liquid outlet is formed in the water dropper suction head. The liquid channel comprises a first channel connected with the liquid outlet, a second channel located below the first channel, a third channel located below the second channel and a transition channel located between the second channel and the third channel, and a gas inlet and outlet groove which extends in the axial direction and is communicated with the first channel is formed in the side wall of the drip suction head. The length of the gas inlet and outlet groove is consistent with the length of the first channel, and the ratio of the length of the first channel to the length of the liquid channel ranges from 0.4 to 0.6. The novel dropper for liquid transfer and dropping solves the problems of poor quantification precision, difficulty in liquid dropping, wall hanging, unbalanced pressure, single function and the like, and is accurate in quantification, convenient and fast to operate, rich in function and stable and reliable in performance.

Description

Technical Field

[0001] This utility model belongs to the field of medical device technology, and in particular relates to a quantitative dripping head and a quantitative dripping tube. Background Technology

[0002] A dropper is a commonly used tool in the chemical, biological, pharmaceutical, food, and cosmetic industries, primarily for the precise transfer of small volumes of liquid. Traditional droppers typically consist of a flexible tube and a squeezeable rubber bulb or bladder. Users create negative pressure by squeezing and releasing the bulb to draw in liquid, then squeeze the bulb again to dispense the liquid. However, because the volume of liquid dispensed is small, air cannot automatically return, causing an imbalance in the internal pressure. This leads to difficulty in dispensing the second drop. Furthermore, the size of the dropper tip's surface area may not match the volume required, resulting in liquid residue buildup on the tube walls and ultimately, poor quantitative accuracy.

[0003] In the prior art, a pipette tip disclosed in Chinese Utility Model Patent Publication No. CN220443854U includes an inner tube, which comprises a sealing part, a tube body, and an inlet end. The sealing part, tube body, and inlet end are all conical, and the inner diameter of the sealing part and tube body has the same rate of change. When the inner diameter of the sealing part and tube body has the same rate of change, the gas reflux speed is the same, which may prevent the gas from passing through quickly and make it difficult to balance the internal pressure of the cavity. Moreover, more seriously, in this design, the inlet end is conical, and the end of the inlet end is pointed and its length is relatively short compared to the length of the inner tube. The liquid suddenly accelerates from the thicker tube body to the pointed end of the inlet end, which will have a large inertia. This may cause the droplet to be "thrown" out before it is fully mature or form a tail, affecting the quantitative accuracy.

[0004] Therefore, it is necessary to provide a quantitative drip tip and a quantitative drip tube to solve the above-mentioned technical problems. Utility Model Content

[0005] The main purpose of this invention is to provide a quantitative dripping head that solves problems such as poor quantitative accuracy, difficulty in dripping, wall adhesion, pressure imbalance, and limited functionality. It provides a new type of quantitative dripping head for liquid transfer and addition that is accurate in quantitative measurement, easy to operate, has rich functions, and stable and reliable performance.

[0006] This utility model achieves the above-mentioned objective through the following technical solution: a quantitative dripping head, comprising an assembly part and a dripping head located at the top of the assembly part, wherein one end of the dripping head forms a liquid outlet, and the interior of the dripping head is provided with a liquid channel communicating with the liquid outlet, the liquid channel including a first channel connected to the liquid outlet, a second channel located below the first channel, a third channel located below the second channel, and a transition channel located between the second channel and the third channel; a gas inlet / outlet groove extending axially and communicating with the first channel is provided on the side wall of the dripping head, the length of the gas inlet / outlet groove being the same as the length of the first channel, the first channel being a straight channel, and the ratio of the length of the first channel to the length of the liquid channel being in the range of 0.4~0.6; the gas inlet / outlet groove is connected to the first channel on the M side inside and to the atmosphere on the N side outside, and the ratio of the distance between the two groove walls on the M side inside the gas inlet / outlet groove to the diameter of the first channel is at most 0.3.

[0007] Furthermore, the second channel, the third channel, and the transition channel are all tapered channels.

[0008] Furthermore, the angle A between the sidewall of the second channel and the vertical direction ranges from 1° to 3°, the angle B between the sidewall of the third channel and the vertical direction ranges from 40° to 50°, and the angle C between the sidewall of the transition channel and the vertical direction ranges from 18° to 28°.

[0009] Furthermore, the dripping head is configured with an annular conical surface on the outer periphery of the top of the first channel, and the angle between the annular conical surface and the horizontal plane is in the range of 55°~65°.

[0010] Furthermore, the ratio of the length to the diameter of the first channel is in the range of 4.5 to 5.5, and the length of the first channel is greater than the length of the second channel.

[0011] Furthermore, the distance between the two walls on the outer N side of the gas inlet / outlet tank is greater than the distance between the two walls on the inner M side.

[0012] Another objective of this utility model is to provide a quantitative dropper, which is achieved by the following technical solution: a quantitative dropper, comprising:

[0013] The dropper body has an internal cavity for containing liquid. The outer cylindrical body of the dropper body is provided with a volume adjustment groove, which includes a number of movable slots with different axial heights and distributed along the circumferential direction of the outer periphery of the dropper body.

[0014] As described above, the metering dropper is detachably mounted on the top of the dropper body, and the liquid channel is in communication with the cavity;

[0015] A protective cap is detachably fitted around the outer periphery of the metering dropper and used to seal the liquid outlet;

[0016] A squeezing assembly is axially movably mounted at the other end of the dropper body and forces liquid into and out of the cavity by changing the volume of the cavity through axial movement. The squeezing assembly has a limiting part that extends into the movable slot. The movable slot limits the pressing distance of the squeezing assembly by limiting the axial movement range of the limiting part. When the squeezing assembly is rotated, the limiting part can move to different movable slots to adjust the pressing distance.

[0017] Furthermore, the extrusion assembly includes a pressing part and a sealing part; the dropper body has an installation groove at one end near the extrusion assembly, and an isolation part is provided between the installation groove and the cavity; the installation groove is open at the end away from the cavity, the pressing part is provided with a guide ring that cooperates with the inner wall of the installation groove to guide the movement, and the limiting part is provided on the guide ring; the pressing part is exposed outside the dropper body, and the sealing part is sealed and assembled inside the cavity.

[0018] Furthermore, a sealing cylinder is provided at one end of the cavity near the extrusion assembly, and a sealing slide is formed inside the sealing cylinder. The sealing part moves up and down inside the sealing cylinder and seals with the inner wall of the sealing slide through plastic deformation. A sealing ring is sleeved on the outer periphery of the sealing part. The outer peripheral surface of the dropper body is provided with an ultrasonic treatment area and an anti-slip texture structure.

[0019] Furthermore, the mounting groove is provided with a reset member that forces the pressing part to reset, one end of the reset member abutting against the isolation part and the other end abutting against the pressing part.

[0020] Compared with existing technologies, the advantages of this utility model's quantitative dropper and quantitative dropper are as follows: This solution, through innovative structural design and parameter optimization, comprehensively solves the problems of poor quantitative accuracy, difficulty in dripping, wall adhesion, pressure imbalance, and limited functionality existing in traditional droppers and existing technologies. It provides a new type of liquid transfer tool that is quantitatively accurate, easy to operate, feature-rich, and has stable and reliable performance, possessing high practical value and market prospects. Specifically:

[0021] 1. It fundamentally solves the problems of difficult dripping and residue sticking to the bottle wall, specifically through the following innovative designs:

[0022] (1) The design of the dripper channel has been optimized: the liquid channel adopts a composite structure of "straight section + multi-stage cone", namely, the first channel is stably formed, the second channel is smoothly accelerated and facilitates gas backflow, the transition channel is smoothly converted, and the third channel is buffered and collected. This conforms to the principle of fluid dynamics and realizes the smooth and continuous flow of liquid from the cavity to the outlet, avoiding the phenomenon of "throwing out" or "tailing" of the droplets.

[0023] (2) The air intake balance design is precise: the ratio of the length of the first channel to the length of the liquid channel is 0.4~0.6, and a gas inlet and outlet groove of the same length as the first channel is also designed. The two work together to ensure that the air pressure inside and outside the cavity can be kept in balance in real time during the entire critical process of droplet formation and dripping, avoiding the problem of interruption or discontinuity of dripping caused by negative pressure, and realizing the smooth and continuous dripping of liquid;

[0024] 2. Scientific design and superior performance: The length-to-diameter ratio (L1 / D1) of the first channel is precisely controlled within the range of 4.5 to 5.5. It works in conjunction with the gas inlet / outlet tank and multi-stage flow channels to achieve the best balance between fluid inertia, viscous force, surface tension and gas pressure balance. This is the core of ensuring the high repeatability and accuracy of droplet volume. The design of the annular conical surface scientifically guides droplet aggregation and directional detachment, further avoiding the problems of wall adhesion and contamination.

[0025] 3. Significantly improves the efficiency of gas reflux and the speed of pressure balance: The inner walls of the first and second channels are polished, and combined with the small-angle conical design of the second channel, an extremely smooth and low-resistance path is provided for gas reflux, so that the internal pressure of the cavity can quickly recover balance after the drop, creating conditions for the next precise drop, and overcoming the technical bottleneck of the difficulty of the second drop in traditional droppers.

[0026] 4. Achieves precise and adjustable quantitative dispensing function: Through the combination of volume adjustment slide and limiting part, users can easily and reliably switch between different pressing strokes simply by rotating the squeezing component, thereby precisely controlling the volume of liquid drawn and dispensed in a single operation (e.g., 25 ml). μL 50 μL (etc.), effectively solving the problem of poor quantitative accuracy of traditional droppers. The symmetrical design of the double slide and double limit part further improves the stability and limit accuracy of the adjustment mechanism, ensuring the consistency of the dosage in each operation;

[0027] 5. Expanded functionality and application scenarios: On the one hand, it integrates ultrasonic processing capabilities, with a specially designed ultrasonic processing area on the dropper body (whether through material thickness increase or material composite), allowing users to directly perform ultrasonic processing on the liquid inside the tube (such as dispersion, homogenization, degassing, cell disruption, etc.), meeting special testing and experimental needs and expanding the application range of the dropper; on the other hand, it has good sealing and protection, with the sealing part and sealing cylinder ensuring the sealing of the cavity; the conformal assembly groove and sealing plug inside the protective cap can effectively protect the precision dropper head, prevent contamination and damage, and extend its service life;

[0028] 6. Improved user experience and ease of operation: The anti-slip textured structure on the outer periphery of the dropper increases friction during operation, prevents slippage, and makes pressing and adjustment operations more stable and effortless; the quantitative drip tip and the dropper body, as well as the protective cap and the quantitative drip tip, are all connected by detachable means (such as threaded connection), which facilitates cleaning, maintenance and replacement, and meets the laboratory's requirements for the hygiene and reusability of instruments. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the quantitative dropper according to an embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram of the lower end of the quantitative dropper in an embodiment of this utility model;

[0031] Figure 3 This is a cross-sectional view of the lower end of the quantitative dropper according to an embodiment of the present invention;

[0032] Figure 4 This is a schematic diagram illustrating how the sealing part and the sealing cylinder achieve a seal in another embodiment of the present invention.

[0033] Figure 5 This is a cross-sectional view of the upper end of the quantitative dropper according to an embodiment of the present invention;

[0034] Figure 6 This is a schematic diagram of the structure of the quantitative dripping head according to an embodiment of the present invention;

[0035] Figure 7 This is an enlarged cross-sectional view of the gas inlet / outlet groove at the top of the quantitative dripping head in an embodiment of this utility model.

[0036] The numbers in the image represent:

[0037] 100-Quantitative Dropper;

[0038] 1-Drip tube body, 11-Cavity, 12-Mounting groove, 13-Isolation section, 14-Sealing cylinder, 141-Sealing slide, 15-Ultrasonic treatment area, 16-Anti-slip textured structure, 17-Volume adjustment slide, 171-Modible slot, 1711-First slot, 1712-Second slot, 1713-Connecting slide, 18-External thread structure;

[0039] 2-Extrusion assembly, 21-Pressing part, 22-Sealing part, 221-Sealing ring, 23-Rod-shaped part, 24-Guide ring, 25-Limiting part;

[0040] 3-Quantitative dripping head, 31-Assembly part, 311-Sealing convex ring, 312-Internal thread structure, 32-Dripping head, 321-Liquid outlet, 322-Liquid channel, 3221-First channel, 3222-Second channel, 3223-Third channel, 3224-Transition channel, 323-Annular conical surface, 324-Gas inlet / outlet groove;

[0041] 4-Reset component; 5-Protective cap. Detailed Implementation

[0042] Please refer to Figures 1-7 This embodiment is a quantitative dropper 100, which includes a dropper body 1, a squeezing component 2 that is movably installed at the bottom of the dropper body 1, a quantitative dropper head 3 installed at the top of the dropper body 1, a reset component 4 that pushes the squeezing component 2 downward to reset it, and a protective cap 5 that surrounds the quantitative dropper head 3.

[0043] To achieve the quantitative adjustable function of the dropper pressing volume, this embodiment provides a volume adjustment groove 17 on the outer periphery of the dropper body 1. The volume adjustment groove 17 includes several movable slots 171 with different axial heights and distributed circumferentially along the outer periphery of the dropper body 1. The squeezing assembly 2 is provided with a limiting part 25, which extends into the movable slots 171. The movable slots 171 limit the vertical movement range of the limiting part 25, thereby limiting the vertical pressing distance of the squeezing assembly 2. When the squeezing assembly 2 is rotated, the limiting part 25 can move into different movable slots 171 to achieve different pressing distances, thereby achieving the adjustment of the dropper pressing volume (i.e., the pressing dose).

[0044] In this embodiment, two volume adjustment grooves 17 are provided and symmetrically arranged on the outer periphery of the dropper body 1. Two limiting parts 25 are also provided, extending into the two volume adjustment grooves 17 respectively. Compared with unilateral limiting, the symmetrical design of the volume adjustment grooves 17 and the limiting parts 25 can improve the reliability and accuracy of the limiting of the limiting parts 25 by the volume adjustment grooves 17.

[0045] In this embodiment, the movable slot 171 includes a first slot 1711 and a second slot 1712 distributed circumferentially along the outer periphery of the dropper body 1. The first slot 1711 and the second slot 1712 have different axial dimensions, and the first slot 1711 and the second slot 1712 are circumferentially connected by a connecting groove 1713, such as... Figure 2 As shown, a first slot 1711 and a second slot 1712 are also provided on the opposite side. In this embodiment, the axial length of the first slot 1711 is greater than the axial length of the second slot 1712. When the limiting part 25 rotates into the first slot 1711, the range of motion of the limiting part 25 is the axial length of the first slot 1711. When the limiting part 25 rotates into the second slot 1712, the range of motion of the limiting part 25 is the axial length of the second slot 1712. Therefore, when the limiting part 25 is located in different slots, it has different axial ranges of motion. As a result, the squeezing assembly 2 will have different axial displacements relative to the dropper body 1, which will lead to different changes in the volume of the internal cavity of the dropper body 1, and thus generate different pressures, thereby achieving different dosage adjustments. In this embodiment, the first slot 1711 corresponds to 50 μL Dose intake, second slot 1712 corresponds to 25 μL Dose taken. In other embodiments, different doses can be flexibly designed by setting different axial dimensions of the movable slot 171.

[0046] In other embodiments, the number of movable slots 171 can be flexibly designed according to actual needs, such as three, four or more. For example, when three movable slots are provided, the movable slots 171 include a first slot, a second slot and a third slot. The first slot, the second slot and the third slot each have different axial dimensions. The first slot and the second slot are circumferentially connected through a first connecting groove, and the second slot and the third slot are axially connected through a second connecting groove.

[0047] The dropper body 1 has a cavity 11 for holding liquid and a mounting groove 12 for mounting the reset component 4 inside. The mounting groove 12 is located at the bottom of the cavity 11. An isolation part 13 is provided between the cavity 11 and the mounting groove 12 to isolate the cavity 11 and the mounting groove 12 while maintaining the sealing of the cavity 11.

[0048] A sealing cylinder 14 is provided on the bottom wall of the cavity 11, extending from the bottom wall of the cavity 11 toward the interior of the cavity 11. A sealing slide 141 is formed inside the sealing cylinder 14. The extrusion assembly 2 has a sealing part 22, which moves up and down within the sealing cylinder 14 and achieves a seal by plastic deformation and engaging with the inner wall of the sealing slide 141. The extrusion assembly 2 changes the pressure inside the cavity 11 by moving the sealing part 22 up and down within the sealing cylinder 14. When the sealing part 22 extrudes into the cavity 11, the pressure inside the cavity 11 increases, releasing the liquid inside the cavity 11. When the sealing part 22 moves away from the cavity 11, the pressure inside the cavity 11 decreases, and under the action of the pressure difference, external liquid enters the cavity 11, absorbing the liquid.

[0049] The specific structure of the sealing part 22 is not limited here and can be set according to the actual situation. For example, it can be set as follows: Figure 3 The ring structure shown can also be configured as follows: Figure 4 The "I"-shaped structure shown is in Figure 4 In the process, a sealing ring 221 can be fitted around the outer periphery of the sealing part 22 to increase the elasticity of the sealing part 22. The sealing ring 221 is made of materials such as nitrile rubber and silicone rubber, which can ensure the compression amount and achieve the best sealing effect.

[0050] For liquids drawn by a dropper, ultrasonic treatment is required under certain special testing conditions to achieve liquid dispersion and homogenization, accelerated dissolution and reaction, degassing and defoaming, or cell disruption and extraction. However, conventional droppers cannot withstand the transmission of ultrasonic energy and are prone to deformation or even damage. To solve this technical problem, this embodiment provides an ultrasonic treatment area 15 on the outer peripheral surface of the dropper body 1. When ultrasonic treatment is required on the liquid inside the cavity 11, the ultrasonic vibrating head of the ultrasonic device can directly contact the ultrasonic treatment area 15. Compared to making the entire dropper body 1 a material that can be ultrasonically treated, this method effectively reduces product manufacturing costs and improves economic efficiency while meeting the requirements for ultrasonic treatment.

[0051] In this embodiment, the ultrasonic treatment area 15 is a thickened material area, which is made of the same material as other areas of the dropper body 1. The material thickness of the ultrasonic treatment area 15 is greater than that of other areas of the dropper body 1. The dropper body 1 can be injection molded from conventional plastic materials (such as PP, PET, PC, COP or COC, etc.), with the material thickened only in the ultrasonic treatment area 15 to withstand the transmission of ultrasonic energy.

[0052] In other embodiments, the ultrasonic treatment area 15 is made of an ultrasonically treatable material, and it is made of a different material from other areas of the dropper body 1. This can be achieved by a two-stage injection molding process, or by sequentially injection molding other areas of the dropper body 1 while leaving the ultrasonic treatment area 15 empty. An ultrasonically treatable material such as PP, PET, PC, COP, or COC is used to injection mold an ultrasonic treatment area filling block. Then, the ultrasonic treatment area filling block and the main structure of the dropper body 1 are molded into an integral structure by hot melt molding.

[0053] The compression assembly 2 also includes a pressing part 21 and a rod-shaped part 23 connecting the pressing part 21 and the sealing part 22. The pressing part 21 is exposed outside the dropper body 1, and the rod-shaped part 23 extends through the mounting groove 12 into the sealing cylinder 14. The reset member 4 is installed in the mounting groove 12, with one end abutting the pressing part 21 and the other end abutting the isolating part 13. When the pressing part 21 is compressed, the reset member 4 is also compressed, and the reset member 4 is compressed and stores energy. When the pressing part 21 is released, the elastic capacity stored in the reset member 4 is released, pushing the pressing part 21 outward to achieve reset. Specifically, when the limiting part 25 is located in the first slot 1711, pressing the pressing part 21 causes the limiting part 25 to move axially to the top of the first slot 1711 at a distance of 50 degrees. μL When the dose is drawn, the reset member 4 is compressed. When the pressing part 21 is released, the elastic capacity stored in the reset member 4 is released and pushes the pressing part 21 in the opposite direction. At this time, the limiting part 25 is reset axially to the bottom end of the first slot 1711. When the limiting part 25 is located in the second slot 1712, the working principle is the same as above, which will not be described again here.

[0054] The bottom of the mounting groove 12 is an open structure, and the pressing part 21 is provided with a guide ring 24 that cooperates with the inner wall of the mounting groove 12 to guide the pressing part 21 to move up and down.

[0055] The metering dropper 3 is a one-piece molded structure and includes an assembly part 31 and a suction head 32 located on top of the assembly part 31. The assembly part 31 is detachably installed on the top of the dropper body 1 and has a sealing ring 311 inside that cooperates with the inner wall of the cavity 11 to achieve a seal. One end of the suction head 32 is adjacent to the assembly part 31 and the other end forms a liquid outlet 321. The inside of the suction head 32 is provided with a liquid channel 322 connecting the liquid outlet 321 and the cavity 11. The liquid channel 322 includes several channels with different structures, including a first channel 3221 connected to the liquid outlet 321, a second channel 3222 located below the first channel 3221, a third channel 3223 located below the second channel 3222, and a transition channel 3224 located between the second channel 3222 and the third channel 3223.

[0056] The dropper head 32 is set with an annular conical surface 323 on the outer periphery of the top of the first channel 3221, and the angle between the annular conical surface 323 and the horizontal plane is in the range of 55°~65°. Preferably, the angle between the annular conical surface 323 and the horizontal plane is 60°. The annular conical surface 323 can guide the droplet to gather and detach in a directional manner, preventing droplet residue and contamination. Specifically, (1) guiding droplet formation: when the liquid is about to drip, this 60° annular conical surface 323 provides an ideal surface for the droplet to adhere and form. The droplet will naturally converge along the annular conical surface 323 to the liquid outlet 321 at the tip. The annular conical surface 323 is set so that the plane where the liquid outlet 321 is located is of a suitable size, which can make the droplet form a sphere of a set size and form a regular sphere, thus forming the droplet; (2) directional detachment: when the weight of the droplet reaches a certain level (overcoming surface tension) When the droplet is "pushed away" from the tip due to the geometry of the cone, instead of spreading along a flat surface, the droplet is ensured to fall in a vertical and controllable direction, which improves the accuracy of the quantification; (3) Anti-wall adhesion and anti-contamination: Without this cone, the droplet may adhere irregularly to the outside of the drip head 32, or a small amount of liquid may remain on the end face after dripping, forming "wall adhesion". This smooth annular cone 323 allows the droplet to be almost "emptied" when it leaves, avoiding residue. At the same time, it also prevents residual liquid from contaminating the drip head 32, affecting the next use or causing cross-contamination.

[0057] The suction head 32 has an axially extending gas inlet / outlet groove 324 on its sidewall, which communicates with the first channel 3221, and the length of the gas inlet / outlet groove 324 is the same as the length of the first channel 3221. Specifically, the gas inlet / outlet groove 324 is a narrow groove formed on the outer peripheral sidewall of the first channel 321, such as... Figure 7 As shown, the gas inlet / outlet groove 324 has its internal M side connected to the first channel 3221 and its external N side connected to the atmosphere. Both walls of the gas inlet / outlet groove 324 are flat, and the distance between the two walls on the external N side is greater than the distance between the two walls on the internal M side. This means the gas inlet / outlet groove 324 has a "V" shaped cross-section, facilitating manufacturing. Furthermore, the ratio of the distance between the two walls on the internal M side to the diameter of the first channel 321 is at most 0.3, ensuring both gas inlet / outlet and preventing liquid in the first channel 321 from flowing out through the gas inlet / outlet groove 324. In this embodiment, the distance between the two walls on the internal M side is 0.2~0.3mm. In other embodiments, the distance between the two walls on the internal M side of the gas inlet / outlet groove 324 can be adjusted according to the diameter of the first channel 321. Therefore, the distance between the two walls on the internal M side of the gas inlet / outlet groove 324 is not limited here and can be set according to the actual size of the metering dropper 3. Correspondingly, the distance between the two walls on the external N side can be adjusted according to the actual situation.

[0058] The reason why the liquid in the first channel 321 cannot flow out through the gas inlet / outlet tank 324 is as follows: (1) Both sides of the gas inlet / outlet tank 324 are flat, while the inner wall of the first channel 321 is arc-shaped. That is, the contact wall between the M side inside the gas inlet / outlet tank 324 and the first channel 321 is very sharp. Figure 7 As shown, when the liquid flows on the solid surface (i.e., the inner wall of the first channel 321), the boundary line of the gas-liquid-solid three phases at the edge of the liquid tends to be "nailed" to the sharp contact wall. In order for the liquid to flow into the gas inlet / outlet channel 324, the boundary line of the gas-liquid-solid three phases at the edge of the liquid must first cross this sharp contact wall. Since there is no additional energy to "unlock", the boundary line will be nailed in place, and the liquid cannot enter the gas inlet / outlet channel 324; (2) The Laplace pressure difference will prevent the liquid from entering the gas inlet / outlet channel 324. This is the most core and quantitative reason. When the liquid tries to flow into the narrower gas inlet / outlet channel 324 with a sharp contact wall, When it is time, it needs to form a meniscus with a very small radius of curvature, which will generate a huge Laplace pressure pointing towards the inside of the first channel 321. This Laplace pressure will strongly push the liquid back into the first channel 321 and prevent the liquid from entering the gas inlet / outlet 324; (3) When the liquid flows into the gas inlet / outlet 324, the liquid needs to make a sharp turn of nearly 90°, which will bring huge interfacial energy loss and kinetic energy loss. Therefore, the liquid will generate flow energy loss when it flows into the gas inlet / outlet 324, and the resistance is large. The liquid will choose the direction with the least path resistance, that is, it will flow directly out along the inner wall of the first channel 321, and the path is smooth.

[0059] The gas inlet / outlet groove 324 is designed to balance the air pressure and ensure the smooth and continuous dripping of liquid. Specifically, when the liquid in the cavity 11 flows out under the influence of gravity, a low-pressure area is formed inside the cavity 11. Without the gas inlet / outlet groove 324, this negative pressure would prevent the liquid from continuing to flow out, or even interrupt the flow, resulting in intermittent dripping, or no dripping at all. The gas inlet / outlet groove 324 allows external air to enter, replenishing the volume vacated by the liquid in a timely manner, thus maintaining the balance between the air pressure inside the cavity and the external atmospheric pressure. The liquid can flow out smoothly and continuously under the action of gravity alone, forming stable and uniform droplets. Moreover, if the dripping liquid contains gas, the mixed gas can be discharged from the gas inlet / outlet 324 during the droplet's fall, so that the droplet can flow out smoothly and continuously, forming stable and uniform droplets. The length of the gas inlet / outlet 324 is the same as the length of the first channel 3221, in order to ensure that the gas pressure can be effectively balanced during the liquid's flow in the entire first channel 3221, and to avoid the formation of new negative pressure zones in some areas.

[0060] The ratio of the length of the first channel 3221 to the length of the liquid channel 322 ranges from 0.4 to 0.6. The first channel 3221, which accounts for 40% to 60% of the length of the liquid channel 322, is the key area for the final formation and detachment of droplets. A longer first channel 3221 ensures that the liquid has enough time and distance to stabilize its flow state before flowing out, and to transition from the previous accelerated flow to a stable, droplet-ready state. This helps to form droplets of uniform size. If the first channel 3221 is too short, the liquid will suddenly accelerate from the larger channels below (second channel 3222, third channel 3223) to the outlet 321 with greater inertia, which may cause the droplets to fail to form. If the liquid is too wet, it will either "flick" out or form a trail, affecting the quantitative accuracy. Maintaining a ratio of 40% to 60% acts as a "buffer" or "stabilizing section," allowing the liquid to smoothly approach the outlet 321. Under the dominance of surface tension, a perfect droplet is formed. This longer first channel 3221 also works in conjunction with the longer gas inlet / outlet channel 324, meaning that the gas pressure can be effectively compensated throughout the critical path of droplet formation. This avoids the generation of new negative pressure zones at any local location in the channel, ensuring that the liquid flows out continuously and smoothly without interruption of dripping or unstable phenomena such as "popping" sounds. Together, they ensure that the gas pressure remains balanced in the critical area of ​​droplet formation.

[0061] The first channel 3221 is a straight channel, and the ratio of the length L1 to the diameter D1 of the first channel 3221 ranges from 4.5 to 5.5. For example, the diameter D1 of the first channel 3221 is 0.96 mm, the length L1 of the first channel 3221 is 4.93 mm, and L1 / D1 = 5.14. In other embodiments, the parameters of diameter D1 and length L1 can be set according to actual conditions.

[0062] Precisely controlling the length-to-diameter ratio (L1 / D1) of the first channel within the range of 4.5 to 5.5 is the optimal ratio that achieves the three major goals of "stable flow", "precise shaping" and "reliable detachment". This design, which achieves the best balance between fluid inertia, viscous force, surface tension and air pressure, is one of the core parameters that ensures the high performance of this quantitative dropper. The specific advantages are as follows:

[0063] (1) Ensure that the droplet flow develops fully and stabilizes the droplet formation: This ratio range ensures that after the liquid enters the first channel 3221, there is enough space and time to eliminate the disturbance and unstable flow state from the lower channel and form a stable and fully developed laminar flow. Only in this stable laminar flow state can the formation and detachment of the droplet at the outlet 321 be dominated only by gravity and surface tension, thereby ensuring the high repeatability and accuracy of the droplet volume. If the length-to-diameter ratio is too small (e.g., L1 / D1<3), the liquid will reach the outlet 321 when it is still in an unstable flow state. The droplets may be "thrown" out and be of different sizes, which will result in poor quantitative accuracy.

[0064] (2) Provide sufficient surface tension action area: The formation of droplets depends on the surface tension of the liquid at the outlet 321. A sufficiently long straight channel provides sufficient action space for the intermolecular forces (i.e. surface tension) of the liquid, which can "constrain" the liquid into an ideal hemispherical or spherical pre-drop state. This promotes the formation of regular spheres of droplets and allows them to fall off completely from the tip when the critical weight is reached, effectively solving the problems of droplet "tailing" and "hanging on the wall".

[0065] (3) In coordination with the gas inlet / outlet channel 324, pressure balance is achieved throughout the entire area: The channel with a length of 4.5 to 5.5 times the diameter, together with the gas inlet / outlet channel 324 of the same length as the first channel 3221, means that the gas pressure can be effectively compensated along the critical path of droplet formation, avoiding the generation of new negative pressure zones at any local position in the channel, ensuring that the liquid flows out continuously and smoothly, without any unstable phenomena such as interruption of dripping or "popping" sounds.

[0066] The second channel 3222 is a tapered channel. The angle A between the sidewall of the second channel 3222 and the vertical direction ranges from 1° to 3°. For example, the diameter D21 of one end of the second channel 3222 is 0.96 mm, the diameter D22 of the other end is 1.1 mm, the length L2 of the second channel 3222 is 3.73 mm, and the included angle A is 1.1°. In other embodiments, the parameters of diameter D21, diameter D22, length L2, and included angle A can be set according to the actual size of the metering dropper.

[0067] The length of the first channel 3221 is greater than the length of the second channel 3222, and the volume of the first channel 3221 is greater than the volume of the second channel 3222. In this way, when the liquid flows back, the liquid can fill the second channel 3222 and enter the position of the third channel 3223, and be partially stored in the third channel 3223. When the next drop is dripped, the droplet can be smoothly transported to the narrow first channel 3221, so that the next droplet can drip smoothly.

[0068] In the existing technology, the polishing level of the first channel 3221 and the second channel 3222 is insufficient, which causes the refluxed gas to adhere to the walls and also prevents the internal pressure of the cavity 11 from reaching an equilibrium state, resulting in pressure loss and inaccurate liquid volume. To further ensure smooth gas reflux, it is preferable to polish the inner walls of the first channel 3221 and the second channel 3222, with a polishing level of #2 being more effective. Specifically, the standard for #2 polishing treatment is: the arithmetic mean deviation of surface roughness Ra ≤ 0.025. μm The height of the ten micro-irregularities, Rz, is ≤0.1. μm Under this polishing level, the return gas enters the second channel 3222 from the first channel 3221. Because the second channel 3222 has a conical structure and its inner wall is precision polished, the return gas will pass through the second channel 3222 quickly. When the return gas reaches the third channel 3223, it will continue to rise until it reaches the liquid surface, which can further ensure the smooth return of gas and make the cavity 11 achieve a better pressure balance.

[0069] The third channel 3223 is a tapered channel, and the angle B between the sidewall of the third channel 3223 and the vertical direction ranges from 40° to 50°. For example, the diameter D31 of one end of the third channel 3223 is 1.70 mm, the diameter D32 of the other end is 4.66 mm, the length L3 of the second channel 3222 is 1.48 mm, and the included angle B is 45°. In other embodiments, the parameters of diameter D31, diameter D32, length L3, and included angle B can be set according to the actual size of the metering dropper.

[0070] Because the angles between the second channel 3222 and the third channel 3223 and the vertical direction differ significantly, a transition channel 3224 is provided between the second channel 3222 and the third channel 3223. The transition channel 3224 is a conical channel, and the angle C between the sidewall of the transition channel 3224 and the vertical direction ranges from 18° to 28°. For example, the diameter D41 of one end of the transition channel 3224 is 1.10 mm, the diameter D42 of the other end is 1.7 mm, the length L4 of the transition channel 3224 is 0.7 mm, and the angle C is 23°. In other embodiments, the parameters of diameter D41, diameter D42, length L4, and angle C can be set according to the actual size of the metering dropper.

[0071] Based on the parameters calculated above, L1 / (L1+L2+L3+L4) = 0.45, which satisfies the ratio of the length of the first channel 3221 to the total length of the liquid channel 322 being in the range of 0.4~0.6, thus achieving the goals of "stable flow state", "precise shaping" and "reliable droplet detachment".

[0072] The first channel 3221 (straight section): This is the "forming chamber" and "stabilizing zone" for the droplets. It's the crucial area for the final formation and detachment of the droplets. The straight section design provides a stable flow environment with consistent velocity and smooth flow patterns. The second channel 3222 (small-angle cone, 1°~3°): This is the "acceleration and convergence zone" for the droplets. It initially accelerates and converges the larger flow of liquid from below, while providing a smooth path for gas recirculation. The small-angle cone design allows for a gradual change in the channel cross-sectional area, enabling a steady increase in liquid velocity and avoiding the negative effects of varying cross-sectional area. The sudden change in flow causes turbulence or bubble generation; its conical structure (smaller at the top and larger at the bottom) acts as a "diffuser" for the top-down gas recirculation, helping to reduce gas velocity and recirculation resistance. Combined with #2 polishing, gas can pass through extremely smoothly, quickly balancing the internal pressure of cavity 11; the transition channel 3224 (medium-angle cone, 18°~28°) is the "flow channel transition zone" for the droplet, connecting the second channel 3222 and the third channel 3223 with huge angle differences, achieving a smooth transition of cross-sectional area and avoiding eddies and dead zones. If the second channel (1.1°) is directly connected to the third channel 3223 (45°), a sharp step will be formed at the connection, which is very easy to generate liquid eddies and gas stagnation (dead zone). This will destroy the stability of the fluid and may lead to liquid residue and cross-contamination. The transition channel 3224 eliminates this step, allowing the fluid to change direction smoothly. The third channel 3223 (large-angle cone, 40°~50°): is the "liquid storage and buffer zone" of the droplet. It is connected to the large cavity of the dropper body 1 and is the collection and distribution point and buffer zone of the liquid. The large-diameter cone-shaped channel can accommodate a large flow of liquid from the cavity 11 and smoothly transport it to the narrow channel below. As the starting section of the liquid channel 322, its large space helps to buffer the pressure fluctuations from the cavity. Compared to the all-straight-channel design in existing technologies, the multi-stage tapered design of this scheme is more in line with fluid dynamics. Straight-channel designs, in order to achieve the transition from large to small diameter, either require a very long length (increasing the dropper height) or form steps at the connection, which is not conducive to fluid flow and gas backflow. The multi-stage tapered channel design of this scheme achieves a smooth and continuous change in cross-sectional area, resulting in higher flow efficiency and faster pressure balance. Stability is required in the critical area of ​​droplet formation (first channel 3221), so a straight section is used. Tapers are used in the sections that require acceleration and guidance (second channel 3222 and third channel 3223). The second channel 3222 focuses on gas backflow and smooth acceleration, while the third channel 3223 focuses on containment and buffering. The single-angle tapered channel in existing technologies cannot simultaneously and optimally meet these conflicting needs.

[0073] The dropper body 1 has an external thread structure 18 on its bottom outer periphery, and the inner wall surface of the assembly part 31 has an internal thread structure 312 that mates with the external thread structure 18. The quantitative dripping head 3 and the dropper body 1 can be detachably installed through the threaded connection.

[0074] The protective cap 5 has an internal mounting groove that conforms to the outer contour of the dripping head 32. A sealing plug is provided at the bottom of the mounting groove to fit into the liquid outlet 321 of the dripping head 32. The protective cap 5 is detachably connected to the metering dripping head 3 via a threaded connection. In other embodiments, the protective cap 5 may also utilize the plastic deformation of the plastic part to achieve a specific interference fit with the metering dripping head 3.

[0075] To improve the operability of the operator and prevent slippage during the pressing and squeezing of the component 2, the outer peripheral surface of the dropper body 1 is also provided with an anti-slip textured structure 16.

[0076] The above descriptions are merely some embodiments of this utility model. For those skilled in the art, various modifications and improvements can be made without departing from the inventive concept of this utility model, and all such modifications and improvements fall within the protection scope of this utility model.

Claims

1. A dosing head, characterized in that: The application relates to a quantitative drop head, which comprises an assembling part and a drop head located on the top of the assembling part, one end of the drop head is provided with a liquid outlet, the inside of the drop head is provided with a liquid channel communicated with the liquid outlet, the liquid channel comprises a first channel communicated with the liquid outlet, a second channel located below the first channel, a third channel located below the second channel and a transition channel located between the second channel and the third channel, the sidewall of the drop head is provided with a gas inlet and outlet groove extending along the axial direction and communicated with the first channel, the length of the gas inlet and outlet groove is consistent with the length of the first channel, the first channel is a straight channel, and the ratio of the length of the first channel to the length of the liquid channel ranges from 0.4 to 0.6; the inside M side of the gas inlet and outlet groove is communicated with the first channel, and the outside N side is communicated with the atmosphere, the ratio of the distance between the two groove walls on the inside M side of the gas inlet and outlet groove to the diameter of the first channel is 0.3 at most.

2. A dosing head as claimed in claim 1, characterized in that: The second channel, the third channel and the transition channel are all tapered channels.

3. A dosing head as claimed in claim 2, characterized in that: The angle A between the sidewall of the second channel and the vertical direction ranges from 1 to 3 degrees, the angle B between the sidewall of the third channel and the vertical direction ranges from 40 to 50 degrees, and the angle C between the sidewall of the transition channel and the vertical direction ranges from 18 to 28 degrees.

4. A dosing head as claimed in claim 1, characterized in that: The top end of the drop head is provided with an annular taper surface on the outer periphery of the first channel, and the angle between the annular taper surface and the horizontal plane ranges from 55 to 65 degrees.

5. A dosing head as claimed in claim 1, characterized in that: The ratio of the length of the first channel to the diameter ranges from 4.5 to 5.5, and the length of the first channel is greater than the length of the second channel.

6. A dosing head as claimed in claim 1, characterized in that: The distance between the two groove walls on the outside N side of the gas inlet and outlet groove is greater than the distance between the two groove walls on the inside M side.

7. A dosing dropper, characterized in that The application relates to a quantitative drop head, which comprises: a drop tube body, the inside of which is formed with a cavity for containing liquid, the outer periphery of the drop tube body is provided with a volume adjusting sliding groove, the volume adjusting sliding groove comprises a plurality of movable clamping grooves with different axial heights and distributed in the circumferential direction of the outer periphery of the drop tube body; the quantitative drop head according to any one of claims 1 to 6 is detachably mounted on the top of the drop tube body, and the liquid channel is communicated with the cavity; a protective cap is detachably sleeved on the outer periphery of the quantitative drop head and used for plugging the liquid outlet; a pressing assembly is axially movably mounted on the other end of the drop tube body and is used for forcing liquid to enter or exit the cavity by axially moving to change the volume of the cavity; the pressing assembly is provided with a limiting part, the limiting part extends into the movable clamping groove, the movable clamping groove limits the axial movement range of the limiting part and further limits the pressing distance of the pressing assembly, and when the pressing assembly is rotated, the limiting part can be moved into different movable clamping grooves to realize the adjustment of the pressing distance.

8. A metering dropper according to claim 7, wherein: The extrusion assembly comprises a pressing part and a sealing part; the dropper body is provided with a mounting groove at one end close to the extrusion assembly, and a separation part is arranged between the mounting groove and the cavity; the mounting groove is open at one end away from the cavity, the pressing part is provided with a guide ring for guiding movement in cooperation with the inner wall of the mounting groove, and the limiting part is arranged on the guide ring; the pressing part is exposed outside the dropper body, and the sealing part is sealingly assembled in the cavity.

9. The quantitative dropper according to claim 8, wherein a sealing cylinder is arranged in the cavity at one end close to the extrusion assembly, a sealing slide is formed in the sealing cylinder, the sealing part moves up and down in the sealing cylinder and sealingly cooperates with the inner wall of the sealing slide through plastic deformation, and a sealing ring is arranged on the outer periphery of the sealing part; and the outer peripheral surface of the dropper body is provided with an ultrasonic treatment area and an anti-skid texture structure.

10. A metering dropper as defined in claim 8, characterized in that: A reset member for forcing the pressing part to reset is arranged in the mounting groove, one end of the reset member abuts against the separation part, and the other end abuts against the pressing part.

Images