Improved piston and fluid dispensing device

Abstract

The utility model relates to the technical field of high-end equipment manufacturing, in particular to an improved piston and a fluid dispensing device. Comprising a piston body, a knife edge structure and a lower conical surface. The knife edge structure is arranged around the circumference of the piston main body, and the lower conical surface is integrally formed at the bottom of the piston main body; the knife edge structure is composed of at least three layers of knife edges, and all the layers of knife edges are sequentially arranged in the axial direction of the piston body. The multiple layers of knife edges are attached to the inner wall of the needle cylinder layer by layer to form a dynamic sealing face, so that external gas is prevented from entering a fluid layer due to linear expansion of the plastic part, and turbulent flow generated when fluid flows is reduced. In addition, the utility model further provides a fluid dispensing device integrated with the improved piston, and the fluid dispensing device is used in combination with an end cover, a needle cylinder and a bottom head plug. The technical effects that the sealing reliability is remarkably improved, the fluid transmission stability is optimized, and the overall durability is enhanced are achieved.

Description

Technical Field

[0001] The present application relates to the technical field of high-end equipment manufacturing, and in particular to an improved piston and fluid dispensing device. Background Art

[0002] In the current dispensing field, the dispensing device is part of a complete integrated system, usually composed of a syringe, piston, adapter, syringe end cap and bottom head plug. The syringe adopts a zero-taper design with a consistent inner diameter; the piston design includes a knife edge and tail support, with a unique channel to prevent air entrapment and provide a smoother contour radius; the adapter connects the syringe to the output end of the fluid distributor unit; the end cap and bottom head plug provide an airtight seal; the above parts constitute the dispensing device accessories.

[0003] In the prior art, pistons have various structural forms and curvature radii, which reduce fluid shear to varying degrees. In specific dispensing practice, due to the linear expansion of plastic parts, when the piston is dispensing with air pressure, the syringe will expand linearly, the piston will also be deformed by pressure, and the gas will enter the fluid side along the edge of the piston. When the air pressure stops, the syringe will return to its initial state. At this time, the gas remaining on the fluid side cannot be discharged, thereby forming atmospheric pressure between the fluid and the piston, pushing the piston to rebound in the opposite direction.

[0004] The dispensing device can precisely control the amount of glue in the syringe by controlling the position of the piston to achieve accurate glue distribution. However, after the piston rebounds, the consistency and accuracy of the dispensing quality cannot be guaranteed; especially some glues that are sensitive to air or water vapor will also deteriorate and become ineffective due to the entry of air.

[0005] Therefore, based on the above problems, the prior art needs to be improved. Utility Model Content

[0006] One purpose of the present application is to provide an improved piston.

[0007] The above technical purpose of the present application is achieved through the following technical solutions: an improved piston, including a piston body, a blade structure and a lower cone; the blade structure is arranged around the circumference of the piston body, and the lower cone is integrally formed at the bottom of the piston body; the blade structure is composed of at least three layers of blades, and each layer of blades is arranged in sequence along the axial direction of the piston body; the multiple layers of blades form a dynamic sealing surface by fitting layer by layer against the inner wall of the syringe, which is used to inhibit external gas from entering the fluid layer due to the linear expansion of the plastic part and reduce turbulence during fluid flow.

[0008] By adopting the above technical solution, in terms of sealing performance, multiple layers of blades are arranged around the circumference of the piston body, and the blades of each layer are arranged in sequence along the axial direction, which can fit the inner wall of the syringe layer by layer to form a dynamic sealing surface, effectively inhibiting the external gas caused by the expansion of the plastic parts from entering the fluid layer, and solving the problem of the piston rebounding due to the entry of gas in the prior art affecting the dispensing quality, ensuring the consistency and accuracy of the dispensing quality, and at the same time avoiding the deterioration and failure of glue that is sensitive to air or water vapor due to the entry of air. In terms of fluid flow, the design of the lower cone surface and the effect of the multiple layers of blades on reducing turbulence make the flow of the fluid in the syringe smoother, reduce the risk of leakage or retention of the fluid in the syringe, and improve the efficiency and stability of dispensing. In addition, the optimization of the overall structure also reduces the entry of impurities and the waste of glue when not dispensing, and improves the practicality and reliability of the dispensing device.

[0009] Optionally, the piston body is made of a modified polyethylene (PE)-based composite material.

[0010] By adopting the above technical solution, the polyethylene (PE)-based composite material has good plasticity, which is easy to process into the required piston shape, ensuring the dimensional accuracy and structural stability of each component. At the same time, by modifying the material, a molecular orientation with high elastic modulus and high tensile strength can be obtained. This allows the piston to better fit the syringe when it faces irregular linear expansion, further enhancing the sealing effect and effectively preventing external gas from entering the fluid layer. Moreover, the material has stable chemical properties and is not easy to react chemically with glue or fluid, and will not have an adverse effect on the quality of the glue, ensuring the reliability of dispensing and product quality, extending the service life of the piston and dispensing device, and reducing the cost of use.

[0011] Optionally, the blade structure consists of four layers of blades, which are, from bottom to top along the axial direction of the piston body, a first layer of forward blades, a second layer of reverse blades, a third layer of reverse blades and a fourth layer of tail support blades.

[0012] By adopting the above technical solution, the first layer of positive blade is in the opposite direction to the cone surface at the bottom of the syringe, which can form an initial sealing interface, reduce the possibility of external gas entering from the source, and lay the foundation for the overall sealing. The second layer of reverse blade is in the opposite direction to the first layer of positive blade. Through the staggered bonding method, it effectively compensates for the stress generated by the linear expansion of the plastic part and avoids the failure of the seal caused by stress. The third layer of reverse blade is in the same direction as the second layer of reverse blade. The two form a secondary pressure-bearing structure, which disperses the sealing pressure and enhances the stability and reliability of the seal. The edge of the fourth layer of tail support blade is clamped with the bottom of the syringe to prevent the piston from rebounding, ensure the precise control of the piston position during the dispensing process, and thus ensure the consistency and accuracy of the dispensing quality. At the same time, it also avoids the deterioration and failure of glue sensitive to air or water vapor caused by the entry of air due to piston rebound.

[0013] Optionally, the setting direction of the first layer of positive blade edge is opposite to the setting direction of the conical surface at the bottom of the syringe, forming an initial sealing interface.

[0014] By adopting the above technical solution, at the beginning of the dispensing process, this setting method can quickly and effectively build the first sealing line of defense between the piston and the syringe, minimizing the chance of external gas entering the fluid layer inside the syringe. Especially when the plastic parts undergo linear expansion due to various factors (such as air pressure changes and temperature effects), this initial sealing interface can resist the intrusion of gas in advance, providing a good foundation for the subsequent sealing of the multi-layer knife edge, and ensuring that the sealing performance of the dispensing device is in a reliable state from the beginning. At the same time, this initial sealing interface also helps to stabilize the fluid layer, reduce fluid pressure fluctuations caused by gas entry, and make the fluid flow in the syringe more stable, thereby improving the accuracy and quality of dispensing and ensuring the consistency and reliability of the dispensing process.

[0015] Optionally, the setting direction of the second layer of reverse blades is opposite to the setting direction of the first layer of forward blades, and the stress caused by the linear expansion of the plastic part is compensated by staggered fitting; the setting direction of the third layer of reverse blades is the same as the setting direction of the second layer of reverse blades, forming a secondary pressure-bearing structure to disperse the sealing pressure.

[0016] By adopting the above technical solution, the second layer of reverse blades is set in the opposite direction to the first layer of forward blades, and the stress generated by the linear expansion of the plastic part is effectively compensated by staggered fitting, which prevents the piston and the syringe from not fitting tightly due to stress concentration, avoids sealing failure, and ensures the reliability of the seal when the plastic part expands. The third layer of reverse blades is in the same direction as the second layer of reverse blades, and together they form a secondary pressure-bearing structure, which can evenly disperse the sealing pressure, so that when the piston is pushed by the air source pressure, the force on each part is more balanced. This not only reduces the risk of seal damage caused by excessive local pressure, but also further enhances the barrier effect against external gas, ensuring that during the dispensing process, even if the syringe expands linearly due to air pressure, it is difficult for external gas to break through the sealing defense line of the multi-layer blades and enter the fluid layer, thereby ensuring the stability and consistency of the dispensing quality and reducing problems such as piston rebound and glue deterioration caused by gas entry.

[0017] Optionally, the edge of the fourth layer tail support blade is clamped to the bottom of the syringe to prevent the piston from rebounding.

[0018] By adopting the above technical solution, when the air pressure stops pushing the piston, the syringe will return to its initial state. If there is no effective restriction, the piston will easily rebound in the opposite direction due to the atmospheric pressure formed between the fluid and the piston. The fourth layer of the tail support blade edge and the clamping setting of the syringe bottom are like setting a solid line of defense for the piston, which can effectively resist this rebound trend. This allows the piston position to be accurately fixed, ensuring that the dispensing device can accurately control the amount of glue in the syringe, thereby achieving accurate glue distribution, greatly improving the consistency and accuracy of the dispensing quality. For those glues that are sensitive to air or water vapor, this design to prevent piston rebound can also avoid air entry due to rebound, effectively preventing the glue from deteriorating and failing, ensuring product quality and production efficiency, while also reducing the cost increase caused by glue waste and quality problems.

[0019] Optionally, the blade structure and the piston body are integrally formed.

[0020] By adopting the above technical solution, in the manufacturing process, the one-piece molding process reduces the assembly steps of parts and components, simplifies the production process, reduces the risk of quality problems caused by improper assembly during the production process, improves production efficiency, and helps reduce production costs. From the perspective of product performance, one-piece molding avoids gaps that may appear due to the splicing of multiple parts, reduces the channels for gas leakage, further enhances the sealing performance of the piston, and better inhibits external gas from entering the fluid layer. Moreover, this structure makes the overall structural strength and stability of the piston higher. When subjected to air pressure, fluid pressure, and stress caused by the expansion of plastic parts, it can disperse the force more evenly, reduce the possibility of local damage, and extend the service life of the piston, thereby improving the reliability and durability of the entire fluid dispensing device.

[0021] The second purpose of this application is to provide a fluid dispensing device.

[0022] The above technical purpose of the present application is achieved through the following technical solutions: a fluid dispensing device, comprising an end cover, a syringe, a bottom head plug and the above-mentioned improved piston, the end cover is arranged on the top of the syringe, the interior of the syringe is hollow and is used to accommodate the improved piston and the fluid, and the bottom head plug is arranged at the bottom of the syringe to close the fluid outlet.

[0023] By adopting the above technical scheme, the end cap, syringe, bottom head plug and improved piston work together to build an efficient and stable dispensing system. With its multi-layer blade structure and special design, the improved piston can effectively inhibit external gas from entering the fluid layer, prevent the piston from rebounding, ensure the precise control of the amount of glue, and thus improve the consistency and accuracy of the dispensing quality, and meet the production needs with high requirements for glue distribution accuracy. The hollow design inside the syringe provides a stable accommodation space for the improved piston and fluid, ensuring the stable flow of the fluid therein. The end cap and the bottom head plug are respectively arranged at the top and bottom of the syringe. The end cap cooperates with the piston to ensure the airtight seal at the top, and the bottom head plug closes the fluid outlet to prevent fluid leakage, further improving the sealing and reliability of the device. The structure of the entire device is simple and reasonable, and the various components cooperate with each other, which effectively solves the problems existing in the existing dispensing device, improves production efficiency and product quality, and reduces production costs.

[0024] In summary, this application has at least the following beneficial effects:

[0025] 1. The multi-layer blade structure of the improved piston can fit the inner wall of the syringe layer by layer to form a dynamic sealing surface, inhibiting external gas from entering the fluid layer due to the linear expansion of the plastic part, preventing the piston from rebounding, ensuring the consistency and accuracy of dispensing quality, and avoiding the deterioration and failure of glue that is sensitive to air or water vapor.

[0026] 2. The lower cone design of the piston and the overall streamlined structure, as well as the multi-layer blades to reduce turbulence, make the fluid flow more smoothly in the syringe, reduce the risk of fluid leakage or retention in the syringe, and improve dispensing efficiency and stability.

[0027] 3. The first layer of positive blade forms the initial sealing interface, the second layer of reverse blade compensates for stress, the third layer of reverse blade disperses the sealing pressure, and the fourth layer of tail support blade prevents rebound. The blades of each layer work together to improve the performance of the piston; and the piston body adopts polyethylene (PE)-based composite materials, and the blade structure and the piston body are integrally formed, which enhances the overall structural strength and stability, improves production efficiency and reduces costs.

[0028] 4. The end cap, syringe, bottom head plug and improved piston cooperate with each other to build a stable dispensing system. The end cap and bottom head plug ensure an airtight seal to prevent fluid leakage, improve the sealing and reliability of the device, and meet the needs of high-precision dispensing production. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the structure of an improved piston;

[0030] Figure 2 is a cross-sectional view of an improved piston;

[0031] Figure 3 A cross-sectional view of a fluid dispensing device.

[0032] Reference numerals

[0033] 1. Piston body; 2. Blade structure; 21. First layer positive blade; 22. Second layer reverse blade; 23. Third layer reverse blade; 24. Fourth layer tail support blade; 3. Lower cone; 4. End cover; 5. Syringe; 6. Bottom head plug. DETAILED DESCRIPTION

[0034] The present application is further described in detail below in conjunction with the accompanying drawings.

[0035] In this embodiment, refer to Figure 1-Figure 2 An improved piston includes a piston body 1, a knife edge structure 2 and a lower cone surface 3, wherein the knife edge structure 2 is arranged around the circumference of the piston body 1, and the lower cone surface 3 is integrally formed at the bottom of the piston body 1; the knife edge structure 2 is composed of at least three layers of knife edges, and each layer of knife edges is sequentially distributed along the axial direction of the piston body 1. This design makes full use of the characteristics of each layer of knife edges to form a multiple protective barrier, effectively preventing external gas from invading the fluid area, and reducing the occurrence of fluid vortex phenomenon.

[0036] Specifically, the piston body 1 is made of a modified polyethylene (PE)-based composite material. After biaxial stretching treatment, the elastic modulus is ≥800 MPa, the tensile strength is ≥15 MPa, the melt index is controlled at 10~30 g / 10 min, and it has a molecular orientation with high elastic modulus and high tensile strength. When the syringe 5 undergoes irregular linear expansion, the piston body 1 can also fit well with the inner wall of the syringe 5 to prevent external gas from entering.

[0037] Specifically, the blade structure 2 and the piston body 1 are integrally formed, and the blade structure 2 is composed of 4 layers of blades, which are the first layer of positive blade 21, the second layer of reverse blade 22, the third layer of reverse blade 23 and the fourth layer of tail support blade 24 from bottom to top along the axial direction of the piston body 1. The setting direction of the first layer of positive blade 21 is opposite to the setting direction of the conical surface at the bottom of the syringe 5, forming an initial sealing interface; the setting direction of the second layer of reverse blade 22 is opposite to the setting direction of the first layer of positive blade 21, and the stress generated by the linear expansion of the plastic part is compensated by staggered fitting; the setting direction of the third layer of reverse blade 23 is the same as the setting direction of the second layer of reverse blade 22, forming a secondary pressure-bearing structure to disperse the sealing pressure; the edge of the fourth layer of tail support blade 24 is clamped with the bottom of the syringe 5 to prevent the piston from rebounding.

[0038] During use, the first layer of forward blade 21 contacts the fluid surface, the second layer of reverse blade 22, the third layer of reverse blade 23 and the fourth layer of tail support blade 24 synchronously seal and support the piston body 1 to move in the syringe 5, so that the piston body 1 can achieve real-time sealing with the syringe 5 during the movement. When the air source pressure is input from the top, the fourth layer of the tail support blade 24 bears the air pressure first. When the improved piston is under pressure as a whole, the first layer of the forward blade 21, the second layer of the reverse blade 22, and the third layer of the reverse blade 23 will also be compressed and squeezed. At this time, the improved piston and the syringe 5 can fit better to ensure air tightness and prevent gas from penetrating from the edges of the piston and the syringe 5; when the air pressure pushes the piston to work, due to the linear expansion problem of the plastic part, the syringe 5 will expand outward under pressure; the improved piston is deformed as a whole under pressure, and a total of four layers of blades, including the first layer of the forward blade 21, the second layer of the reverse blade 22, the third layer of the reverse blade 23 and the fourth layer of the tail support blade 24, cooperate with the inner wall of the syringe 5. Under the joint action of the four layers of sealing surfaces, the improved piston and the syringe 5 always remain sealed during movement to prevent external gas from entering the fluid layer; external gas cannot enter the fluid layer across the piston, and when the air source is suspended, the piston will not rebound. When dispensing is not required, the multi-layer blade structure 2 of the piston can prevent fluid from overflowing and prevent glue or fluid from flowing back into the syringe 5, thereby reducing waste and impurities.

[0039] In other embodiments, the blade structure 2 may be composed of 3 layers, 5 layers or more blades, and the blade form may be forward or reverse, without limiting any combination of blade directions and angles.

[0040] Specifically, the lower conical surface 3 is integrally formed at the bottom of the piston body 1 , and an annular spoiler groove (depth 2-3 mm, penetrating 30%-50% of the height) can be extended from the end of the lower conical surface 3 to form a fluid guide channel with the inner wall of the syringe 5 .

[0041] The implementation principle of this embodiment is as follows: by adding a knife edge structure 2, a sealing surface is added between the piston body 1 and the syringe 5. When the piston body 1 and the syringe 5 move relative to each other, the added sealing surface can more effectively ensure the real-time seal between the two, and prevent external gas from entering the fluid layer due to the expansion of the plastic; when the plastic inevitably undergoes irregular deformation, the deformation of the piston body 1 and the syringe 5 will fit as closely as possible under the action of the multi-layer knife edges. Even if a slight leakage occurs, the gas entering the fluid layer will be greatly reduced through the layer-by-layer decompression of the multi-layer knife edges.

[0042] Reference Figure 3, a fluid dispensing device, consisting of an end cap 4, a syringe 5, a bottom head plug 6 and an improved piston. The syringe 5 contains the improved piston and the fluid medium. The bottom head plug 6 is sealed and connected to the syringe 5 through a thread, and has an integrated needle interface; the end cap 4 is arranged at the top of the syringe 5 and is connected to the air source device through an adapter. During operation, the air source device applies a controllable air pressure of 0.1~5 MPa to push the improved piston to move axially in the syringe 5, and squeeze the fluid out through the needle. The improved piston adopts a tapered design with a wide bottom and a narrow top. The cross-sectional area of ​​the fluid channel gradually decreases as the piston moves downward, forming a progressive flow channel. When the fluid is pushed to the needle, the air is preferentially discharged through the wider gap at the top of the piston to avoid being trapped at the bottom of the needle, reducing the risk of air resistance and intermittent flow interruption. The piston surface is polished, and combined with the tapered flow channel design, the fluid flow resistance coefficient is lower than that of the traditional flat-head piston, thereby reducing the occurrence of turbulence.

[0043] The embodiments of this specific implementation method are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, all equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. An improved piston, characterized in that: The invention comprises a piston body (1), a knife edge structure (2) and a lower conical surface (3); the knife edge structure (2) is arranged around the circumference of the piston body (1), and the lower conical surface (3) is integrally formed at the bottom of the piston body (1); the knife edge structure (2) is composed of at least three layers of knife edges, and each layer of knife edges is arranged in sequence along the axial direction of the piston body (1); the multiple layers of knife edges are formed into a dynamic sealing surface by laminating the inner wall of the syringe (5) layer by layer, so as to suppress the external gas from entering the fluid layer due to the linear expansion of the plastic part, and reduce the turbulence of the fluid when it flows.

2. An improved piston according to claim 1, characterized in that: The piston body (1) is made of a modified polyethylene (PE)-based composite material.

3. An improved piston according to claim 1, characterized in that: The blade structure (2) is composed of four layers of blades, which are, from bottom to top along the axial direction of the piston body (1), a first layer of positive blade (21), a second layer of reverse blade (22), a third layer of reverse blade (23) and a fourth layer of tail support blade (24).

4. An improved piston according to claim 3, characterized in that: The setting direction of the first layer of positive blade edge (21) is opposite to the setting direction of the conical surface at the bottom of the syringe (5), forming an initial sealing interface.

5. An improved piston according to claim 4, characterized in that: The setting direction of the second layer of reverse blades (22) is opposite to that of the first layer of forward blades (21), and the stress generated by the linear expansion of the plastic part is compensated by staggered bonding; the setting direction of the third layer of reverse blades (23) is the same as that of the second layer of reverse blades (22), forming a secondary pressure-bearing structure to disperse the sealing pressure.

6. An improved piston according to claim 5, characterized in that: The edge of the fourth layer tail support blade (24) is clamped with the bottom of the syringe (5) to prevent the piston from rebounding.

7. An improved piston according to claim 1, characterized in that: The knife edge structure (2) and the piston body (1) are integrally formed.

8. A fluid dispensing device, characterized in that: It comprises an end cover (4), a syringe (5), a bottom head plug (6) and the improved piston according to any one of claims 1 to 7, wherein the end cover (4) is arranged on the top of the syringe (5), the inside of the syringe (5) is hollow and is used to accommodate the improved piston and fluid, and the bottom head plug (6) is arranged on the bottom of the syringe (5) and is used to close the fluid outlet.

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