Push syringe and injection venting method
By designing an injector with a float valve, the problems of liquid waste and contamination during syringe venting are solved, enabling automatic gas discharge without liquid waste, making it suitable for applications with strict injection dosage requirements.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-21
- Publication Date
- 2026-04-07
AI Technical Summary
Existing syringes are prone to waste of injection fluid and environmental pollution during the air venting process, making them unsuitable for occasions with strict requirements on injection dosage.
Design an injection device comprising a syringe, a piston rod, and a float valve. The float valve automatically adjusts the connection between the liquid reservoir and the gas passage under the action of liquid buoyancy, so as to achieve automatic gas discharge without wasting liquid.
Without adjusting the position of the syringe plunger, it automatically expels gas from the injection solution, avoiding liquid waste and environmental pollution, making it suitable for applications with strict dosage requirements.
Smart Images
Figure CN120132126B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of medical device technology, and in particular to an injector and an injection air release method. Background Technology
[0002] In medical practice, syringes are commonly used for drug administration, vaccination, blood drawing, and contrast agent injection. Before performing an injection, it is often necessary to manually remove any gas mixed in with the syringe to prevent air bubbles from entering the patient's body with the injection fluid, causing discomfort or even serious complications.
[0003] During manual venting, in order to ensure that the gas inside the syringe is completely expelled, the operator often squeezes out a portion of the injection fluid from the injection port. This results in waste of the injection fluid and makes it unsuitable for occasions where the injection dosage is strictly required. In addition, the expelled injection fluid may also pollute the environment. Summary of the Invention
[0004] The main objective of this invention is to provide an injector that can expel gas mixed in the injection solution while avoiding waste and environmental pollution caused by the injection solution being expelled along with it.
[0005] To achieve the above objectives, the present invention provides an injection device comprising:
[0006] A syringe, wherein the lower end of the syringe is provided with an injection port that communicates with the inner cavity of the syringe;
[0007] A piston push rod is slidably fitted in the inner cavity of the syringe in a vertical direction. The portion of the inner cavity of the syringe between the lower end of the piston push rod and the injection port forms a liquid storage cavity. An air passage is provided inside the piston push rod. The upper end of the air passage communicates with the outside, and the lower end of the air passage extends to the lower end of the piston push rod.
[0008] A float valve is movably connected to the lower end of the piston rod in the vertical direction. When the float valve is at a first height position relative to the piston rod, the lower end of the air passage communicates with the liquid storage chamber, allowing gas in the liquid storage chamber to enter the air passage. When the float valve is at a second height position relative to the piston rod under the buoyancy of the liquid in the liquid storage chamber, the float valve forms a blockage between the lower end of the air passage and the liquid storage chamber, preventing liquid in the liquid storage chamber from entering the air passage. The second height position is higher than the first height position.
[0009] In one embodiment, the injector further includes a one-way valve disposed in the air passage, the one-way valve allowing gas to flow from the lower end of the air passage to the upper end of the air passage, and the one-way valve preventing gas from flowing from the upper end of the air passage to the lower end of the air passage.
[0010] In one embodiment, a first seal is provided between the one-way valve and the cavity wall of the air passage.
[0011] In one embodiment, the lower end of the air passage is provided with an annular flange extending radially inward, and the float valve has a limiting shoulder, a connecting neck and a float portion connected sequentially from top to bottom. The connecting neck is movably inserted into the inner ring of the annular flange, and the limiting shoulder is used to abut against the upper end face of the annular flange.
[0012] When the float valve is at the first height position relative to the piston push rod, there is a preset gap between the limiting shoulder, the connecting neck, the float portion and the annular flange, the preset gap forming an exhaust channel, and the exhaust channel communicating with the air passage and the liquid storage chamber; when the float valve is at the second height position relative to the piston push rod, the float portion fits against the lower end face of the annular flange to form a sealing effect between the air passage and the liquid storage chamber.
[0013] In one embodiment, the maximum cross-sectional area of the float portion is greater than the maximum cross-sectional area of the limiting shoulder portion.
[0014] In one embodiment, the lower end face of the annular flange extends downward in a direction away from the central axis; the upper side face of the float portion forms a sealing surface, which extends downward in a direction away from the central axis.
[0015] When the float valve is at the second height position relative to the piston push rod, the sealing surface is in contact with the lower end face of the annular flange.
[0016] In one embodiment, the bottom surface of the float portion extends downward along a direction close to the central axis.
[0017] In one embodiment, the limiting shoulder has a weight-reducing cavity that extends downward to the float portion. The bottom surface of the weight-reducing cavity extends downward in a direction close to the central axis. The solid portion between the bottom surface of the weight-reducing cavity and the bottom surface of the float portion forms an elastic lever arm. The inner end of the elastic lever arm is used to deflect upward under the buoyancy of the liquid in the reservoir cavity, so as to drive the outer end of the elastic lever arm to deflect outward in a direction away from the central axis.
[0018] In one embodiment, the thickness of the elastic lever arm in the vertical direction gradually decreases along the direction close to the central axis.
[0019] In one embodiment, the piston push rod has a receiving cavity, the upper part of the receiving cavity is connected to the lower end of the air passage, the annular flange is disposed on the lower part of the receiving cavity, and the limiting shoulder is located in the receiving cavity.
[0020] In one embodiment, the injector further includes a second seal, which is fitted onto the outer cylindrical surface of the piston rod and seals against the inner wall of the syringe. The height of the second seal is within the height range covered by the receiving cavity.
[0021] In one embodiment, the receiving cavity includes a first chamber and a second chamber, the upper part of the first chamber is connected to the lower end of the airway, the lower part of the first chamber is connected to the upper part of the second chamber, the annular flange is disposed on the lower part of the second chamber, and the limiting shoulder is located in the second chamber; the cross-sectional area of the second chamber is larger than the cross-sectional area of the first chamber.
[0022] The injector also includes a one-way valve, which is snap-fitted into the first chamber; the one-way valve allows gas to flow from the lower end of the air passage to the upper end of the air passage, and the one-way valve is used to prevent gas from flowing from the upper end of the air passage to the lower end of the air passage.
[0023] In one embodiment, the injector further includes a second seal, which is fitted onto the outer cylindrical surface of the piston rod and seals against the inner wall of the syringe. The height of the second seal is within the height range covered by the second chamber.
[0024] In one embodiment, the height of the first chamber is higher than the height of the one-way valve, and there is a first preset distance between the bottom surface of the one-way valve and the second chamber in the vertical direction.
[0025] In one embodiment, a stop structure is provided at the upper opening of the syringe;
[0026] The upper end of the piston rod is provided with a first limiting flange extending radially outward; the upper end of the stop structure is used to abut against the first limiting flange to prevent the piston rod from moving downward relative to the syringe.
[0027] In one embodiment, the piston rod has a second limiting flange extending radially outward at its middle portion, and the second limiting flange slides in the inner cavity of the syringe in the vertical direction; the lower end of the stop structure is used to abut against the second limiting flange to prevent the piston rod from moving upward relative to the syringe.
[0028] In one embodiment, when the upper end of the stop structure abuts against the first limiting flange, there is a second preset distance between the float valve and the bottom surface of the liquid storage cavity.
[0029] In one embodiment, the injector further includes a second seal, which is fitted onto the outer cylindrical surface of the piston rod and forms a sealing fit with the inner wall of the syringe.
[0030] In one embodiment, the float valve is made of an elastic material.
[0031] In one embodiment, the float valve has a weight-reducing cavity.
[0032] In one embodiment, the syringe is made of a transparent material, and a background strip is provided on the surface of the syringe to indicate the total amount of liquid in the reservoir.
[0033] In one embodiment, the piston push rod has at least two air outlets, which are arranged at intervals along the circumference of the piston push rod, and the at least two air outlets are connected to the upper end of the air passage.
[0034] In one embodiment, the upper end of the piston rod is provided with a first finger ring.
[0035] The present invention also proposes an injection venting method, wherein the injection venting method is performed using the aforementioned injector, and the injection venting method includes the following steps:
[0036] Immerse the injection port into the target injection solution;
[0037] Pull the piston rod upward to draw the target injection solution into the reservoir through the injection port;
[0038] Stop pulling the piston rod upward and seal the injection port;
[0039] Push the piston rod downwards so that the gas mixed in the reservoir enters the gas passage through the float valve and is discharged outwards until the float valve moves upwards relative to the piston rod to the second height position under the buoyancy of the target injection liquid in the reservoir.
[0040] In the technical solution of this invention, a float valve is provided between the liquid storage chamber of the syringe and the air passage of the piston rod. During the venting process after liquid aspiration, the communication state between the liquid storage chamber and the air passage can be adaptively changed by the movement of the float valve relative to the piston rod. When the float valve is at the first height position relative to the piston rod, the air passage is connected to the liquid storage chamber, and the gas in the liquid storage chamber can be discharged outward through the air passage. After the gas in the liquid storage chamber is emptied, the float valve moves relative to the piston rod to the second height position under the buoyancy of the liquid in the liquid storage chamber. At this time, the float valve forms a sealing effect between the air passage and the liquid storage chamber, which can prevent the liquid in the liquid storage chamber from leaking along the air passage. Based on the above solution, the gas mixed in the liquid storage chamber can be emptied without adjusting the placement of the syringe and without the liquid in the liquid storage chamber being discharged together, thereby reducing the waste of injection liquid. It is applicable to occasions with strict requirements for injection dosage and can avoid the problem of environmental pollution caused by accidental discharge of injection liquid. Attached Figure Description
[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0042] Figure 1 A schematic diagram of the overall front view of the injector in its initial state according to an embodiment of the present invention;
[0043] Figure 2 A schematic cross-sectional view of the injector provided by the present invention in its initial state;
[0044] Figure 3 A schematic diagram of the overall front view of the injector provided by the present invention in the suction state in one embodiment;
[0045] Figure 4 A schematic cross-sectional view of the injector provided by the present invention in a suction state.
[0046] Figure 5 A partial cross-sectional view of the injector provided by the present invention when the float valve is at a first height position relative to the piston rod in one embodiment of the injector;
[0047] Figure 6 A schematic diagram of the overall cross-sectional structure of the injector provided by the present invention when the float valve is at the second height position relative to the piston rod in one embodiment of the injector;
[0048] Figure 7This is a partial cross-sectional structural diagram of the injector provided by the present invention when the float valve is at the second height position relative to the piston rod.
[0049] Explanation of icon numbers:
[0050] 1. Syringe; 11. Injection port; 12. Liquid reservoir; 13. Stop structure; 14. Background strip; 15. Second ring; 16. Third ring;
[0051] 2. Piston push rod; 21. Air passage; 22. Annular flange; 23. Exhaust passage; 24. Receiving cavity; 25. First limiting flange; 26. Second limiting flange; 27. Air outlet; 28. First finger ring; 241. First chamber; 242. Second chamber;
[0052] 3. Float valve; 31. Limiting shoulder; 32. Connecting neck; 33. Float part; 311. Weight reduction cavity; 331. Sealing surface; 332. Elastic lever arm;
[0053] 4. Check valve;
[0054] 5. First sealing element;
[0055] 6. Second sealing element.
[0056] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0057] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0058] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.
[0059] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.
[0060] In medical practice, syringes are commonly used for drug administration, vaccination, blood drawing, and contrast agent injection. Before performing an injection, it is often necessary to manually remove any gas mixed in with the syringe to prevent air bubbles from entering the patient's body with the injection fluid, causing discomfort or even serious complications.
[0061] During manual venting, in order to ensure that the gas inside the syringe is completely expelled, the operator often squeezes out a portion of the injection fluid from the injection port. This results in waste of the injection fluid and makes it unsuitable for occasions where the injection dosage is strictly required. In addition, the expelled injection fluid may also pollute the environment.
[0062] To address the aforementioned problems, this invention provides an injection device designed to expel gas mixed in the injection solution while avoiding the waste and environmental pollution caused by the injection solution being expelled along with it.
[0063] Please see Figures 1 to 7 The injector provided by the present invention includes:
[0064] The syringe 1 has an injection port 11 at its lower end, which is connected to the inner cavity of the syringe 1.
[0065] The piston rod 2 slides in the upper and lower direction within the inner cavity of the syringe 1. The portion of the inner cavity of the syringe 1 between the lower end of the piston rod 2 and the injection port 11 forms a liquid storage chamber 12. The piston rod 2 is provided with an air passage 21, the upper end of which is connected to the outside, and the lower end of which extends to the lower end of the piston rod 2.
[0066] A float valve 3 is movably connected to the lower end of the piston rod 2 in the vertical direction. When the float valve 3 is at the first height position relative to the piston rod 2, the lower end of the air passage 21 is connected to the liquid storage chamber 12 to allow gas in the liquid storage chamber 12 to enter the air passage 21. When the float valve 3 is at the second height position relative to the piston rod 2 under the buoyancy of the liquid in the liquid storage chamber 12, the float valve 3 forms a blockage between the lower end of the air passage 21 and the liquid storage chamber 12 to prevent liquid in the liquid storage chamber 12 from entering the air passage 21. The second height position is higher than the first height position.
[0067] In this embodiment, the upper end of the piston rod 2 is located outside the syringe 1. The operator can drive the piston rod 2 to move up and down relative to the syringe 1 by holding the upper end of the piston rod 2. The circumferential sidewall of the lower end of the piston rod 2 can be sealed with the inner wall of the syringe 1 in the circumferential direction. When the operator drives the piston rod 2 to move upward relative to the syringe 1, the liquid at the injection port 11 can be drawn into the reservoir 12 based on the negative pressure. When the operator drives the piston rod 2 to move downward relative to the syringe 1, the liquid in the reservoir 12 can be discharged outward through the injection port 11 based on the positive pressure, thereby completing the injection operation. The liquid drawn into the reservoir 12 and used for injection includes, but is not limited to, drugs, saline, blood, contrast agents, etc. The injection port 11 can be used to connect puncture devices such as needles, so that the above-mentioned liquid can be injected into the human body after puncturing the skin with puncture devices.
[0068] The float valve 3 can be movably connected to the lower end of the piston rod 2 using structures such as snaps, barbs, and pins. This ensures that the float valve 3 has a certain degree of freedom of movement relative to the piston rod 2 in the vertical direction while preventing complete separation between the float valve 3 and the piston rod 2. The float valve 3 needs to be positioned directly opposite the lower opening of the air passage 21. When the float valve 3 is in a low position (i.e., when the float valve 3 is at the first height position relative to the piston rod 2), there is a certain gap between a portion of the float valve 3 and the lower end of the piston rod 2. In other words, the float valve 3 does not block the lower opening of the air passage 21 at this time, and the gas in the liquid storage chamber 12 can enter the air passage 21 through the gap between the float valve 3 and the lower end of the piston rod 2. When the float valve 3 is in a high position (i.e., when the float valve 3 is at the second height position relative to the piston rod 2), the float valve 3 and the lower end of the piston rod 2 are completely attached and block the lower opening of the air passage 21. At this time, neither the gas nor the liquid in the liquid storage chamber 12 can enter the air passage 21.
[0069] It is understandable that the aforementioned first height position can refer to a height range. When the float valve 3 is in different positions relative to the piston push rod 2 within this height range, there is a gap between a part of the float valve 3 and the lower end of the piston push rod 2 that allows gas to pass through, only the specific size of the gap is different.
[0070] Based on the above settings, in actual operation, the injector is in the following state when no aspiration operation is performed: Figure 1 and Figure 2 In the initial state shown, the operator can first immerse the injection port 11 into the liquid to be injected, and then proceed as follows: Figure 3 and Figure 4 As shown, the piston rod 2 is pulled upwards to draw liquid through the injection port 11 into the storage chamber 12. The float valve 3 will also move upwards synchronously under the action of the piston rod 2. When the liquid in the storage chamber 12 reaches a preset value, the upward pulling of the piston rod 2 stops. At this time, the gas mixed in the liquid, due to its lower density, will float above the liquid in the storage chamber 12 and contact the float valve 3, provided the injector's position remains unchanged. Due to the presence of this gas, the float valve 3 has not yet fully contacted the liquid in the storage chamber 12. Under its own weight, the float valve 3... Figure 5 As shown, the float valve 3 is currently in a low position (i.e., at the first height position) relative to the piston rod 2, and the float valve 3 does not block the lower opening of the air passage 21. The operator can then block the injection port 11 to prevent liquid from being discharged from the injection port 11, and then push the piston rod 2 downward. Under the pressure of the lower end of the piston rod 2, the gas in the reservoir 12 will be squeezed and enter the air passage 21 through the gap between the float valve 3 and the lower end of the piston rod 2. As the piston rod 2 continues to press down, the gas in the reservoir 12 will continuously enter the air passage 21 and be discharged from the upper end of the air passage 21. During this process, as the gas is continuously discharged, the contact area between the float valve 3 and the liquid in the reservoir 12 will gradually increase, and the buoyancy of the liquid on the float valve 3 will also gradually increase. Under the action of this gradually increasing buoyancy, the float valve 3 will overcome its own weight and gradually move upward relative to the piston rod 2. The gap between the float valve 3 and the lower end of the piston rod 2 will also gradually decrease as the float valve 3 moves upward. Figure 6 and Figure 7 As shown, when the float valve 3 moves upward relative to the piston rod 2 to the high position (i.e., at the second height position), the gas in the reservoir 12 has been completely vented through the air passage 21. At this time, the lower ends of the float valve 3 and the piston rod 2 are completely attached and block the lower opening of the air passage 21. The liquid in the reservoir 12 will not be able to enter the air passage 21. This avoids leakage of some liquid in the reservoir 12 through the air passage 21 due to excessive downward pressure of the piston rod 2. Based on the above operation, the venting operation can be completed without adjusting the position of the injector and without preventing the liquid in the reservoir 12 from being discharged. Subsequently, the seal on the injection port 11 can be released, and the liquid in the reservoir 12 can be pushed out of the injection port 11 by the piston rod 2 for injection operation.
[0071] Therefore, the injector provided in this embodiment has a float valve 3 installed between the liquid storage chamber 12 of the syringe 1 and the air passage 21 of the piston rod 2. During the venting process after liquid aspiration, the float valve 3 adaptively changes the communication state between the liquid storage chamber 12 and the air passage 21 by moving relative to the piston rod 2. When the float valve 3 is at the first height position relative to the piston rod 2, the air passage 21 is connected to the liquid storage chamber 12, and the gas in the liquid storage chamber 12 can be discharged outward through the air passage 21. After the gas in the liquid storage chamber 12 is vented, the float valve 3 floats relative to the liquid in the liquid storage chamber 12. Under the action of force, the piston push rod 2 moves to the second height position. At this time, the float valve 3 forms a sealing effect between the air passage 21 and the liquid storage chamber 12, which can prevent the liquid in the liquid storage chamber 12 from leaking along the air passage 21. Based on the solution of this embodiment, the gas mixed in the liquid storage chamber 12 can be emptied without adjusting the placement of the injector and without the liquid in the liquid storage chamber 12 being discharged together. This can reduce the waste of injection solution, is applicable to occasions with strict requirements for injection dosage, and can avoid the problem of environmental pollution caused by accidental discharge of injection solution.
[0072] In one embodiment, refer to Figures 1 to 7 The injector also includes a one-way valve 4, which is disposed in the air passage 21. The one-way valve 4 allows gas to flow from the lower end of the air passage 21 to the upper end of the air passage 21, and the one-way valve 4 is used to prevent gas from flowing from the upper end of the air passage 21 to the lower end of the air passage 21.
[0073] Specifically, the check valve 4 is located above the float valve 3. A relatively large chamber can be provided in the air passage 21 for the installation of the check valve 4. The check valve 4 can be a gravity-type check valve, a spring-loaded check valve, a diaphragm-type check valve, etc., which are not limited here. Among them, the gravity-type check valve 4 usually includes a spherical or conical valve core and a valve seat, with the valve core located above the valve seat. When gas enters from below, the air pressure pushes the valve core up, and the gas can flow through the gap between the valve seat and the valve core. When the gas stops flowing or flows in the reverse direction, the valve core falls back under the action of gravity, closing the valve seat and preventing the gas from flowing in the reverse direction. The spring-loaded check valve 4 usually includes a spring, a valve core, and a valve seat. The spring can apply a downward elastic force to the valve core, making the valve core press tightly against the valve seat and closing the valve. When the gas pressure is greater than the elastic force of the spring, the valve core is pushed up, and the gas can pass through. When the gas pressure decreases or reverses, the spring can press the valve core back to the valve seat, closing the valve. A diaphragm-type check valve typically includes a flexible diaphragm and a valve seat, with the diaphragm covering the valve seat. When gas enters from one side, the gas pressure deforms the diaphragm, pushing it to the other side of the valve seat, opening the passage for gas to pass through. When the gas stops or flows in the opposite direction, the diaphragm returns to its original shape and closes the passage, preventing the gas from flowing in the opposite direction.
[0074] By setting a one-way valve 4, the flow direction of the gas can be restricted, preventing external gas from entering the float valve 3 and the liquid storage chamber 12 through the air passage 21, thus disrupting the relationship between the gas pressure and the liquid buoyancy and interfering with the exhaust operation. This ensures that the gas in the liquid storage chamber 12 can be smoothly discharged from bottom to top through the air passage 21.
[0075] In one embodiment, refer to Figures 1 to 7 A first sealing element 5 is provided between the one-way valve 4 and the cavity wall of the air passage 21.
[0076] Specifically, the first sealing element 5 can be a sealing ring, sealing ring, etc.; taking the sealing ring as an example, a sealing ring groove can be provided on the outer wall of the one-way valve 4, and the first sealing element 5 can be snapped into the sealing ring groove. The outer side of the first sealing element 5 fits against the cavity wall of the air passage 21, so as to achieve a sealing fit between the one-way valve 4 and the cavity wall of the air passage 21.
[0077] By setting the first sealing element 5, the sealing between the one-way valve 4 and the air passage 21 can be guaranteed, preventing external gas from entering the float valve 3 and the liquid storage chamber 12 through the gap between the outer wall of the one-way valve 4 and the cavity wall of the air passage 21, thus interfering with the exhaust operation.
[0078] In one embodiment, refer to Figures 1 to 7 The float valve 3 is made of an elastic material; specifically, the float valve 3 can be made of elastic materials such as rubber or polyurethane. This allows the float valve 3 to have a certain elastic deformation capability, making it easier to install and disassemble. At the same time, the elastic deformation characteristics of the float valve 3 can better adapt to the shape of the lower end of the piston rod 2. When the float valve 3 is at the second height position relative to the piston rod 2, it can fit more tightly against the corresponding position of the lower end of the piston rod 2, thereby reducing the gap between the float valve 3 and the piston rod 2 and improving the sealing effect.
[0079] In one embodiment, refer to Figures 1 to 7 The lower end of the air passage 21 is provided with an annular flange 22 extending radially inward. The float valve 3 has a limiting shoulder 31, a connecting neck 32 and a float portion 33 connected sequentially from top to bottom. The connecting neck 32 is movably inserted into the inner ring of the annular flange 22. The limiting shoulder 31 is used to abut against the upper end face of the annular flange 22.
[0080] When the float valve 3 is at the first height position relative to the piston push rod 2, there is a preset gap between the limiting shoulder 31, the connecting neck 32, the float part 33 and the annular flange 22. The preset gap forms the exhaust channel 23, which is connected to the air passage 21 and the liquid storage chamber 12. When the float valve 3 is at the second height position relative to the piston push rod 2, the float part 33 fits against the lower end face of the annular flange 22 to form a sealing effect between the air passage 21 and the liquid storage chamber 12.
[0081] In this embodiment, the annular flange 22 is arranged circumferentially. The cross-sectional area of the connecting neck 32 is smaller than that of the inner ring of the annular flange 22. The cross-sectional areas of the limiting shoulder 31 and the float portion 33 are both larger than those of the inner ring of the annular flange 22. The length of the connecting neck 32 in the vertical direction is greater than the thickness of the annular flange 22 in the vertical direction. This allows the connecting neck 32 to have a certain margin of movement relative to the annular flange 22 in both the radial direction (i.e., the horizontal direction under the illustrated angle) and the axial direction (i.e., the vertical direction under the illustrated angle). The lower side of the limiting shoulder 31 is used to abut against the upper end face of the annular flange 22 to form a limiting effect. This ensures that the piston push rod 2 can drive the float valve 3 to move upward through the annular flange 22 while preventing the float valve 3 from detaching from the piston push rod 2.
[0082] When the float valve 3 is at the first height position relative to the piston push rod 2, such as Figure 4 and Figure 5 As shown, the lower side of the limiting shoulder 31 does not abut against the upper end face of the annular flange 22, and the upper side of the float portion 33 does not fit against the lower end face of the annular flange 22. At this time, a first gap L1 is formed between the limiting shoulder 31 and the upper end face of the annular flange 22, a second gap L2 is formed between the periphery of the connecting neck 32 and the inner ring of the annular flange 22, and a third gap L3 is formed between the float portion 33 and the lower end face of the annular flange 22. The interconnected first gap L1, second gap L2, and third gap L3 together constitute a preset gap (that is, constitute an exhaust channel 23). The upper end of the exhaust channel 23 is connected to the air passage 21, and the lower end of the exhaust channel 23 is connected to the liquid storage chamber 12. At this time, the gas in the liquid storage chamber 12 can enter the air passage 21 through the exhaust channel 23 and be discharged outward.
[0083] As the float valve 3 gradually rises relative to the piston rod 2 under the buoyancy of the liquid in the reservoir 12, the third gap L3 between the float portion 33 and the lower end face of the annular flange 22 gradually decreases; when the float valve 3 reaches the second height position relative to the piston rod 2, such as Figure 6 and Figure 7 As shown, the upper side of the float portion 33 is in contact with the lower end face of the annular flange 22. At this time, the exhaust channel 23 will be blocked, which can prevent the liquid in the liquid storage chamber 12 from entering the air passage 21 through the exhaust channel 23.
[0084] In this embodiment, by setting the float valve 3 to the above-mentioned simple structural form, the float valve 3 and the piston push rod 2 can be connected movably while avoiding separation between the float valve 3 and the piston push rod 2. This ensures that the float valve 3 has the opening and closing functions that a valve should have, so that the venting operation and the sealing operation after venting can be carried out smoothly.
[0085] In one embodiment, refer to Figures 1 to 7 The maximum cross-sectional area of the float portion 33 is greater than the maximum cross-sectional area of the limiting shoulder portion 31. This allows the limiting shoulder portion 31 to form the small head portion of the float valve 3, and the float portion 33 to form the large head portion of the float valve 3. Since the volume of the limiting shoulder portion 31 is relatively small, it is easy to pass the limiting shoulder portion 31 through the inner ring of the annular flange 22 and into the air passage 21 during assembly, and it is also easy to disassemble and replace it later. Since the volume of the float portion 33 is relatively large, the contact area between the float portion 33 and the liquid in the liquid storage chamber 12 can be increased, thereby increasing the buoyancy of the float valve 3 and ensuring that the float valve 3 can be smoothly raised from the first height position to the second height position under the action of buoyancy during the exhaust process.
[0086] In one embodiment, refer to Figures 1 to 7 The lower end face of the annular flange 22 extends downward in a direction away from the central axis X; the upper side face of the float portion 33 forms a sealing surface 331, which extends downward in a direction away from the central axis X.
[0087] When the float valve 3 is in the second height position relative to the piston push rod 2, the sealing surface 331 is in contact with the lower end face of the annular flange 22.
[0088] In this embodiment, the main body of the syringe 1, the main body of the piston rod 2, and the main body of the float valve 3 can all be configured as rotating bodies. Taking the orientation shown in the figure as an example, the central axis X can refer to the vertical central axis of the syringe 1, the vertical central axis of the piston rod 2, or the vertical central axis of the float valve 3. The vertical central axes of the syringe 1, the piston rod 2, and the float valve 3 can be collinear. In subsequent embodiments, any reference to the central axis X will be understood in accordance with the above description and will not be repeated.
[0089] The lower end face of the annular flange 22 extends in a direction that has both a radial component (i.e., a horizontal component at the angle shown in the figure) and an axial component (i.e., a vertical component at the angle shown in the figure). The lower end face of the annular flange 22 gradually rises in a radially inward direction (i.e., towards the central axis X). The upper side of the float portion 33 also extends in a direction that has both a radial component (i.e., a horizontal component at the angle shown in the figure) and an axial component (i.e., a vertical component at the angle shown in the figure). The upper side of the float portion 33 gradually rises in a radially inward direction (i.e., towards the central axis X). This allows the shape of the upper side of the float portion 33 to match the shape of the lower end face of the annular flange 22, thereby ensuring that the upper side of the float portion 33 fits tightly against the lower end face of the annular flange 22. The lower end face of the annular flange 22 and the upper side face of the float portion 33 can be inclined along a straight line to form a planar structure; the lower end face of the annular flange 22 and the upper side face of the float portion 33 can also extend along an arc to form a structure such as Figure 5 and Figure 7 The surface structure shown is not limited here.
[0090] Preferably, the lower end face of the annular flange 22 extends along the arc direction, and the upper side face of the float portion 33 also extends along the arc direction. This utilizes the high adaptability between the curved surfaces to ensure the contact area between the lower end face of the annular flange 22 and the upper side face of the float portion 33. This can minimize the problem of insufficient contact between the lower end face of the annular flange 22 and the upper side face of the float portion 33 due to dimensional deviations, thereby ensuring the tightness of the fit and the sealing effect between the float portion 33 and the annular flange 22.
[0091] Based on the above configuration, at the end of the exhaust operation, the float valve 3 moves upward relative to the piston push rod 2 to the second height position, and the upper side of the float part 33 fits against the lower end face of the annular flange 22 to form a sealing effect, such as Figure 7 As shown, at this time, the pressing force F generated by the upper side of the float part 33 against the lower end face of the annular flange 22 has a first vertical upward component F1 and a second horizontal component F2. The second component F2 can push the corresponding part of the piston rod 2 to press against the inner wall of the syringe 1 radially outward. In this way, the sealing effect between the piston rod 2 and the syringe 1 can be improved by utilizing the abutting action between the float valve 3 and the piston rod 2, which can better prevent the liquid in the liquid storage chamber 12 from leaking outward through the gap between the piston rod 2 and the syringe 1.
[0092] In one embodiment, refer to Figures 1 to 7 The bottom surface of the float portion 33 extends downward along the direction close to the central axis X.
[0093] Specifically, when the float valve 3 is made of an elastic material, and the float part 33 is configured as follows: Figure 5 and Figure 7 When the shape shown is low in the center and high on the periphery, on the one hand, it can increase the contact area between the float part 33 and the liquid, thereby increasing the buoyancy. On the other hand, the buoyancy of the liquid can cause the downwardly protruding central area of the float part 33 to undergo a certain degree of elastic deformation upward. This deformation is equivalent to squeezing the central area of the float part 33 upward. This can further drive the periphery of the float part 33 to undergo elastic deformation radially outward, thereby further improving the tightness of the fit between the float part 33 and the annular flange 22, and thus improving the sealing effect. At the same time, the radially outward elastic deformation of the periphery of the float part 33 can further push the corresponding part of the piston rod 2 to adhere radially outward to the inner wall of the syringe 1, thereby further improving the sealing effect between the piston rod 2 and the syringe 1.
[0094] In one embodiment, refer to Figures 1 to 7The limiting shoulder 31 has a weight-reducing cavity 311, which extends downward to the float part 33. The bottom surface of the weight-reducing cavity 311 extends downward in a direction close to the central axis X. The solid part between the bottom surface of the weight-reducing cavity 311 and the bottom surface of the float part 33 forms an elastic lever arm 332. The inner end of the elastic lever arm 332 is used to deflect upward under the buoyancy of the liquid in the liquid storage cavity 12, so as to drive the outer end of the elastic lever arm 332 to deflect outward in a direction away from the central axis X.
[0095] By setting up a weight-reducing chamber 311, the weight of the float valve 3 can be reduced, increasing the difference between the buoyancy force on the float valve 3 and its own weight. This allows the float valve 3 to rise from the first height position to the second height position under the action of buoyancy, so as to smoothly complete the venting operation.
[0096] The weight-reducing cavity 311 can be configured as follows: Figure 5 and Figure 7 The bottom of the weight-reducing cavity 311 is tapered, so that the bottom surface of the weight-reducing cavity 311 extends downward along the direction close to the central axis X. Based on the configuration of the previous embodiment, the bottom surface of the float portion 33 also extends downward along the direction close to the central axis X. This allows the solid portion between the bottom surface of the weight-reducing cavity 311 and the bottom surface of the float portion 33 to form an elastic lever arm 332 structure. The thickness of this elastic lever arm 332 structure is approximately equal at all points in the radial direction (thickness refers to the shortest straight-line distance between the bottom surface of the weight-reducing cavity 311 and the bottom surface of the float portion 33 in the vertical direction). Thus, referring to the relevant description in the previous embodiment, when the buoyancy of the liquid causes the downwardly protruding central area of the float portion 33 to undergo a certain degree of elastic deformation upward, it is equivalent to upward... Pushing the inner end of the elastic lever arm 332 (i.e., the end located at the central axis X) causes the elastic lever arm 332 to deflect, causing the outer end of the elastic lever arm 332 (i.e., the end located on the outer periphery) to shift away from the central axis X. This, in turn, can radially and outwardly compress the lower end face of the annular flange 22, further improving the tightness of the fit between the float part 33 and the annular flange 22, and enhancing the sealing effect. At the same time, it can further push the corresponding part of the piston rod 2 radially and outwardly to press tightly against the inner wall of the syringe 1, thereby further enhancing the sealing effect between the piston rod 2 and the syringe 1.
[0097] In this embodiment, by extending the weight-reducing cavity 311 to a position close to the bottom surface of the float part 33, the float valve 3 as a whole forms a hollow structure, which can reduce the rigidity of the float part 33 and increase the degree of deformation of the float part 33 under the action of buoyancy, thereby further improving the sealing effect between the float part 33 and the annular flange 22, and at the same time further improving the sealing effect between the piston rod 2 and the syringe 1.
[0098] In one embodiment, refer to Figures 1 to 7 The thickness of the elastic lever arm 332 in the vertical direction gradually decreases along the direction close to the central axis X.
[0099] In this embodiment, the elastic lever arm 332 is designed with varying thicknesses, ensuring that the thinner area near the central axis X undergoes more significant elastic deformation under buoyancy. This allows the elastic lever arm 332 to deflect outwards in a direction away from the central axis X, causing the outer end of the elastic lever arm 332 to press tightly against the lower end face of the annular flange 22. This further improves the tightness of the fit between the float part 33 and the annular flange 22, enhancing the sealing effect. Simultaneously, it further pushes the corresponding part of the piston rod 2 radially outwards to press tightly against the inner wall of the syringe 1, thereby further improving the sealing effect between the piston rod 2 and the syringe 1.
[0100] In one embodiment, refer to Figures 1 to 7 The piston rod 2 has a receiving cavity 24 inside. The upper part of the receiving cavity 24 is connected to the lower end of the air passage 21. The annular flange 22 is provided on the lower part of the receiving cavity 24. The limiting shoulder 31 is located in the receiving cavity 24.
[0101] By providing a receiving cavity 24 inside the piston rod 2, on the one hand, it can provide a receiving space for the limiting shoulder 31, and on the other hand, it can reduce the wall thickness at the corresponding position of the piston rod 2. This makes it easier for the thinner wall position on the piston rod 2 opposite to the receiving cavity 24 to deform radially outward under the compressive force applied by the float valve 3, thereby squeezing the inner wall of the syringe 1. This results in a better sealing effect between the outer wall of the piston rod 2 and the inner wall of the syringe 1.
[0102] In one embodiment, refer to Figures 1 to 7 The injector also includes a second seal 6, which is fitted onto the outer cylindrical surface of the piston rod 2. The second seal 6 is in sealing cooperation with the inner wall of the syringe 1, and the height of the second seal 6 is within the height range covered by the receiving cavity 24.
[0103] Specifically, the second sealing element 6 can be a sealing ring, sealing ring, etc. Taking a sealing ring as an example, a sealing ring groove can be provided on the outer cylindrical surface of the piston rod 2, and the second sealing element 6 can be snapped into the sealing ring groove. The outer side of the second sealing element 6 is in contact with the inner wall of the syringe 1. The dimensions of the second sealing element 6 and the sealing ring groove can be set according to the dynamic sealing standard. In this way, while ensuring that the piston rod 2 can slide relative to the syringe 1, a sealing fit can be achieved between the outer cylindrical surface of the piston rod 2 and the inner wall of the syringe 1, preventing the liquid in the liquid storage chamber 12 from leaking outward through the gap between the outer cylindrical surface of the piston rod 2 and the inner wall of the syringe 1. At the same time, it can prevent external gas from entering the liquid storage chamber 12 through the gap between the outer cylindrical surface of the piston rod 2 and the inner wall of the syringe 1.
[0104] Preferably, the second sealing element 6 can be configured as multiple and arranged at intervals along the axial direction of the piston rod 2 (i.e., the vertical direction shown in the figure). While improving the sealing effect, it can form at least two fulcrums between the outer cylindrical surface of the piston rod 2 and the inner wall of the syringe 1, so that the piston rod 2 can move stably up and down in the inner cavity of the syringe 1, and avoid the piston rod 2 from deflecting relative to the syringe 1 during the movement.
[0105] When the height of the second seal 6 is within the height range covered by the receiving cavity 24 (i.e., the highest point of the second seal 6 is not higher than the highest point of the receiving cavity 24, and the lowest point of the second seal 6 is not lower than the lowest point of the receiving cavity 24), referring to the previous embodiment, when the target position on the piston rod 2 with a thinner wall thickness opposite to the receiving cavity 24 deforms radially outward under the pressure applied by the float valve 3, it can directly drive the second seal 6 located at the target position to squeeze the inner wall of the syringe 1 outward, thereby improving the tightness of the fit between the second seal 6 and the outer cylindrical surface of the piston rod 2 and the inner wall of the syringe 1. This can improve the sealing effect between the outer wall of the piston rod 2 and the inner wall of the syringe 1, while better avoiding the reduction of the smoothness of the piston rod 2 sliding up and down relative to the syringe 1 due to the direct contact between the rigid part of the piston rod 2 and the inner wall of the syringe 1.
[0106] In one embodiment, refer to Figures 1 to 7 The receiving cavity 24 includes a first chamber 241 and a second chamber 242. The upper part of the first chamber 241 is connected to the lower end of the airway 21, and the lower part of the first chamber 241 is connected to the upper part of the second chamber 242. An annular flange 22 is disposed on the lower part of the second chamber 242, and a limiting shoulder 31 is located in the second chamber 242. The cross-sectional area of the second chamber 242 is larger than that of the first chamber 241.
[0107] The injector also includes a one-way valve 4, which is snapped into the first chamber 241. The one-way valve 4 allows gas to flow from the lower end of the air passage 21 to the upper end of the air passage 21, and the one-way valve 4 is used to prevent gas from flowing from the upper end of the air passage 21 to the lower end of the air passage 21.
[0108] By setting the receiving cavity 24 as a stepped first chamber 241 and second chamber 242, it can meet the snap-fit installation requirements of the small-sized one-way valve 4. On the other hand, by setting the cross-sectional area of the second chamber 242 to be larger, the wall thickness of the target position on the piston rod 2 opposite to the second chamber 242 can be reduced as much as possible. This makes it easier for the target position to deform radially outward under the compressive force applied by the float valve 3, so as to improve the sealing effect between the piston rod 2 and the syringe 1 by squeezing the inner wall of the syringe 1 through the target position.
[0109] The outer wall of the one-way valve 4 and the wall of the second chamber 242 can be sealed by the first sealing element 5 to prevent external gas from entering the float valve 3 and the liquid storage chamber 12 through the gap between the outer wall of the one-way valve 4 and the wall of the second chamber 242, thus interfering with the exhaust operation.
[0110] In one embodiment, refer to Figures 1 to 7 The injector also includes a second seal 6, which is fitted onto the outer cylindrical surface of the piston rod 2. The second seal 6 is in sealing cooperation with the inner wall of the syringe 1, and the height of the second seal 6 is within the height range covered by the second chamber 242.
[0111] The second sealing element 6 can be a sealing ring, sealing ring, etc. The setting method of the second sealing element 6 can refer to the above embodiment, and will not be repeated here.
[0112] When the height of the second seal 6 is within the height range covered by the second chamber 242 (i.e., the highest point of the second seal 6 is not higher than the highest point of the second chamber 242, and the lowest point of the second seal 6 is not lower than the lowest point of the second chamber 242), referring to the above embodiment, when the target position on the piston rod 2 with a thinner wall thickness opposite to the second chamber 242 deforms radially outward under the pressure applied by the float valve 3, it can directly drive the second seal 6 located at the target position to squeeze the inner wall of the syringe 1 outward, thereby improving the tightness of the fit between the second seal 6 and the outer cylindrical surface of the piston rod 2 and the inner wall of the syringe 1. This can improve the sealing effect between the outer wall of the piston rod 2 and the inner wall of the syringe 1, while better avoiding the reduction of the smoothness of the piston rod 2 sliding up and down relative to the syringe 1 due to the direct contact between other rigid parts of the piston rod 2 and the inner wall of the syringe 1.
[0113] In one embodiment, refer to Figure 5 The height of the first chamber 241 is higher than the height of the one-way valve 4, and there is a first preset distance H1 between the bottom surface of the one-way valve 4 and the second chamber 242 in the vertical direction.
[0114] As illustrated, by setting a first preset distance H1, a buffer space can be formed below the one-way valve 4. Even if the float valve 3 touches the top surface of the second chamber 242 (that is, the interface between the first chamber 241 and the second chamber 242) during the rising process, the float valve 3 cannot directly contact the one-way valve 4. This can avoid damage to related devices and affect the normal use of the injector caused by the collision between the float valve 3 and the one-way valve 4.
[0115] In one embodiment, refer to Figures 1 to 7 The upper opening of the syringe 1 is provided with a stop structure 13;
[0116] The upper end of the piston rod 2 is provided with a first limiting flange 25 extending radially outward; the upper end of the stop structure 13 is used to abut against the first limiting flange 25 to prevent the piston rod 2 from moving downward relative to the syringe 1.
[0117] In one embodiment, refer to Figures 1 to 7 The piston rod 2 has a second limiting flange 26 extending radially outward in the middle part. The second limiting flange 26 slides in the inner cavity of the syringe 1 in the vertical direction. The lower end of the stop structure 13 is used to abut against the second limiting flange 26 to prevent the piston rod 2 from moving upward relative to the syringe 1.
[0118] Illustrationly, the stop structure 13 can be configured as a flange structure detachably connected to the upper opening of the syringe 1 via a snap-fit connection, threaded connection, pin connection, etc.; the first limiting flange 25 and the second limiting flange 26 on the piston rod 2 respectively form a ring-shaped structure. Through the abutting cooperation between the stop structure 13 and the first limiting flange 25 and the second limiting flange 26, the sliding of the piston rod 2 in the inner cavity of the syringe 1 can be limited, which can prevent the piston rod 2 from being pulled out of the syringe 1 due to excessive upward pulling by the operator during the liquid aspiration process, and at the same time, it can prevent the float valve 3 from colliding with the bottom of the inner cavity of the syringe 1 due to excessive downward pressure by the operator during the exhaust and injection processes.
[0119] In addition, the second limiting flange 26 can cooperate with the second sealing member 6 below to limit the piston rod 2 in the radial direction, so as to prevent the piston rod 2 from shaking excessively relative to the syringe 1.
[0120] In one embodiment, refer to Figures 1 to 7 When the upper end of the stop structure 13 abuts against the first limiting flange 25, there is a second preset distance between the float valve 3 and the bottom surface of the liquid storage chamber 12.
[0121] By setting a second preset distance, the bottom surface of the inner cavity of syringe 1 (i.e., the bottom surface of the liquid storage chamber 12) can retain a certain safety capacity. This prevents the float valve 3 from directly impacting the bottom of the inner cavity of syringe 1 and causing damage. Consequently, damage to the float valve 3 can prevent changes in buoyancy and other related parameters, thus avoiding adverse effects on the accuracy of the venting operation. The space corresponding to the second preset distance contains a portion of gas. This gas does not affect the liquid aspiration operation and can be discharged during subsequent venting operations.
[0122] In one embodiment, refer to Figures 1 to 7 The syringe 1 is made of transparent material, and a background strip 14 is provided on the surface of the syringe 1. The background strip 14 is used to indicate the total amount of liquid in the liquid storage chamber 12.
[0123] When the syringe 1 is made of a transparent material, it is easier for the operator to observe the liquid status in the reservoir 12. The background strip 14 can be set on the surface of the syringe 1 by means of attachment, etching, etc. The background strip 14 can use scale lines, color blocks, patterns, etc. to indicate the total amount of liquid in the reservoir 12, so as to help the operator to know the current total amount of liquid in real time and intuitively according to the markings of the background strip 14, and to accurately determine whether the current total amount of liquid in the reservoir 12 meets the preset requirements.
[0124] In one embodiment, refer to Figures 1 to 7 The piston push rod 2 has at least two air outlets 27, which are arranged at intervals along the circumference of the piston push rod 2, and the at least two air outlets 27 are connected to the upper end of the air passage 21.
[0125] By setting at least two air outlets 27, it can be ensured that the gas in the air passage 21 can be discharged outward evenly and smoothly from multiple directions, avoiding the obstruction of gas flow at the upper end of the air passage 21 from affecting the normal operation of the exhaust.
[0126] In one embodiment, refer to Figures 1 to 7 The upper end of the piston rod 2 is provided with a first finger ring 28.
[0127] By setting the first finger ring 28, the operator can better apply force to the piston rod 2. In practical applications, the operator can insert their finger into the first finger ring 28 and move the first finger ring 28 up and down, thereby conveniently driving the piston rod 2 to move up and down relative to the syringe 1, so as to conveniently complete the liquid aspiration, degassing and injection operations.
[0128] Among them, the first ring 28 can be as follows Figure 1 The first limiting flange 25 is shown as being disposed on its upper end face. In some embodiments, a horizontally extending transverse stiffener may be provided on the upper side of the first ring 28, and the suspended positions at both ends of the transverse stiffener may be connected to the left and right sides of the first ring 28 by two vertical stiffeners respectively, thereby enhancing the structural strength of the first ring 28.
[0129] Preferably, refer to Figures 1 to 7 The syringe 1 is equipped with a second finger ring 15 and a third finger ring 16, which are arranged at intervals along the circumference of the syringe 1. In actual operation, the operator can insert the index and middle fingers into the second finger ring 15 and the third finger ring 16 respectively, and insert the thumb into the first finger ring 28. This makes it easier and more convenient to drive the piston rod 2 to move up and down relative to the syringe 1, thus solving the problem of poor grip of the syringe and conforming more to the force application characteristics of the human body.
[0130] This invention also provides a method for injecting air to escape; please refer to [link / reference]. Figures 1 to 7The injection venting method is performed using the injector in any of the above embodiments, and the injection venting method includes the following steps:
[0131] Immerse the injection port 11 into the target injection solution;
[0132] Pull the piston rod 2 upward to draw the target injection solution into the reservoir 12 through the injection port 11;
[0133] Stop pulling the piston rod 2 upward and block the injection port 11;
[0134] Push the piston rod 2 downwards so that the gas mixed in the liquid storage chamber 12 enters the air passage 21 through the float valve 3 and is discharged outwards until the float valve 3 moves upwards relative to the piston rod 2 to the second height position under the buoyancy of the target injection liquid in the liquid storage chamber 12.
[0135] In this embodiment, the target injection solution includes, but is not limited to, drugs, saline, blood, contrast agents, etc.; the injection port 11 can be used to connect a needle or other puncture device so that the target injection solution can be injected into the human body after the skin is punctured by the puncture device.
[0136] In actual operation, the injector is in the following state when no aspiration operation is performed: Figure 1 and Figure 2 In the initial state shown, the operator can first immerse the injection port 11 into the target injection solution, and then proceed as follows: Figure 3 and Figure 4 As shown, the piston rod 2 is pulled upwards to draw the target injection solution through the injection port 11 into the reservoir 12. The float valve 3 will also move upwards synchronously under the action of the piston rod 2. When the target injection solution in the reservoir 12 reaches a preset value, the upward pulling of the piston rod 2 stops. At this time, the gas mixed in with the target injection solution, due to its lower density, will float above the target injection solution in the reservoir 12 and contact the float valve 3, provided the injector's position remains unchanged. Due to the presence of this gas, the float valve 3 has not yet fully contacted the target injection solution in the reservoir 12. Under the weight of the float valve 3 itself, as... Figure 5As shown, the float valve 3 is currently in a low position relative to the piston rod 2 (i.e., in the first height position), and the float valve 3 does not block the lower opening of the air passage 21. The operator can then block the injection port 11 to prevent the target injection liquid from being discharged from the injection port 11, and then push the piston rod 2 downward. Under the pressure of the lower end of the piston rod 2, the gas in the reservoir 12 will be squeezed and enter the air passage 21 through the gap between the float valve 3 and the lower end of the piston rod 2. As the piston rod 2 continues to be pressed down, Gas in the reservoir 12 will continuously enter the air passage 21 and be discharged outward from the upper end of the air passage 21. During this process, as gas is continuously discharged, the contact area between the float valve 3 and the target injection liquid in the reservoir 12 will gradually increase, and the buoyancy force generated by the target injection liquid on the float valve 3 will also gradually increase. Under the action of this gradually increasing buoyancy force, the float valve 3 will overcome its own gravity and gradually move upward relative to the piston rod 2. The gap between the float valve 3 and the lower end of the piston rod 2 will also gradually decrease as the float valve 3 moves upward. Figure 6 and Figure 7 As shown, when the float valve 3 moves upward relative to the piston rod 2 to the high position (i.e., at the second height position), the gas in the reservoir 12 has been completely emptied through the air passage 21. At this time, the lower end of the float valve 3 and the piston rod 2 are completely attached and block the lower opening of the air passage 21. The target injection liquid in the reservoir 12 will not be able to enter the air passage 21. This can prevent some of the target injection liquid in the reservoir 12 from leaking through the air passage 21 due to excessive downward pressure of the piston rod 2. Subsequently, the blockage of the injection port 11 can be released, and the target injection liquid in the reservoir 12 can be pushed out of the injection port 11 by the piston rod 2 to perform the injection operation.
[0137] Therefore, in this embodiment, a float valve 3 is installed between the liquid storage chamber 12 of the syringe 1 and the air passage 21 of the piston rod 2. During the venting process after liquid aspiration, the movement of the float valve 3 relative to the piston rod 2 adaptively changes the communication state between the liquid storage chamber 12 and the air passage 21. When the float valve 3 is at the first height position relative to the piston rod 2, the air passage 21 is connected to the liquid storage chamber 12, and the gas in the liquid storage chamber 12 can be discharged outward through the air passage 21. After the gas in the liquid storage chamber 12 is vented, the float valve 3, under the buoyancy of the target injection liquid in the liquid storage chamber 12, moves away from the liquid storage chamber 12. When the piston rod 2 is moved to the second height position, the float valve 3 forms a blockage between the air passage 21 and the reservoir 12, preventing the target injection solution in the reservoir 12 from leaking along the air passage 21. Based on this scheme, the gas mixed in the reservoir 12 can be vented without adjusting the position of the injector and without causing the target injection solution in the reservoir 12 to be discharged. This reduces the waste of the target injection solution, is applicable to occasions with strict requirements on injection dosage, and avoids the problem of environmental pollution caused by the accidental discharge of the target injection solution.
[0138] The specific structure of the injector can be referred to the above embodiments. Since this injection venting method adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be described in detail here.
[0139] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.
Claims
1. An injection device, characterized in that, The injector includes: A syringe, wherein the lower end of the syringe is provided with an injection port that communicates with the inner cavity of the syringe; A piston push rod is slidably fitted in the inner cavity of the syringe in a vertical direction. The portion of the inner cavity of the syringe between the lower end of the piston push rod and the injection port forms a liquid storage cavity. An air passage is provided inside the piston push rod. The upper end of the air passage communicates with the outside, and the lower end of the air passage extends to the lower end of the piston push rod. A float valve is movably connected to the lower end of the piston rod in the vertical direction. During the venting process after liquid extraction, the movement of the float valve relative to the piston rod adaptively changes the communication state between the liquid storage chamber and the gas passage. When the float valve is at a first height position relative to the piston rod, the lower end of the gas passage is connected to the liquid storage chamber, allowing gas in the liquid storage chamber to enter the gas passage and be discharged outward through it. After the gas in the liquid storage chamber is vented, the float valve moves relative to the piston rod to a second height position under the buoyancy of the liquid in the liquid storage chamber. The float valve forms a blockage between the lower end of the gas passage and the liquid storage chamber to prevent liquid in the liquid storage chamber from entering the gas passage. The second height position is higher than the first height position. The lower end of the air passage is provided with an annular flange extending radially inward. The float valve has a limiting shoulder, a connecting neck, and a float portion connected sequentially from top to bottom. The connecting neck is movably inserted into the inner ring of the annular flange. The limiting shoulder is used to abut against the upper end face of the annular flange. When the float valve is at the first height position relative to the piston push rod, there is a preset gap between the limiting shoulder, the connecting neck, the float portion, and the annular flange. The preset gap forms an exhaust channel, which communicates with the air passage and the liquid storage chamber. When the float valve is at the second height position relative to the piston push rod, the float portion fits against the lower end face of the annular flange to form a sealing effect between the air passage and the liquid storage chamber. The limiting shoulder is provided with a weight-reducing cavity, which extends downward to the float portion. The bottom surface of the weight-reducing cavity extends downward in a direction close to the central axis. The solid portion between the bottom surface of the weight-reducing cavity and the bottom surface of the float portion forms an elastic lever arm. The inner end of the elastic lever arm is used to deflect upward under the buoyancy of the liquid in the reservoir cavity, so as to drive the outer end of the elastic lever arm to deflect outward in a direction away from the central axis.
2. The injector as described in claim 1, characterized in that, The injector also includes a one-way valve disposed in the air passage. The one-way valve allows gas to flow from the lower end of the air passage to the upper end of the air passage, and the one-way valve is used to prevent gas from flowing from the upper end of the air passage to the lower end of the air passage. And / or, the thickness of the elastic lever arm in the vertical direction gradually decreases along the direction close to the central axis.
3. The injector as described in claim 2, characterized in that, A first sealing element is provided between the one-way valve and the cavity wall of the air passage; And / or, the maximum cross-sectional area of the float portion is greater than the maximum cross-sectional area of the limiting shoulder portion; And / or, the lower end face of the annular flange extends downward in a direction away from the central axis; the upper side of the float portion forms a sealing surface, which extends downward in a direction away from the central axis; when the float valve is at the second height position relative to the piston push rod, the sealing surface is in contact with the lower end face of the annular flange.
4. The injector as described in claim 3, characterized in that, The bottom surface of the float portion extends downward along the direction close to the central axis; And / or, the piston push rod is provided with a receiving cavity, the upper part of the receiving cavity is connected to the lower end of the air passage, the annular flange is provided on the lower part of the receiving cavity, and the limiting shoulder is located in the receiving cavity.
5. The injector as described in claim 4, characterized in that, The piston push rod has a receiving cavity, the upper part of which is connected to the lower end of the air passage, the annular flange is provided on the lower part of the receiving cavity, and the limiting shoulder is located in the receiving cavity.
6. The injector as described in claim 5, characterized in that, The injector further includes a second seal, which is fitted onto the outer cylindrical surface of the piston rod. The second seal is in sealing cooperation with the inner wall of the syringe. The height of the second seal is within the height range covered by the receiving cavity. And / or, the receiving cavity includes a first chamber and a second chamber, the upper part of the first chamber is connected to the lower end of the airway, the lower part of the first chamber is connected to the upper part of the second chamber, the annular flange is disposed on the lower part of the second chamber, and the limiting shoulder is located in the second chamber; the cross-sectional area of the second chamber is larger than the cross-sectional area of the first chamber; the injector also includes a one-way valve, the one-way valve being snap-fitted into the first chamber; the one-way valve allows gas to flow from the lower end of the airway to the upper end of the airway, and the one-way valve is used to prevent gas from flowing from the upper end of the airway to the lower end of the airway.
7. The injector as described in claim 6, characterized in that, The injector also includes a second seal, which is fitted onto the outer cylindrical surface of the piston rod. The second seal is in sealing cooperation with the inner wall of the syringe. The height of the second seal is within the height range covered by the second chamber. And / or, the height of the first chamber is higher than the height of the one-way valve, and there is a first preset distance between the bottom surface of the one-way valve and the second chamber in the vertical direction.
8. The injector as claimed in claim 1, characterized in that, The upper opening of the syringe is provided with a stop structure; The upper end of the piston rod is provided with a first limiting flange extending radially outward; the upper end of the stop structure is used to abut against the first limiting flange to prevent the piston rod from moving downward relative to the syringe. And / or, the piston rod is provided with a second limiting flange extending radially outward at its middle part, and the second limiting flange is slidably fitted in the inner cavity of the syringe in the vertical direction; the lower end of the stop structure is used to abut against the second limiting flange to prevent the piston rod from moving upward relative to the syringe. And / or, the injector further includes a second seal, which is fitted onto the outer cylindrical surface of the piston rod and is in a sealing fit with the inner wall of the syringe. And / or, the float valve is made of an elastic material; And / or, the syringe is made of a transparent material, and the surface of the syringe is provided with a background strip, which is used to indicate the total amount of liquid in the reservoir; And / or, the piston push rod is provided with at least two air outlets, the at least two air outlets are arranged at intervals along the circumference of the piston push rod, and the at least two air outlets are connected to the upper end of the air passage; And / or, the upper end of the piston rod is provided with a first finger ring.
9. The injector as described in claim 8, characterized in that, When the upper end of the stop structure abuts against the first limiting flange, there is a second preset distance between the float valve and the bottom surface of the liquid storage cavity.
10. A method for injecting air to release vent gas, characterized in that, The injection venting method is performed using the syringe as described in any one of claims 1 to 9, and the injection venting method includes the following steps: Immerse the injection port into the target injection solution; Pull the piston rod upward to draw the target injection solution into the reservoir through the injection port; Stop pulling the piston rod upward and seal the injection port; Push the piston rod downwards so that the gas mixed in the reservoir enters the gas passage through the float valve and is discharged outwards until the float valve moves upwards relative to the piston rod to the second height position under the buoyancy of the target injection liquid in the reservoir.
Citation Information
Patent Citations
Vent piston
CN119013062A
Fuel oil pipeline exhaust device and engine
CN217270557U