Needleless injector
By designing a liquid-passing body, a needle-free injection head and a liquid outlet valve in a needle-free syringe, and using the liquid pressure to control the flow of the liquid, the problems of low syringe injection efficiency and unstable effect are solved, and efficient and stable liquid injection is achieved.
Patent Information
- Application Number
- CN202510848079.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-24
- Publication Date
- 2025-09-23
AI Technical Summary
Existing needle-free syringes have low injection efficiency and unstable injection effects, which can easily cause pain and discomfort to the human body.
A needle-free syringe is designed, which includes a liquid-passing body, a needle-free injection head and a liquid outlet valve. By setting a first valve core between the transition cavity and the liquid outlet cavity of the liquid-passing body, the flow of the liquid medicine is controlled by utilizing the change in the liquid medicine pressure, thereby achieving stable distribution and efficient injection of the liquid medicine.
The injection efficiency of the needle-free syringe is improved, the stable injection of the liquid medicine is ensured, the generation of bubbles is reduced, a larger dose is injected per unit time, and pain and discomfort are reduced.
Smart Images
Figure CN120679036A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of medical devices, and in particular to a needle-free syringe. Background Art
[0002] Needle-free syringes do not require needles. Instead, they are medical devices that apply high pressure to liquid medicine so that it can be injected into the patient's skin, subcutaneous tissue or muscle through a microhole at the end. This can greatly reduce the pain and psychological burden of injections.
[0003] Most of the current needle-free syringes are single-head injections, which can only achieve small doses of injection per unit time, and the injection efficiency is not high, otherwise it will cause pain and discomfort to the human body.
[0004] Therefore, it is necessary to provide a needle-free syringe with higher injection efficiency and stable injection effect. Summary of the Invention
[0005] The technical problem to be solved by the present invention is to provide a needle-free syringe with high injection efficiency and stable injection effect.
[0006] In order to solve the above technical problems, the present invention provides a needle-free syringe, comprising a liquid-passing body, a needle-free injection head and a liquid outlet valve.
[0007] The liquid-passing body is provided with a liquid outlet cavity, a transition cavity and a power cavity. The transition cavity is used for pre-filling the liquid medicine. The cross-sectional area of the transition cavity is smaller than the cross-sectional area of the liquid outlet cavity. A first piston is provided in the power cavity and is connected to a power source.
[0008] The needle-free injection head is provided with a distribution cavity and at least two injection holes, wherein the injection holes connect the distribution cavity with the outside world;
[0009] The liquid outlet valve includes a valve body and a first valve core, the valve body is sealed and connected to at least one of the liquid-passing main body and the needle-free injection head, the valve body is provided with an axially penetrating liquid flow channel opposite to the distribution chamber, the outer peripheral surface of the first valve core and the inner side wall of the liquid outlet chamber have a first gap, the first valve core is provided with a first liquid guide groove at one end away from the transition chamber, the first liquid guide groove is arranged toward the valve body opening, and is connected with the liquid flow channel and the first gap, the first valve core is provided at one end of the liquid outlet chamber close to the transition chamber, the first valve core can move back and forth axially as the pressure of the liquid medicine in the transition chamber changes, so that the first gap is connected to or disconnected from the transition chamber.
[0010] As an improvement of the above-mentioned scheme, the valve body is provided with a first abutment chamber, the first abutment chamber is coaxially arranged with the liquid flow channel, a first elastic return member is provided in the first abutment chamber, the first valve core is provided with a second abutment chamber arranged opposite to the first abutment chamber, and the first elastic return member abuts against the second abutment chamber.
[0011] As an improvement to the above-mentioned solution, a first convex ring and a second convex ring are respectively provided at both ends of the first valve core. The first convex ring and the second convex ring are both protruding toward the outer peripheral surface of the first valve core and are both adapted to the liquid outlet cavity. The first liquid guide groove axially penetrates the first convex ring and is connected to the second abutment cavity. A second liquid guide groove is provided on the second convex ring. The second liquid guide groove axially penetrates the second convex ring and is connected to the first gap.
[0012] As an improvement to the above solution, a sealing groove is provided on the end surface of the first valve core opposite to the transition cavity, and a first sealing member for sealing the transition cavity is provided in the sealing groove.
[0013] As an improvement of the above-mentioned scheme, the distribution chamber includes a central chamber, and guide grooves radially arranged from the central chamber, the injection holes are arranged in a circumferential array of the central chamber, the injection holes are connected to the central chamber through the corresponding guide grooves, and the liquid flow channel is coaxially arranged with the central chamber.
[0014] As an improvement of the above-mentioned solution, an assembly cavity is further provided in the needle-free injection head, a first plane is provided in the assembly cavity, the distribution cavity is opened on the first plane, and the cross-section of the guide groove is arc-shaped. The first plane abuts against the end face of the valve body, and the valve body is sealed with the assembly cavity.
[0015] As an improvement of the above scheme, the injection hole includes a first chamber, a second chamber, and a third chamber. The first chamber is connected to the outside, the second chamber connects the first chamber and the third chamber, and the third chamber is connected to the distribution chamber. The cross-sectional areas of the first chamber and the third chamber are constant, and the cross-sectional area of the first chamber is smaller than the cross-sectional area of the third chamber. The cross-sectional area of the second chamber gradually increases in the direction away from the first chamber.
[0016] As an improvement to the above scheme, it also includes a liquid inlet valve and a liquid inlet joint, the liquid-passing main body is also provided with a liquid inlet chamber that cross-communicates with the transition chamber, the liquid inlet joint is provided with a liquid inlet channel that communicates with the liquid inlet chamber, the liquid inlet valve includes a second valve core and a second elastic reset member, the outer peripheral surface of the second valve core and the inner side wall of the liquid inlet chamber have a second gap, the second gap is communicated with the transition chamber, the second valve core is provided with a third abutting chamber on the side facing away from the liquid inlet joint, and a fourth abutting chamber is provided in the liquid inlet chamber that is arranged opposite to the third abutting chamber, the second elastic reset member abuts against the third and fourth abutting chambers, and can drive the second valve core to move in a direction close to the liquid inlet channel and disconnect the second gap from the liquid inlet channel.
[0017] As an improvement to the above-mentioned solution, a third convex ring and a fourth convex ring are respectively provided at both ends of the second valve core. The third convex ring and the fourth convex ring are both protruding toward the outer peripheral surface of the second valve core and are both adapted to the liquid inlet cavity. A third liquid guide groove is provided at the end of the second valve core away from the transition cavity. The third liquid guide groove axially penetrates the third convex ring and is communicated with the third abutting cavity and the second gap. A fourth liquid guide groove is provided on the fourth convex ring. The fourth liquid guide groove axially penetrates the fourth convex ring and is communicated with the second gap.
[0018] As an improvement of the above-mentioned scheme, the power chamber is coaxially arranged with the transition chamber and the liquid outlet chamber, the cross-sectional area of the transition chamber is smaller than the cross-sectional area of the power chamber, and the first piston reciprocates in the power chamber to drive the medicine liquid in the transition chamber into the liquid outlet chamber, or the medicine liquid in the liquid inlet channel into the transition chamber.
[0019] The implementation of the present invention has the following beneficial effects:
[0020] The present invention discloses a needle-free syringe, wherein a distribution chamber and at least two injection holes are provided on the needle-free injection head, the cross-sectional area of the transition chamber of the liquid-passing main body is set to be smaller than the cross-sectional area of the liquid outlet chamber, the first valve core is arranged in the liquid outlet chamber, and the outer peripheral surface of the first valve core and the inner side wall of the liquid outlet chamber have a first gap, the end of the first valve core away from the transition chamber is provided with a first liquid guide groove arranged towards the valve body opening, the first liquid guide groove connects the first gap and the liquid flow channel on the valve body, the liquid flow channel is opposite to the distribution chamber of the needle-free injection head, and at least two injection holes connecting the distribution chamber and the outside are provided on the needle-free injection head, when the first piston of the power chamber is driven by the power source to compress the liquid in the transition chamber, the first valve core moves axially at the end of the liquid outlet chamber close to the transition chamber, specifically moves in a direction away from the transition chamber, when the first valve core When it is not in contact with the valve body, the medicine in the transition chamber enters the liquid outlet chamber and passes through the first gap. A part of it passes through the first liquid guide groove and enters the liquid flow channel, and another part passes through the gap between the first valve core and the first valve body and enters the liquid flow channel. The flow rate of the medicine entering the liquid channel is larger, and the flow rate is relatively small, which helps the distribution chamber and each injection hole to be filled with medicine, and can reduce the generation of bubbles to a certain extent, and improve the flow consistency of each injection hole; after that, the first valve core maintains contact with the valve body, and the medicine in the transition chamber enters the liquid outlet chamber, and passes through the first gap and the first liquid guide groove into the liquid flow channel, and is replenished into the distribution chamber and the injection hole connected thereto, so as to achieve stable injection; the medicine is ejected simultaneously through at least two injection holes on the needle-free injection head, and a larger dose injection can be achieved per unit time, and the injection efficiency is higher. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is a schematic structural diagram of an embodiment of a needle-free syringe of the present invention;
[0022] Figure 2 yes Figure 1 A cross-sectional view of the liquid-passing body through the symmetry plane;
[0023] Figure 3 yes Figure 1 Cross-sectional view through the plane of symmetry;
[0024] Figure 4 yes Figure 3 Schematic diagram of the liquid pumping state structure;
[0025] Figure 5 yes Figure 3 Schematic diagram of the injection state structure;
[0026] Figure 6 yes Figure 3 A schematic diagram of the enlarged structure of part A;
[0027] Figure 7 yes Figure 3 Schematic diagram of the enlarged structure of part B;
[0028] Figure 8 is a cross-sectional view of the first valve core through the symmetry plane;
[0029] Figure 9 It is a left view of the first valve core;
[0030] Figure 10 It is a right side view of the first valve core;
[0031] Figure 11 This is a schematic structural diagram of an embodiment of a needle-free injection head;
[0032] Figure 12 yes Figure 11 Left side view of the corresponding needle-free injection head;
[0033] Figure 13 1 is a schematic structural diagram of another embodiment of a needle-free injection head;
[0034] Figure 14 yes Figure 13 Left side view of the corresponding needle-free injection head. DETAILED DESCRIPTION
[0035] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be described in further detail below with reference to the accompanying drawings.
[0036] like Figures 1 to 10 As shown, the present invention discloses an embodiment of a needle-free syringe, comprising a liquid-passing body 1, a needle-free injection head 2 and a liquid outlet valve 3, wherein the liquid-passing body 1 is provided with a liquid outlet chamber 11, a transition chamber 12 and a power chamber 13, wherein the transition chamber 12 is used to pre-fill the liquid, and the cross-sectional area of the transition chamber 12 is smaller than the cross-sectional area of the liquid outlet chamber 11, and a first piston 4 is provided in the power chamber 13, and the first piston 4 is connected to the power source; the needle-free injection head 2 is provided with a distribution chamber 21 and at least two injection holes 22, and the injection holes 22 connect the distribution chamber 21 with the outside world; the liquid outlet valve 3 includes a valve body 31 and a first valve core 32, and the valve body 31 is connected to the liquid-passing body 1 and the needle-free injection head 2. At least one sealed connection, the valve body 31 is provided with an axially penetrating liquid flow channel 311 opposite to the distribution chamber 21, the outer peripheral surface of the first valve core 32 and the inner side wall of the liquid outlet chamber 11 have a first gap a, the first valve core 32 is provided with a first liquid guide groove 321 at the end away from the transition chamber 12, the first liquid guide groove 321 is opened toward the valve body 31, and is connected with the liquid flow channel 311 and the first gap a, the first valve core 32 is provided at the end of the liquid outlet chamber 11 close to the transition chamber 12, the first valve core 32 can move back and forth axially as the pressure of the liquid in the transition chamber 12 changes, so that the first gap a is connected to or disconnected from the transition chamber 12.
[0037] In this embodiment, a distribution chamber 21 and at least two injection holes 22 are provided in the needle-free injection head 2, and the cross-sectional area of the transition chamber 12 of the liquid-passing body 1 is set to be smaller than the cross-sectional area of the liquid outlet chamber 11. The first valve core 32 is provided in the liquid outlet chamber 11, and a first gap a is formed between the outer peripheral surface of the first valve core 32 and the inner side wall of the liquid outlet chamber 11. The end of the first valve core 32 away from the transition chamber 12 is provided with a first liquid guide groove 321 opened toward the valve body 31. The first liquid guide groove 321 connects the first gap a with the liquid flow channel 311 on the valve body 31. The liquid flow channel 311 is opposite to the distribution chamber 21 of the needle-free injection head 2. At least two injection holes 22 connecting the distribution chamber 21 with the outside world are provided on the needle-free injection head 2. When the first piston 4 of the power chamber 13 is driven by the power source to compress the liquid in the transition chamber 12, the first valve core 32 moves axially at the end of the liquid outlet chamber 11 close to the transition chamber 12, specifically moves in the direction away from the transition chamber 12. When the first valve core When 32 does not abut against the valve body 31, the medicine in the transition chamber 12 enters the liquid outlet chamber 11 and passes through the first gap a. A part of it passes through the first liquid guide groove 321 and enters the liquid flow channel 311, and another part passes through the gap between the first valve core 32 and the first valve body 31 and enters the liquid flow channel 311. The flow of medicine entering the liquid flow channel is larger, and the flow velocity is relatively small, which helps the distribution chamber 21 and each injection hole 22 to be filled with medicine, and to a certain extent, it can reduce the generation of bubbles and improve the flow consistency of each injection hole 22; thereafter, the first valve core 32 maintains abutment with the valve body 31, and the medicine in the transition chamber 12 enters the liquid outlet chamber 11 and passes through the first gap a and the first liquid guide groove 321 into the liquid flow channel 311, and is replenished to the distribution chamber 21 and the injection hole 22 connected thereto, so as to achieve stable injection; the medicine is ejected simultaneously through at least two injection holes 22 on the needle-free injection head 2, so that a larger dose injection can be achieved per unit time, and the injection efficiency is higher.
[0038] Specifically, the valve body 31 of this embodiment is provided with a first abutment cavity 312, which is coaxially arranged with the liquid passage 311. A first elastic return member 33 is disposed within the first abutment cavity 312. The first valve core 32 is provided with a second abutment cavity 322, which is arranged opposite the first abutment cavity 312. The first elastic return member 33 abuts against the second abutment cavity 322. When the liquid pressure in the transition cavity 12 applied to the first valve core 32 is less than the elastic force of the first elastic return member 33, the first valve core 32 will move toward the transition cavity 12 or remain in a state of blocking the transition cavity 12.
[0039] A first protruding ring 323 and a second protruding ring 324 are respectively provided at both ends of the first valve core 32. The first protruding ring 323 and the second protruding ring 324 both protrude from the outer circumference of the first valve core 32 and fit within the liquid outlet cavity 11. The first protruding ring 323 and the second protruding ring 324 serve as guides during axial movement of the first valve core 32, thereby improving the stability of the axial movement of the first valve core 32 and thereby stabilizing the flow rate during injection.
[0040] The first liquid-conducting groove 321 axially penetrates the axial groove of the first protruding ring 323 and is a radial groove communicating with the second abutting cavity 322. The second protruding ring 324 is provided with a second liquid-conducting groove 325 axially penetrating the second protruding ring 324 and communicating with the first gap a, so that the liquid medicine in the transition cavity 12 can flow into the first gap a.
[0041] The first liquid guiding groove 321 and the second liquid guiding groove 325 are preferably tangent to the outer peripheral surface of the first valve core 32 to reduce unnecessary disturbances during the flow of the liquid medicine.
[0042] In this embodiment, a sealing groove 326 is provided on the end surface of the first valve core 32 opposite the transition chamber 12. A first sealing member is housed within the sealing groove 326 for sealing the transition chamber 12. When the first sealing member contacts the outlet chamber, the first gap a is disconnected from the transition chamber 12. When the pressure of the liquid medicine in the transition chamber 12 increases, driving the first valve core 32 away from the transition chamber 12, the first sealing member releases its seal on the transition chamber 12, and the first gap a is connected to the transition chamber 12. Because the cross-sectional area of the transition chamber 12 is smaller than that of the outlet chamber 11, the pressure acting on the surface of the first valve core 32 increases as the contact area with the liquid medicine increases. This helps propel the first valve core 32 to quickly move until it contacts the valve body 31, thereby accelerating the injection of the liquid medicine.
[0043] In this embodiment, the power chamber 13 of the liquid-passing body 1 is preferably coaxially arranged with the transition chamber 12 and the liquid outlet chamber 11, so that the cross-sectional area of the transition chamber 12 is smaller than that of the power chamber 13. During injection, the pre-filled liquid in the transition chamber 12 more easily pushes the first valve core 32 at high speed, increasing the initial velocity of the liquid and helping to increase the injection speed. The power chamber 13 is provided with a first piston 4, which reciprocates within the power chamber 13 to drive the liquid in the transition chamber 12 into the liquid outlet chamber 11, or the liquid in the liquid inlet channel 61 into the transition chamber 12.
[0044] The distribution chamber 21 of the needle-free injection head 2 of this embodiment specifically includes a central cavity 211, and guide grooves 212 radially arranged from the central cavity 211. The injection holes 22 are arranged in a circumferential array in the central cavity 211. The injection holes 22 are connected to the central cavity 211 through the corresponding guide grooves 212. In this embodiment, the liquid flow channel 311 is coaxially arranged with the central cavity 211. When the liquid in the liquid flow channel 311 collides with the central cavity 211, it will radially and evenly spurt outward, making the flow of each guide groove 212 more balanced and the flow uniformity of each injection hole 22 better. Figures 11 to 14 The needle-free injection head 2 structure is provided with 4 injection holes 22 and 6 injection holes 22 evenly distributed.
[0045] Of course, if the injection efficiency requirement is lower, the needle-free injection head of this embodiment can also be provided with only one injection hole. By replacing the needle-free injection head 2 with a different number of injection holes 22, such as one injection hole, two injection holes, three injection holes, four injection holes, five injection holes, or six injection holes, the injection efficiency can be adjusted.
[0046] The injection hole 22 of the needle-free injection head 2 specifically includes a first chamber 221, a second chamber 222, and a third chamber 223. The first chamber 221 is connected to the outside, the second chamber 222 connects the first chamber 221 and the third chamber 223, and the third chamber 223 is connected to the distribution chamber 21. The cross-sectional areas of the first chamber 221 and the third chamber 223 are constant, which is more convenient for processing and molding, and more convenient for stabilizing the injection effect. The cross-sectional area of the first chamber 221 is smaller than the cross-sectional area of the third chamber 223. The cross-sectional area of the second chamber 222 gradually increases in the direction away from the first chamber 221. The flow cross-sectional area of the liquid medicine becomes smaller when it flows through the second chamber 222, which promotes the increase of flow rate.
[0047] At the same time, in this embodiment, a positioning plane 23 corresponding to the injection hole 22 is set at the front end of the needle-free injection head 2. The first chamber 221 of the injection hole 22 is opened on the positioning plane 23, and the positioning planes 23 of each injection hole 22 are located in the same plane. The cross-sectional area of the positioning plane 23 is close to the cross-sectional area of the third chamber 223. During injection, the positioning plane 23 is directly brought into contact with the human skin, and there is no need to install a support cover separately, which further simplifies the assembly structure and consumables costs.
[0048] The needle-free injection head 2 also includes an assembly chamber 24. A first plane 241 is provided within the assembly chamber 24. The distribution chamber 21 is located on the first plane 241, and the cross-section of the guide groove 212 is arc-shaped. The first plane 241 abuts the end face of the valve body 31. A positioning boss is provided at the end of the valve body 31 abutting the first plane 241. The positioning boss abuts the end face of the liquid-passing body 1, and the other end extends into the liquid outlet chamber 11 of the liquid-passing body 1. The valve body 31 is sealed against the circumferential sidewalls of the assembly chamber 24 and the circumferential sidewalls of the liquid outlet chamber 11. The inner circumferential sidewalls of the assembly chamber 24 of the needle-free injection head 2 are provided with internal threads. The assembly chamber 24 is threadedly connected to one end of the liquid-passing body 1 where the liquid outlet chamber 11 is provided, thereby achieving the positioning and assembly of the valve body 31.
[0049] In this embodiment, the power chamber 13 is coaxially arranged with the transition chamber 12, the liquid outlet chamber 11, and the injection hole 22. The liquid passage body 1 is further provided with a liquid inlet chamber 14 that intersects and communicates with the transition chamber 12. The liquid inlet chamber 14 is used to inject liquid medicine into the transition chamber 12. The liquid inlet chamber 14 is provided with a liquid inlet valve 5 and a liquid inlet connector 6 connected thereto. The liquid inlet connector 6 is provided with a liquid inlet channel 61 that communicates with the liquid inlet chamber 14. In this embodiment, the liquid inlet connector 6 is a Luer connector equipped with a sealing ring that seals against the inner wall of the liquid inlet chamber 14.
[0050] The liquid inlet valve 5 specifically includes a second valve core 51 and a second elastic return member 52. The first valve core 32 and the second valve core 51 of this embodiment preferably adopt exactly the same structure, which is easier to assemble. Specifically, the outer peripheral surface of the second valve core 51 and the inner side wall of the liquid inlet chamber 14 have a second gap b, and the second gap b is connected to the transition chamber 12. The second valve core 51 is provided with a third abutment chamber 511 on the side facing away from the liquid inlet joint 6, and a fourth abutment chamber 141 is provided in the liquid inlet chamber 14, which is opposite to the third abutment chamber 511. The second elastic return member 52 abuts against the third abutment chamber 511 and the fourth abutment chamber 141, and can drive the second valve core 51 to move in the direction close to the liquid inlet channel 61, and disconnect the second gap b from the liquid inlet channel 61. A third convex ring and a fourth convex ring are respectively provided at both ends of the second valve core 51. The third convex ring and the fourth convex ring are both protruding toward the outer peripheral surface of the second valve core 51 and are both adapted to the liquid inlet chamber 14. A third liquid guide groove 512 is provided at the end of the second valve core 51 away from the transition chamber 12. The third liquid guide groove 512 axially penetrates the third convex ring and is communicated with the third abutting chamber 511 and the second gap b. A fourth liquid guide groove 513 is provided on the fourth convex ring. The fourth liquid guide groove 513 axially penetrates the fourth convex ring and is communicated with the second gap b.
[0051] In this embodiment, the first elastic return member 33 and the second elastic return member 52 are preferably compression springs.
[0052] In this embodiment, the liquid inlet connector 6 is also provided with a liquid inlet pipe 7, within which a second piston 8 is disposed. The liquid inlet pipe 7, second piston 8, and liquid inlet connector 6 constitute a conventional syringe. When the second piston 8 draws the medicinal liquid into the liquid inlet pipe 7, the second piston 8 seals the medicinal liquid within the liquid inlet pipe 7 by inserting the liquid inlet pipe 7 into the liquid inlet cavity 14 of the liquid-passing body 1. By pushing the second piston 8, pressure is applied to the medicinal liquid within the liquid inlet pipe 7. The second valve core 51 overcomes the pressure of the second elastic return member 52 and moves away from the liquid inlet connector 6. The second gap b communicates with the liquid inlet channel 61, thereby pre-filling the transition chamber 12 with the medicinal liquid. Furthermore, by pulling the first piston 4, the medicinal liquid in the liquid inlet channel 61 can enter the transition chamber 12.
[0053] The operation of the needle-free injector according to the embodiment of the present invention will be described below with reference to the accompanying drawings.
[0054] Pumping status: Figure 4 As shown, the first piston 4 moves to the right, and negative pressure is formed in the transition chamber 12. The first valve core 32 moves to the right due to the suction force of the transition chamber 12 and the force of the first elastic return member 33 until it is limited by the liquid-passing body 1; at the same time, the second valve core 51 overcomes the elastic force of the second elastic return member 52 under the action of negative pressure and moves downward, and the medicinal liquid enters the transition chamber 12 through the second gap bb.
[0055] Injection status: Figure 5 As shown, the first piston 4 moves to the left, pushing the medicinal liquid in the transition chamber 12 to gather to the left, and forming a thrust on the first valve core 32. The first valve core 32 moves to the left until it is limited by the valve body 31. The medicinal liquid flows into the liquid flow channel 311 of the valve body 31 through the second liquid guide groove 325, the first gap a, and the first liquid guide groove 321, and is distributed to the various injection holes 22 for exit through the distribution chamber 21 of the needle-free injection head 2; at the same time, the second valve core 51 moves upward under the action of the hydraulic pressure in the transition chamber 12 and the elastic force of the second elastic return member 52 until it is limited by the Luer connector. At this time, the medicinal liquid cannot flow into the transition chamber 12 through the second gap b.
[0056] The liquid-passing body 1 of the needle-free syringe of this embodiment is preferably made of medical-grade plastic, so that the internal state of the needle-free syringe can be visualized, which reduces the processing cost and material cost compared with metal materials; the materials of the needle-free injection head 2, liquid inlet connector 6, etc. are also preferably made of medical-grade plastic, so that they can be used as disposable consumables, avoiding repeated cleaning and sterilization operations, and avoiding the risk of cross infection caused by repeated cleaning and non-standard sterilization operations.
[0057] The above disclosure is only a preferred embodiment of the present invention and certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.
Claims
1. A needle-free syringe, characterized in that: Including liquid main body, needle-free injection head and liquid outlet valve, The liquid-passing body is provided with a liquid outlet cavity, a transition cavity and a power cavity. The transition cavity is used for pre-filling the liquid medicine. The cross-sectional area of the transition cavity is smaller than the cross-sectional area of the liquid outlet cavity. A first piston is provided in the power cavity and is connected to a power source. The needle-free injection head is provided with a distribution cavity and at least two injection holes, wherein the injection holes connect the distribution cavity with the outside world; The liquid outlet valve includes a valve body and a first valve core, the valve body is sealed and connected to at least one of the liquid-passing main body and the needle-free injection head, the valve body is provided with an axially penetrating liquid flow channel opposite to the distribution chamber, the outer peripheral surface of the first valve core and the inner side wall of the liquid outlet chamber have a first gap, the first valve core is provided with a first liquid guide groove at one end away from the transition chamber, the first liquid guide groove is arranged toward the valve body opening, and is connected with the liquid flow channel and the first gap, the first valve core is provided at one end of the liquid outlet chamber close to the transition chamber, the first valve core can move back and forth axially as the pressure of the liquid medicine in the transition chamber changes, so that the first gap is connected to or disconnected from the transition chamber.
2. The needle-free injector according to claim 1, wherein The valve body is provided with a first abutment cavity, the first abutment cavity is coaxially arranged with the liquid flow channel, a first elastic return member is provided in the first abutment cavity, the first valve core is provided with a second abutment cavity arranged opposite to the first abutment cavity, and the first elastic return member abuts against the second abutment cavity.
3. The needle-free injector according to claim 2, characterized in that A first convex ring and a second convex ring are respectively provided at both ends of the first valve core. The first convex ring and the second convex ring are both protruded toward the outer peripheral surface of the first valve core and are both adapted to the liquid outlet cavity. The first liquid guide groove axially penetrates the first convex ring and is communicated with the second abutment cavity. A second liquid guide groove is provided on the second convex ring. The second liquid guide groove axially penetrates the second convex ring and is communicated with the first gap.
4. The needle-free injector according to claim 1, wherein A sealing groove is provided on the end surface of the first valve core opposite to the transition cavity, and a first sealing member for sealing the transition cavity is provided in the sealing groove.
5. The needle-free injector according to claim 1, wherein The distribution chamber includes a central chamber and guide grooves radially arranged from the central chamber. The injection holes are arranged in a circumferential array of the central chamber. The injection holes are connected to the central chamber through the corresponding guide grooves. The liquid flow channel is coaxially arranged with the central chamber.
6. The needle-free injector according to claim 1, wherein An assembly cavity is also provided in the needle-free injection head. A first plane is provided in the assembly cavity. The distribution cavity is opened on the first plane, and the cross-section of the guide groove is arc-shaped. The first plane abuts against the end face of the valve body, and the valve body is sealed with the assembly cavity.
7. The needle-free injector according to claim 1, wherein The injection hole includes a first chamber, a second chamber, and a third chamber. The first chamber is connected to the outside, the second chamber connects the first chamber and the third chamber, and the third chamber is connected to the distribution chamber. The cross-sectional areas of the first chamber and the third chamber are constant, and the cross-sectional area of the first chamber is smaller than the cross-sectional area of the third chamber. The cross-sectional area of the second chamber gradually increases in the direction away from the first chamber.
8. The needle-free injector according to claim 1, wherein It also includes a liquid inlet valve and a liquid inlet joint. The liquid-passing main body is also provided with a liquid inlet chamber that cross-communicates with the transition chamber. The liquid inlet joint is provided with a liquid inlet channel that communicates with the liquid inlet chamber. The liquid inlet valve includes a second valve core and a second elastic reset member. The outer peripheral surface of the second valve core and the inner side wall of the liquid inlet chamber have a second gap. The second gap is communicated with the transition chamber. The second valve core is provided with a third abutting chamber on the side facing away from the liquid inlet joint. A fourth abutting chamber arranged opposite to the third abutting chamber is provided in the liquid inlet chamber. The second elastic reset member abuts against the third and fourth abutting chambers, and can drive the second valve core to move in a direction close to the liquid inlet channel and disconnect the second gap from the liquid inlet channel.
9. The needle-free injector according to claim 8, characterized in that A third convex ring and a fourth convex ring are respectively provided at both ends of the second valve core. The third convex ring and the fourth convex ring are both protruding toward the outer peripheral surface of the second valve core and are both adapted to the liquid inlet cavity. A third liquid guide groove is provided at one end of the second valve core away from the transition cavity. The third liquid guide groove axially penetrates the third convex ring and is communicated with the third abutting cavity and the second gap. A fourth liquid guide groove is provided on the fourth convex ring. The fourth liquid guide groove axially penetrates the fourth convex ring and is communicated with the second gap.
10. The needle-free injector according to claim 8, wherein The power chamber is coaxially arranged with the transition chamber and the liquid outlet chamber. The cross-sectional area of the transition chamber is smaller than the cross-sectional area of the power chamber. The first piston reciprocates in the power chamber to drive the medical liquid in the transition chamber into the liquid outlet chamber, or the medical liquid in the liquid inlet channel into the transition chamber.