Injection device capable of preventing liquid leakage

Abstract

The utility model belongs to the technical field of medical instruments, and particularly relates to a leakage-proof injection device which comprises an infusion catheter, a dispensing mechanism and a motor, the dispensing mechanism comprises a main body used for containing liquid medicine, a liquid inlet and a liquid outlet, and the liquid inlet and the liquid outlet are fixedly arranged on the main body and communicated with the main body. A liquid inlet and a liquid outlet are formed in the main body, a piston is movably arranged in the main body, the motor is used for controlling the piston to move in the main body, and the liquid conveying guide pipe is communicated with the liquid inlet. A limiting type drainage scheme is provided by adopting the design of a metal plugging section with multiple convex positions and matching with a spring and a stepped inner pipe (such as the liquid inlet and the liquid outlet); according to the limiting type drainage scheme, the liquid medicine can be guided through the drainage channel to complete rapid medicine suction or injection under the action of corresponding suction force or thrust, and meanwhile the problems that a traditional valve is prone to blockage, liquid leakage and the like can be solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of medical equipment, and in particular relates to an injection device that prevents liquid leakage. Background Art

[0002] Injection is a method of injection without a traditional capillary needle. It does not require a needle to pierce the flesh. Instead, the injection pusher generates a certain pressure through a mechanically stable driving module, and under the action of pressure, the drug solution is diffused and injected into the subcutaneous tissue of the injection object. The injection device can eject target molecules at various tissue depths ranging from dermis to muscle according to the force generated by the syringe. It is usually used for large-scale vaccination in animals. Although the injection device is more complicated than the needle syringe device, the injection device has significant advantages.

[0003] For example, the invention with application number 201580067944.3 discloses an injection device for dispensing medicines to animals, including a container receiver, a dispensing mechanism and a radio frequency identification system. This solution not only realizes injection, but also effectively solves the problem that the existing injection devices do not provide medicine traceability. However, its dispensing mechanism does not take leakage prevention measures, and it is very likely to leak during use, thereby causing the problem of drug waste.

[0004] In the prior art, a spring steel ball valve or a rubber head valve is usually used as a one-way valve for a liquid inlet or a liquid outlet. However, this traditional valve design is very prone to leakage or blockage due to wear or jamming.

[0005] For example, the utility model with application number 202022260566.1 discloses a continuous syringe, in which the above-mentioned traditional valve is adopted.

[0006] For another example, the utility model with application number 202321595362.0 discloses an injection device capable of continuous and automatic injection, comprising: a shell, an injection module arranged at the first end of the shell, the injection module comprising an injection head assembly; wherein the injection head assembly comprises: a main body for containing liquid, a push rod is arranged inside the main body; and a first one-way valve is arranged at the outlet end of the main body; and an infusion unit, the infusion unit comprises: an infusion pipeline, the first end of the infusion pipeline is used to be connected to the liquid storage module, the second end of the infusion pipeline is connected to the main body, and a second one-way valve is arranged inside the second end of the infusion pipeline; an air suction valve is also arranged on the infusion pipeline; and a motor for driving the push rod to reciprocate. Although the injection device in the above scheme can alleviate the injection risks such as bubble generation, leakage or improper user operation during long-term continuous injection to a certain extent, it uses steel balls to seal the infusion pipe and the liquid outlet. Since the contact area between the steel balls and the infusion pipe and the liquid outlet is very small, it is difficult to ensure its sealing. When the steel balls are worn, the steel balls cannot fit completely with the infusion pipe and the liquid outlet, which will cause leakage in the syringe.

[0007] Therefore, there is an urgent need for an injection device with better anti-leakage effect. Utility Model Content

[0008] The utility model aims to provide an injection device which prevents liquid leakage, so as to improve the leakage resistance of the syringe.

[0009] In order to solve the technical problems mentioned above, the utility model specifically adopts the following technical solutions: a liquid leakage-proof injection device, comprising an infusion catheter, a dispensing mechanism and a motor, the dispensing mechanism comprising a main body for containing a liquid medicine, and a liquid inlet and a liquid outlet fixedly arranged on the main body and connected to the main body, a piston is movably arranged inside the main body, the motor is used to control the movement of the piston inside the main body, the infusion catheter is connected to the liquid inlet; the liquid inlet is provided with a first liquid inlet area and a second liquid inlet area in sequence along the liquid inlet direction, and the inner diameter of the second liquid inlet area is smaller than the first liquid inlet area, so as to form a first step at the connection between the first and second liquid inlet areas, a sealing member is provided at the first end of the first liquid inlet area, and the sealing member is provided with an opening connected to the infusion catheter; and a first blocking block is provided in the liquid inlet, and a first spring that drives the first blocking block to reciprocate in the liquid inlet, the first blocking block comprises a first blocking section and a first connecting section, and the second end of the first blocking section is provided with at least two limiting protrusions;

[0010] The liquid outlet is provided with a first liquid outlet area and a second liquid outlet area in sequence along the liquid outlet direction, and the inner diameter of the second liquid outlet area is smaller than that of the first liquid outlet area, so as to form a second step between the first and second liquid outlet areas. The liquid outlet is provided with a second blocking block and a second spring driving the second blocking block to reciprocate in the liquid outlet. The second blocking block comprises: a second blocking section and a second connecting section, and at least two limiting protrusions are provided at the second end of the second blocking section; wherein, when the injection device is in a drug suction state, the bottom surface of the limiting protrusion of the first blocking section abuts against the first step, and two adjacent limiting protrusions cooperate with the first step to form a first drainage channel for liquid inlet; the second blocking section is inserted into the first liquid outlet area to seal the liquid outlet; when the injection device is in an injection state, the first blocking section is inserted into the opening to seal the infusion catheter, the second blocking section abuts against the second step, and a second drainage channel for liquid inlet is formed between two adjacent limiting protrusions of the second blocking section and the second step.

[0011] As an improvement, a conical area is provided at the first end of the first liquid outlet area, and the inner diameter of the conical area gradually increases along the liquid outlet direction; wherein, when the injection device is in a liquid suction state, the outer inclined surface (also referred to as: slope) of the second blocking section abuts against the conical area; when the injection device is in a liquid outlet state, the conical area and the outer slope of the second blocking section form a third drainage channel, and under the action of the piston, the medicinal liquid passes through the third drainage channel and the second drainage channel in sequence to form a high-pressure liquid that is ejected outward.

[0012] As an improvement, a first fixing seat is fixedly provided at one end of the output shaft of the motor, and a mounting block is provided at one end of the dispensing mechanism close to the first fixing seat, the first fixing seat includes a connecting portion, a mounting portion and an elastic member for locking the mounting block, the connecting portion is provided with an opening matching the mounting block, a cavity is reserved between the connecting portion and the mounting portion for the mounting block to rotate, the mounting portion is provided with a groove, one end of the elastic member is fixedly provided in the groove, and the mounting block is provided with a mounting hole matching the elastic member.

[0013] As an improvement, a connecting piece is further provided between the first fixing seat and the motor, and the connecting piece is a connecting piece with a hollow interior, one end of the connecting piece is fixedly connected to the motor, and the other end of the connecting piece is fixedly connected to the first fixing seat.

[0014] As an improvement, a transition zone is provided at the second end of the main body, and correspondingly, a docking position corresponding to the transition zone is provided at the first end of the connector, and when the main body is fixedly connected to the connector, the transition zone is snapped into the docking position; wherein, the inner diameter of the transition zone gradually increases in the direction from the first end to the second end, and the inner diameter of the transition zone is larger than the inner diameter of the cavity of the connector; the inner wall of the cavity at the first end of the main body is configured to be pointed, and the inner diameter of the pointed portion gradually decreases in the direction from the second end to the first end of the main body.

[0015] As an improvement, the number of the limiting protrusions on the first blocking block and the second blocking block is respectively 4.

[0016] As an improvement, a mounting groove is provided on the side wall of the piston, two retaining rings are symmetrically arranged in the mounting groove, and an O-ring is arranged between the two retaining rings.

[0017] As an improvement, both the first blocking section and the second blocking section are made of metal blocking blocks.

[0018] As an improvement, the dispensing mechanism further comprises a needle end, the needle end is connected to the liquid outlet, and the inner diameter of the needle end gradually decreases from an end close to the liquid outlet to an end far from the liquid outlet.

[0019] As an improvement, the free end of the infusion catheter is provided with a mounting seat for mounting a medicine bottle, and an exhaust valve for exhausting the air inside the medicine bottle.

[0020] The principle and beneficial effects of the utility model are:

[0021] During needle-free injection, it is necessary to ensure that the drug solution has a large hydraulic pressure at the moment it flows out of the injection device, so as to ensure that the drug solution can pierce the skin and complete the injection. In this way, during repeated injections, the existing spring steel ball valve or rubber head valve is very likely to leak or become blocked due to wear or jamming during long-term injections.

[0022] In order to improve the working stability under high-frequency and high-pressure injection working regulation, the present application provides a limited drainage solution by adopting a metal sealing section design with multiple convex positions in conjunction with a spring and a stepped inner tube (such as a liquid inlet and a liquid outlet). This limited drainage solution can guide the drug liquid through the drainage channel to complete rapid drug absorption or injection under the corresponding suction or thrust, and at the same time avoid problems such as blockage and leakage that are prone to occur in traditional valves.

[0023] Among them, the cooperation between the metal sealing section and the rubber gasket can avoid blockage of the liquid inlet while effectively preventing backflow.

[0024] At the same time, this solution uses a second fixed seat, a connecting piece, and a first fixed seat that are connected to the motor in sequence to perform a self-locking quick-release connection with the main body, and limits the main body through the fixed seat and the fixed rod, thereby effectively improving the working stability of the detachable dispensing mechanism under frequent strong vibration conditions. At the same time, the design of coordinated use of a pointed piston and a transition zone can enable the connecting piece and the fixed seat to be quickly docked during the detachable installation process, that is, the installation process is more convenient and quick. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the utility model or the prior art, the drawings required for use in the embodiments or the prior art description are briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, each element or part is not necessarily drawn according to the actual proportion. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can also be obtained based on these drawings without paying creative labor.

[0026] Figure 1 A three-dimensional diagram of the overall structure of an embodiment of the utility model;

[0027] Figure 2 A cross-sectional view of the overall structure of an embodiment of the utility model;

[0028] Figure 3 A cross-sectional view of a dispensing mechanism portion of an embodiment of the utility model;

[0029] Figure 4 It is an enlarged structural cross-sectional view of the injection end of an embodiment of the utility model;

[0030] Figure 5 It is an enlarged structural schematic diagram of the first or second one-way valve in the embodiment of the utility model;

[0031] Figure 6 This is a schematic diagram of the dispensing mechanism during installation in the embodiment of the utility model;

[0032] Figure 7 This is a schematic diagram of the dispensing mechanism after installation in the embodiment of the utility model;

[0033] Figure 8 It is a cross-sectional view of the first mounting seat in the embodiment of the utility model;

[0034] Fig. 9 It is a schematic diagram of the installation of the first or second one-way valve in the embodiment of the utility model.

[0035] Markings in the figure: 1. medicine bottle; 2. mounting seat; 3. control panel; 4. infusion catheter; 5. dispensing mechanism; 51. main body; 52. liquid inlet; 521. first spring; 522. first blocking block; 53. liquid outlet; 531. second spring; 532. second blocking block; 6. motor; 7. exhaust valve; 8. telescopic part; 9. induction switch; 10. piston; 11. limiting protrusion; 12. mounting block; 13. first fixed seat; 131. third spring; 132. movable block; 133. connecting part; 134. mounting part; 14. connecting part; 15. second fixed seat. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0037] Herein, the suffixes such as "module", "component" or "unit" used to represent elements are only used to facilitate the description of the present invention, and have no specific meanings. Therefore, "module", "component" or "unit" can be used in a mixed manner.

[0038] In this document, the terms "upper", "lower", "inner", "outer", "front", "rear", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0039] In this document, unless otherwise clearly specified or limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0040] Herein "and / or" includes any and all combinations of one or more of the associated listed items.

[0041] Herein, "plurality" means two or more than two, ie, it includes two, three, four, five, etc.

[0042] This embodiment is basically as shown in the attached Figure 1-9 As shown:

[0043] like Figure 1 , Figure 2 As shown, the utility model provides a detachable syringe, including a shell, a dispensing mechanism 5, an infusion catheter 4 and a motor 6, wherein the motor 6 is fixed on the shell, and the dispensing mechanism 5 is detachably arranged at the output end of the motor 6, the infusion catheter 4 is connected with the dispensing mechanism 5 for providing liquid medicine to the dispensing mechanism 5, and the free end of the infusion catheter 4 extends out of the shell, and a mounting seat 2 for mounting a medicine bottle 1 is arranged at its free end, and an exhaust valve 7 for exhausting the air inside the medicine bottle 1 is also arranged, and the range of a single drug dispensing of the syringe is 0.2-2ml, and a control panel 3 is arranged outside the shell for convenient operation.

[0044] like Figure 3 , Figure 4 The dispensing mechanism 5 includes a main body 51 for containing liquid medicine, a liquid inlet 52 arranged above the main body 51 and connected thereto, and a liquid outlet 53 arranged at the injection end and connected to the main body 51, wherein the length of the main body 51 is 55-60 mm, the liquid inlet 52 is provided with a first liquid inlet area and a second liquid inlet area in sequence along the liquid inlet direction, and the inner diameter of the second liquid inlet area is smaller than the first liquid inlet area, so as to form a first step at the connection between the first and second liquid inlet areas, a sealing member is provided at the first end of the first liquid inlet area, and the sealing member is provided with an opening connected to the infusion catheter 4, and the specific sealing member is a rubber gasket; the liquid outlet 53 is provided with a first liquid outlet area and a second liquid outlet area in sequence along the liquid outlet direction thereof, and the inner diameter of the second liquid outlet area is smaller than the first liquid outlet area, so as to form a second step between the first and second liquid outlet areas.

[0045] In some embodiments, a tapered region is disposed at the first end of the first liquid outlet region, and the inner diameter of the tapered region gradually increases along the liquid outlet direction.

[0046] In some embodiments, the inclination angle inside the conical area is the same as or similar to the inclination angle of the pointed part of the second blocking block 532, so that when the liquid outlet 53 is in a closed state, the pointed part of the second blocking block 532 (i.e., the outer inclined surface) just fits against the conical area, thereby enhancing its sealing performance; at the same time, a needle end is also provided at the outlet end of the liquid outlet 53, and the inner diameter of the needle end gradually decreases from the end close to the liquid outlet 53 to the end away from the liquid outlet 53.

[0047] This solution adopts multiple approaches (including sealing the liquid inlet end with a sloped sealing section, setting a rubber gasket at the liquid inlet, setting the liquid inlet end of the liquid outlet to a slope, and adding a retaining ring on the piston), which effectively improves the anti-leakage function of the injection device.

[0048] In some embodiments, a telescopic part 8 is installed on the needle end side of the main body 51 through a fourth spring. At the same time, a sensing switch 9 corresponding to the telescopic part 8 is arranged on the main body 51. The sensing switch 9 is fixed to the bottom of the main body 51 by bolts. At the same time, in order to protect the telescopic part 8 and limit the telescopic part 8, an outer cover is connected to the outside of the telescopic part 8 by a snap-on. When not injecting, the telescopic part 8 is outside the sensing range of the sensing switch 9 under the action of the fourth spring. During injection, the telescopic part 8 is brought into contact with the animal skin to compress the fourth spring, and the telescopic part 8 approaches the sensing switch 9 and reaches within the sensing range of the sensing switch 9. The sensing switch 9 controls the dispensing mechanism 5 to perform injection.

[0049] In some embodiments, a first one-way valve is disposed in the liquid inlet 52, such as Figure 5 The first one-way valve includes a first blocking block 522 and a first spring 521 that drives the first blocking block 522 to reciprocate in the liquid inlet 52. The first blocking block 522 includes a first blocking section and a first connecting section (wherein the first spring is sleeved on the first connecting section). The first blocking section is sloped on one side close to the infusion catheter 4. When the injection device is inhaling medicine, the first blocking block 522 is subjected to a first force and deviates in a first direction under the action of the first force. At this time, an annular gap is formed between the outer wall of the first blocking section and the liquid outlet end of the infusion catheter 4, so that the drug liquid can enter the liquid inlet 52 from the infusion catheter 4 and then flow into the inside of the main body 51. When the injection device is injecting, the first blocking block 522 is subjected to a second force applied by the drug liquid, and the first blocking section moves in the second direction and is close to the liquid outlet end of the infusion catheter 4, thereby limiting the reflux of the drug liquid into the infusion catheter 4, wherein the first direction is the direction from the liquid inlet end to the liquid outlet end of the liquid inlet 52, and the second direction is opposite to the first direction.

[0050] In some embodiments, a second one-way valve is provided in the liquid outlet 53. Specifically, the second one-way valve includes a second blocking block 532 and a second spring 531 that drives the second blocking block 532 to reciprocate in the liquid outlet 53. The second blocking block 532 includes a second blocking section and a second connecting section (wherein the second spring is sleeved on the second connecting section). The side of the second blocking section close to the main body 51 is sloped. When the injection device is sucking medicine, the second blocking section is subjected to a third force and moves along the third direction under the action of the third force. The second blocking block 532 moves toward and is close to the liquid outlet end of the main body 51, thereby limiting the outflow of the medicinal liquid from the liquid outlet 53; when the injection device is injecting, the second blocking block 532 is subjected to the fourth force exerted by the medicinal liquid, and is offset along the fourth direction under the action of the fourth force. At this time, an annular gap is formed between the outer wall of the second blocking segment and the liquid outlet end of the main body 51, so that the medicinal liquid can enter the liquid outlet 53 from the main body 51, and then be sprayed out from the injection device to complete the injection; the fourth direction is the direction from the liquid inlet end to the liquid outlet end of the liquid outlet 53, and the third direction is opposite to the fourth direction.

[0051] The sloped shape of the blocking section means that its size gradually increases from the first end to the second end (ie, the end connected to the connecting section).

[0052] In some embodiments, the first blocking block 522 and the second blocking block 532 may have the same shape and size, and the cross-sectional angle of the slope portion thereof is 90-135°.

[0053] In some embodiments, four limiting protrusions 11 may be provided on the side walls of the first blocking section and the second blocking section respectively. The limiting protrusions 11 are evenly distributed on the first blocking section and the second blocking section. A drainage channel is formed between adjacent limiting protrusions 11, with a total of four drainage channels. When the liquid inlet 52 is opened, the bottom of the limiting protrusion 11 on the first blocking section is located on the first step, and the first blocking block 522 can be limited by the first step to prevent the first blocking block 522 from blocking the lower part and thus preventing liquid from entering. At the same time, during the liquid intake process, the medicinal liquid flows to the drainage channel through the sloped first blocking section, and then flows to the inside of the main body 51 through the lower part, which can make the medicinal liquid more uniform during the flow process, thereby balancing the pressure generated by the medicinal liquid on the first blocking block 522; and similarly, when the liquid outlet 53 is in the open state, the bottom of the limiting protrusion 11 on the second blocking section is located on the second step, and the second blocking block 532 can be limited by the second step to prevent the second blocking block 532 from blocking the liquid outlet and preventing the liquid from discharging.

[0054] To further ensure the sealing of the first one-way valve, a rubber gasket is provided at the end where the liquid inlet 52 is connected to the infusion tube 4. A through hole is opened in the rubber gasket and the corresponding part of the infusion tube 4, and the pointed part of the first blocking block 522 is located in the through hole.

[0055] Preferably, at least the blocking sections of the first blocking block 522 and the second blocking block 532 in this solution are made of metal material with a tensile strength of more than 300 MPa. Under the impact of high-pressure drug flow during needle-free injection, the metal blocking blocks are extremely prone to wear, and the rubber gasket can effectively protect them.

[0056] In some embodiments, a piston 10 is movably disposed inside the main body 51, a mounting groove is disposed on the side wall of the piston 10, two retaining rings are symmetrically disposed inside the mounting groove, an O-ring is disposed between the two retaining rings, and the outer diameter of the O-ring may be greater than the outer diameter of the retaining ring. During the needle-free injection process, the injection pressure is usually 60-70 MPa, so in this solution, two retaining rings are disposed to protect the O-ring, thereby preventing leakage caused by damage to the O-ring, and a piston rod is fixedly disposed on one side of the piston 10 connected to the motor 6.

[0057] In order to further ensure the installation stability of each component and achieve the anti-vibration effect, a first fixing seat 13, a connecting member 14 and a second fixing seat 15 which are fixedly connected in sequence are arranged between the main body 51 and the motor 6. Specifically, the first fixing seat 13, the connecting member 14 and the second fixing seat 15 can be integrally formed.

[0058] Among them, the connecting member 14 is a cylindrical connecting member 14 with a hollow interior, the free end of the piston rod passes through the internal cavity of the connecting member 14 and is connected to the output shaft of the motor 6, and the length of the connecting member 14 is 50-60mm, its outer diameter is 35-40mm, and its inner diameter is 4-7mm. The second fixing seat 15 is fixed to the shell, the outer shell of the motor 6 and the connecting member 14 respectively.

[0059] like Figure 6 , Figure 7In order to facilitate installation and disassembly, the present invention is provided with a one-button disassembly structure for convenient disassembly, including a first fixing seat 13 and a mounting block 12 integrally arranged on the main body 51. Specifically, the first fixing seat 13 includes a connecting portion 133, a mounting portion 134 and an elastic member for locking the mounting block 12. The connecting portion 133 is provided with an opening matching the mounting block 12. A cavity for the mounting block 12 to rotate is reserved between the connecting portion 133 and the mounting portion 134. A groove is provided on the mounting portion 134. One end of the elastic member is fixedly arranged in the groove. A through hole matching the elastic member is provided on the mounting block 12. Two groups of elastic members and through holes are correspondingly arranged and are symmetrically arranged at 180°. The specific elastic member includes a third spring 131 and an active spring 132. Block 132, one end of the third spring 131 is fixedly arranged inside the groove, and the other end is fixedly connected to the movable block 132. When the elastic member is not affected by external force, a part of the movable block 132 is located outside the groove; when the mounting block 12 enters the opening from the first angle, the elastic member is staggered with the through hole. At this time, the elastic member is not affected by external force and is in a natural state; when the mounting block 12 is rotated, the elastic member is compressed by the pressure of the mounting block 12; when the mounting block 12 is rotated 90° clockwise or counterclockwise to reach the second angle, the groove is aligned with the through hole, and the pressure of the mounting block 12 on the elastic member is reduced, and the elastic member is extended, so that a part of the movable block 132 is located in the through hole, and the mounting block 12 is locked, thereby achieving the purpose of self-locking.

[0060] In order to further ensure the stability of the dispensing mechanism 5, a fixing rod is also provided, and corresponding through holes are respectively provided on the main body 51 and the first fixing seat 13. After the main body 51 is fixed to the first fixing seat 13 through the mounting block 12, the fixing rod is passed through the through holes on the main body 51 and the first fixing seat 13 in turn, thereby achieving fixation of the main body 51 and the first fixing seat 13.

[0061] This solution uses the three-way joint and the piston with the above-mentioned specific structure. At the same time, the device cooperates with the mounting block and the first fixing seat to comprehensively provide a detachable injection device with good leakage prevention effect.

[0062] In some embodiments, a transition zone is provided at the second end of the main body 51, and correspondingly, a docking position corresponding to the transition zone is provided at the first end of the connector 14. When the main body 51 is fixedly connected to the connector 14, the transition zone is snapped into the docking position; wherein, the inner diameter of the transition zone gradually increases from its first end to the second end, and the inner diameter of the transition zone is larger than the inner diameter of the cavity of the connector 14, so as to ensure that the piston 10 enters the main body 51 more smoothly; the interior of the cavity at the first end of the main body 51 is configured to be pointed, and the inner diameter of the pointed part gradually decreases from the second end to the first end of the main body 51, so that the medicine has a sufficiently large hydraulic pressure when flowing out of the main body 51, and this part matches the shape of the pointed part of the piston 10, so that when the piston 10 reaches the first end of the main body 51, the medicine inside the main body 51 can be completely discharged.

[0063] During specific use, first insert the mounting block 12 into the opening of the connecting portion 133. At this time, the third spring 131 is in a compressed state under the action of the mounting block 12, and the entire movable block 132 is located inside the groove. Then rotate the dispensing mechanism 5 to make the mounting block 12 rotate in the cavity until the through hole on the mounting block 12 is aligned with the movable block 132. At this time, the force of the mounting block 12 on the third spring 131 disappears, and the third spring 131 is extended, so that a part of the movable block 132 enters the through hole and clamps the mounting block 12, thereby achieving the installation and fixation of the dispensing mechanism 5; when disassembling, rotate the dispensing mechanism 5 in the opposite direction to make the movable block 132 disengage from the through hole, and the mounting block 12 can be aligned with the opening of the connecting portion 133 again and can be taken out. Compared with the disassembly method of removing bolts in the prior art, this disassembly method only needs to rotate the dispensing mechanism 5 by a fixed angle, without the need to screw the bolts one by one and remove them, which is more convenient and quick.

[0064] When the piston 10 does not move, the liquid inlet 52 and the liquid outlet 53 are both in a closed state, that is, the first blocking block 522 is in contact with the rubber gasket, and the second blocking block 532 is in contact with the liquid inlet end of the liquid outlet 53 for sealing; when in use, the piston 10 is first driven to the right by the motor 6 to absorb liquid. At this time, the first blocking block 522 leaves the rubber gasket under the action of suction, the first spring 521 is compressed, and the bottom of the limiting protrusion 11 contacts the first step, and four uniform drainage channels are formed between adjacent limiting protrusions 11. The liquid medicine enters the interior of the main body 51 from the infusion catheter 4 through the upper part, the drainage channel and the lower part. At the same time, the second blocking block 532 is in contact with the liquid inlet end of the liquid outlet 53 under the joint action of the spring and suction. The second spring 531 is compressed at the same time, and the first blocking block 522 is more tightly held with the rubber gasket under the action of the liquid pressure, thereby preventing the liquid from flowing out of the liquid outlet 53; after the liquid is sucked, the piston 10 stops moving, and the liquid inlet 52 and the liquid outlet 53 are both in a closed state; then the piston 10 is driven to move left by the motor 6 for injection, and at this time, the second blocking block 532 leaves the liquid inlet end of the liquid outlet 53 under the action of the liquid pressure, and the bottom of the limiting protrusion 11 of the second blocking block 532 contacts the second step, so that the liquid outlet 53 is in an open state, and the liquid is injected through the right part, the drainage channel of the second blocking block 532 and the left part. At the same time, the second spring 531 is compressed, and the first blocking block 522 is more closely fitted with the rubber gasket under the action of the liquid pressure, which effectively prevents the liquid inlet 52 from flowing back during injection.

[0065] This solution can effectively resist vibration while achieving more convenient and quick disassembly through the mutual cooperation between the mounting block 12, the first fixing seat 13, the connecting piece 14, the second fixing seat 15 and the housing.

[0066] It is worth noting that the detachable syringe-related structure mentioned in this solution is not only applicable to needle-free syringes, but also to syringes with needles.

[0067] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0068] The embodiments of the utility model are described above in conjunction with the accompanying drawings, but the utility model is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the utility model, ordinary technicians in this field can also make many forms without departing from the scope of protection of the utility model and the claims, which all fall within the protection of the utility model.

Claims

1. A leak-proof injection device, comprising an infusion catheter (4), a dispensing mechanism (5) and a motor (6), characterized in that: The dispensing mechanism (5) comprises a main body (51) for containing liquid medicine, and a liquid inlet (52) and a liquid outlet (53) fixedly arranged on the main body (51) and connected to the main body (51); a piston (10) is movably arranged inside the main body (51); the motor (6) is used to control the movement of the piston (10) inside the main body (51); and the infusion catheter (4) is connected to the liquid inlet (52); The liquid inlet (52) is provided with a first liquid inlet area and a second liquid inlet area in sequence along the liquid inlet direction, and the inner diameter of the second liquid inlet area is smaller than that of the first liquid inlet area, so as to form a first step at the connection between the first liquid inlet area and the second liquid inlet area, and a sealing member is provided at the first end of the first liquid inlet area, and the sealing member is provided with an opening communicated with the infusion catheter (4); and a first blocking block (522) is provided in the liquid inlet (52), and a first spring (521) for driving the first blocking block (522) to reciprocate in the liquid inlet (52), the first blocking block (522) comprises a first blocking section and a first connecting section, and the second end of the first blocking section is provided with at least two limiting protrusions (11); The liquid outlet (53) is provided with a first liquid outlet area and a second liquid outlet area in sequence along the liquid outlet direction thereof, and the inner diameter of the second liquid outlet area is smaller than that of the first liquid outlet area, so as to form a second step between the first liquid inlet area and the second liquid inlet area. The liquid outlet (53) is provided with a second blocking block (532) and a second spring (531) for driving the second blocking block (532) to reciprocate in the liquid outlet (53), the second blocking block (532) comprising: a second blocking section and a second connecting section, and the second end of the second blocking section is provided with at least two limiting protrusions (11); Wherein, when the injection device is in a drug inhalation state, the bottom surface of the limiting protrusion (11) of the first blocking section abuts against the first step, and two adjacent limiting protrusions (11) cooperate with the first step to form a first drainage channel for liquid inlet; the second blocking section is inserted into the first liquid outlet area to seal the liquid outlet (53); when the injection device is in an injection state, the first blocking section is inserted into the opening to seal the infusion catheter (4), the second blocking section abuts against the second step, and a second drainage channel for liquid inlet is formed between the two adjacent limiting protrusions (11) of the second blocking section and the second step.

2. A liquid leakage-proof injection device according to claim 1, characterized in that: A conical area is provided at the first end of the first liquid outlet area, and the inner diameter of the conical area gradually increases along the liquid outlet direction; wherein, when the injection device is in a liquid suction state, the outer inclined surface of the second blocking section abuts against the conical area; when the injection device is in a liquid outlet state, the conical area and the outer inclined surface of the second blocking section form a third drainage channel, and under the action of the piston (10), the liquid medicine passes through the third drainage channel and the second drainage channel in sequence to form a high-pressure liquid that is ejected outward.

3. A liquid leakage-proof injection device according to claim 1, characterized in that: A first fixing seat (13) is fixedly arranged at one end of the output shaft of the motor (6); a mounting block (12) is arranged at one end of the dispensing mechanism (5) close to the first fixing seat (13); the first fixing seat (13) comprises a connecting portion (133), a mounting portion (134) and an elastic member for locking the mounting block (12); the connecting portion (133) is provided with an opening matching the mounting block (12); a cavity for the mounting block (12) to rotate is reserved between the connecting portion (133) and the mounting portion (134); a groove is arranged on the mounting portion (134); one end of the elastic member is fixedly arranged in the groove; and the mounting block (12) is provided with a mounting hole matching the elastic member.

4. A liquid leakage-proof injection device according to claim 3, characterized in that: A connecting piece (14) is also provided between the first fixing seat (13) and the motor (6); the connecting piece (14) is an internally hollow connecting piece (14); one end of the connecting piece (14) is fixedly connected to the motor (6), and the other end is fixedly connected to the first fixing seat (13).

5. A liquid leakage-proof injection device according to claim 4, characterized in that: The second end of the main body (51) is provided with a transition zone, and correspondingly, the first end of the connecting piece (14) is provided with a docking position corresponding to the transition zone. When the main body (51) is fixedly connected to the connecting piece (14), the transition zone is snapped into the docking position; wherein the inner diameter of the transition zone gradually increases along the direction from the first end to the second end thereof, and the inner diameter of the transition zone is greater than the inner diameter of the cavity of the connecting piece (14); the inner wall of the cavity at the first end of the main body (51) is arranged to be pointed, and the inner diameter of the pointed portion gradually decreases along the direction from the second end to the first end of the main body (51).

6. A liquid leakage-proof injection device according to claim 1, characterized in that: The number of the limiting protrusions (11) on the first blocking block (522) and the number of the second blocking block (532) are respectively four.

7. A liquid leakage-proof injection device according to claim 1, characterized in that: A mounting groove is provided on the side wall of the piston (10), two retaining rings are provided in the mounting groove, and an O-shaped sealing ring is provided between the two retaining rings.

8. A liquid leakage-proof injection device according to claim 1, characterized in that: The first blocking section and the second blocking section both use metal blocking blocks.

9. The anti-leakage injection device according to claim 1, characterized in that: The dispensing mechanism (5) further comprises a needle end, the needle end being in communication with the liquid outlet (53), and the inner diameter of the needle end gradually decreasing from an end close to the liquid outlet (53) to an end away from the liquid outlet (53).

10. The anti-leakage injection device according to claim 1, characterized in that: The free end of the infusion catheter (4) is provided with a mounting seat (2) for mounting the medicine bottle (1), and an exhaust valve (7) for exhausting the air inside the medicine bottle (1).

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