Syringe structure and injection device

Abstract

The application provides an injector structure and an injection device. The injection device comprises an injector structure and an injector body. The injector structure comprises a shell, a limiting structure, a driving structure, a protection structure and a first elastic member. The limiting structure comprises a first sleeve and a first limiting member. The first limiting member is connected to the first sleeve and can be distally limited in the shell. The driving structure can drive the injection of medicine and simultaneously release the limiting relationship between the first limiting member and the shell. The protection structure comprises a second sleeve and a second limiting member. The second sleeve can be retracted into the shell or extended out of the shell. The second sleeve can be distally limited in the first sleeve. The first elastic member is abutted between the second sleeve and the shell. After the injection of medicine is completed and the injection needle is pulled out, the second limiting member is proximally limited in the shell, and the first sleeve is distally limited in the shell. In this way, the replacement of the injector during the injection of the same patient can be avoided as much as possible.

Description

Technical Field

[0001] The present application belongs to the technical field of medical devices, and more specifically, relates to a syringe structure and an injection device. Background Art

[0002] In the medical industry, in order to prevent cross infection, disposable syringes are becoming more and more popular among patients and medical staff and are widely used in clinical practice.

[0003] Traditional disposable syringes typically feature a protective structure that conceals the needle, locking the syringe in place while in use. Specifically, when the needle is inserted into the injection site, the protective structure retracts into the syringe. When the needle is removed from the injection site, the protective structure extends beyond the distal end of the housing and locks against the housing, effectively self-destructing the syringe, rendering the needle unusable and ensuring the syringe's single-use performance.

[0004] However, when using a syringe, after the injection needle is inserted into the injection site, if the patient is not mentally prepared and has a stress reaction, or if the injection needle is not inserted into the accurate injection position of the injection site, the injection needle needs to be pulled out from the injection site. At this time, the syringe is locked and cannot be used again, and a new syringe needs to be replaced, which causes economic waste. Summary of the Invention

[0005] One of the purposes of the embodiments of the present application is to provide a syringe structure, aiming to solve the technical problem in the related art that the syringe self-destructs when the injection needle is pulled out without injection, resulting in energy waste.

[0006] To solve the above technical problems, the technical solutions adopted in the embodiments of the present application are:

[0007] In a first aspect, a syringe structure is provided for use with a syringe body, the syringe body comprising a drug chamber bottle containing a drug, a plunger for sealing one end of the drug chamber bottle, and an injection needle mounted at the other end of the drug chamber bottle; the syringe structure has an axial direction, with two opposite ends of the syringe structure along the axial direction being a proximal end and a distal end, respectively; the syringe structure comprises:

[0008] a housing configured to secure the chamber bottle therein;

[0009] The limiting structure includes a first sleeve and a first limiting member; the first sleeve is configured to be sleeved between the housing and the medicine chamber bottle and can move axially relative to the housing; the first limiting member is connected to the first sleeve and configured to be elastically movable relative to the first sleeve and can be limited to the housing toward the distal end;

[0010] The driving structure is configured to move distally relative to the housing to drive the drug in the injection chamber bottle and simultaneously drive the first limiting member to release the limiting relationship between the first limiting member and the housing;

[0011] The protective structure includes a second sleeve and a second stopper, wherein the second sleeve is configured to be disposed within the housing and sleeved outside the medicine chamber bottle, and is capable of axial movement relative to the housing to be retracted into the housing, or extended outside the distal end of the housing and cover the injection needle of the syringe body; the second sleeve is configured to be distally limited to the first sleeve;

[0012] The first elastic member is held between the second sleeve and the housing and is configured to drive the second sleeve and the first sleeve to move distally together after the limiting relationship between the first limiting member and the housing is released, so that the second sleeve extends out of the distal end of the housing;

[0013] The second limiting member is connected to the second sleeve and is configured to be able to move elastically relative to the second sleeve; when the limiting relationship between the first limiting member and the shell is released and the second sleeve extends out of the distal end of the shell, the second limiting member is limited to the shell toward the proximal end, and the first sleeve is limited to the shell toward the distal end.

[0014] In one embodiment, the first limiting member includes a first elastic arm provided on the first sleeve and a hook provided on the first elastic arm, and the hook is configured to be able to elastically hook the shell toward the distal end and to be able to detach from the shell under the drive of the driving structure.

[0015] In one embodiment, the housing includes a first shell and a fixing member disposed in the first shell, the fixing member is configured to assemble the medicine chamber bottle and position the medicine chamber bottle in the first shell; the fixing member has a movable groove extending axially therethrough, the first elastic arm is movably disposed in the movable groove, and the hook portion hooks the fixing member toward the distal end.

[0016] In one embodiment, the fixing member includes a fixing body and a first limiting portion provided on the fixing body. The fixing body is provided in the first shell and is configured to assemble the medicine chamber bottle. The first limiting portion and the fixing body define a movable groove; the first limiting member also includes a second limiting portion provided on the first elastic arm. The second limiting portion is spaced apart on the distal side of the hook portion, and the limiting structure can axially clamp the first limiting portion through the second limiting portion and the hook portion to limit it to the fixing member.

[0017] In one embodiment, a first protrusion is protruding from the inner circumference of the shell; the second limiting member includes a spring plate provided on the second sleeve, the spring plate is inclined relative to the outer circumference of the second sleeve, and is configured to be able to elastically resist the first protrusion toward the proximal end, or the second limiting member includes a movable member and an elastic structure connected between the movable member and the second sleeve, and the movable member can elastically resist the first protrusion toward the proximal end under the action of the elastic structure.

[0018] In one embodiment, the first sleeve is sleeved outside the second sleeve, the outer circumference of the second sleeve is provided with a second protrusion, the inner circumference of the first sleeve is provided with a third protrusion, and the second protrusion can abut against the third protrusion toward the distal end;

[0019] Alternatively, the second sleeve is sleeved outside the first sleeve, the inner circumference of the second sleeve is provided with a fourth convex portion, the outer circumference of the first sleeve is provided with a fifth convex portion, and the fourth convex portion can abut against the fifth convex portion toward the distal end.

[0020] In one embodiment, a sixth protrusion is provided on the inner circumference of the shell. When the first limiting member is limited to the shell toward the distal end, the first sleeve is located at the proximal end of the sixth protrusion. The sixth protrusion is configured to press against the first sleeve toward the proximal end when the limiting relationship between the first limiting member and the shell is released and the first elastic member drives the first sleeve to move toward the distal end.

[0021] In one embodiment, the syringe structure also includes an unlocking switch, which is provided on the shell and is configured to be movable relative to the shell to switch between a locked position and an unlocked position; the unlocking switch limits the driving structure in the locked position so that the driving structure is locked relative to the shell; the unlocking switch unlocks the driving structure relative to the shell in the unlocking position so that the driving structure can move toward the distal end.

[0022] In one embodiment, the driving structure is provided with a limit slot; the unlocking switch includes a switch body and a locking portion provided on the switch body, the switch body is axially limited to the shell, and can rotate relative to the shell to switch between a locked position and an unlocked position; when the unlocking switch is in the locked position, the locking portion is inserted into the limit slot to limit the axial movement of the driving structure; when the unlocking switch is in the unlocking position, the locking portion is disengaged from the limit slot to enable the driving structure to move axially relative to the shell.

[0023] In a second aspect, an injection device is provided, comprising a syringe body and a syringe structure, wherein the syringe body is assembled in the syringe structure.

[0024] The beneficial effects of the syringe structure and injection device provided in the embodiments of the present application are:

[0025] In the syringe structure provided by the embodiments of the present application, after the injection needle is inserted into the injection site, when the drive mechanism drives the injection of the drug in the drug chamber bottle under external force, the drive mechanism simultaneously drives the first stopper to release the retaining relationship between the first stopper and the housing. Thus, when the injection needle is withdrawn from the injection site, the second sleeve, under the elastic force of the first elastic member, drives the first sleeve distally, thereby achieving relative locking between the stopper structure, the protective structure, and the housing. This locks the injection device, thereby maintaining the protective structure in a state covering the injection needle and preventing further distal movement. At this point, the injection needle cannot be exposed for reuse, thus achieving the disposable function of the injection device. Prior to driving the injection of the drug, that is, when the injection device is not injecting the drug, the drive mechanism has not released the retaining relationship between the first stopper and the housing. At this time, the protective structure, the stopper structure, and the housing are not relatively locked, that is, the injection device is not locked. The second sleeve can move axially relative to the housing to expose or cover the injection needle, accordingly, the injection needle can be used multiple times. With this arrangement, after the injection needle is inserted into the injection site, if the patient is not mentally prepared and has a stress reaction, or the injection needle is not inserted into the accurate injection position of the injection site, the injection needle can be pulled out and inserted into the injection site again before the drive structure drives or triggers the plunger to inject the drug. Thus, the drug injection can be carried out after adjusting the specific injection position or the patient's psychological preparation. This can avoid as much as possible the need to replace the syringe and drug when injecting the same patient, thereby helping to reduce energy waste and injection costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0027] Figure 1 This is a three-dimensional schematic diagram of the injection device provided in Example 1 of the present application in the initial state;

[0028] Figure 2 for Figure 1 Exploded view of

[0029] Figure 3 for Figure 1 Cross-section Figure 1 ;

[0030] Figure 4 for Figure 1 Cross-section Figure 2 ;

[0031] Figure 5 for Figure 1 Partial schematic diagram of the provided injection device Figure 1 ;

[0032] Figure 6 A schematic diagram of the injection device with the injection needle inserted into the injection site and the unlocking switch in the unlocked position;

[0033] Figure 7 for Figure 6 sectional view of

[0034] Figure 8 for Figure 6 A cross-sectional view of the provided injection device after drug injection;

[0035] Figure 9 for Figure 8 A cross-sectional view of the provided injection device after the injection needle is removed;

[0036] Figure 10 for Figure 1 Partial schematic diagram of the provided injection device Figure 2 ;

[0037] Figure 11 for Figure 1 A three-dimensional schematic diagram of a driving body of a driving structure of an injection device is provided;

[0038] Figure 12 for Figure 1 A three-dimensional schematic diagram of the limiting structure of the provided injection device;

[0039] Figure 13 for Figure 1 A three-dimensional schematic diagram of a fixing member of the provided injection device;

[0040] Figure 14 for Figure 1 A three-dimensional schematic diagram of the protective structure of the provided injection device;

[0041] Figure 15 for Figure 1 A three-dimensional schematic diagram of the unlocking switch of the provided injection device;

[0042] Figure 16 for Figure 6 A partial schematic diagram of an injection device;

[0043] Figure 17 This is a three-dimensional schematic diagram of the injection device provided in Example 2 of the present application in an initial state;

[0044] Figure 18 for Figure 17 A cross-sectional view of the injection device is shown.

[0045] Among them, the reference numerals in the figures are:

[0046] 10 - syringe body; 11 - chamber bottle; 12 - plunger; 13 - injection needle; 20 - housing; 201 - movable groove; 202 - slide groove; 203 - limiting surface; 21 - first housing; 22 - fixing member; 221 - fixing body; 222 - first limiting portion; 23 - first protrusion; 24 - sixth protrusion; 25 - second housing; 30 - limiting structure; 31 - first sleeve; 311 - third protrusion; 32 - first limiting member; 321 - first elastic arm; 322 - hook; 323-second limiting part; 40-driving structure; 401-limiting groove; 41-driving body; 411-main body; 412-driving arm; 42-push rod; 421-rod body; 422-hook; 43-second elastic member; 50-protective structure; 51-second sleeve; 511-second protrusion; 52-second limiting part; 60-first elastic member; 70-unlocking switch; 71-switch body; 72-locking part; 73-sliding part; Y1-first axial direction; Y2-second axial direction. DETAILED DESCRIPTION

[0047] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0048] In the description of this application, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0049] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means more than two, unless otherwise specifically defined, where "more than two includes two."

[0050] In this application, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components or interactions between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.

[0051] The following is a detailed description with reference to the accompanying drawings and embodiments:

[0052] Example 1

[0053] Please also refer to Figures 1 to 3 In a first aspect, an embodiment of the present application provides an injection device, which includes a syringe structure and a syringe body 10. The syringe body 10 is assembled in the syringe structure and is used in conjunction with the syringe structure.

[0054] The injection device has an axial direction, and the two opposite ends of the injection device along the axial direction are respectively a proximal end and a distal end. The proximal end refers to the end of the injection device away from the injected site during the injection process, and the distal end refers to the end of the injection device close to the injected site during the injection process. Figure 1 The schematic symbol a, the far end is as follows Figure 1 Schematic reference numeral b. It will be appreciated that the syringe body 10 and syringe structure also have the aforementioned proximal and distal ends. The axial direction includes a first axial direction Y1 and a second axial direction Y2. Both the first axial direction Y1 and the second axial direction Y2 are parallel to the axial direction and are in opposite directions. Hereinafter, "proximal" generally refers to the first axial direction Y1, and "distal" generally refers to the second axial direction Y2.

[0055] Specifically, if Figure 2 and Figure 3 As shown, the syringe body 10 includes a medicine chamber bottle 11, a plunger 12 encapsulated at one end of the medicine chamber bottle 11, and an injection needle 13 provided at the other end of the medicine chamber bottle 11. Specifically, the medicine chamber bottle 11 is used to store medicine, and the injection needle 13 is provided at the distal end of the medicine chamber bottle 11 and is connected to the medicine chamber bottle 11. The plunger 12 is used to encapsulate the proximal end of the medicine chamber bottle 11, and can move toward the distal end in the medicine chamber bottle 11 under the drive of an external force to push the medicine in the medicine chamber bottle 11, thereby pressing the medicine in the medicine chamber bottle 11 out of the injection needle 13 to achieve the injection of the medicine. During the injection process, the injection needle 13 is inserted into the injection site, which can be the arm, buttocks, waist, etc. of the human body or animal.

[0056] Please also refer to Figure 1 and Figure 2A second aspect of an embodiment of the present application provides a syringe structure, which includes a housing 20, a limiting structure 30, a driving structure 40, a protective structure 50 and a first elastic member 60.

[0057] like Figures 1 to 3 As shown, the housing 20 is configured to fix the medicine chamber bottle 11 of the syringe body 10 therein, that is, when the syringe structure is used in conjunction with the syringe body 10 , the medicine chamber bottle 11 is fixed in the housing 20 .

[0058] like Figures 2 to 5 As shown, the limiting structure 30 includes a first sleeve 31 and a first limiting member 32. The first sleeve 31 is configured to be sleeved between the housing 20 and the medicine chamber bottle 11, and the first sleeve 31 is capable of axial movement relative to the housing 20. The first limiting member 32 is connected to the first sleeve 31 and is configured to be elastically movable relative to the first sleeve 31 and capable of being distally limited in the housing 20, thereby limiting the limiting structure 30 distally in the housing 20. Specifically, the first limiting member 32 is connected to the proximal end of the first sleeve 31.

[0059] like Figure 2 、 Figure 3 and Figure 5 As shown, the drive structure 40 is configured to be axially movable on the housing 20. The drive structure 40 can move distally relative to the housing 20 under the action of an external force. When the drive structure 40 moves distally relative to the housing 20 under the action of an external force, the drive structure 40 drives the drug in the injection chamber bottle 11; at the same time, the drive structure 40 also drives the first limiting member 32 to release the limiting relationship between the first limiting member 32 and the housing 20. Figure 5 As shown, the driving structure 40 is provided at the proximal end of the limiting structure 30 and the medicine chamber bottle 11 , which helps the user to drive the driving structure 40 .

[0060] like Figure 1 and Figure 2 、 Figures 4 to 9 The protective structure 50 includes a second sleeve 51 and a second limiter 52. The second sleeve 51 is configured to be arranged in the shell 20 and to be sleeved on the outside of the medicine chamber bottle 11. The second sleeve 51 can move axially relative to the shell 20 to retract into the shell 20 or extend outside the distal end of the shell 20. When the second sleeve 51 moves proximally, the second sleeve 51 can be retracted into the shell 20; when the second sleeve 51 moves distally, the second sleeve 51 can extend outside the distal end of the shell 20 and cover the injection needle 13 of the syringe body 10, thereby hiding the injection needle 13. In addition, the second sleeve 51 is configured to be limited to the first sleeve 31 distally, so as to prevent the second sleeve 51 from extending indefinitely outside the distal end of the shell 20.

[0061] like Figures 2 to 4 、 Figures 7 to 9 The first elastic member 60 is arranged between the second sleeve 51 and the shell 20, and is configured to drive the second sleeve 51 and the first sleeve 31 to move together to the distal end after the limiting relationship between the first limiting member 32 and the shell 20 is released, so that the second sleeve 51 extends out of the distal end of the shell 20. The first elastic member 60 can be a spring, a tension spring, a spring piece, or the like.

[0062] As shown in Figure 5 and Figure 9 , the second limiting member 52 is connected to the second sleeve 51 and is configured to be elastically movable relative to the second sleeve 51. After the limiting relationship between the first limiting member 32 and the shell 20 is released, the second sleeve 51 extends out of the distal end of the shell 20 under the elastic action of the first elastic member 60, and covers the injection needle 13. Under the condition that the drug injection is completed and the injection needle 13 is pulled out of the injection site, the second limiting member 52 is proximally limited to the shell 20, so that the protection structure 50 is proximally limited to the shell 20, and the first sleeve 31 is distally limited to the shell 20.

[0063] It should be noted that in the initial state of the injection device, as shown in Figure 1 、 Figures 3 to 5 , the first limiting member 32 is distally limited to the shell 20, so that the limiting structure 30 is distally limited to the shell 20. The second sleeve 51 extends out of the distal end of the shell 20 under the elastic force of the first elastic member 60 to cover the injection needle 13. At this time, the second sleeve 51 is also distally limited to the first sleeve 31, so as to indirectly make the protection structure 50 distally limited to the shell 20. The second sleeve 51 cannot move distally under the action of the first sleeve 31, but the second sleeve 51 can move proximally relative to the first sleeve 31 to retract into the shell 20 and expose the injection needle 13.

[0064] During use of the injection device, the injection needle 13 is first inserted into the injection site, and the second sleeve 51 moves proximally under the reaction force of the injection site and retracts into the shell 20. The first elastic member 60 is in a compressed and stored state under the extrusion action of the second sleeve 51, as shown in Figure 6 and Figure 7 . Then, the driving structure 40 moves distally under the action of external force, as shown in Figure 8As shown, the driving structure 40 drives the medicine in the injection chamber bottle 11 during the process of distal movement, thereby completing the injection of the medicine; at the same time, when the driving structure 40 moves to the distal end and reaches the position, it drives the first limiting member 32 distally to separate the first limiting member 32 from the shell 20, that is, the limiting relationship between the first limiting member 32 and the shell 20 is released. Finally, after the injection of the drug is completed, the injection needle 13 is pulled out from the injected site, and the reaction force of the injected site on the second sleeve 51 is gradually removed. The second sleeve 51 moves distally under the elastic force of the first elastic member 60 to extend out of the distal end of the shell 20 and cover the injection needle 13; since the limiting relationship between the first limiting member 32 and the shell 20 is removed, and the second sleeve 51 is distally limited to the first sleeve 31, then during the process of the second sleeve 51 moving distally under the action of the first elastic member 60, the second sleeve 51 drives the first sleeve 31 to move distally together, so that the second limiting member 52 on the second sleeve 51 is proximally limited to the shell 20, and the first sleeve 31 is distally limited to the shell 20. It can be understood that the first sleeve 31 is distally limited to the shell 20, the second sleeve 51 is distally limited to the first sleeve 31, and the second limiting member 52 on the second sleeve 51 is proximally limited to the shell 20, as shown in FIG. Figure 9 As shown, the limiting structure 30, the protective structure 50 and the housing 20 are relatively locked in the axial direction, so that the protective structure 50 cannot move distally again to expose the injection needle 13, and the injection needle 13 cannot be used again.

[0065] The syringe structure provided in the embodiment of the present application, during use, after the injection needle 13 is inserted into the injection site, when the drive structure 40 moves distally under external force to drive the injection of medicine, and when the drive structure 40 moves distally to the position, it drives the first limit member 32 to release the limiting relationship between the first limit member 32 and the shell 20. In this way, when the injection needle 13 is pulled out from the injection site, the second sleeve 51 drives the first sleeve 31 to move distally under the elastic force of the first elastic member 60 to achieve relative locking between the limiting structure 30, the protective structure 50 and the shell 20, that is, the injection device is in a locked state, so that the protective structure 50 is maintained in a state of covering the injection needle 13 and cannot move distally again. At this time, the injection needle 13 cannot be exposed for use again, thereby realizing the disposable use function of the injection device. Before the injection device is actuated to inject the drug, that is, when the drug is not injected, the drive structure 40 has not released the limiting relationship between the first limiter 32 and the housing 20. At this time, the protective structure 50, the limiter structure 30, and the housing 20 cannot achieve relative locking, that is, the injection device is not locked. The second sleeve 51 can move axially relative to the housing 20 to expose or cover the injection needle 13. Accordingly, the injection needle 13 can be used multiple times. In this way, after the injection needle 13 is inserted into the injection site, if the patient is not mentally prepared and has a stress reaction, or the injection needle 13 is not inserted into the injection site at the correct injection position, the injection needle 13 can be removed before the drive structure 40 is actuated to inject the drug and then inserted into the injection site again. After adjusting the specific injection position or the patient's mental preparation, the drug injection can be performed again. This can minimize the need to replace the syringe when injecting the same patient, thereby helping to reduce energy waste and injection costs. In addition, the automatic injector provided in the embodiment of the application is very simple in structure, easy to manufacture, and low in cost.

[0066] Accordingly, the injection device provided in the embodiment of the present application, due to the adoption of the syringe structure involved above, also has the advantage of being able to adjust the specific injection position or the patient's psychological preparation before performing the drug injection. This can avoid as much as possible the need to replace the syringe and drug when injecting the same patient, thereby helping to reduce energy waste and reduce injection costs.

[0067] Alternatively, as Figure 5 As shown, there are multiple first limiting members 32, and the multiple first limiting members 32 are spaced apart and distributed in the first sleeve 31. In the initial state, the multiple first limiting members 32 are all limited to the far end of the shell 20, thereby improving the limiting strength between the limiting structure 30 and the shell 20.

[0068] Alternatively, as Figure 9As shown, the second limiting member 52 is in plurality, and the plurality of second limiting members 52 are distributed at intervals on the second sleeve 51. When the drug injection is completed and the injection needle 13 is pulled out from the injection site, the plurality of second limiting members 52 are all proximally limited in the housing 20, thereby enhancing the relative locking strength between the housing 20, the limiting structure 30 and the protection structure 50.

[0069] Optionally, the driving structure 40 is moved distally relative to the housing 20 to drive the drug in the drug injection chamber bottle 11, and the specific scheme is as follows:

[0070] As Figure 4 , Figure 5 , Figures 7 to 10 In the embodiment, the driving structure 40 is an automatic driving structure, and the driving structure 40 comprises a driving body 41, a push rod 42 and a second elastic member 43. The driving body 41 is arranged in the housing 20 and can be moved distally relative to the housing 20 under the action of external force, wherein the driving body 41 is used to drive the first limiting member 32 distally when it is moved distally to the position, so as to release the limiting relationship between the first limiting member 32 and the housing 20. The push rod 42 comprises a rod body 421 and a clamping hook 422, the clamping hook 422 is arranged at the proximal end of the rod body 421 and can be elastically moved relative to the rod body 421. The rod body 421 and the clamping hook 422 are both located in the housing 20, the distal end part of the rod body 421 penetrates into the drug chamber bottle 11 and can push the plunger 12 in the drug chamber bottle 11. The clamping hook 422 is located outside the drug chamber bottle 11 and is axially opposite to the driving body 41. The second elastic member 43 is arranged between the rod body 421 and the housing 20 and is used to provide the rod body 421 and the housing 20 with elastic force in the axial direction. Wherein, the second elastic member 43 can be arranged as a spring, a tension spring, a spring sheet and other structures with elastic performance.

[0071] In the initial state, the hook 422 elastically hooks the outer shell 20 distally, and the second elastic member 43 is in the force storage state. In use, after the injection needle 13 pierces the injection site, when the driving body 41 of the driving structure 40 moves distally under the external force, the driving body 41 extrudes the hook 422 distally to make the hook 422 disengage from the outer shell 20, thereby releasing the limiting relationship between the push rod 42 and the outer shell 20. At this time, the second elastic member 43 resets and drives the rod body 421 to move distally, so that the plunger 12 drives the medicine in the medicine chamber bottle 11 distally under the pushing action of the rod body 421. Understandably, when the driving body 41 of the driving structure 40 moves distally under the external force, the limiting relationship between the push rod 42 and the outer shell 20 is released, so that the plunger 12 pushes the medicine distally under the action of the push rod 42 and the second elastic member 43, without the need for the user to continuously push the driving structure 40. That is, the driving structure 40 triggers automatic injection, so that the push rod 42 automatically pushes the plunger 12 to realize the injection of the medicine in the medicine chamber bottle 11. Based on this, the injection device provided in this embodiment is an injection device that can automatically inject medicine. In this way, after the medicine is injected, the push rod 42 and the plunger 12 are difficult to return to the initial state, thereby further realizing the performance of one-time use of the injection device. Wherein one end of the second elastic member 43 is connected to the rod body 421, and the other end abuts against the outer shell 20. When the limiting relationship between the hook 422 and the outer shell 20 is removed, the second elastic member 43 resets to drive the rod body 421 to move distally. In this process, the second elastic member 43 can move distally together with the rod body 421 and disengage from the outer shell 20, as shown in Figure 8 and Figure 9 Thus, the performance of one-time use of the injection device can be further realized.

[0072] Optionally, as shown in Figure 3 , Figure 7 , Figure 8 and Figure 11As shown, the driving body 41 includes a main body 411 and a driving arm 412 arranged on the main body 411. The main body 411 is located on the proximal side of the hook 422 and is directly opposite to the hook 422. The driving arm 412 is located on the proximal side of the first limiting member 32 and is directly opposite to the first limiting member 32. When the driving structure 40 moves distally under the action of external force, the main body 411 drives the hook 422 distally to release the limiting relationship between the hook 422 and the shell 20, so that the rod body 421 moves distally under the restoring action of the second elastic member 43, so as to drive the plunger 12 to push the medicine in the medicine chamber bottle 11; when the driving body 41 moves to the full position, the driving arm 412 drives the first limiting member 32 distally to separate the first limiting member 32 from the shell 20, thereby releasing the limiting relationship between the first limiting member 32 and the shell 20. In this way, when the injection needle 13 is pulled out from the injection site, the first elastic member 60 can drive the first sleeve 31 and the second sleeve 51 to move distally until the second limiting member 52 on the second sleeve 51 is proximally limited to the shell 20, and the first sleeve 31 is distally limited to the shell 20, so as to achieve relative locking between the limiting structure 30, the protective structure 50 and the shell 20. When there are multiple first position-limiting members 32 , the number of the driving arms 412 is also correspondingly set to be multiple, and the multiple driving arms 412 are used to drive the multiple first position-limiting members 32 in a one-to-one correspondence.

[0073] In one embodiment, please refer to Figure 5 and Figure 12 The first limiting member 32 includes a first elastic arm 321 and a hook portion 322 provided on the first elastic arm 321. The first elastic arm 321 is provided at the proximal end of the first sleeve 31, and the hook portion 322 is provided at the proximal end of the first elastic arm 321. The hook portion 322 and the first elastic arm 321 can move elastically relative to the first sleeve 31. In the initial state of the injection device, as shown in FIG. Figures 3 to 5 As shown, the hook portion 322 hooks the housing 20 toward the distal end, thereby achieving a limiting effect between the limiting structure 30 and the housing 20; when the injection needle 13 is inserted into the injection site and the driving structure 40 is driven to the distal end to inject the drug under the action of an external force, the driving structure 40 squeezes the hook portion 322 toward the distal end to separate the hook portion 322 from the housing 20, thereby releasing the limiting relationship between the first limiting member 32 and the housing 20, as shown in FIG. Figure 8 As shown, when the injection needle 13 is pulled out from the injection site, the first elastic member 60 drives the first sleeve 31 and the second sleeve 51 to move distally until the first sleeve 31 is distally limited to the housing 20 and the second limiting member 52 is proximally limited to the housing 20, as shown in FIG. Figure 9This arrangement allows the limiting relationship between the first limiting member 32 and the housing 20 to be easily released under the drive of the driving structure 40, thereby facilitating the relative locking effect between the limiting structure 30, the protective structure 50 and the housing 20 after the injection needle 13 is withdrawn from the injection site, that is, facilitating the self-destruction effect of the injection device.

[0074] The driving arm 412 of the driving structure 40 is used to press the hook portion 322 toward the distal end so that the hook portion 322 is separated from the housing 20 , thereby releasing the limiting relationship between the first limiting member 32 and the housing 20 .

[0075] Among them, such as Figure 5 As shown, the hook portion 322 extends radially outward from the first elastic arm 321 . Of course, in other embodiments, the hook portion 322 may also extend radially inward from the first elastic portion.

[0076] Optionally, please also refer to Figure 5 and Figure 13 The fixing member 22 has a limiting surface 203. When the injection device is in the initial state, the hook portion 322 hooks the limiting surface 203, and the fixing member 22 limits the limiting structure 30 through the limiting surface 203. For example, Figure 5 and Figure 13 As shown, the hook portion 322 protrudes radially outward and extends from the first elastic arm 321. Accordingly, the limiting surface 203 is gradually inclined from the proximal end to the distal end in the radial outward direction, thereby improving the limiting effect of the hook portion 322 and the limiting surface 203.

[0077] In one embodiment, please refer to Figures 2 to 5 The housing 20 includes a first shell 21 and a fixing member 22, and the fixing member 22 is fixed in the first shell 21. The fixing member 22 is assembled with the medicine chamber bottle 11 so that the medicine chamber bottle 11 is fixed in the first shell 21. Figure 5 and Figure 13 As shown, the fixing member 22 is provided with a movable groove 201, and the movable groove 201 is arranged to pass through the fixing member 22 along the axial direction. Figure 5 As shown, in the initial state of the injection device, the first elastic arm 321 is movably disposed within the movable slot 201, with the hook portion 322 distally hooked onto the fixing member 22. It should be noted that when the drive structure 40 drives the hook portion 322, the first elastic arm 321 is driven by the hook portion 322 to move within the movable slot 201, allowing the hook portion 322 to disengage from the fixing member 22, thereby releasing the restraining relationship between the first retaining member 32 and the housing 20. This arrangement, along with the provision of the movable slot 201, facilitates the elastic movement of the first elastic arm 321, thereby facilitating the release of the restraining relationship between the first retaining member 32 and the housing 20.

[0078] Among them, when the medicine is pushed and injected by the plunger 12 and the injection needle 13 is pulled out from the injection site, the first elastic member 60 is reset to drive the first sleeve 31 and the second sleeve 51 to reset toward the distal end, so that the first sleeve 31 is limited to the first shell 21 toward the distal end, and the second limiting member 52 is limited to the first shell 21 toward the proximal end, thereby achieving relative locking between the first shell 21, the limiting structure 30, the protective structure 50, and the fixing member 22.

[0079] Alternatively, as Figure 1 、 Figure 2 and Figure 4 As shown, the housing 20 further includes a second housing 25, which is fixed to the first housing 21. The push rod 42 is disposed in the second housing 25, and before the injection of the drug, the hook 422 is distally held against the second housing 25. Figures 1 to 8 The driving structure 40 is movably provided on the second housing 25 and can be driven distally relative to the second housing 25 under the action of an external force to drive the hook 422, thereby releasing the limiting relationship between the hook 422 and the second housing 25. The rod 421 drives the medicine in the medicine chamber bottle 11 distally under the elastic force of the second elastic member 43, as shown in FIG. Figure 9 shown.

[0080] In one embodiment, please refer to Figure 5 and Figure 13 The fixing member 22 includes a fixing body 221 and a first limiting portion 222. The first limiting portion 222 is provided on the fixing body 221 and defines the above-mentioned movable groove 201 with the fixing body 221. The fixing body 221 is provided in the first shell 21 and is configured to assemble the medicine chamber bottle 11. Figure 12 As shown, the first limiting member 32 also includes a second limiting portion 323, the second limiting portion 323 is arranged on the first elastic arm 321, the second limiting portion 323 is spaced apart on the distal side of the hook portion 322, and the first limiting member 32 can axially clamp the first limiting portion 222 through the second limiting portion 323 and the hook portion 322, thereby limiting the fixing member 22. When the cam 322 is in the closed position, the first stop 222 is in the closed position, and the second stop 223 is in the closed position, so the cam 322 is pressed against the first stop 222 and the second stop 223 is pressed against the second stop 223. When the cam 322 is in the closed position, the first stop 222 is pressed against the second stop 223. When the cam 322 is in the closed position, the first stop 222 is pressed against the second stop 223. When the cam 322 is in the closed position, the first stop 222 is pressed against the second stop 223.

[0081] In one embodiment, please refer to Figure 4 、 Figure 9 and Figure 14 The inner circumference of the housing 20 is provided with a first protrusion 23. Specifically, the first protrusion 23 is provided on the inner circumference of the first shell 21. The second stopper 52 includes a spring element provided on the second sleeve 51. The spring element is arranged at an angle relative to the outer circumference of the second sleeve 51 and is arranged away from the second sleeve 51 in a direction from distal to proximal. The spring element is configured to elastically abut the first protrusion 23 toward the proximal end.

[0082] It should be noted that the injection device is in the initial state. Figure 4 As shown, the spring fragments are spaced apart and located on the proximal side of the first protrusion 23. During use of the injection device, when the injection needle 13 is inserted into the injected site, the second sleeve 51 moves proximally under the reaction force of the injected site, and the spring fragments also move proximally. After the drug injection is completed, when the injection needle 13 is pulled out from the injected site, the second sleeve 51 moves distally under the elastic force of the first elastic member 60, and the second sleeve 51 also drives the first sleeve 31 to move distally. At this time, the spring fragments move distally under the drive of the second sleeve 51, and pass through the first protrusion 23 and elastically move toward the second sleeve 51 under the action of the first protrusion 23. When the second sleeve 51 moves distally into place, the spring fragments are located on the distal side of the first protrusion 23, and the spring fragments are reset and abut against the first protrusion 23 proximally, thereby achieving a proximal limiting effect of the protective structure 50, as shown in FIG. Figure 9 shown.

[0083] In another embodiment, the second stopper 52 may be configured to not include a spring, but instead include a movable member and an elastic structure, with the elastic structure connected between the movable member and the second sleeve 51. Under the action of the elastic structure, the movable member can extend beyond the outer periphery of the second sleeve 51 and elastically abut the first protrusion 23 proximally. It is understood that in the initial state of the injection device, the movable member is spaced proximally from the first protrusion 23. When the injection needle 13 is withdrawn from the injection site, the movable member elastically presses the first protrusion 23 distally under the action of the elastic structure and the second sleeve 51. When the second sleeve 51 moves distally into position, the movable member is located distally from the first protrusion 23 and elastically abuts the first protrusion 23 proximally. The movable member may be configured as a pin, a wedge-shaped block, or other similar structure.

[0084] In one embodiment, please refer to Figures 3 to 5The first sleeve 31 is sleeved over the second sleeve 51. The outer circumference of the second sleeve 51 is provided with a second protrusion 511, and the inner circumference of the first sleeve 31 is provided with a third protrusion 311. The second protrusion 511 is capable of distally abutting the third protrusion 311. It is understood that when the injection device is in the initial state, the second sleeve 51 has a tendency to move distally under the elastic force of the first elastic member 60. The second protrusion 511 is located proximal to the third protrusion 311 and is capable of distally abutting the third protrusion 311. This has the effect of distally restraining the second sleeve 51 within the first sleeve 31. At this time, the second sleeve 51 can move proximally and then continue to move distally until the second protrusion 511 distally abuts the third protrusion 311. When the drug injection is completed and the injection needle 13 is pulled out from the injection site, the second protrusion 511 is distally pressed against the third protrusion 311, the first sleeve 31 is distally limited to the first shell 21, and the spring piece on the second sleeve 51 is proximally pressed against the first shell 21, thereby achieving a relative locking effect between the protective structure 50, the limiting structure 30 and the shell 20.

[0085] In other embodiments, the second sleeve 51 can be sleeved outside the first sleeve 31, so that the above-mentioned third protrusion 311 and second protrusion 511 are not provided on the first sleeve 31 and the second sleeve 51, but: the inner circumference of the second sleeve 51 is provided with a fourth protrusion, and the outer circumference of the first sleeve 31 is provided with a fifth protrusion. The fourth protrusion can abut the fifth protrusion toward the distal end, thereby achieving relative limitation between the second sleeve 51 and the first sleeve 31. When the drug injection is completed and the injection needle 13 is pulled out from the injected site, a relative locking effect can be achieved between the protective structure 50, the limiting structure 30 and the shell 20.

[0086] In one embodiment, please refer to Figure 3 、 Figure 4 、 Figures 7 to 9The outer shell 20 is provided with a sixth protrusion 24 on its inner circumference. Specifically, the sixth protrusion 24 is provided on the inner circumference of the first housing 21. When the first stopper 32 is distally restrained within the outer shell 20, the first sleeve 31 is positioned proximally of the sixth protrusion 24. The sixth protrusion 24 is configured to proximally abut the first sleeve 31 when the first stopper 32 and the outer shell 20 are released and the first elastic member 60 drives the first sleeve 31 distally. It can be understood that before the drug is injected, or when the drug injection is completed and the injection needle 13 has not been pulled out from the injected site, the first sleeve 31 is spaced apart and located on the proximal side of the sixth protrusion 24; when the drug injection is completed and the injection needle 13 is pulled out from the injected site, the second sleeve 51 moves distally under the elastic force of the first elastic member 60, and drives the first sleeve 31 to move, so that the first sleeve 31 moves distally and abuts against the sixth protrusion 24 distally, thereby achieving the limitation between the shell 20 and the limiting structure 30. Since the second limiting member 52 abuts against the first protrusion 23 proximally at this time, a relative locking effect is achieved between the shell 20, the limiting structure 30 and the protective structure 50.

[0087] In one embodiment, please refer to Figure 5 、 Figure 15 and Figure 16 The syringe structure further includes an unlocking switch 70 , which is disposed on the housing 20 and is configured to be movable relative to the housing 20 to switch between a locked position and an unlocked position. Specifically, the unlocking switch 70 is movably disposed on the second housing 25 .

[0088] When the unlocking switch 70 is in the locked position, Figure 5 As shown, the unlocking switch 70 limits the driving structure 40 so that the driving structure 40 and the housing 20 are relatively locked, that is, the axial movement of the driving structure 40 is limited, so that the driving structure 40 can be prevented from driving the injection operation. Figure 16 As shown, the unlocking switch 70 and the driving structure 40 are relatively avoided, that is, the driving structure 40 and the shell 20 are relatively unlocked. At this time, the driving structure 40 can move toward the distal end relative to the unlocking switch 70 and the shell 20 under the action of external force to drive the injection operation, and at the same time drive the first limit member 32 to release the limiting relationship between the first limit member 32 and the shell 20.

[0089] With such a configuration, when the injection needle 13 is inserted into the injection site, the unlocking switch 70 needs to be switched from the locked position to the unlocked position first, and the driving structure 40 can drive the injection of the drug under the action of an external force, and at the same time release the limiting relationship between the first limiting member 32 and the shell 20. Therefore, when the patient is not mentally prepared and has a stress reaction, or the injection needle 13 is not inserted into the accurate injection position of the injection site, the driving structure 40 is prevented from being mistakenly triggered, resulting in the release of the limiting relationship between the first limiting member 32 and the shell 20. Therefore, when the patient is not mentally prepared and has a stress reaction, or the injection needle 13 is not inserted into the accurate injection position of the injection site, the injection needle 13 is prevented from being pulled out from the injection site, causing the injection device to be locked and self-destructed. In this way, the situation where the automatic syringe needs to be replaced when performing injection work on the same patient can be avoided as much as possible, thereby helping to reduce energy waste and injection costs.

[0090] In one embodiment, please refer to Figure 5 、 Figure 15 and Figure 16 The drive structure 40 defines a limiting slot 401. Specifically, the limiting slot 401 is defined in the drive arm 412 and is a notched slot. The unlocking switch 70 includes a switch body 71 and a locking portion 72 disposed on the switch body 71. The switch body 71 is axially limited to the housing 20 and is rotatable relative to the housing 20 to switch between a locked position and an unlocked position.

[0091] When the unlocking switch 70 is in the locked position, Figure 5 As shown, the locking portion 72 is inserted into the limiting groove 401 to achieve axial limitation between the unlocking switch 70 and the driving structure 40. Since the switch body 71 is axially limited to the housing 20, the axial limitation between the driving structure 40 and the housing 20 is indirectly achieved, thereby limiting the axial movement of the driving structure 40. In this way, the driving structure 40 cannot drive the injection of the drug to the distal end, and it is also unable to release the limiting relationship between the first limiting member 32 and the housing 20 to the distal end. At this time, the second sleeve 51 can repeatedly move axially relative to the housing 20 under the action of the injected part, that is, the injection needle 13 can be used repeatedly, so that the specific injection position of the injection needle 13 and the patient's psychological preparation can be well adjusted. When the unlocking switch 70 is in the unlocking position, as shown in FIG. Figure 16 As shown, the locking portion 72 is disengaged from the limiting groove 401, that is, the limiting relationship between the unlocking switch 70 and the driving structure 40 is removed, and the driving structure 40 can move axially relative to the unlocking switch 70, that is, the driving structure 40 can move axially relative to the shell 20, then the driving structure 40 can move distally relative to the shell 20 to drive the injection of the drug, and at the same time release the limiting relationship between the first limiting member 32 and the shell 20, so as to facilitate the locking and self-destruction effects of the injection device after the injection needle 13 is pulled out.

[0092] Optionally, the locking portion 72 can be provided in plurality, and the plurality of locking portions 72 are spaced apart on the switch body 71 . Accordingly, a plurality of limiting grooves 401 are also provided, and the plurality of locking portions 72 are used to be plugged in and matched with the plurality of limiting grooves 401 in a one-to-one correspondence.

[0093] Alternatively, as Figure 15 As shown, the unlocking switch 70 further includes a sliding portion 73, which is provided on the locking portion 72. Figure 1 and Figure 6 As shown, the housing 20 defines a slot 202, into which the sliding portion 73 is inserted, thereby axially limiting the unlocking switch 70 and the housing 20. The slot 202 is defined within the second housing 25. Furthermore, when the switch body 71 rotates relative to the housing 20 to switch between the locked and unlocked positions, the sliding portion 73 slides along the slot 202. This improves the switching stability and flexibility of the switch body 71 while maintaining the axial limiting effect between the unlocking switch 70 and the housing 20.

[0094] Example 2

[0095] The difference between this embodiment and the first embodiment is that the driving structure 40 drives the medicine in the injection chamber bottle 11 in a different way, that is, manual injection. Specifically, the driving body 41 of the driving structure 40 drives the push rod 42 in a different way. The specific scheme of this embodiment is as follows:

[0096] Please also refer to Figure 17 and Figure 18 The driving body 41 is connected to the push rod 42, or the driving body 41 is distally abutted against the proximal end of the push rod 42. When the injection device is in use, after the injection needle 13 is inserted into the injection site, the user can continuously push the driving body 41 so that the driving body 41 continuously pushes the push rod 42 distally under the pushing action of the user, thereby causing the plunger 12 to distally inject the medicine in the medicine chamber bottle 11 under the continuous pushing action of the push rod 42. When the injection is completed, the distal end of the driving body 41 releases the limiting relationship between the first limiting member 32 and the housing 20, thereby facilitating the relative locking effect between the limiting structure 30, the protective structure 50 and the housing 20 after the injection needle 13 is pulled out from the injection site, that is, facilitating the self-destruction effect of the injection device.

[0097] In this embodiment, the injection of the drug is achieved by manual continuous pushing.

[0098] Based on this, the injection device provided in this embodiment needs to be manually driven continuously to inject the medicine when in use.

[0099] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A syringe structure for use with a syringe body, the syringe body comprising a medicine chamber bottle containing a medicine, a plunger for sealing one end of the medicine chamber bottle, and an injection needle mounted on the other end of the medicine chamber bottle; the syringe structure has an axial direction, and the two opposite ends of the syringe structure along the axial direction are respectively a proximal end and a distal end; characterized in that The syringe structure comprises: a housing configured to secure the chamber bottle therein; The limiting structure includes a first sleeve and a first limiting member; the first sleeve is configured to be sleeved between the housing and the medicine chamber bottle and can move axially relative to the housing; the first limiting member is connected to the first sleeve and configured to be elastically movable relative to the first sleeve and can be distally limited to the housing; a driving structure configured to move distally relative to the housing to drive the injection of the medicine in the medicine chamber bottle and simultaneously drive the first limiting member to release the limiting relationship between the first limiting member and the housing; The protective structure includes a second sleeve and a second stopper, wherein the second sleeve is configured to be disposed within the housing and sleeved outside the medicine chamber bottle, and is capable of axial movement relative to the housing to be retracted into the housing or extended outside the distal end of the housing and cover the injection needle; the second sleeve is configured to be distally limited to the first sleeve; a first elastic member abutting between the second sleeve and the housing and configured to drive the second sleeve and the first sleeve to move distally together after the limiting relationship between the first limiting member and the housing is released, so that the second sleeve extends out of the distal end of the housing; The second limiting member is connected to the second sleeve and is configured to be elastically movable relative to the second sleeve; when the limiting relationship between the first limiting member and the housing is released and the second sleeve extends beyond the distal end of the housing, the second limiting member is proximally limited to the housing and the first sleeve is distally limited to the housing; The first limiting member includes a first elastic arm provided on the first sleeve and a hook portion provided on the first elastic arm, wherein the hook portion is configured to elastically hook the housing toward the distal end and to be detached from the housing under the drive of the driving structure; There are multiple first limiting members, and the multiple first limiting members are distributed on the first sleeve at intervals.

2. The syringe structure according to claim 1, wherein: The outer shell includes a first shell and a fixing member arranged in the first shell, the fixing member is configured to assemble the medicine chamber bottle and make the medicine chamber bottle located in the first shell; the fixing member has a movable groove running through it along the axial direction, the first elastic arm can be movably passed through the movable groove, and the hook hooks the fixing member toward the distal end.

3. The syringe structure according to claim 2, wherein: The fixing member includes a fixing body and a first limiting portion provided on the fixing body. The fixing body is provided in the first shell and is configured to assemble the medicine chamber bottle. The first limiting portion and the fixing body define the movable groove; the first limiting member also includes a second limiting portion provided on the first elastic arm, the second limiting portion is spaced apart on the distal side of the hook portion, and the first limiting member can axially clamp the first limiting portion through the second limiting portion and the hook portion to limit it to the fixing member.

4. The syringe structure according to any one of claims 1 to 3, characterized in that: The inner circumference of the shell is protruded with a first convex portion; the second limiting member includes a spring plate provided on the second sleeve, the spring plate is inclined relative to the outer circumference of the second sleeve, and is configured to be able to elastically press the first convex portion toward the proximal end, or the second limiting member includes a movable member and an elastic structure connected between the movable member and the second sleeve, and the movable member can elastically press the first convex portion toward the proximal end under the action of the elastic structure.

5. The syringe structure according to any one of claims 1 to 3, characterized in that: The first sleeve is sleeved on the outside of the second sleeve, the outer circumference of the second sleeve is provided with a second convex portion, the inner circumference of the first sleeve is provided with a third convex portion, and the second convex portion can abut against the third convex portion toward the distal end; Alternatively, the second sleeve is sleeved outside the first sleeve, a fourth convex portion is provided on the inner circumference of the second sleeve, a fifth convex portion is provided on the outer circumference of the first sleeve, and the fourth convex portion can abut against the fifth convex portion toward the distal end.

6. The syringe structure according to any one of claims 1 to 3, characterized in that: A sixth protrusion is provided on the inner circumference of the shell. When the first limiting member is limited to the distal end of the shell, the first sleeve is located at the proximal end of the sixth protrusion. The sixth protrusion is configured to press against the first sleeve toward the proximal end when the limiting relationship between the first limiting member and the shell is released and the first elastic member drives the first sleeve to move toward the distal end.

7. The syringe structure according to any one of claims 1 to 3, characterized in that: The syringe structure further includes an unlocking switch, the unlocking switch being provided on the housing and being configured to be movable relative to the housing to switch between a locked position and an unlocked position; The unlocking switch limits the driving structure at the locked position so that the driving structure and the housing are locked relative to each other; the unlocking switch unlocks the driving structure and the housing relative to each other in the unlocked position so that the driving structure can move toward the distal end.

8. The syringe structure according to claim 7, wherein: The driving structure is provided with a limiting groove; the unlocking switch includes a switch body and a locking portion provided on the switch body, the switch body is axially limited to the housing and can rotate relative to the housing to switch between the locked position and the unlocked position; when the unlocking switch is in the locked position, the locking portion is inserted into the limiting groove to limit the axial movement of the driving structure; when the unlocking switch is in the unlocking position, the locking portion is disengaged from the limiting groove to enable the driving structure to move axially relative to the housing.

9. An injection device, characterized in that: The invention comprises a syringe body and the syringe structure according to any one of claims 1 to 8, wherein the syringe body is assembled in the syringe structure.

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