Injection device

Abstract

The present application is applicable to the technical field of injectors, and provides an injection device. The injection device comprises a protective assembly. The protective assembly comprises a housing, a protective shell and a cap body, the protective shell is movably mounted in the housing and at least partially extends out of the proximal end of the housing, and the cap body is mounted at the proximal end of the housing. The cap body is provided with a first limiting structure, the protective shell is provided with a second limiting structure, and the cap body has a locked state in which the first limiting structure works in conjunction with the second limiting structure and restricts the second limiting structure from moving toward the distal end of the housing, and an unlocked state in which the first limiting structure moves to provide clearance for the second limiting structure. When the cap body in the unlocked state is removed from the protective shell, the protective shell can trigger the injection device by moving toward the distal end of the housing. The injection device provided by the present application can reduce the risk of accidental triggering of the protective shell when the injection device is dropped, and thus has high reliability and good user experience.

Description

Injection device Technical Field

[0001] This application belongs to the field of drug delivery device technology, and more specifically, relates to an injection device. Background Technology

[0002] In recent years, with rapid economic development and a rapid improvement in people's living standards, the medical and health issues of chronic non-communicable diseases such as psoriasis, arthritis, Crohn's disease, ulcerative colitis, rheumatoid arthritis, and ankylosing spondylitis have gradually received attention. Since most drugs for treating these chronic non-communicable diseases require single-dose injections and frequent injections, injection devices for administering these drugs have also developed rapidly.

[0003] Existing injection devices can generally be divided into simple disposable syringes, semi-automatic syringes, and fully automatic syringes. Simple disposable syringes often use an interference fit between the needle cap assembly and the syringe body to seal the injection needle assembly. The disadvantage of this design is that it is easy to prick the hand after using the needle cap, which may cause secondary infection. Semi-automatic and fully automatic syringes, on the other hand, mostly have a cap body connected to the triggering mechanism over the needle cap. Before using the syringe to inject, the needle cap assembly consisting of the needle cap and the cap body is removed. Then, the syringe is triggered by the triggering mechanism to start the drug injection. After the injection is completed, the protective cover automatically extends and locks, covering the needle tip. This method solves the problem of secondary infection.

[0004] However, existing semi-automatic and fully automatic injectors are prone to cap detachment due to accidental drops, vibrations, or other reasons when not injecting, which may trigger the protective cover and / or the injection, indirectly increasing the patient's usage costs and wasting resources. Summary of the Invention

[0005] The purpose of this application is to provide an injection device that solves the technical problems in the prior art where the cap structure of the injection device is easy to detach, leading to easy contamination of the syringe needle and easy accidental triggering of the injection device.

[0006] To achieve the above objectives, according to one aspect of this application, an injection device is provided, comprising: a protective component, the protective component including a housing, a protective shell, and a cap, the protective shell being movably installed within the housing and extending at least partially from the proximal end of the housing, the cap being installed at the proximal end of the housing; a first limiting structure is provided on the cap, and a second limiting structure is provided on the protective shell; the cap has a locked state in which the first limiting structure cooperates with the second limiting structure and restricts the movement of the second limiting structure toward the distal end of the housing, and an unlocked state in which the first limiting structure avoids the second limiting structure; when the cap is removed from the protective shell in the unlocked state, the protective shell can trigger the injection device by moving toward the distal end of the housing.

[0007] Optionally, a cap mounting portion is provided at the near end of the outer shell, and the cap is rotatably mounted on the cap mounting portion. The cap can switch between a locked state and an unlocked state by rotation. When the cap switches between the locked and unlocked states by rotation, an audible feedback is generated. A first rotation limiting structure is provided on the cap mounting portion, and a second rotation limiting structure is provided on the cap. Through the cooperation of the second rotation limiting structure and the first rotation limiting structure, the rotation stroke of the cap can be limited. When the cap is in the unlocked state, the cap can be removed from the near end of the outer shell by moving away from the outer shell.

[0008] Optionally, one of the first rotation limiting structure and the second rotation limiting structure is a limiting groove, and the other of the first rotation limiting structure and the second rotation limiting structure is a limiting rib. The limiting groove and the limiting rib are adapted to each other, and the rotation stroke of the cap can be limited by the cooperation of the limiting groove and the limiting rib.

[0009] Optionally, the limiting rib abuts against the limiting groove.

[0010] Optionally, a stop structure is provided in the limiting groove. The stop structure is used to divide the limiting groove into a locking groove segment and an unlocking groove segment. When the limiting rib slides between the locking groove segment and the unlocking groove segment, the stop structure can abut against the limiting rib to increase the rotational resistance of the cap.

[0011] Optionally, the width of the locking groove is the same as the width of the limiting rib.

[0012] Optionally, the cap body includes a cap body main body and a connecting post disposed within the cap body main body. The connecting post extends along the length direction of the cap body, and a first limiting structure is provided on the outer side wall of the connecting post, and a second limiting structure is provided on the inner side wall of the protective shell.

[0013] Optionally, the first limiting structure includes a first rib limiting portion disposed on the outer side wall of the connecting post and extending along the length direction of the connecting post; the second limiting structure includes a limiting protrusion disposed on the inner side wall of the protective shell and extending along the circumferential direction of the protective shell, wherein the first rib limiting portion can cooperate with the limiting protrusion to restrict the protective shell from moving to the far end of the outer shell.

[0014] Optionally, the limiting protrusion is provided with a clearance portion, which is used to make way for the first protruding rib limiting portion. During the assembly of the cap body with the outer shell and the protective shell, the proximal end of the first protruding rib limiting portion can pass through the clearance portion and abut against the distal end of the limiting protrusion after the cap body rotates in the first direction, so as to restrict the protective shell from moving to the distal end of the outer shell.

[0015] Optionally, the second limiting structure further includes a second rib limiting portion, which cooperates with the first rib limiting portion to limit the rotation of the cap body; the first rib limiting portion includes a first rib and a second rib, both of which are disposed on the outer side wall of the connecting post and extend along the length direction of the connecting post, the first rib and the second rib being spaced apart circumferentially along the connecting post; the second rib limiting portion includes a third rib, which is disposed on the inner side wall of the protective shell and extends along the length direction of the protective shell; the first rib cooperates with the third rib to limit the rotation of the cap body in a first direction, and the second rib cooperates with the third rib to limit the rotation of the cap body in a second direction; or, the first rib limiting portion includes a fourth rib, which is disposed on the outer side wall of the connecting post and extends along the length direction of the connecting post; the second rib limiting portion includes a fifth rib and a sixth rib, the fifth rib... Both the fifth and sixth ribs are disposed on the inner sidewall of the protective shell and extend along the length of the protective shell. The fifth and sixth ribs are spaced apart circumferentially along the protective shell. The fifth rib is used to cooperate with the fourth rib to restrict the cap body from rotating in the first direction, and the sixth rib is used to cooperate with the fourth rib to restrict the cap body from rotating in the second direction. Alternatively, the first rib limiting portion includes a seventh rib, which is disposed on the outer sidewall of the connecting post and extends along the length of the connecting post. The second rib limiting portion includes an eighth rib, which is disposed on the inner sidewall of the protective shell and extends along the length of the protective shell. One of the two opposite sidewalls of the eighth rib in the circumferential direction of the protective shell is used to cooperate with the seventh rib to restrict the cap body from rotating in the first direction. The other of the two opposite sidewalls of the eighth rib in the circumferential direction of the protective shell is used to cooperate with the seventh rib to restrict the cap body from rotating in the second direction.

[0016] Optionally, a bridging surface is formed at the distal end of the bridging structure between the connecting post and the cap body, and a notch is formed between the proximal end face of the first rib and the second rib and the bridging surface. When the cap body is in a locked state, the limiting protrusion is located within the notch.

[0017] Optionally, the height of the notch segment is equal to the width of the limiting protrusion.

[0018] Optionally, when the first rib limiting portion includes a first rib and a second rib, the clearance portion includes a first clearance opening and a second clearance opening. The second clearance opening is adjacent to a third rib in a first direction. The first clearance opening is used to clearance the first rib, and the second clearance opening is used to clearance the second rib. During the assembly of the cap body with the outer shell and the protective shell, the proximal ends of the first rib and the second rib can pass through the first clearance opening and the second clearance opening respectively, and abut against the distal end of the limiting protrusion after the cap body rotates in the first direction, thereby restricting the movement of the protective shell to the distal end of the outer shell. When the first rib limiting portion includes a fourth rib, the clearance portion includes a third clearance opening, which is adjacent to a sixth rib in a first direction. The third clearance opening is used to make way for the fourth rib. During the assembly of the cap body with the outer shell and the protective shell, the proximal end of the fourth rib can pass through the third clearance opening and abut against the distal end of the limiting protrusion after the cap body rotates in the first direction, so as to restrict the movement of the protective shell to the distal end of the outer shell. When the first rib limiting part includes the seventh rib, the clearance part includes the fourth clearance opening. The fourth clearance opening is adjacent to one side wall of the eighth rib in the first direction. The fourth clearance opening is used to make way for the seventh rib. During the assembly of the cap body with the outer shell and the protective shell, the proximal end of the seventh rib can pass through the fourth clearance opening and abut against the distal end of the limiting protrusion after the cap body rotates in the first direction, so as to restrict the movement of the protective shell to the distal end of the outer shell.

[0019] Optionally, the width of the first rib is different from the width of the second rib, the size of the first clearance opening is adapted to the width of the first rib, and the size of the second clearance opening is adapted to the width of the second rib.

[0020] Optionally, the injection device further includes a chamber assembly, which includes a chamber body, a gasket, and a syringe. The chamber body is movably installed within a protective housing, the syringe is installed within the chamber body, and the gasket is installed between the syringe and the chamber body. The injection device also includes a drive assembly, which is installed within the housing. The drive assembly has a avoidance state for avoiding the syringe and a push state for pushing the syringe to inject. When the drive assembly switches from the avoidance state to the push state, the chamber assembly buffers the impact between the syringe and the chamber body through the gasket.

[0021] Optionally, the syringe contains a medical product.

[0022] Optionally, the pharmaceutical product is a pharmaceutical formulation containing an active compound selected from one or more of insulin or its derivatives or analogs, GLP-1 compounds or their derivatives or analogs; preferably, the pharmaceutical formulation contains bofanglutide, or a pharmaceutically acceptable salt, amide or ester thereof.

[0023] According to another aspect of this application, an injection device is provided, the injection device including a protective component, the protective component including a housing, a protective shell, and a cap, the protective shell being movably installed inside the housing and extending at least partially from the proximal end of the housing, the cap being installed at the proximal end of the housing; a first limiting structure is provided on the cap, and a second limiting structure is provided on the protective shell, when the cap is installed at the proximal end of the housing and is in a locked state, the cooperation of the first limiting structure and the second limiting structure restricts the movement of the protective shell towards the distal end of the housing.

[0024] Optionally, the cap body includes a cap body main body and a connecting post disposed within the cap body main body. The connecting post extends along the length direction of the cap body, and a first limiting structure is provided on the outer side wall of the connecting post, and a second limiting structure is provided on the inner side wall of the protective shell.

[0025] Optionally, the first limiting structure includes a first rib limiting portion disposed on the outer side wall of the connecting post and extending along the length direction of the connecting post; the second limiting structure includes a limiting protrusion disposed on the inner side wall of the protective shell and extending along the circumferential direction of the protective shell, wherein the first rib limiting portion can cooperate with the limiting protrusion to restrict the protective shell from moving to the far end of the outer shell.

[0026] Optionally, the limiting protrusion is provided with a clearance portion, which is used to make way for the first protruding rib limiting portion. During the assembly of the cap body with the outer shell and the protective shell, the proximal end of the first protruding rib limiting portion can pass through the clearance portion and abut against the distal end of the limiting protrusion after the cap body rotates in the first direction, so as to restrict the protective shell from moving to the distal end of the outer shell.

[0027] Optionally, the second limiting structure further includes a second rib limiting portion, which is used to cooperate with the first rib limiting portion to limit the rotation of the cap body.

[0028] Optionally, the first rib limiting portion includes a first rib and a second rib, both of which are disposed on the outer side wall of the connecting post and extend along the length direction of the connecting post. The first rib and the second rib are spaced apart along the circumference of the connecting post. The second rib limiting portion includes a third rib, which is disposed on the inner side wall of the protective shell and extends along the length direction of the protective shell. The first rib is used to cooperate with the third rib to restrict the cap body from rotating in a first direction, and the second rib is used to cooperate with the third rib to restrict the cap body from rotating in a second direction.

[0029] Optionally, when the first rib limiting portion includes a first rib and a second rib, the clearance portion includes a first clearance opening and a second clearance opening. The second clearance opening is adjacent to the third rib in the first direction. The first clearance opening is used to make way for the first rib, and the second clearance opening is used to make way for the second rib. During the assembly of the cap body with the outer shell and the protective shell, the proximal ends of the first rib and the second rib can pass through the first clearance opening and the second clearance opening respectively, and after the cap body rotates in the first direction, it abuts against the distal end of the limiting protrusion to restrict the movement of the protective shell to the distal end of the outer shell.

[0030] The beneficial effects of the injection device provided in this application are as follows: Compared with the prior art, the injection device provided in this application, by setting a first limiting structure on the cap and a second limiting structure on the protective shell, enables the cap installed at the near end of the outer shell to restrict the movement of the protective shell to the far end of the outer shell through the cooperation of the first limiting structure and the second limiting structure. This reduces the risk of the protective shell being accidentally triggered when the injection device is dropped, when the injection device is not in use, i.e., when the protective shell does not trigger the injection device. This effectively improves the reliability of the injection device provided in this application and enhances the user experience. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 is a schematic diagram of the injection device provided in an embodiment of this application;

[0033] Figure 2 is a schematic diagram of the injection device from another perspective provided in an embodiment of this application;

[0034] Figure 3 is an explosion diagram of the injection device provided in an embodiment of this application;

[0035] Figure 4 is a schematic diagram of the structure of the outer shell provided in an embodiment of this application;

[0036] Figure 5 is a schematic diagram of the outer shell from another perspective provided in an embodiment of this application;

[0037] Figure 6 is a structural schematic diagram of the cap body provided in an embodiment of this application;

[0038] Figure 7 is a schematic diagram of the cap body from another perspective provided in an embodiment of this application;

[0039] Figure 8 is a schematic diagram of the structure of the protective shell provided in an embodiment of this application;

[0040] Figure 9 is a schematic diagram of the protective shell from another perspective provided in an embodiment of this application;

[0041] Figure 10 is a magnified view of a portion of region A in Figure 9;

[0042] Figure 11 is a schematic diagram of the structure of the gasket provided in the embodiment of this application;

[0043] Figure 12 is a schematic diagram of the structure of the drug chamber body provided in the embodiment of this application;

[0044] Figure 13 is a schematic diagram of the structure of the drug chamber body from another perspective provided in an embodiment of this application;

[0045] Figure 14 is a schematic diagram of the syringe provided in an embodiment of this application;

[0046] Figure 15 is a perspective view of the syringe provided in an embodiment of this application;

[0047] Figure 16 is a schematic diagram of the top cap provided in an embodiment of this application;

[0048] Figure 17 is a schematic diagram of the drive rod provided in an embodiment of this application;

[0049] Figure 18 is a cross-sectional schematic diagram of the drive rod provided in an embodiment of this application;

[0050] Figure 19 is a schematic diagram of the structure of the drive spring provided in an embodiment of this application;

[0051] Figure 20 is a schematic diagram of the small push rod provided in an embodiment of this application;

[0052] Figure 21 is a schematic diagram of the push rod spring provided in an embodiment of this application;

[0053] Figure 22 is a schematic diagram of the structure of the large push rod provided in an embodiment of this application;

[0054] Figure 23 is a cross-sectional schematic diagram of the large push rod provided in the embodiment of this application;

[0055] Figure 24 is a schematic diagram of the push rod drive component provided in an embodiment of this application;

[0056] Figure 25 is a cross-sectional schematic diagram of the push rod drive component provided in an embodiment of this application;

[0057] Figure 26 is a schematic diagram of the push handle provided in an embodiment of this application;

[0058] Figure 27 is a schematic diagram of the pre-injection device provided in an embodiment of this application;

[0059] Figure 28 is a schematic diagram of the structure of the injection device provided in the embodiment of this application, in which the triggering component is in the second state but injection has not started;

[0060] Figure 29 is a schematic diagram of the structure of the injection device provided in the embodiment of this application;

[0061] Figure 30 is a schematic diagram of the structure of the injection device after injection is completed according to an embodiment of this application;

[0062] Figure 31 is a schematic diagram of the structure of the injection device provided in the embodiment of this application, in which the injection is completed and the protective shell extends from the proximal end of the injection device;

[0063] Figure 32 is a cross-sectional schematic diagram of the injection device before injection provided in an embodiment of this application;

[0064] The details of the reference numerals used in the above figures are as follows:

[0065] 10. Protection components;

[0066] 11. Outer shell; 111. Cap mounting part; 1111. Limiting groove; 11111. Locking groove section; 11112. Unlocking groove section; 1112. Stopping structure; 112. Mounting protrusion; 113. Unlocking mark; 114. First limiting rib; 115. Second snap-fit ​​structure; 116. First limiting platform;

[0067] 12. Protective shell; 121. Limiting protrusion; 1211. First clearance opening; 1212. Second clearance opening; 122. Third protruding rib; 123. First cylindrical body; 1231. Tapered cylinder; 1232. Viewing window groove; 12321. First limiting surface; 124. Second snap-fit ​​structure;

[0068] 13. Hat body; 131. Hat body main body; 1311. Limiting rib; 1312. Indicator mark; 1313. Direction mark; 1314. Anti-slip strip; 132. Connecting post; 1321. First inner hole; 133. First rib; 134. Second rib; 135. Bridging surface;

[0069] 20. Pharmacy chamber components;

[0070] 21. Medicine chamber body; 211. First stepped surface; 212. First cylindrical body; 2121. Guide limiting protrusion; 213. Fourth snap-fit ​​structure; 214. Protrusion mounting groove;

[0071] 22. Washer; 221. Hollow body; 2211. Clearance hole; 222. Mounting protrusion;

[0072] 23. Syringe; 231. Medicine cartridge; 232. Rubber stopper; 233. Needle cap;

[0073] 30. Driver components;

[0074] 31. Top cap; 311. Top cap body; 3111. Annular boss; 31111. First snap-fit ​​position; 312. Arc boss; 313. First snap-fit ​​structure;

[0075] 32. Drive rod; 321. Round cap structure; 322. First snap-fit ​​structure; 323. Mounting rib; 3231. Second limiting surface; 3232. First spring contact surface; 324. Spring arm; 325. Circumferential snap-fit; 326. Inner groove surface;

[0076] 33. Drive spring;

[0077] 34. Push rod drive component; 341. Second main body cylinder; 3411. Mounting through hole; 3412. Limiting rib; 342. Relief notch; 3421. Notch surface; 343. First snap-fit ​​surface; 344. Second spring abutment surface;

[0078] 35. Small push rod; 351. First push rod truncated cone; 352. First support rod;

[0079] 36. Large push rod; 361. First main body cylinder; 3611. Guide hole; 36111. Third spring contact surface; 362. Annular groove; 3621. First locking surface; 3622. Second locking surface;

[0080] 37. Push rod spring;

[0081] 38. Push handle; 381. Main ring; 382. Ring spring buckle; 3821. Third buckle structure; 383. First mounting hole; 384. Third snap-fit ​​surface. Detailed Implementation

[0082] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0083] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly or indirectly on that other element. When an element is referred to as being "connected to" another element, it can be directly or indirectly connected to that other element. Unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0084] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0085] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0086] It should be noted that, in this application, "distal" refers to the end furthest from the injection site, while "proximal" refers to the end closest to the injection site.

[0087] As described in the background section, in recent years, with rapid economic development and a rapid improvement in people's living standards, the medical and health issues of chronic non-communicable diseases such as psoriasis, arthritis, Crohn's disease, ulcerative colitis, rheumatoid arthritis, and ankylosing spondylitis have gradually received attention. Since most medications for treating these chronic non-communicable diseases require single-dose injections and frequent administration, injection devices for administering these drugs have also developed rapidly. Existing injection devices can generally be divided into simple disposable syringes, semi-automatic syringes, and fully automatic syringes. Simple disposable syringes often use an interference fit between the needle cap assembly and the syringe body to seal the injection needle assembly. The disadvantage of this design is that removing the needle cap after use can easily cause hand injuries and potentially secondary infections. Semi-automatic and fully automatic syringes, on the other hand, mostly use a cap body connected to a trigger mechanism over the needle cap. Before injection, the needle cap assembly (comprising the needle cap and cap body) is removed, and then the syringe is triggered by the trigger mechanism to begin drug injection. After injection, the protective cover automatically extends and locks, covering the needle tip. This method solves the problem of secondary infection. However, existing semi-automatic and fully automatic injectors are prone to cap detachment due to accidental drops, vibrations, or other reasons when not injecting, which may trigger the protective cover and / or the injection, indirectly increasing the cost of use for patients and wasting resources.

[0088] Referring to Figures 1 to 31, in order to solve the above-mentioned problems, according to one aspect of this application, an embodiment of this application provides an injection device, which includes: a protective component 10, the protective component 10 including a housing 11, a protective shell 12, and a cap 13, the protective shell 12 being movably installed inside the housing 11 and extending at least partially from the proximal end of the housing 11, the cap 13 being installed at the proximal end of the housing 11; a first limiting structure is provided on the cap 13, and a second limiting structure is provided on the protective shell 12, the cap 13 having a locked state in which the first limiting structure cooperates with the second limiting structure and limits the movement of the second limiting structure toward the distal end of the housing 11, and an unlocked state in which the first limiting structure avoids the second limiting structure; when the cap 13 in the unlocked state is moved off the protective shell 12, the protective shell 12 can trigger the injection device by moving toward the distal end of the housing 11. The injection device has a first limiting structure on the cap 13 and a second limiting structure on the protective shell 12. This allows the cap 13, which is installed near the outer shell 11, to restrict the movement of the protective shell 12 to the far end of the outer shell 11 through the cooperation of the first and second limiting structures. This reduces the risk of the protective shell being accidentally triggered when the injection device is dropped, even when the injection device is not in use, i.e., when the protective shell 12 does not trigger the injection device. This effectively improves the reliability of the injection device and enhances the user experience.

[0089] In one alternative embodiment, the outer casing 11 is cylindrical, specifically, it can be a cylindrical or polygonal cylindrical shape.

[0090] In an alternative embodiment, the proximal end of the protective shell 12 extends at least partially from the proximal end of the outer shell 11.

[0091] Referring to Figures 4, 5, 8, 9 and 10, in one optional embodiment, a first limiting rib 114 is provided on the inner sidewall of the outer shell 11, and a viewing window groove 1232 is provided on the sidewall of the protective shell 12. A first limiting surface 12321 is provided at the far end of the viewing window groove 1232. When the protective shell 12 moves towards the proximal end of the outer shell 11, the outer shell 11 can abut against the first limiting surface 12321 through the first limiting rib 114 to limit the movement of the protective shell 12.

[0092] Referring to Figures 4 to 7, in one specific embodiment, the near end of the outer shell 11 is provided with a cap mounting portion 111, and the cap 13 is rotatably mounted on the cap mounting portion 111. The cap 13 can switch between a locked state and an unlocked state by rotation. A first rotation limiting structure is provided on the cap mounting portion 111, and a second rotation limiting structure is provided on the cap 13. Through the cooperation of the second rotation limiting structure and the first rotation limiting structure, the rotational stroke of the cap 13 can be limited. When the cap 13 is in the unlocked state, the cap 13 can be removed from the near end of the outer shell 11 by moving away from the outer shell 11. By providing a first rotation limiting structure on the cap mounting portion 111 and a second rotation limiting structure on the cap 13, the rotational stroke of the cap 13, which is rotatably mounted on the cap mounting portion 111, can be limited through the cooperation of the first and second rotation limiting structures.

[0093] In one specific embodiment, one of the first and second rotational limiting structures is a limiting groove 1111, and the other is a limiting rib 1311. The limiting groove 1111 and the limiting rib 1311 are adapted to each other. Through the cooperation of the limiting groove 1111 and the limiting rib 1311, the rotational stroke of the cap 13 can be limited. With this arrangement, the rotational stroke of the cap 13 can be limited by the cooperation of the limiting groove 1111 and the limiting rib 1311.

[0094] Referring to Figures 4 to 7, in a specific embodiment, a stop structure 1112 is provided in the limiting groove 1111. The stop structure 1112 is used to divide the limiting groove 1111 into a locking groove segment 11111 and an unlocking groove segment 11112. When the limiting rib 1311 slides between the locking groove segment 11111 and the unlocking groove segment 11112, the stop structure 1112 can abut against the limiting rib 1311 to increase the rotational resistance of the cap 13. By setting a stop structure 1112 in the limiting groove 1111, the limiting groove 1111 can be divided into a locking groove section 11111 and an unlocking groove section 11112 by the stop structure 1112. When the limiting rib 1311 is located in the locking groove section 11111, the limiting rib 1311 can slide towards the unlocking groove section 11112 during the process of the cap 13 switching from the locked state to the unlocked state, and abut against the stop structure 1112, thereby increasing the resistance encountered by the cap 13 when rotating, and preventing the cap 13 in the locked state from switching from the locked state to the unlocked state when falling, thereby reducing the risk of the cap 13 falling off and the protective shell 12 being accidentally triggered, effectively improving the reliability of the injection device and enhancing the user experience. Meanwhile, the stop structure 1112 ensures that during assembly and before injection, when installing the cap 13, the installer or user experiences a feeling of increased resistance followed by decreased resistance as the limiting rib 1311 enters the locking groove 11111 via the stop structure 1112. There is also audible feedback from the engagement of the two parts, making installation and locking clearer and more convenient. Preferably, the width of the locking groove 11111 is only the width to accommodate the limiting rib 1311, ensuring that the cap 13 has no rotational play during locking, resulting in a more secure fit.

[0095] In an optional embodiment, after the cap body 13 switches from the locked state to the unlocked state, the limiting rib 1311 is located in the unlocking groove 11112 and corresponds to the end of the unlocking groove 11112 that is away from the locking groove 11111.

[0096] In one optional embodiment, the end of the unlocking groove 11112 away from the locking groove 11111 is the rotation end of the cap 13, i.e. the unlocking end. When the cap 13 is in the unlocked state, the limiting rib 1311 is located at the rotation end of the unlocking groove 11112.

[0097] In an optional embodiment, the limiting rib 1311 can abut against the limiting groove 1111. Through the frictional resistance between the limiting rib 1311 and the limiting groove 1111, the cap body 13 can remain fixed in the circumferential direction of the outer shell 11 without being subjected to external force.

[0098] In an optional embodiment, the distal end of the cap mounting portion 111 is provided with a mounting protrusion 112, which is used to engage with the cap body 13 or to have an interference fit with the cap body 13, thereby locking the cap body 13 in the axial direction. When the mounting protrusion 112 engages with the cap body 13 or has an interference fit with the cap body 13, the distal end face of the mounting protrusion 112 is parallel to the distal end face of the cap body 131.

[0099] In an alternative embodiment, the mounting protrusion 112 is an annular protrusion extending circumferentially along the housing 11.

[0100] Referring to Figures 6 and 7, in one specific embodiment, the cap 13 includes a cap body 131 and a connecting post 132 disposed within the cap body 131. The connecting post 132 extends along the length of the cap 13 and is used to install a needle cap. By confining the needle cap within the connecting post 132, the needle cap can be separated from the needle inside the syringe when the cap is pulled out. A first limiting structure is provided on the outer side wall of the connecting post 132, and a second limiting structure is provided on the inner side wall of the protective shell 12. By providing a connecting post 132 extending along the length of the cap 13 within the cap body 131, and by providing the first limiting structure on the outer side wall of the connecting post 132 and the second limiting structure on the inner side wall of the protective shell 12, the cap 13 can be restricted from moving towards the distal end of the outer shell 11 through the cooperation of the first limiting structure and the second limiting structure of the protective shell 12. In an alternative embodiment, the distal end of the engagement post 132 may at least partially penetrate within the protective housing 12.

[0101] In one alternative embodiment, the connecting post 132 is coaxially arranged with the cap body 131.

[0102] In one alternative embodiment, the main body 131 of the cap is cylindrical.

[0103] In an alternative embodiment, the distal end of the connecting post 132 extends at least partially beyond the distal end of the cap body 131.

[0104] In an optional embodiment, a bridging structure is provided between the connecting post 132 and the cap body 131. By providing a bridging structure between the connecting post 132 and the cap body 131, the stress between the connecting post 132 and the cap body 131 can be reduced, thereby improving the structural stability of the cap body 13.

[0105] In an optional embodiment, an indicator mark 1312 is provided on the outer side wall of the cap body 131, and an unlock mark 113 is provided on the near-end outer side wall of the outer shell 11. When the cap body 13 is in the unlocked state, the position of the indicator mark 1312 corresponds to the position of the unlock mark 113, thereby indicating to the user that the cap body 13 has been unlocked. At the same time, the indicator mark 1312 and the unlock mark 113 can also be used as positioning marks during the production and assembly process.

[0106] In one optional embodiment, an anti-slip strip 1314 is provided on the outer side wall of the hat body 131, which can increase the friction when the user twists the hat body 13.

[0107] In an optional embodiment, the anti-slip strip 1314 and the indicator mark 1312 are spaced apart on the outer side wall of the hat body 131. When the user pinches the hat body 13 through the anti-slip strip 1314, the indicator mark 1312 can be exposed, so that the user can easily confirm the status of the hat body 13.

[0108] In an optional embodiment, the anti-slip strip 1314 is a structure that facilitates the rotation of the hat body 13. For example, an axially recessed structure is provided on the outer side wall of the hat body 131, and anti-slip stripes are provided on the recessed structure to form the anti-slip strip 1314.

[0109] Referring to Figures 6 to 9, in one specific embodiment, the first limiting structure includes a first rib limiting portion disposed on the outer side wall of the connecting post 132 and extending along the length direction of the connecting post 132; the second limiting structure includes a limiting protrusion 121 disposed on the inner side wall of the protective shell 12 and extending circumferentially along the protective shell 12. The first rib limiting portion can cooperate with the limiting protrusion 121 to restrict the movement of the protective shell 12 towards the distal end of the outer shell 11. By providing a first rib limiting portion extending along the length direction of the connecting post 132 on the outer side wall of the connecting post 132 and a limiting protrusion 121 extending circumferentially along the inner side wall of the protective shell 12, the injection device can restrict the movement of the protective shell 12 towards the distal end of the outer shell 11 through the cooperation of the first rib limiting portion and the limiting protrusion 121.

[0110] Referring to Figures 6 to 9, in a specific embodiment, the limiting protrusion 121 in this embodiment is provided with a clearance portion, which is used to make way for the first protruding rib limiting portion. During the assembly of the cap 13 with the outer shell 11 and the protective shell 12, the proximal end of the first protruding rib limiting portion can pass through the clearance portion and abut against the distal end of the limiting protrusion 121 after the cap 13 rotates in the first direction, so as to restrict the protective shell 12 from moving to the distal end of the outer shell 11. By providing a clearance portion on the limiting protrusion 121, the outer shell 11 can make way for the first protruding rib limiting portion during the process of installing the cap body 13 onto the cap body mounting portion 111. This allows the first protruding rib limiting portion to pass through the limiting protrusion 121 on the side of the limiting protrusion 121 away from the cap body 13 along the length direction of the outer shell 11. At this time, rotating the cap body 13 in the first direction will cause the side of the limiting protrusion 121 away from the cap body 13 along the length direction of the outer shell 11 to abut against the first protruding rib limiting portion, thereby restricting the protective shell 12 from moving to the distal end of the outer shell 11. At the same time, the clearance portion can also make way for the first protruding rib limiting portion when unlocking and removing the cap body.

[0111] In one specific embodiment, the first direction is the rotation direction of the cap 13 when it switches from the unlocked state to the locked state.

[0112] Referring to Figures 6 to 9 and Figure 32, in one specific embodiment, the second limiting structure further includes a second rib limiting portion, which cooperates with the first rib limiting portion to restrict the rotation of the cap body. The first rib limiting portion includes a first rib 133 and a second rib 134, both of which are disposed on the outer side wall of the connecting post 132 and extend along the length of the connecting post 132. The first rib 133 and the second rib 134 are spaced apart circumferentially along the connecting post 132. The second rib limiting portion includes a third rib 122, which is disposed on the inner side wall of the protective shell 12 and extends along the length of the protective shell 12. The first rib 133 cooperates with the third rib 122 to restrict the rotation of the cap body 13 in the first direction. The rib 134 is used to cooperate with the third rib 122 to restrict the cap body 13 from rotating in the second direction. When the cap body is installed in the cap body mounting part, the cooperation between the first rib 133 and / or the second rib 134 and the limiting protrusion 121 can restrict the protective shell 12 from moving to the distal end of the outer shell 11. The cooperation between the first rib 133 and the third rib 122 can restrict the cap body 13 from rotating in the first direction. The cooperation between the second rib 134 and the third rib 122 can restrict the cap body 13 from rotating in the second direction. Furthermore, when the cap body is installed in the cap body mounting part, the third rib 122 and the first rib 133 and / or the second rib 134 at least partially overlap in the axial direction of the injection device so that the third rib 122 can abut against the first rib 133 and / or the second rib 134.

[0113] In one specific embodiment, the second direction is the rotation direction of the cap 13 when it switches from the locked state to the unlocked state.

[0114] In one specific embodiment, when the limiting rib 1311 is located in the locking groove 11111 and the cap 13 is in a locked state by being screwed along the first direction, the side wall of the first rib 133 can abut against the side wall of the third rib 122, thereby restricting the cap 13 from continuing to rotate along the first direction.

[0115] In another embodiment, the first rib limiting portion includes a fourth rib, which is disposed on the outer side wall of the connecting post and extends along the length direction of the connecting post. The second rib limiting portion includes a fifth rib and a sixth rib, both of which are disposed on the inner side wall of the protective shell 12 and extend along the length direction of the protective shell 12. The fifth rib and the sixth rib are spaced apart circumferentially along the protective shell 12. The fifth rib is used to cooperate with the fourth rib to restrict the cap body 13 from rotating in a first direction, and the sixth rib is used to cooperate with the fourth rib to restrict the cap body 13 from rotating in a second direction. When the cap body is installed in the cap body mounting portion, the fourth rib is located between the fifth rib and the sixth rib. The fourth rib and the fifth rib and / or the sixth rib at least partially overlap in the axial direction of the injection device, so that the fourth rib can abut against the fifth rib and / or the sixth rib.

[0116] In another embodiment, the first rib limiting portion includes a seventh rib, which is disposed on the outer side wall of the connecting post and extends along the length direction of the connecting post. The second rib limiting portion includes an eighth rib, which is disposed on the inner side wall of the protective shell 12 and extends along the length direction of the protective shell 12. One of the two opposing side walls of the protective shell 12 in the circumferential direction is used to cooperate with the seventh rib to limit the rotation of the cap 13 in a first direction; the other of the two opposing side walls of the protective shell 12 in the circumferential direction is used to cooperate with the seventh rib to limit the rotation of the cap 13 in a second direction. When the cap is mounted on the cap mounting portion, the seventh rib is located between the two opposing side walls of the protective shell 12 in the circumferential direction, and the seventh rib and the eighth rib at least partially overlap in the axial direction of the injection device so that the seventh rib can abut against the eighth rib.

[0117] In one specific embodiment, where the first rib limiting portion includes a first rib 133 and a second rib 134, the clearance portion includes a first clearance opening 1211 and a second clearance opening 1212. The second clearance opening 1212 is adjacent to the third rib 122 in a first direction. The first clearance opening 1211 is used to clearance the first rib 133, and the second clearance opening 1212 is used to clearance the second rib 134. During the assembly of the cap body 13 with the outer shell 11 and the protective shell 12, the first rib 133 and... The proximal end of the second rib 134 can pass through the first clearance opening 1211 and the second clearance opening 1212 respectively, and after the cap body 13 rotates in the first direction, it abuts against the distal end of the limiting protrusion 121 to restrict the protective shell 12 from moving to the distal end of the outer shell 11; wherein, the first clearance opening 1211 and the second clearance opening 1212 connect the two opposite sides of the limiting protrusion 121 in the axial direction of the injection device, and when the cap body rotates to the side of the first rib 133 and the third rib 122 abut against each other, the limiting rib 1311 is located in the locking groove section 11111. By providing a first clearance opening 1211 and a second clearance opening 1212 on the limiting protrusion 121, the protective shell 12 can make way for the first protruding rib 133 and the second protruding rib 134 respectively through the first clearance opening 1211 and the second clearance opening 1212 during the process of installing the cap body 13 onto the cap body mounting part 111. This allows the first protruding rib 133 and the second protruding rib 134 to pass through the limiting protrusion 121 on the side of the outer shell 11 away from the cap body 13 along the length direction. If the cap body is rotated in the first direction, the side of the limiting protrusion 121 away from the cap body 13 along the length direction of the outer shell 11 can abut against the first protruding rib 133 and the second protruding rib 134 respectively, thereby restricting the movement of the protective shell 12 to the far end of the outer shell 11.

[0118] In one specific embodiment, during the assembly or unlocking of the cap 13 with the outer shell 11 and the protective shell 12, the proximal end of the second protruding rib 134 can penetrate or disengage from the second clearance opening 1212. Since the second clearance opening 1212 is adjacent to the third protruding rib 122 in the first direction, after the second protruding rib 134 is inserted, the cap 13 can only rotate in the first direction. After the cap 13 rotates, the second protruding rib 134 can abut against the distal end of the limiting protrusion 121 to restrict the protective shell 12 from moving to the distal end of the outer shell 11.

[0119] In one specific embodiment, when the limiting rib 1311 is located in the unlocking groove 11112 and is screwed to the unlocked state in the second direction, the side wall of the second rib 134 can abut against the side wall of the third rib 122, thereby restricting the cap 13 from continuing to rotate in the second direction.

[0120] In an optional embodiment, when the cap body 13 is installed on the cap body mounting part 111, the distal surfaces of the first protruding rib 133 and the second protruding rib 134 are located on the side away from the cap body body 131 in the distal direction of the cap body body 131.

[0121] In an alternative embodiment, after the cap body is installed, the first rib 133 and the second rib 134 are located on both sides of the third rib 122, respectively.

[0122] In an optional embodiment, a bridging surface 135 is formed at the distal end of the bridging structure between the connecting post 132 and the cap body 131. A notch is formed between the proximal end faces of the first rib 133 and the second rib 134 and the bridging surface 135. When the cap body 13 is in the locked state, the limiting protrusion 121 is located within the notch. It should be noted that the height of the notch is equal to the width of the limiting protrusion 121 to prevent the protective shell from moving axially within the notch.

[0123] It should be noted that, for ease of molding, the bridging surface 135 corresponding to the notch is also set as an axial notch.

[0124] In an optional embodiment, the outer wall of the cap body 131 provided in this embodiment is provided with a direction mark 1313. The direction mark 1313 is formed by an arrow-shaped protrusion or recess provided on the outer wall of the cap body 131. The direction indicated by the direction mark 1313, that is, the direction indicated by the arrow structure, is the second direction, which is used to indicate the rotation direction of the cap body 13 when unlocking to the user.

[0125] In an optional embodiment, during the process of mounting the cap body 13 onto the cap body mounting portion 111, the distal end face of the limiting protrusion 121 provided in this embodiment can be parallel to and in contact with the proximal end face of the first protrusion 133 and the proximal end face of the second protrusion 134.

[0126] In an optional embodiment, when the cap body 13 is mounted on the cap body mounting part 111, the proximal end face of the first protruding rib 133 and the proximal end face of the second protruding rib 134 slide in contact with the distal end face of the limiting protrusion 121. During the state switching process of the cap body 13, the proximal end face of the first protruding rib 133 and the proximal end face of the second protruding rib 134 can slide on the distal end face of the limiting protrusion 121.

[0127] In one optional embodiment, the width of the first rib 133 is different from the width of the second rib 134, the size of the first clearance opening 1211 is adapted to the width of the first rib 133, and the size of the second clearance opening 1212 is adapted to the width of the second rib 134. By setting the widths of the first rib 133 and the second rib 134 to be different, and making the size of the first clearance opening 1211 adapted to the width of the first rib 133, and the size of the second clearance opening 1212 adapted to the width of the second rib 134, it is possible to prevent the assembler from forcibly assembling the cap body 13 in an incorrect manner. If the cap body 13 is forcibly assembled, it will be impossible to assemble the cap body 13 because the width of the first rib 133 does not match the size of the second clearance opening 1212, and the width of the second rib 134 does not match the size of the first clearance opening 1211.

[0128] In one alternative embodiment, the first rib 133 and the second rib 134 are arranged in a group.

[0129] In one optional embodiment, the first rib limiting portion includes multiple sets of first ribs 133 and second ribs 134, and the second rib limiting portion includes multiple third ribs 122. The limiting protrusion 121 is provided with multiple first clearance openings 1211 and multiple second clearance openings 1212. The multiple sets of first ribs 133 and second ribs 134 are arranged at intervals along the circumference of the connecting post 132. The multiple third ribs 122 correspond one-to-one with the multiple sets of first ribs 133 and second ribs 134. The multiple first clearance openings 1211 correspond one-to-one with the multiple first ribs 133, and the multiple second clearance openings 1212 correspond one-to-one with the multiple second ribs 134.

[0130] In one optional embodiment, the first rib limiting portion includes two sets of first ribs 133 and second ribs 134, and the second rib limiting portion includes two third ribs 122. The limiting protrusion 121 is provided with two first clearance openings 1211 and two second clearance openings 1212. The two sets of first ribs 133 and second ribs 134 are arranged at intervals along the circumference of the connecting post 132. The two third ribs 122 correspond one-to-one with the two sets of first ribs 133 and second ribs 134. The two first clearance openings 1211 correspond one-to-one with the two first ribs 133, and the two second clearance openings 1212 correspond one-to-one with the two second ribs 134.

[0131] In one specific embodiment, when the cap body 13 is in the unlocked state, the position of the first protruding rib 133 is axially aligned with the position of the first clearance opening 1211, and the position of the second protruding rib 134 is axially aligned with the position of the second clearance opening 1212. At this time, moving the cap body 13 away from or into the outer shell 11 can axially separate the cap body 13 from the protective shell 12 or screw it in and lock it after assembly.

[0132] In one optional embodiment, a direction mark 1313 is provided on the outer side wall of the cap body 131. The direction indicated by the direction mark 1313 is a second direction, which is used to indicate to the user the rotation direction when the cap body 13 is unlocked.

[0133] In another embodiment, the first rib limiting portion includes a fourth rib, and the clearance portion includes a third clearance opening. The third clearance opening is adjacent to the sixth rib in the first direction and is used to clearance the fourth rib. During the assembly of the cap 13 with the outer shell 11 and the protective shell 12, the proximal end of the fourth rib can pass through the third clearance opening and abut against the distal end of the limiting protrusion after the cap 13 rotates in the first direction, thereby restricting the movement of the protective shell 12 towards the distal end of the outer shell 11. In this embodiment, during the assembly or unlocking of the cap 13 with the outer shell 11 and the protective shell 12, the proximal end of the fourth rib can enter or exit the third clearance opening. Since the third clearance opening is adjacent to the sixth rib in the first direction, after the fourth rib enters, the cap 13 can only rotate in the first direction. After the cap 13 rotates, the fourth rib can abut against the distal end of the limiting protrusion 121, thereby restricting the movement of the protective shell 12 towards the distal end of the outer shell 11.

[0134] In one alternative embodiment, the fifth rib and the sixth rib are arranged in a group.

[0135] In one optional embodiment, the first rib limiting portion includes a plurality of fourth ribs, the second rib limiting portion includes a plurality of sets of fifth ribs and sixth ribs, and the limiting protrusion is provided with a plurality of third clearance openings. The plurality of fourth ribs are arranged at intervals along the circumference of the connecting column, the plurality of sets of fifth ribs and sixth ribs correspond one-to-one with the plurality of fourth ribs, and the plurality of third clearance openings correspond one-to-one with the plurality of fourth ribs.

[0136] In one optional embodiment, the first rib limiting portion includes two fourth ribs, and the second rib limiting portion includes two sets of fifth and sixth ribs. Two third clearance openings are provided on the limiting protrusion. The two fourth ribs are spaced apart circumferentially along the connecting post. The two sets of fifth and sixth ribs correspond one-to-one with the two fourth ribs, and the two third clearance openings correspond one-to-one with the two fourth ribs. In another embodiment, the first rib limiting portion includes a seventh rib, and the clearance portion includes a fourth clearance opening. The fourth clearance opening is adjacent to the sidewall of the eighth rib, which cooperates with the seventh rib to restrict the cap 13 from rotating in the second direction, in the first direction. The fourth clearance opening is used to make way for the seventh rib. During the assembly of the cap 13 with the outer shell 11 and the protective shell 12, the proximal end of the seventh rib can pass through the fourth clearance opening and abut against the distal end of the limiting protrusion after the cap 13 rotates in the first direction, thereby restricting the protective shell 12 from moving towards the distal end of the outer shell 11. In this embodiment, during the assembly or unlocking of the cap body 13 with the outer shell 11 and the protective shell 12, the proximal end of the seventh protruding rib can penetrate or disengage from the fourth clearance opening. Since the fourth clearance opening is adjacent to the side wall of the eighth protruding rib in the first direction, which cooperates with the seventh protruding rib to restrict the rotation of the cap body 13 in the second direction, the seventh protruding rib can make the cap body 13 rotate only in the first direction after it is inserted. After the cap body 13 rotates, the seventh protruding rib can abut against the distal end of the limiting protrusion 121 to restrict the movement of the protective shell 12 towards the distal end of the outer shell 11.

[0137] Referring to Figures 6 to 9, in one specific embodiment, the limiting protrusion 121 in this embodiment is provided with a first clearance opening 1211. The first clearance opening 1211 is used to make way for the first protruding rib 133. During the assembly of the cap 13 with the outer shell 11 and the protective shell 12, the proximal end of the first protruding rib 133 can pass through the first clearance opening 1211. After the cap 13 rotates along the first direction, it abuts against the distal end of the limiting protrusion 121 to restrict the protective shell 12 from moving toward the distal end of the outer shell 11.

[0138] In an optional embodiment, when the limiting rib 1311 is located within the unlocking groove 11112 and the cap 13 is rotated in the first direction in the unlocked state, the limiting rib 1311 will contact the stop structure 1112 as the cap 13 is rotated, and an interference fit will be generated in the radial direction of the injection device. At this time, the rotation resistance of the cap 13 increases. When the limiting rib 1311 rotates past the stop structure 1112 as the cap 13 is rotated, a "click" sound and a sudden decrease in rotation resistance will occur as feedback. At this time, the limiting rib 1311 moves into the locking groove 11111. At the same time, the first rib 133 axially contacts the first clearance opening 1211. The second rib 134 is rotated from its axial position to a position where it is restricted from moving toward the far end of the outer shell 11 by the limiting protrusion 121 and is restricted from continuing to rotate in the first direction by one side wall of the third rib 122. The second rib 134 is rotated from its axial position corresponding to the position of the second clearance opening 1212 to a position where it is restricted from moving toward the far end of the outer shell 11 by the limiting protrusion 121 and avoids the third rib 122. When the injection device falls, it will not cause the cap 13 to rotate and fall off, and it will not cause the protective shell 12 to trigger the injection device due to the cap 13 falling off. At the same time, it will not cause the protective shell 12 to vibrate due to the injection device falling and trigger the injection device. When the limiting rib 1311 is located within the locking groove 11111 and the cap 13 needs to be switched from the locked state to the unlocked state, the user can rotate the cap 13 in the direction indicated by the direction mark 1313, that is, rotate the cap 13 in the second direction. The limiting rib 1311 will move into the unlocking groove 11112 after passing the stop structure 1112, and can then continue to rotate to the end of the rotation of the unlocking groove 11112, that is, the unlocking end. At the same time, the first rib 133, which was restricted by the limiting protrusion 121 to move towards the far end of the outer shell 11 and was restricted by the side wall of the third rib 122 to continue rotating in the first direction, rotates to the position where it is axially aligned with the first clearance opening 1211. At the corresponding position, the second rib 134, which was restricted by the limiting protrusion 121 from moving towards the far end of the outer shell 11 and avoiding the third rib 122, rotates to a position axially corresponding to the second clearance opening 1212; thereby allowing the first rib 133 and the second rib 134 on the cap 13 to disengage from the protective shell 12 and the outer shell 11 respectively through the first clearance opening 1211 and the second clearance opening 1212, and when the limiting rib 1311 rotates to the end of the rotation of the unlocking groove section 11112, the other side wall of the third rib 122 will abut against the side wall of the second rib 134, thus also restricting the cap 13 from further rotating in the second direction. At this time, the indicator mark 1312 of the cap 13 is aligned with the unlocking mark 113 of the outer shell 11, and the cap 13 switches from the locked state to the unlocked state.

[0139] Referring to Figures 3 and 11 to 31, in one specific embodiment, the injection device further includes a drug chamber assembly 20. The drug chamber assembly 20 includes a drug chamber body 21, a gasket 22, and a syringe 23. The drug chamber body 21 is movably installed inside the protective shell 12, the syringe 23 is installed inside the drug chamber body 21, and the gasket 22 is installed between the syringe 23 and the drug chamber body 21. The injection device also includes a drive assembly 30, which is installed inside the shell 11. The drive assembly 30 has a avoidance state for avoiding the syringe 23 and a push state for pushing the syringe 23 to inject. When the drive assembly 30 switches from the avoidance state to the push state, the drug chamber assembly 20 buffers the impact between the syringe 23 and the drug chamber body 21 through the gasket 22. By providing a washer 22 between the syringe 23 and the drug chamber body 21, the injection device can buffer the impact between the syringe 23 and the drug chamber body 21 when the drive component 30 switches from the avoidance state to the push state, thereby avoiding rigid impact between the syringe 23 and the drug chamber body 21 and improving the reliability of the injection device.

[0140] Referring to Figures 14 and 15, in an optional embodiment, the syringe 23 includes a cartridge 231, a rubber stopper 232, and a needle cap 233. A needle is provided at the proximal end of the cartridge 231. The needle cap 233 is detachably fitted onto the needle to seal it. The rubber stopper 232 is movably installed inside the cartridge 231. When the needle cap 233 is removed from the needle, pushing the rubber stopper 232 towards the proximal end of the cartridge 231 allows the liquid medicine between the rubber stopper 232 and the cartridge 231 to flow out from the needle. The cartridge 231 is made of a transparent material, which allows the user to easily observe the liquid medicine inside the cartridge 231. A limiting lug is provided on the distal outer wall of the cartridge 231, which is used to engage with the distal end of the washer 22.

[0141] In an optional embodiment, the needle cap 233 is engaged with the connecting post 132. When the cap body 13 is installed on the cap body mounting part 111, the connecting post 132 can at least partially pass through the protective shell 12. The connecting post 132 is provided with a first inner hole 1321 for accommodating the needle cap 233. A first closing structure is provided at the distal end of the first inner hole 1321. The first closing structure is a protrusion structure that protrudes towards the center of the first inner hole 1321 in the radial direction. The first closing structure is located at the distal end of the needle cap 233. During the process of removing the cap body 13 from the cap body mounting part 111, the first inner hole 1321 can engage with the distal end of the needle cap 233 through the first closing structure, so that the needle cap 233 separates from the proximal end of the cartridge 231 as the cap body 13 is removed.

[0142] Referring to Figure 11, in an optional embodiment, the washer 22 includes a hollow body 221 and a mounting protrusion 222. The mounting protrusion 222 is disposed on the proximal end face of the hollow body 221 and is used to cooperate with the medicine chamber body 21 so that the washer 22 is fixedly installed at the distal end of the medicine chamber body 21. The hollow body 221 is provided with a clearance through hole 2211. The hollow body 221 is sleeved on the medicine cartridge 231 through the clearance through hole 2211 and is located at the distal end of the medicine chamber body 21. Between the proximal end of the limiting lug and the distal end of the drug chamber body 21, the proximal end of the hollow body 221 is in contact with the proximal end of the limiting lug, and the distal end of the hollow body 221 is in contact with the proximal end of the limiting lug. The cross-sectional shape of the hollow body 221 in the radial direction of the syringe 23 is adapted to the cross-sectional shape of the limiting lug in the radial direction of the syringe 23, which improves the shock absorption effect of the hollow body 221. During the assembly process, the proximal end of the syringe 23 can be inserted into the drug chamber body 21 through the clearance through hole 2211.

[0143] Referring to Figures 12 and 13, in an optional embodiment, a protruding mounting groove 214 is formed at the distal end of the drug chamber body 21. The protruding mounting groove 214 extends along the length direction of the drug chamber body 21, and the washer 22 can be installed at the distal end of the drug chamber body 21 by the cooperation of the mounting protrusion 222 with the protruding mounting groove 214. The drug chamber body 21 includes a first cylindrical body 212, in which a first mounting vertical rib and a second mounting vertical rib are spaced apart. The first mounting vertical rib and the second mounting vertical rib both extend along the length direction of the first cylindrical body 212 and are arranged facing each other on the tangential surface in the radial direction of the injection device. A protruding mounting groove 214 is formed between the first mounting vertical rib and the second mounting vertical rib. When the mounting protrusion 222 cooperates with the protruding mounting groove 214, the mounting protrusion 222 abuts against the first mounting vertical rib and the second mounting vertical rib on opposite sides in the circumferential direction of the first cylindrical body 212, respectively. A guide limiting protrusion 2121 is provided on the proximal outer side of the cylindrical body 212. The guide limiting protrusion 2121 extends along the length direction of the first cylindrical body 212. The first cylindrical body 212 slides with the protective shell 12 through the guide limiting protrusion 2121 to guide and limit the movement of the drug chamber body 21 relative to the protective shell 12. A first stepped surface 211 is formed on the proximal outer side of the first cylindrical body 212. The first stepped surface 211 is perpendicular to the axis of the first cylindrical body 212. The outer diameter of the first cylindrical body 212 located on the proximal side of the first stepped surface 211 is smaller than the outer diameter of the first cylindrical body 212 located on the distal side of the first stepped surface 211. When the drug chamber body 21 moves toward the proximal end of the injection device, the first cylindrical body 212 abuts against the outer shell 11 through the first stepped surface 211, restricting the movement of the drug chamber body 21 toward the proximal end of the injection device, thereby limiting the depth of the needle of the injection device piercing the skin.

[0144] In one optional embodiment, the first mounting rib and the second mounting rib form a protruding foot mounting structure. There are multiple protruding foot mounting structures, which are spaced apart along the circumference of the medicine chamber body 21. There are multiple mounting protrusions 222, and each of the multiple mounting protrusions 222 corresponds to one of the multiple protruding foot mounting structures.

[0145] Referring to Figures 8, 9, 12, and 13, in one optional embodiment, the protective shell 12 includes a first cylindrical body 123. The proximal end of the first cylindrical body 123 is a tapered cylinder 1231. A limiting protrusion 121 is located inside the proximal end of the tapered cylinder 1231. The diameter of the tapered cylinder 1231 is smaller than the diameter of the distal end of the first cylindrical body 123. A viewing window groove 1232 is provided on the side wall of the first cylindrical body 123. The viewing window groove 1232 is an opening connecting the inner and outer side walls of the first cylindrical body 123. The viewing window groove 1232 extends along the length direction of the first cylindrical body 123. The structure of 1232 is adapted to the structure of the guide limiting protrusion 2121. The first cylindrical body 212 is movably inserted into the first cylindrical body 123. The guide limiting protrusion 2121 is at least partially inserted into the window groove 1232 and slides with the window groove 1232. When the drug chamber body 21 moves relative to the protective shell 12 toward the proximal end of the injection device, the two opposite side walls of the guide limiting protrusion 2121 in the circumferential direction of the first cylindrical body 212 can slide with the two adjacent side walls of the window groove 1232 in the circumferential direction of the first cylindrical body 123 to limit the movement of the drug chamber body 21.

[0146] In an optional embodiment, a first limiting platform 116 is provided on the inner sidewall of the outer shell 11. The outer shell 11 can abut against the first step surface 211 through the first limiting platform 116 to limit the movement of the drug chamber body 21. A viewing window opening is provided on the outer shell 11. The position of the viewing window opening corresponds to the position of the viewing window groove 1232. The viewing window opening allows the user to observe the drug chamber body 21 from outside the injection device through the viewing window opening and the viewing window groove 1232.

[0147] In an optional embodiment, the drive assembly 30 includes a top cap 31, a trigger assembly, and a push rod assembly. The top cap 31 is installed at the distal end of the housing 11 to seal the distal end of the housing 11. As shown in Figure 16, the top cap 31 is provided with a first snap-fit ​​structure 313, and the distal end of the housing 11 is provided with a second snap-fit ​​structure 115. One of the first snap-fit ​​structure 313 and the second snap-fit ​​structure 115 is a snap-fit, and the other of the first snap-fit ​​structure 313 and the second snap-fit ​​structure 115 is a slot. The top cap 31 can be detachably installed on the distal end of the housing 11 through the cooperation of the first snap-fit ​​structure 313 and the second snap-fit ​​structure 115. When the top cap 31 is detachably installed on the distal end of the housing 11 through the cooperation of the first snap-fit ​​structure 313 and the second snap-fit ​​structure 115, the proximal end face of the top cap 31 abuts against the distal end face of the housing 11 to make the connection between the top cap 31 and the housing 11 more secure.

[0148] In an optional embodiment, the top cap 31 includes a top cap body 311, which is a distally closed cylindrical structure. Two arc-shaped protrusions 312 are provided at the proximal end of the top cap body 311. A first snap-fit ​​structure 313 is provided on the outer circumferential side of the arc-shaped protrusions 312. An annular protrusion 3111 is provided inside the top cap body 311. The annular protrusion 3111 is located at the proximal end of the top cap body 311 and is at least partially located between the two arc-shaped protrusions 312. A first snap-fit ​​position 31111 is provided on the annular protrusion 31111. The first snap-fit ​​position 31111 is used to cooperate with the drive rod 32 of the trigger assembly to fix the drive rod 32.

[0149] In an optional embodiment, the first snap-fit ​​structure 313 includes a plurality of snaps, which are spaced apart circumferentially along the top cap 31. The second snap-fit ​​structure 115 includes a plurality of slots, which correspond one-to-one with the plurality of snaps.

[0150] Referring to Figures 16 to 26, in an optional embodiment, both the trigger component and the push rod component are installed inside the housing 11. The output end of the trigger component has a third latching structure, and the output end of the push rod component has a fourth latching structure. The trigger component has a first state where the output end of the push rod component connects to the output end of the trigger component through the cooperation of the third and fourth latching structures, thus avoiding the syringe 23; and a second state where the third latching structure avoids the fourth latching structure, and the output end of the push rod component pushes the syringe 23 to inject. When the drive component 30 is in the avoidance state, the trigger component is in the first state; when the drive component 30 is in the pushing state, the trigger component is in the second state. The distal end of the protective shell 12 is driven to the input end of the trigger component. When the protective shell 12 moves towards the distal end of the injection device, the protective shell 12 can trigger the trigger component, causing it to switch from the first state to the second state, thereby triggering the injection device.

[0151] Referring to Figures 17 to 19, 24, and 25, in an optional embodiment, the triggering assembly includes a drive rod 32, a push rod drive member 34, and a drive spring 33. The push rod assembly includes a large push rod 36, a small push rod, and a push rod spring 37. The distal end of the drive rod 32 is fixedly connected to the top cap 31 and extends along the length of the outer shell 11. The push rod drive member 34 is movably sleeved on the drive rod 32 along the length of the drive rod 32. The drive spring 33 is sleeved on the drive rod 32, and both ends of the drive spring 33 abut against the drive rod 32 and the push rod drive member 34, respectively, to apply elastic force to the push rod drive member 34. The drive rod 32 forms the output end of the triggering assembly, and the push rod drive member 34 forms the input end of the triggering assembly. When the triggering assembly is in the first state, the drive spring 33 is at least partially compressed and can be further compressed.

[0152] Referring to Figure 17, in an optional embodiment, the drive rod 32 is provided with a first spring abutment surface 3232, and the first end of the drive spring 33 abuts against the drive rod 32 through the first spring abutment surface 3232; an inner groove surface 326 is provided inside the drive rod 32, the inner groove surface 326 is located at the distal end of the drive rod 32, and is used to abut against the distal end surface of the small push rod 35 to restrict the small push rod 35 from moving to the distal end of the drive rod 32; the inner sidewall of the drive rod 32 is provided with A second limiting rib is provided, located at the distal end of the drive rod 32 and corresponding to the distal end of the small push rod 35. This rib engages with the outer wall of the distal end of the small push rod 35 to limit its radial movement. A round cap structure 321 is provided at the distal end of the drive rod 32. A first snap-fit ​​structure 322 is provided on the outer wall of the round cap structure 321. The outer wall of the round cap structure 321 contacts and engages with the inner wall of the annular boss 3111. The distal end face of the drive rod 32 and the annular boss 311... The drive rod 32 and the top cap 31 are connected by the engagement of the first snap-fit ​​structure 322 and the first snap-fit ​​position 31111, thereby restricting the movement of the drive rod 32 relative to the top cap 31. Multiple mounting ribs 323 are provided on the outer side wall of the drive rod 32. These mounting ribs 323 are located near the end of the round cap structure 321 and are spaced apart circumferentially along the drive rod. Each mounting rib 323 includes a first rib segment and a second rib segment, which are spaced along the drive rod. The length of the rod 32 is arranged sequentially, with the first rib segment located near the end of the second rib segment. The radial dimension of the first rib segment is lower than that of the second rib segment. A second limiting surface 3231 is formed at the near end of the first rib segment. During the process of the push rod driving member 34 moving towards the far end of the injection device, the driving rod 32 contacts and engages with the push rod driving member 34 through the second limiting surface 3231 to restrict the push rod driving member 34 from moving towards the far end of the injection device. A first spring abutment surface 3232 is formed at the near end of the second rib segment.

[0153] Referring to Figures 24 and 25, in an optional embodiment, the proximal end of the drive rod 32 has a plurality of spring walls, and the spring arm 324 extends along the length direction of the drive rod 32. The proximal end of the spring wall is provided with a circumferential latch 325, which forms a third latching structure. The circumferential latch 325 can swing away from or towards the axis of the drive rod 32 through the spring arm 324. When the triggering component is in the first state, the circumferential latch 325 is housed in the mounting through hole 3411, and the inner sidewall of the circumferential latch 325 cooperates with the fourth latching structure. When the triggering component is in the second state, the circumferential latch 325 protrudes from the proximal end of the mounting through hole 3411 and swings away from the axis of the drive rod 32, so that the inner sidewall of the circumferential latch 325 avoids the fourth latching structure.

[0154] In one optional embodiment, there are multiple second limiting ribs, which are spaced apart along the circumferential direction of the drive rod 32.

[0155] In an optional embodiment, the push rod drive member 34 is provided with a second spring abutment surface 344. The second end of the drive spring 33 abuts against the push rod drive member 34 through the second spring abutment surface 344. The proximal end of the push rod drive member 34 is provided with a first snap-fit ​​surface 343. During the process of the push rod drive member 34 moving relative to the protective shell 12 towards the distal end of the injection device, the first snap-fit ​​surface 343 can engage with the second snap-fit ​​structure 124 provided on the distal end of the protective shell 12, which extends into the interior of the protective shell 12, thereby restricting the movement of the push rod drive member 34 relative to the protective shell 12 towards the distal end of the injection device. When the protective shell 12 pushes the push rod drive member 34 towards the distal end of the injection device, the drive spring 33 can be compressed. When the triggering component is in the second state and the push rod drive 34 is not subjected to external force (i.e., the protective shell does not apply additional force to the push rod drive 34 in the direction of the distal end of the injection device), the push rod drive 34 can move towards the proximal end of the injection device under the action of the drive spring 33. The protective shell 12 can move towards the proximal end of the injection device under the drive of the push rod drive 34 and cover the proximal end of the cartridge 231. The distal end of the push rod drive 34 is provided with multiple clearance notches 342, the positions of the multiple clearance notches 342 correspond one-to-one with the positions of multiple mounting ribs 323, and the proximal end of the clearance notches 342 is provided with a notch surface 3421. The push rod drive 34 contacts the second limiting surface 3231 through the notch surface 3421. The push rod drive 34 consists of a first snap-fit ​​surface 343 and a second spring abutment surface 344, which are spaced apart and positioned near the proximal end of the push rod drive 34. Both the first snap-fit ​​surface 343 and the second spring abutment surface 344 extend circumferentially along the push rod drive 34. The second spring abutment surface 344 is located at the distal end of the first snap-fit ​​surface 343. The push rod drive 34 includes a second main cylinder 341, within which a mounting through hole 3411 is formed. The mounting through hole 3411 extends along the length of the second main cylinder 341. The proximal end of the drive rod 32 is inserted into the push rod drive 34 from the distal end of the mounting through hole 3411. A limiting rib 3412 is provided on the inner wall of the mounting through hole 3411, extending along the length of the mounting through hole 3411. Rib 3412 slides with the outer side of circumferential buckle 325 to compress the outer side of circumferential buckle 325, causing elastic deformation of spring arm 324 and driving circumferential buckle 325 to swing towards the axis of drive rod 32, so that circumferential buckle 325 can contact and engage with first snap-fit ​​surface 3621, thereby allowing drive rod 32 to clamp large push rod 36; under the compression of limiting rib 3412, circumferential buckle 325 can cause elastic deformation of spring arm 324 and move towards the axis of drive rod 32. When large push rod 36 avoids circumferential buckle 325, multiple circumferential buckles 325 can circumferentially engage under the compression of limiting rib 3412. At this time, the outer diameter of circumferential buckle 325 can be smaller than the outer diameter of spring wall before compression.When the trigger assembly is in the first state, the push rod drive member 34 abuts against the outer wall of the circumferential latch 325 via the proximal end of the limiting rib 3412, thereby restricting the push rod drive member 34 from moving towards the proximal end of the injection device, and thus compressing the drive spring 33 between the push rod drive member 34 and the drive rod 32.

[0156] Referring to Figures 20 to 23, in an optional embodiment, the small push rod 35 is installed inside the drive rod 32 and extends along the length of the housing 11 to guide the movement of the large push rod 36 and the push rod spring 37. The distal end of the small push rod 35 is connected to the drive rod 32. The large push rod 36 is movably sleeved on the small push rod 35 along the extension direction of the small push rod 35. The push rod spring 37 is sleeved on the small push rod 35, and both ends of the push rod spring 37 abut against the large push rod 36 and the small push rod 35 respectively to apply a spring force to the large push rod 36. The large push rod 36 forms the output end of the push rod assembly. When the trigger assembly is in the first state, the push rod spring 37 is at least partially compressed.

[0157] Referring to Figure 20, in an optional embodiment, the small push rod 35 includes a first push rod frustum 351 and a first support rod 352. The first support rod 352 is disposed on the near end face of the first push rod frustum 351. The far end face of the first push rod frustum 351 abuts against the inner groove surface 326 to restrict the small push rod 35 from moving to the far end of the drive rod 32. The outer wall of the first push rod frustum 351 abuts against the side of the second limiting rib near the first push rod frustum 351.

[0158] Referring to Figures 22 and 23, in an optional embodiment, the large push rod 36 includes a first main body cylinder 361. A guide hole 3611 is provided on the first main body cylinder 361, extending along the length of the first main body cylinder 361. The opening of the guide hole 3611 is located at the distal end of the first main body cylinder 361. The bottom wall of the guide hole 3611 forms a third spring abutment surface 36111, located at the proximal end of the large push rod 36. The large push rod 36 passes through the opening of the guide hole 3611 to the small push rod. The proximal end of the small push rod 35 is fitted onto the small push rod 35, and the push rod spring 37 is compressed inside the large push rod 36. Sliding the large push rod 36 toward the distal end of the injection device can compress the push rod spring 37. The proximal end of the large push rod 36 passes through the distal end of the cartridge 231 at least partially inside the cartridge 231. When the triggering component is in the second state and the needle cap 233 is separated from the proximal end of the cartridge 231, the push rod spring 37 can push the large push rod 36 to slide toward the proximal end of the injection device, thereby pushing the rubber stopper 232 to move toward the proximal end of the injection device so that the liquid medicine is discharged from the needle at the proximal end of the cartridge 231.

[0159] Referring to Figures 22 and 23, in an optional embodiment, the first main body cylinder 361 is provided with an annular groove 362. The annular groove 362 is located radially outward of the first main body cylinder 361 and extends circumferentially along the first main body cylinder 361. The annular groove 362 forms a fourth snap-fit ​​structure. When the trigger component is in the first state, the position of the annular groove 362 corresponds to the position of the circumferential snap 325, and the inner sidewall of the circumferential snap 325 engages with the annular groove 362. The annular groove 362 forms a first snap-fit ​​surface 3621 and a second snap-fit ​​surface 3622 on two opposite sidewalls along the length direction of the first main body cylinder 361, respectively. 2. A first engaging surface 3621 is formed on the side wall of one of the two opposing side walls in the length direction of the first main body cylinder 361, away from the proximal end of the first main body cylinder 361. When the trigger assembly is in the first state, the first engaging surface 3621 engages with the inner side wall of the circumferential buckle 325 to restrict the large push rod 36 from moving towards the proximal end of the injection device, thereby compressing the push rod spring 37 between the large push rod 36 and the small push rod 35. A second engaging surface 3622 is formed on the side wall of one of the two opposing side walls in the length direction of the first main body cylinder 361, near the proximal end of the first main body cylinder 361. The second engaging surface 3622 is used to contact and engage with the push handle 38.

[0160] In one optional embodiment, the push rod spring 37 is sleeved on the outside of the first support rod 352, the first end of the push rod spring 37 abuts against the near end face of the first push rod frustum 351, the large push rod 36 is provided with a third spring abutment surface 36111, and the second end of the push rod spring 37 abuts against the third spring abutment surface 36111.

[0161] Referring to Figure 26, in an optional embodiment, the push handle 38 is provided with a first mounting hole 383 and a third snap-fit ​​structure 3821. The push handle 38 is sleeved on the large push rod 36 through the first mounting hole 383, and is engaged with the annular groove 362 through the third snap-fit ​​structure 3821, and is in contact with the second snap-fit ​​surface 3622. The push handle 38 includes a main ring 381, and an annular spring buckle 382 is provided on the distal end surface of the main ring 381. The annular spring buckle 382 is formed by multiple spring pieces. The first mounting hole 383 is formed in the middle of the main ring 381 and the annular spring buckle 382. The third snap-fit ​​structure 3821 is provided on the inner side of the annular spring buckle 382. The annular spring buckle 382 can be engaged with the annular groove 362 through the third snap-fit ​​structure 3821 and is in contact with the second snap-fit ​​surface 3622. The distal end surface of the annular spring buckle 382 extends from the outer side of the annular spring buckle 382 towards the annular spring buckle 382. In the middle of 2, it gradually tilts away from the annular main ring 381. The distal end face of the annular spring buckle 382 slides and engages with the circumferential buckle 325. When the triggering component switches from the first state to the second state, the distal end face of the annular spring buckle 382 can guide the circumferential buckle 325, causing the circumferential buckle 325 to move away from the central axis of the drive rod 32, thereby separating the circumferential buckle 325 from the annular groove 362 to release the push rod spring 37 to push the large push rod 36. The push handle 38 is provided with a third engagement surface 384. The push handle 38 is connected to the fourth buckle structure 213 provided at the distal end of the medicine chamber body 21 through the third engagement surface 384. The proximal end face of the main ring 381 can abut against the distal end face of the medicine cartridge 231, so that when the triggering component is in the second state, the injection device can push the medicine cartridge 231 and the medicine chamber together to move towards the proximal end of the injection device through the movement of the push handle 38.

[0162] In an optional embodiment, when the triggering component is in the second state, the large push rod 36 avoids the circumferential latch 325, and the input end of the triggering component is not subjected to external force, the push rod drive member 34 can move towards the proximal end of the injection device under the elastic force of the drive spring 33. As the push rod drive member 34 moves, the circumferential latch 325 can undergo elastic deformation of the spring arm 324 under the compression of the limiting rib 3412, and move towards the direction closer to the axis of the drive rod 32, until the circumferential latch 325 moves to the far end of the limiting rib 3412. When the circumferential latch 325 is located at the far end of the limiting rib 3412, the engagement between the circumferential latch 325 and the limiting rib 3412 disengages. Under the action of the elastic force of the spring arm 324, the circumferential latch 325 moves away from the central axis of the drive rod 32. If the push rod drive member 34 moves towards the far end of the injection device, the proximal end of the circumferential latch 325 will abut against the far end face of the limiting rib 3412, thereby restricting the push rod drive member 34 from moving towards the far end of the injection device, and thus restricting the protective shell 12 from moving towards the far end of the injection device.

[0163] In an optional embodiment, as the push rod drive 34 moves toward the proximal end of the injection device by the elastic force applied by the drive spring 33, the push rod drive 34 can push the protective shell 12 toward the proximal end of the injection device. The needle will be gradually retracted into the protective shell 12 as it extends. When the distal end of the limiting rib 3412 moves to the proximal side of the circumferential buckle 325, the protective shell 12 completely retracts the needle. At this time, if the protective shell 12 is pushed toward the distal end of the injection device, the proximal end of the circumferential buckle 325 will abut against the distal end surface of the limiting rib 3412, thereby restricting the movement of the protective shell 12 toward the distal end of the injection device and preventing the needle from leaking out after injection.

[0164] In an optional embodiment, when assembling the cap 13 of the injection device, first pinch the anti-slip strip 1314 of the cap 13 and align the indicator mark 1312 of the cap 13 with the unlock mark 113 of the outer shell 11. At this time, the first rib 133 and the second rib 134 of the cap 13 correspond to the first clearance opening 1211 and the second clearance opening 1212 of the protective shell 12, respectively. Then, insert the connecting post 132 of the cap 13 into the protective shell 12 from the proximal end of the protective shell 12. The first rib 133 and the second rib 134 of the cap 13 can smoothly pass through the first clearance opening 1211 and the second clearance opening 1212 of the protective shell 12 to reach the interior of the protective shell 12, so that the first inner hole 1321 of the cap 13 contains the needle cap 2. 33. The proximal surfaces of the first rib 133 and the second rib 134 of the cap body 13 are parallel to the distal surfaces of the limiting protrusions 121 of the protective shell 12. The distal surface of the cap body 131 is parallel to the distal surface of the mounting protrusions 112 of the outer shell 11. The limiting rib 1311 of the cap body 13 is located in the limiting groove 1111 of the outer shell 11. At this time, the assembly of the cap body 13 in the unlocked state is completed. If the cap body 13 is continued to be turned in the direction indicated by the direction mark 1313 of the cap body 13, the side wall of the second rib 134 near the third rib 122 will contact the side wall of the third rib 122 of the protective shell 12 near the second rib 134. The cap body 13 will be blocked and cannot be turned further. At this time, the cap body 13 reaches the limit position of the unlocking stroke to prevent over-unlocking.

[0165] In one optional embodiment, when the cap 13 is in the unlocked state, twisting the cap 13 in the opposite direction indicated by the direction mark 1313 will cause the stop structure 1112 of the outer shell 11 to contact the limiting rib 1311 of the cap 13, resulting in increased twisting resistance. When the limiting rib 1311 of the cap 13 passes the stop structure 1112 of the outer shell 11, there will be a double feedback of a clicking sound and a momentary decrease in resistance, indicating that the cap 13 is locked in place. If twisting continues, the side wall of the first rib 133 of the cap 13 near the third rib 122 will contact the side wall of the third rib 122 of the protective shell 12 near the first rib 13. When the side wall of 3 contacts, the cap 13 will be blocked and cannot be turned any further. At this time, the cap 13 reaches the locked limit position. After the cap 13 is locked in place, turn the cap 13 according to the direction indicated by the direction mark 1313. When a click sound and the resistance increases and then decreases are observed, the unlocking process begins. At this time, the cap 13 still has the locking function and cannot be pulled out. Continue to turn the cap 13 until the indicator mark 1312 of the cap 13 is aligned with the unlock mark 113 of the outer shell 11. At this time, the injection cap 13 will switch from the locked state to the unlocked state. Then, remove the cap 13 from the proximal end of the injection assembly to start the injection.

[0166] In an optional embodiment, before injection is performed using the injection assembly, the cap 13 is first twisted in the direction indicated by the direction mark 1313. When a clicking sound and a sudden increase followed by a decrease in resistance occur, the unlocking process begins. The cap 13 is continued to be twisted until the indicator mark 1312 of the cap 13 aligns with the unlocking mark 113 of the outer shell 11. At this time, the first rib 133 and the second rib 134 of the cap 13 correspond to the first clearance opening 1211 and the second clearance opening 1212 of the protective shell 12. The cap 13 is then removed from the proximal end of the injection assembly. The cap 13 and the needle cap 233 are separated from the proximal end of the injection device, and the unlocking of the injection device is completed.

[0167] Referring to Figures 27 to 31, in one optional embodiment, after the injection device is unlocked, the injection assembly can be used for injection. During injection, the injection device is first pressed vertically onto the injection site. The protective shell 12 and the push rod drive 34 move together toward the distal end of the injection device, compressing the drive spring 33. After the trigger component is triggered, the circumferential latch 325 of the drive rod 32 separates from the engagement with the annular groove 362. The push rod spring 37 is released, pushing the large push rod 36 to move toward the proximal end of the injection device. The large push rod 36 pushes the push handle 38 and the drug chamber assembly 20 (with the needle cap 233 removed) together to move toward the proximal end of the injection device. As the drug chamber assembly 20 moves, the needle pierces the skin, and the first stepped surface 211 of the drug chamber body 21 contacts the first limiting platform 116 of the outer shell 11. The large push rod 36 continues to push the rubber stopper 232 to inject the medicine until the injection is completed and the needle is pulled out. At this time, the drive spring 33 is released, pushing the protective shell 12 and the push rod drive 34 to move towards the proximal end of the injection device. The first limiting surface 12321 of the window groove 1232 of the protective shell 12 abuts against the first limiting rib 114 provided on the inner side wall of the outer shell 11, thereby restricting the movement of the protective shell 12 towards the proximal end of the injection device. If the protective shell 12 is moved towards the distal end of the injection device by external force, the distal end surface of the limiting rib 3412 of the push rod drive 34 abuts against the proximal end surface of the circumferential buckle 325 of the drive rod 32, thereby restricting the movement of the protective shell 12 towards the distal end of the injection device and preventing the needle from being exposed and causing injury.

[0168] In one alternative embodiment, the syringe contains a medical product.

[0169] In one alternative embodiment, the pharmaceutical product is a pharmaceutical formulation containing an active compound selected from one or more of insulin or its derivatives or analogs, GLP-1 compounds or their derivatives or analogs; preferably, the pharmaceutical formulation contains bovangravitide, or a pharmaceutically acceptable salt, amide or ester thereof.

[0170] It should be noted that the protective shell 12 provided in this embodiment triggers the triggering component by pushing the push rod drive member 34, causing the push rod drive member 34 to move a preset distance relative to the drive rod 32 towards the distal end of the injection device. Therefore, in other embodiments, the injection device provided in this embodiment can also trigger the triggering component through the protective shell 12 and / or other components. For example, when the drive rod is movably installed inside the outer shell 11, the push rod drive member 34 can be pushed by the protective shell 12, causing the push rod drive member 34 to move a first distance relative to the drive rod 32 towards the distal end of the injection device. Then, the drive rod 32 can be pushed by other components, causing the drive rod 32 to move a second distance relative to the push rod drive member 34 towards the proximal end of the injection device. This achieves the goal of moving the push rod drive member 34 a preset distance relative to the drive rod 32 towards the distal end of the injection device, thereby triggering the triggering component.

[0171] In summary, the injection device provided in this embodiment has at least the following beneficial technical effects: By setting a first limiting structure on the cap 13 and a second limiting structure on the protective shell 12, the cap 13 installed at the near end of the outer shell 11 can restrict the protective shell 12 from moving to the far end of the outer shell 11 through the cooperation of the first limiting structure and the second limiting structure. This reduces the risk of accidental triggering of the protective shell when the injection device is dropped when the cap 13 is in the locked state, effectively improving the reliability of the injection device and enhancing the user experience.

[0172] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An injection device, characterized in that, The injection device includes: A protective assembly (10) includes a housing (11), a protective shell (12), and a cap (13), wherein the protective shell (12) is movably mounted inside the housing (11) and extends at least partially from the proximal end of the housing (11), and the cap (13) is mounted on the proximal end of the housing (11); The cap body (13) is provided with a first limiting structure, and the protective shell (12) is provided with a second limiting structure. The cap body (13) has a locked state in which the first limiting structure cooperates with the second limiting structure and restricts the second limiting structure from moving to the far end of the shell (11), and an unlocked state in which the first limiting structure avoids the second limiting structure. When the cap (13) in the unlocked state is removed from the protective shell (12), the protective shell (12) can trigger the injection device by moving toward the distal end of the outer shell (11).

2. The injection device according to claim 1, characterized in that, The near end of the outer shell (11) is provided with a cap mounting part (111), and the cap (13) is rotatably mounted on the cap mounting part (111). The cap (13) can switch between the locked state and the unlocked state by rotating. Preferably, the cap (13) can generate sound feedback when it switches between the locked state and the unlocked state by rotating. Preferably, a first rotation limiting structure is provided on the cap mounting part (111), and a second rotation limiting structure is provided on the cap body (13). By cooperating with the first rotation limiting structure, the rotation stroke of the cap body (13) can be limited. When the cap body (13) is in the unlocked state, the cap body (13) can be removed from the proximal end of the outer shell (11) by moving away from the outer shell (11).

3. The injection device according to claim 2, characterized in that, One of the first rotation limiting structure and the second rotation limiting structure is a limiting groove (1111), and the other of the first rotation limiting structure and the second rotation limiting structure is a limiting rib (1311). The limiting groove (1111) and the limiting rib (1311) are adapted to each other. Through the cooperation of the limiting groove (1111) and the limiting rib (1311), the rotation stroke of the cap (13) can be limited. Preferably, the limiting rib (1311) abuts against the limiting groove (1111).

4. The injection device according to claim 3, characterized in that, A stop structure (1112) is provided in the limiting groove (1111). The stop structure (1112) is used to divide the limiting groove (1111) into a locking groove segment (11111) and an unlocking groove segment (11112). When the limiting rib (1311) slides between the locking groove segment (11111) and the unlocking groove segment (11112), the stop structure (1112) can abut against the limiting rib (1311). Preferably, the width of the locking groove (11111) is the width that accommodates the limiting rib (1311).

5. The injection device according to any one of claims 1 to 4, characterized in that, The cap body (13) includes a cap body main body (131) and a connecting post (132) disposed in the cap body main body (131). The connecting post (132) extends along the length direction of the cap body (13). The outer side wall of the connecting post (132) is provided with the first limiting structure, and the inner side wall of the protective shell (12) is provided with the second limiting structure.

6. The injection device according to claim 5, characterized in that, The first limiting structure includes a first protruding rib limiting part, which is disposed on the outer side wall of the connecting column and extends along the length direction of the connecting column. The second limiting structure includes a limiting protrusion (121), which is disposed on the inner sidewall of the protective shell (12). The limiting protrusion (121) extends circumferentially along the protective shell (12). The first rib limiting portion can cooperate with the limiting protrusion (121) to restrict the protective shell (12) from moving to the far end of the outer shell (11).

7. The injection device according to claim 6, characterized in that, The limiting protrusion (121) is provided with a clearance portion, which is used to make way for the first rib limiting portion. During the assembly of the cap (13) with the outer shell (11) and the protective shell (12), the proximal end of the first rib limiting portion can pass through the clearance portion and abut against the distal end of the limiting protrusion (121) after the cap (13) rotates in the first direction, so as to restrict the protective shell (12) from moving to the distal end of the outer shell (11).

8. The injection device according to claim 7, characterized in that, The second limiting structure further includes a second rib limiting part, which is used to cooperate with the first rib limiting part to limit the rotation of the cap body; The first rib limiting portion includes a first rib (133) and a second rib (134). The first rib (133) and the second rib (134) are both disposed on the outer side wall of the connecting post (132) and extend along the length direction of the connecting post (132). The first rib (133) and the second rib (134) are circumferentially spaced along the connecting post (132). The second rib limiting portion includes a third rib (122). The third rib (122) is disposed on the inner side wall of the protective shell (12) and extends along the length direction of the protective shell (12). The first rib (133) is used to cooperate with the third rib (122) to restrict the cap body (13) from rotating in a first direction. The second rib (134) is used to cooperate with the third rib (122) to restrict the cap body (13) from rotating in a second direction. Alternatively, the first rib limiting portion includes a fourth rib, the fourth rib being disposed on the outer side wall of the connecting post and extending along the length direction of the connecting post; the second rib limiting portion includes a fifth rib and a sixth rib, the fifth rib and the sixth rib being disposed on the inner side wall of the protective shell (12) and extending along the length direction of the protective shell (12); the fifth rib and the sixth rib are spaced apart along the circumference of the protective shell (12); the fifth rib is used to cooperate with the fourth rib to restrict the cap body (13) from rotating in the first direction; the sixth rib is used to cooperate with the fourth rib to restrict the cap body (13) from rotating in the second direction. Alternatively, the first rib limiting portion includes a seventh rib, which is disposed on the outer side wall of the connecting post and extends along the length direction of the connecting post; the second rib limiting portion includes an eighth rib, which is disposed on the inner side wall of the protective shell (12) and extends along the length direction of the protective shell (12); one of the two opposite side walls of the protective shell (12) in the circumferential direction is used to cooperate with the seventh rib to restrict the cap (13) from rotating in the first direction; the other of the two opposite side walls of the protective shell (12) in the circumferential direction is used to cooperate with the seventh rib to restrict the cap (13) from rotating in the second direction. Preferably, a bridging surface (135) is formed at the distal end of the bridging structure between the connecting post (132) and the cap body (131), and a notch is formed between the proximal end face of the first rib (133) and the second rib (134) and the bridging surface (135). When the cap body (13) is in a locked state, the limiting protrusion (121) is located within the notch. Preferably, the height of the notch segment is equal to the width of the limiting protrusion (121).

9. The injection device according to claim 8, characterized in that, When the first rib limiting portion includes the first rib (133) and the second rib (134), the clearance portion includes a first clearance opening (1211) and a second clearance opening (1212). The second clearance opening (1212) is adjacent to the third rib (122) in the first direction. The first clearance opening (1211) is used to clearance the first rib (133), and the second clearance opening (1212) is used to clearance the second rib (134). 34) During the assembly of the cap body (13) with the outer shell (11) and the protective shell (12), the proximal ends of the first protruding rib (133) and the second protruding rib (134) can pass through the first clearance opening (1211) and the second clearance opening (1212) respectively, and after the cap body (13) rotates along the first direction, it abuts against the distal end of the limiting protrusion (121) to restrict the protective shell (12) from moving toward the distal end of the outer shell (11); Preferably, when the first rib limiting portion includes the fourth rib, the yielding portion includes a third yielding opening, the third yielding opening is adjacent to the sixth rib in the first direction, the third yielding opening is used to yield the fourth rib, and during the assembly of the cap (13) with the outer shell (11) and the protective shell (12), the proximal end of the fourth rib can pass through the third yielding opening, and after the cap (13) rotates along the first direction, it abuts against the distal end of the limiting protrusion to restrict the movement of the protective shell (12) toward the distal end of the outer shell (11); Preferably, when the first rib limiting portion includes the seventh rib, the yielding portion includes a fourth yielding opening, which is adjacent to one sidewall of the eighth rib in the first direction. The fourth yielding opening is used to yield the seventh rib. During the assembly of the cap (13) with the outer shell (11) and the protective shell (12), the proximal end of the seventh rib can pass through the fourth yielding opening and abut against the distal end of the limiting protrusion after the cap (13) rotates in the first direction, thereby restricting the movement of the protective shell (12) toward the distal end of the outer shell (11). Preferably, the width of the first rib (133) is different from the width of the second rib (134), the size of the first clearance opening (1211) is adapted to the width of the first rib (133), and the size of the second clearance opening (1212) is adapted to the width of the second rib (134).

10. The injection device according to any one of claims 1 to 4, characterized in that, The injection device further includes a drug chamber assembly (20), which includes a drug chamber body (21), a gasket (22) and a syringe (23). The drug chamber body (21) is movably installed inside the protective shell (12), the syringe (23) is installed inside the drug chamber body (21), and the gasket (22) is installed between the syringe (23) and the drug chamber body (21). The injection device further includes a drive assembly (30) which is installed inside the housing (11). The drive assembly (30) has a avoidance state for avoiding the syringe (23) and a push state for pushing the syringe (23) to inject. When the drive assembly (30) switches from the avoidance state to the push state, the drug chamber assembly (20) buffers the impact between the syringe (23) and the drug chamber body (21) through the gasket (22). Optionally, the syringe contains a medical product; Optionally, the pharmaceutical product is a pharmaceutical formulation containing an active compound selected from one or more of insulin or its derivatives or analogs, GLP-1 compounds or their derivatives or analogs; preferably, the pharmaceutical formulation contains bovangravitide, or a pharmaceutically acceptable salt, amide or ester thereof.

11. An injection device, characterized in that, The injection device includes: A protective assembly (10) includes a housing (11), a protective shell (12), and a cap (13), wherein the protective shell (12) is movably mounted inside the housing (11) and extends at least partially from the proximal end of the housing (11), and the cap (13) is mounted on the proximal end of the housing (11); The cap (13) is provided with a first limiting structure, and the protective shell (12) is provided with a second limiting structure. When the cap (13) is installed on the near end of the outer shell (11) and is in a locked state, the protective shell (12) is restricted from moving to the far end of the outer shell (11) by the cooperation of the first limiting structure and the second limiting structure.

12. The injection device according to claim 11, characterized in that, The cap body (13) includes a cap body main body (131) and a connecting post (132) disposed in the cap body main body (131). The connecting post (132) extends along the length direction of the cap body (13). The outer side wall of the connecting post (132) is provided with the first limiting structure, and the inner side wall of the protective shell (12) is provided with the second limiting structure.

13. The injection device according to claim 12, characterized in that, The first limiting structure includes a first protruding rib limiting part, which is disposed on the outer side wall of the connecting column and extends along the length direction of the connecting column. The second limiting structure includes a limiting protrusion (121), which is disposed on the inner sidewall of the protective shell (12). The limiting protrusion (121) extends circumferentially along the protective shell (12). The first rib limiting portion can cooperate with the limiting protrusion (121) to restrict the protective shell (12) from moving to the far end of the outer shell (11).

14. The injection device according to claim 13, characterized in that, The limiting protrusion (121) is provided with a clearance portion, which is used to make way for the first rib limiting portion. During the assembly of the cap (13) with the outer shell (11) and the protective shell (12), the proximal end of the first rib limiting portion can pass through the clearance portion and abut against the distal end of the limiting protrusion (121) after the cap (13) rotates in the first direction, so as to restrict the protective shell (12) from moving to the distal end of the outer shell (11).

15. The injection device according to claim 14, characterized in that, The second limiting structure further includes a second rib limiting part, which is used to cooperate with the first rib limiting part to limit the rotation of the cap body; Preferably, the first rib limiting portion includes a first rib (133) and a second rib (134), both the first rib (133) and the second rib (134) are disposed on the outer side wall of the connecting post (132) and extend along the length direction of the connecting post (132). The first rib (133) and the second rib (134) are circumferentially spaced along the connecting post (132). The second rib limiting portion includes a third rib (122), the third rib (122) is disposed on the inner side wall of the protective shell (12) and extends along the length direction of the protective shell (12). The first rib (133) is used to cooperate with the third rib (122) to restrict the cap body (13) from rotating in a first direction. The second rib (134) is used to cooperate with the third rib (122) to restrict the cap body (13) from rotating in a second direction. Preferably, when the first rib limiting portion includes the first rib (133) and the second rib (134), the clearance portion includes a first clearance opening (1211) and a second clearance opening (1212). The second clearance opening (1212) is adjacent to the third rib (122) in the first direction. The first clearance opening (1211) is used to clearance the first rib (133), and the second clearance opening (1212) is used to clearance the second rib. (134) During the assembly of the cap body (13) with the outer shell (11) and the protective shell (12), the proximal ends of the first protruding rib (133) and the second protruding rib (134) can pass through the first clearance opening (1211) and the second clearance opening (1212) respectively, and after the cap body (13) rotates along the first direction, it abuts against the distal end of the limiting protrusion (121) to restrict the protective shell (12) from moving toward the distal end of the outer shell (11).

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