A semi-throw type injection pen

Abstract

The application relates to a semi-throwing injection pen, which comprises a main machine and a medicine cartridge in detachable connection; the main machine comprises a first shell, a driving mechanism and a pushing piece, the driving mechanism is installed on the first shell; the pushing piece is connected to the power output end of the driving mechanism and can move in a first direction under the driving of the driving mechanism; the medicine cartridge comprises a second shell and a needle cylinder, the second shell is detachably fixedly connected with the first shell, the needle cylinder comprises a cylinder body, a needle head and a piston, the cylinder body is fixedly connected with the second shell, the needle head is fixedly connected with the cylinder body and communicates with the inside of the cylinder body, and the piston is slidably arranged in the cylinder body; in an assembled state, the pushing piece is located on the side of the piston away from the needle head along the first direction, and the projection plane of the piston covers the projection plane of the pushing piece along the first direction. After injection is completed, the medicine cartridge is detached from the main machine and discarded or recycled, the whole injection pen does not need to be discarded, the use cost of the injection pen is saved, and the generation of medical waste is reduced.

Description

Technical Field

[0001] This application relates to the field of medical syringe technology, and in particular to a semi-disposable injection pen. Background Technology

[0002] In diseases requiring long-term injection therapy, such as diabetes and growth hormone deficiency, subcutaneous or intramuscular injections are commonly used methods of drug administration. Traditional syringe operation relies on professional skills, has low dosage control accuracy, and is inconvenient for patients to administer drugs themselves. Therefore, portable injection pens that integrate drug storage and injection functions have become the mainstream devices.

[0003] Among existing injection pens, pre-filled devices, such as the Smegglutide injection pen, are widely used, enabling precise and convenient drug delivery, and are suitable for diabetes treatment and weight management. Mechanical injection pens are mostly single-use designs, with the pen body integrated with a pre-filled cartridge containing a specific dose of medication, eliminating the need for an additional cartridge and simplifying the operation process.

[0004] However, these disposable mechanical injection pens are discarded after use, which on the one hand leads to high costs per use and increases the economic burden on patients for long-term treatment; on the other hand, the large number of discarded pens with integrated structures creates significant pressure on medical waste disposal, which is not conducive to the conservation of medical resources and environmental friendliness. Utility Model Content

[0005] Therefore, it is necessary to provide a semi-disposable injection pen that does not require the entire pen to be discarded after injection, thereby reducing the cost of using the injection pen and reducing the generation of medical waste.

[0006] This application provides a semi-disposable injection pen, including a detachably connected main unit and a cartridge; the main unit includes a first housing, a drive mechanism, and a pusher, the drive mechanism being mounted on the first housing; the pusher is connected to the power output end of the drive mechanism and is capable of moving along a first direction under the drive of the drive mechanism; the cartridge includes a second housing and a syringe, the second housing being detachably and fixedly connected to the first housing, the syringe including a barrel, a needle, and a piston, the barrel being fixedly connected to the second housing, the needle being fixedly connected to the barrel and communicating with the interior of the barrel, and the piston being slidably disposed within the barrel; in the assembled state, along the first direction, the pusher is located on the side of the piston away from the needle and projects along the first direction, the projection surface of the piston covering the projection surface of the pusher.

[0007] In one embodiment, the travel distance of the pusher along the first direction is not less than the sliding distance of the piston in the syringe along the first direction.

[0008] In one embodiment, the pusher is provided with a sensor, which is electrically connected to the drive mechanism, and the drive mechanism is able to receive the electrical signal at least when the sensor is in contact with the piston.

[0009] In one embodiment, the driving mechanism includes a drive motor and a lead screw. The drive motor is fixedly disposed inside the first housing, and one end of the lead screw is fixedly connected to the output shaft of the drive motor. The pusher is threadedly connected to the lead screw.

[0010] In one embodiment, the first housing is provided with a cartridge holder slot, and the pusher extends to the center of the cartridge holder slot; the second housing is provided with a plug section that matches the cartridge holder slot, the plug section has a through hole, and the syringe opening end of the second housing is directly opposite the through hole.

[0011] In one embodiment, a locking structure for securing the first housing and the second housing is provided between them.

[0012] In one embodiment, the locking structure includes a sliding groove and a slider, the groove having a first guide section and a second guide section, the first guide section extending along the first direction, the second guide section connecting with the first guide section, and the second guide section extending circumferentially around the first direction;

[0013] The groove is formed on the first housing and the slider is fixed on the second housing. The end of the first guide section away from the second guide section extends to the edge of the first housing.

[0014] or

[0015] The groove is formed on the second housing and the slider is fixed on the first housing. The end of the first guide section away from the second guide section extends to the edge of the second housing.

[0016] In one embodiment, the semi-disposable injection pen further includes a protective component and an elastic component, the protective component being slidably disposed along the first direction, and one end of the elastic component being fixedly connected to the second housing and the other end being connected to the protective component;

[0017] When the protective component is in a protective state, its projection along the direction perpendicular to the first direction covers the projection surface of the needle tip.

[0018] In one embodiment, the elastic element is fixedly connected to the protective element.

[0019] In one embodiment, the semi-disposable injection pen further includes a pen cap structure, which includes a cap body, a protective member, and a connector. The cap body is detachably connected to the second housing, the protective member surrounds the needle tip, and the connector is fixedly connected to the cap body and the protective member.

[0020] Compared with the prior art, the semi-disposable injection pen provided in this application has at least the following advantages:

[0021] 1) The syringe in the syringe is pre-filled with medicine. The main unit drives the pusher to move and penetrate into the syringe through the drive mechanism, and pushes the piston to move, so that the medicine in the syringe can be injected from the needle. The syringe and the main unit are connected in a detachable manner. After the injection is completed, the syringe can be removed from the main unit for disposal or recycling. The pusher can be reset under the reverse drive of the drive mechanism. There is no need to discard the entire injection pen, saving the cost of using the injection pen and reducing the generation of medical waste.

[0022] 2) The cartridge holder slot and the insertion section of the second housing in this application ensure that the pusher is aligned with the syringe piston after the cartridge is connected to the main unit, guaranteeing the effectiveness of use. At the same time, the smooth surface of the pusher will not interfere with the second housing, making use smoother.

[0023] 3) The syringe of this application can be pre-filled with a single dose of medication as needed, allowing for precise control of the injection dosage and facilitating home self-injection. Furthermore, because the syringe has a protective component, removing the protective component would allow air to enter the syringe, affecting the efficacy of the medication. The single-use syringe of this application ensures that the efficacy of the medication meets requirements for each injection.

[0024] 4) The cartridge and the main unit are connected in a detachable manner, so that the main unit shell can be made into a shape that is easy to hold (such as a cylinder or elliptical cylinder), and the cartridge shell can be made into a shape that prevents rolling (such as a triangular prism), which can simultaneously meet the requirements of easy to hold and prevent rolling. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology 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.

[0026] Figure 1 A perspective view of a semi-disposable injection pen according to an embodiment of this application;

[0027] Figure 2 An exploded perspective view of a semi-disposable injection pen according to an embodiment of this application;

[0028] Figure 3 This is a side cross-sectional view of a semi-disposable injection pen according to an embodiment of this application;

[0029] Figure 4 This is a side cross-sectional view of a host computer according to an embodiment of this application;

[0030] Figure 5 This is a side cross-sectional view of a cartridge according to an embodiment of this application;

[0031] Figure 6 This is a side cross-sectional view of the protective member and the elastic member according to an embodiment of this application;

[0032] Figure 7 This is a side cross-sectional view of a pen cap structure according to an embodiment of this application;

[0033] Figure 8 This is a schematic diagram illustrating the locking structure through a three-dimensional explosion of the host and cartridge according to an embodiment of this application.

[0034] Figure 9 This is a perspective view of the main unit and the cartridge case assembled according to an embodiment of this application;

[0035] Figure 10 This is a perspective view of the main unit, cartridge case, and protective component after assembly and before and after injection use, according to an embodiment of this application.

[0036] Figure 11 This is a perspective view of the main unit, cartridge, and protective components assembled according to an embodiment of this application and used during injection.

[0037] Reference numerals: 10, Main unit; 101, First housing; 1011, Outer shell; 1012, Inner shell; 1013, Cartridge holder slot; 102, Drive mechanism; 1021, Drive motor; 1022, Lead screw; 1023, Charging interface; 103, Pushing component; 1031, Sensing component; 20, Cartridge; 201, Second housing; 2011, Limiting block; 2012, Insertion section; 2013, Through... 202. Hole; 2021. Syringe body; 2022. Needle; 2023. Piston; 2024. Material holding space; 30. Locking structure; 301. Slide groove; 3011. First guide slide section; 3012. Second guide slide section; 302. Slider; 40. Protective component; 401. Limiting groove; 50. Elastic component; 60. Pen cap structure; 601. Cap body; 602. Protective component; 603. Connecting component. Detailed Implementation

[0038] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0039] To alleviate the high cost and large amount of medical waste generated by existing mechanical injection pens, this application provides a semi-disposable injection pen. After use, the entire pen does not need to be discarded; instead, the non-reusable part is discarded, while the other part can be reused multiple times, reducing usage costs and effectively reducing the generation of medical waste.

[0040] See Figures 1 to 11 This application provides a semi-disposable injection pen, including a main unit 10 and a cartridge 20. The main unit 10 includes a first housing 101, a drive mechanism, and a pusher 103. The cartridge 20 includes a second housing 201 and a syringe 202. The drive mechanism is mounted on the first housing 101, and the pusher 103 is connected to the power output end of the drive mechanism and can move along a first direction under the drive of the drive mechanism 102. In this application, the first direction is consistent with the length direction of the injection pen. The second housing 201 is detachably fixedly connected to the first housing 101, thereby allowing the main unit 10 and the cartridge 20 to be detachably separated. The syringe 202 includes a barrel 2021, a needle 2022, and a piston 2023. The barrel 2021 is fixedly connected to the second housing 201. When the second housing 201 is assembled with the first housing 101, the barrel 2021 is also physically connected to the main unit 10. When the second housing 201 is disassembled from the first housing 101, the barrel 2021 is also physically separated from the main unit 10 along with the second housing 201. The needle 2022 is fixedly connected to the barrel 2021 and communicates with the interior of the barrel 2021. The piston 2023 is slidably disposed within the barrel 2021. It can be understood that the barrel 2021 has a material-containing space 2024 that can be used for pre-filling drugs. The cross-section of the piston 2023 is adapted to the material-containing space 2024, and the material-containing space 2024 is divided into two parts. The part of the space near the needle 2022 contains drugs, while the other part of the space does not contain drugs. The piston 2023 slides in the material space 2024 and injects the drug from one side of the needle 2022. The sliding distance of the piston 2023 is proportional to the amount of drug injected.

[0041] In the assembled state of this semi-disposable injection pen, along the first direction, the pusher 103 is located on the side of the piston 2023 away from the needle 2022, and its projection along the first direction covers the projection surface of the pusher 103. This design allows the pusher 103 to slide into the material-containing space 2024 under the driving action of the drive mechanism 102, and push the piston 2023 to slide towards the needle 2022, thereby completing the injection of the drug.

[0042] The injection pen is used for subcutaneous or intramuscular injection. The main unit 10 in this application does not directly contact the skin, muscle, or medication during use, while the cartridge 20 does. Therefore, the main unit 10 and cartridge 20 are detachably connected. After injection, the cartridge 20 can be removed from the main unit 10 and discarded. The moving part (i.e., the pusher 103) in the main unit 10 is reset by the drive mechanism 102. This semi-disposable injection pen effectively reduces user costs and minimizes medical waste.

[0043] In some preferred embodiments of this application, the travel of the pusher 103 along the first direction is not less than the sliding travel of the piston 2023 in the syringe 202 along the first direction.

[0044] For example, when the syringe 202's material storage space 2024 is pre-filled, the piston 2023 is positioned at the opening of the material storage space 2024, and after the main unit 10 and the cartridge 20 are assembled, the pusher is in contact with the piston 2023. At this time, if the user's required injection dose is exactly the full dose in the material storage space 2024, the piston 2023's sliding stroke in the syringe 202 is at its maximum. If the pusher 103, which pushes the piston 2023, moves less along the first direction than the piston 2023's sliding stroke, the final injected drug dose will be less than the user's injection requirement. Therefore, in this embodiment, the pusher 103's movement stroke must be equal to the piston 2023's sliding stroke to meet the user's injection needs.

[0045] If, after the main unit 10 and the cartridge 20 are assembled, the pusher is not in contact with the piston 2023, the drive mechanism 102 will drive the pusher to slide until it contacts the piston 2023, and then drive the pusher to push the piston 2023 to slide together. At this time, to meet the user's injection needs, the movement stroke of the pusher 103 must be greater than the sliding stroke of the piston 2023.

[0046] In summary, the travel distance of the pusher 103 is designed to be no less than the sliding travel distance of the piston 2023, which can meet the user's injection needs within the maximum dose range of the drug pre-filled syringe 202.

[0047] In some preferred embodiments of this application, the pusher 103 is provided with a sensor 1031, which is electrically connected to the drive mechanism 102. The drive mechanism 102 can receive the electrical signal at least when the sensor 1031 contacts the piston 2023. For example, a circuit connection is established between the sensor 1031 and the drive mechanism 102. When the sensor 1031 contacts the piston 2023, it changes the resistance of the sensor 1031 in the circuit, thereby changing the current in the circuit. Based on the change in current, an electrical signal is fed back to the drive mechanism 102, which then controls the driving stroke of the pusher 103 based on the received electrical signal. Specifically, the contact position between the sensor 1031 and the piston 2023 is set as the initial position. At this time, the distance that the drive mechanism 102 drives the pusher 103 to slide is equal to the distance that the piston 2023 slides. The distance that the piston 2023 slides is proportional to the amount of drug injected. Therefore, the amount of drug injected can be controlled by the distance that the drive mechanism 102 drives the pusher 103 to slide.

[0048] Alternatively, the sensing element 1031 can be a pressure sensor. After the sensing element 1031 and the piston 2023 make certain squeezing contact, the sensor releases an electrical signal to the drive mechanism 102. At this time, the position of the pusher 103 is set as the initial position. Similarly, the amount of drug injected can be controlled by controlling the sliding distance of the pusher 103.

[0049] Of course, in other embodiments, the amount of drug prefilled in the syringe 202 is a calculated amount, that is, the drug dosage in the syringe 202 is exactly the amount of drug to be injected by the user. In this case, the drive mechanism only needs to drive the pusher 103 to push the piston 2023 to the deepest part of the syringe 202.

[0050] In some preferred embodiments of this application, the drive mechanism 102 includes a drive motor 1021 and a lead screw 1022. The drive motor 1021 is fixedly disposed inside the first housing 101, and one end of the lead screw 1022 is fixedly connected to the output shaft of the drive motor 1021. The pusher 103 is threadedly connected to the lead screw 1022. The movement stroke of the pusher 103 is precisely controlled by the drive control of the drive motor 1021 and the lead screw 1022. In other embodiments, a drive mechanism 102 capable of linearly driving the pusher, such as a linear guide or a pneumatic push rod, can also be used.

[0051] In addition, the drive mechanism 102 has a charging interface 1023. Since the host 10 needs to be reused, in order to ensure the driving reliability of the drive mechanism 102, the charging interface 1023 is provided so that the drive mechanism 102 can be charged or functioned by an external power source, thereby extending the service life of the host 10.

[0052] In some preferred embodiments of this application, the first housing 101 is provided with a cartridge case slot 1013, and the pusher 102 extends into the center of the cartridge case slot 1013. The second housing 201 is provided with a plug-in section 2012 that matches the cartridge case slot 1013. The plug-in section 2012 has a through hole 2013 and is located at the opening end of the syringe 202 of the second housing 201, directly opposite the through hole 2013. This design, with the cartridge case slot 1013 and the plug-in section 2012 fitting together, provides guidance and positioning for the insertion and engagement of the first housing 101 and the second housing 201, thereby achieving the assembly and positioning of the pusher 102 and the syringe 202. During the assembly of the main unit 10 and the cartridge 20, the pusher 102 passes through the through hole 2013 and faces the open end of the syringe 202, so that the pusher 102 can accurately enter the syringe 202 and push the piston 2023 during the subsequent translational feeding process. This avoids interference and collision between the pusher 102 and the body 2021 or other parts of the cartridge 20, and improves the structural reliability of the pusher 102.

[0053] In some preferred embodiments of this application, a locking structure 30 for fixing the first housing 101 and the second housing 201 is provided between them, reducing the need for bolts and other fasteners in the detachable connection between the first housing 101 and the second housing 201. The disassembly and assembly of bolts and other fasteners are cumbersome and require the use of screwdrivers and other tools, thus affecting the ease of replacing and installing the cartridge 20 in the injection pen.

[0054] In a further preferred embodiment of this application, the locking structure 30 includes a groove 301 and a slider 302. The frictional sliding engagement of the groove 301 and the slider 302 enables the quick assembly and disassembly of the first housing 101 and the second housing 201. Specifically, the groove 301 can be disposed on the first housing 101, and the slider 302 can be fixedly disposed on the second housing 201, or the groove 301 can be disposed on the second housing 201, and the slider 302 can be fixedly disposed on the first housing 101. In this embodiment, the groove 301 is formed on the first housing 101, and the slider 302 is fixedly disposed on the second housing 201. Furthermore, the first housing 101 includes an outer shell 1011 and an inner shell 1012 that interlock with each other. The groove 301 is formed in the inner shell 1012 to conceal the locking structure 30 and improve aesthetics.

[0055] In addition, to improve the connection reliability of the slide groove 301 and the slider 302, the slide groove 301 has a first guide section 3011 and a second guide section 3012. The first guide section 3011 extends along a first direction, and the second guide section 3012 is connected to the first guide section 3011 and extends circumferentially around the first direction. Specifically, when the slide groove 301 is formed on the first housing 101, the end of the first guide section 3011 away from the second guide section 3012 extends to the edge of the first housing 101. At this time, the slider 302 slides into the first guide section 3011 from the end away from the second guide section 3012, and slides along the first guide section 3011 (that is, along the first direction) until it reaches the junction of the second guide section 3012 and the first guide section 3011. At this time, the first housing 101 and the second housing 201 are rotated relative to each other around the first direction, so that the slider 302 slides along the second guide section 3012, thereby restricting the sliding of the slider 302 along the first direction, thereby restricting the relative sliding of the first housing 101 and the second housing 201 in the first direction, and achieving the function of connection and fixation.

[0056] Similarly, when the slide groove 301 is provided on the second housing 201, the end of the first guide slide section 3011 of the slide groove 301 away from the second guide slide section 3012 needs to extend to the edge of the second housing 201 so that the slider 302 fixed on the first housing 101 can slide into the first guide slide section 3011 along the first direction.

[0057] In some preferred embodiments of this application, the semi-disposable injection pen further includes a protective member 40 and an elastic member 50. The protective member 40 is slidably disposed along a first direction, and one end of the elastic member 50 is fixedly connected to the second housing 201, while the other end is connected to the protective member 40. The main function of the protective member 40 is to prevent the needle 2022 from being exposed and accidentally puncturing the needle before and after use. Specifically, when the protective member 40 is in the protective state, its projection along the perpendicular first direction covers the projection surface of the needle 2022.

[0058] Understandably, when the injection pen is used for normal injection, the protective member 40 contacts the muscle and slides along the first direction under the action of mutual compression, thereby exposing the needle 2022 relative to the protective member 40 from the first direction, so that the syringe 202 can inject drugs subcutaneously or intramuscularly. It should be noted that during this process, the elastic member 50 stores elastic potential energy under the action of the protective member 40.

[0059] After the injection pen completes the injection, the protective component 40 is no longer in contact with the muscle. At this time, the protective component 40 slides along the first direction under the action of the elastic component 50 and returns to the protective state.

[0060] In a further preferred embodiment of this application, the elastic element 50 is fixedly connected to the protective element 40. Specifically, the elastic element 50 is a spring element, one end of which is fixedly connected to the second housing 201, and the other end is fixedly connected to the protective element 40, so as to limit the sliding stroke of the protective element 40.

[0061] In some embodiments of this application, the protective member 40 is slidably engaged with the second housing 201, a limiting block 2011 is provided on the second housing 201, and a limiting groove 401 is formed on the protective member 40. The sliding stroke of the protective member 40 is further limited by the sliding engagement of the limiting block 2011 and the limiting groove 401.

[0062] In some preferred embodiments of this application, the semi-disposable injection pen further includes a pen cap structure 60, which includes a cap 601, a protective element 602, and a connector 603. The cap 601 is detachably connected to the second housing 201, the protective element 602 surrounds the needle tip 2022, and the connector 603 fixes the cap 601 and the protective element 602 together. Before the cartridge 20 is installed on the main unit 10 and before the injection pen is used for injection, the pen cap structure 60 remains connected to the second housing 201 and protects the needle tip 2022 through the protective element 602. When the injection pen needs to be used, the cap 601 is removed from the second housing 201, and the protective element 602 is detached along with it through the connector 603.

[0063] It is important to note that when the injection pen is not in use, the protective element 602 is closer to the needle 2022 than the protective element 40. Furthermore, the difference between the protective elements 602 and 40 is that the primary function of the protective element 602 is to protect the needle 2022 during periods of inactivity of the cartridge 20 and the injection pen, preventing the needle 2022 from being exposed. Since the needle 2022 is connected to the fluid container 2024, exposure of the needle 2022 would allow air intrusion and contamination of the medication, affecting its efficacy. The protective element 40's function is to prevent accidental contact or puncture by the needle 2022 before and after use of the injection pen.

[0064] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0065] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. Therefore, the patent protection scope of this application should be determined by the appended claims.

Claims

1. A semi-disposable injection pen, characterized in that, Includes a detachably connected main unit (10) and a cartridge (20); The host (10) includes: First shell (101); Drive mechanism (102), said drive mechanism (102) is mounted on the first housing (101); and A pusher (103) is connected to the power output end of the drive mechanism (102) and can move along a first direction under the drive of the drive mechanism (102); The cartridge (20) includes: A second housing (201) is detachably and fixedly connected to the first housing (101); and A syringe (202) includes a barrel (2021), a needle (2022), and a piston (2023). The barrel (2021) is fixedly connected to the second housing (201). The needle (2022) is fixedly connected to the barrel (2021) and communicates with the interior of the barrel (2021). The piston (2023) is slidably disposed inside the barrel (2021). In the assembled state, along the first direction, the pusher (103) is located on the side of the piston (2023) away from the needle (2022), and projected along the first direction, the projection surface of the piston (2023) covers the projection surface of the pusher (103).

2. The semi-disposable injection pen according to claim 1, characterized in that, The travel of the pusher (103) along the first direction is not less than the travel of the piston (2023) along the first direction in the syringe (202).

3. The semi-disposable injection pen according to claim 1, characterized in that, The pusher (103) is provided with a sensor (1031), which is electrically connected to the drive mechanism (102), and the drive mechanism (102) can receive the electrical signal at least when the sensor (1031) is in contact with the piston (2023).

4. The semi-disposable injection pen according to claim 1, characterized in that, The drive mechanism (102) includes: A drive motor (1021), the drive motor (1021) being fixedly disposed within the first housing (101); and A lead screw (1022), one end of which is fixedly connected to the output shaft of the drive motor (1021); The pusher (103) is threadedly connected to the lead screw (1022).

5. The semi-disposable injection pen according to claim 4, characterized in that, The first housing (101) is provided with a cartridge holder slot (1013), and the pusher (103) extends to the center of the cartridge holder slot (1013); the second housing (201) is provided with a plug section (2012) that matches the cartridge holder slot (1013), the plug section (2012) has a through hole (2013), and the opening end of the syringe (202) in the second housing (201) is directly opposite the through hole (2013).

6. The semi-disposable injection pen according to claim 1, characterized in that, A locking structure (30) for fixing the first housing (101) and the second housing (201) is provided between the first housing (101) and the second housing (201).

7. The semi-disposable injection pen according to claim 6, characterized in that, The locking structure (30) includes a sliding groove (301) and a slider (302) that are in sliding engagement. The groove (301) has a first guide section (3011) and a second guide section (3012). The first guide section (3011) extends along the first direction, and the second guide section (3012) is connected to the first guide section (3011) and extends circumferentially around the first direction. The slide groove (301) is formed on the first housing (101) and the slider (302) is fixed on the second housing (201). The first guide section (3011) extends to the edge of the first housing (101) at one end away from the second guide section (3012). or The groove (301) is formed on the second housing (201) and the slider (302) is fixed on the first housing (101). The first guide section (3011) extends to the edge of the second housing (201) at one end away from the second guide section (3012).

8. The semi-disposable injection pen according to claim 1, characterized in that, The semi-disposable injection pen also includes a protective component (40) and an elastic component (50). The protective component (40) is slidably disposed along the first direction. One end of the elastic component (50) is fixedly connected to the second housing (201) and the other end is connected to the protective component (40). When the protective component (40) is in a protective state, it is projected along the direction perpendicular to the first direction, and the projection surface of the protective component (40) covers the projection surface of the needle (2022).

9. The semi-disposable injection pen according to claim 8, characterized in that, The elastic element (50) is fixedly connected to the protective element (40).

10. The semi-disposable injection pen according to claim 1, characterized in that, The semi-disposable injection pen also includes a pen cap structure (60), which includes: A cover (601) is detachably connected to the second housing (201); Protective element (602), said protective element (602) surrounding the needle tip (2022); and A connector (603) is fixedly connected to the cover (601) and the protective member (602).

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