Injection device

Abstract

The utility model discloses an injection device which comprises a shell, a main driving shaft, an extrusion screw, a transmission seat and a limiting sleeve, the main driving shaft is arranged on the inner side of the shell, an axial hole is formed in the main driving shaft, a limiting face is arranged on the inner wall of the axial hole, and a guide tooth part is arranged on the inner wall of the axial hole in the axial direction of the axial hole; the extrusion screw rod is in threaded connection with the inner side of the shell, and the tail part of the extrusion screw rod is arranged in the axial hole; the transmission seat is rotationally arranged on the shell, the transmission seat and the extrusion screw rod are arranged in a circumferential limiting manner and are arranged in an axial sliding manner, and the main driving shaft is used for driving the extrusion screw rod to rotate; the limiting sleeve is in threaded connection with the extrusion screw rod, a plurality of positioning tooth parts are arranged on the peripheral surface of the limiting sleeve at intervals, and the guide tooth parts are embedded in tooth grooves between the adjacent positioning tooth parts. A plurality of positioning tooth parts are arranged on the outer circumferential face of the limiting sleeve at intervals, when the limiting sleeve is assembled to the axial hole, the guide tooth parts on the inner circumferential face of the axial hole can easily slide into tooth grooves between the adjacent positioning tooth parts, and the limiting sleeve is convenient to assemble.

Description

Technical Field

[0001] The utility model relates to an injection device. Background Art

[0002] During the treatment process, some drugs can be injected into patients by an injection device, such as semaglutide for diabetes.

[0003] In the related art, an injection device usually includes a main drive shaft and a limit sleeve. Among them, an axial hole is provided along the axial direction of the main drive shaft, a strip-shaped protrusion is arranged on the inner side of the axial hole in the axial direction, a strip-shaped groove is arranged on the outer peripheral surface of the limit sleeve in the axial direction, the limit sleeve is arranged in the axial hole of the main drive shaft, and the strip-shaped protrusion is slidably arranged in the strip-shaped groove. Thus, the limit sleeve and the main drive shaft are circumferentially restricted.

[0004] Among them, when the staff assembles the limit sleeve on the main drive shaft, the end of the strip-shaped protrusion needs to be aligned with the end of the strip-shaped groove, so as to assemble the limit sleeve into the axial hole. However, the assembly difficulty between the main drive shaft and the limit sleeve is relatively large, resulting in a relatively high working intensity of the staff. Summary of the Utility Model

[0005] The utility model aims to at least solve one of the technical problems existing in the prior art. For this purpose, the utility model provides an injection device with convenient assembly.

[0006] The embodiment of the present application provides an injection device, including:

[0007] A housing;

[0008] A main drive shaft, arranged inside the housing, an axial hole is provided along the central axis of the main drive shaft, a guiding port is formed at the end of the main drive shaft for the axial hole, a limiting surface facing the guiding port is provided on the inner wall of the axial hole, a guiding tooth part is arranged on the inner wall of the axial hole along its axial direction, one end of the guiding tooth part extends towards the guiding port, and the other end extends towards the limiting surface;

[0009] An extrusion screw, threadedly connected to the inside of the housing, the tail of the extrusion screw is arranged in the axial hole, and the head of the extrusion screw is used to extrude the tail of the medicine bottle;

[0010] A transmission seat, rotatably arranged on the housing, the transmission seat is circumferentially restricted and axially slidably arranged with the extrusion screw, and the main drive shaft is used to be in transmission connection with the transmission seat to drive the extrusion screw to rotate through the transmission seat;

[0011] A limiting sleeve, threadedly connected to the extrusion screw, and a plurality of positioning tooth portions are provided at intervals on the outer peripheral surface of the limiting sleeve, and the guiding tooth portion is embedded in the tooth groove between adjacent positioning tooth portions.

[0012] According to some embodiments of the present invention, the cross sections of the positioning tooth portion and the guiding tooth portion are triangular.

[0013] According to some embodiments of the present invention, the injection device further includes:

[0014] A torsion spring, sleeved on the outside of the main drive shaft and connected to the housing and the main drive shaft;

[0015] A clutch assembly for maintaining the position of the main drive shaft after rotational adjustment;

[0016] Wherein, a first circumferential limiting portion is spaced in the circumferential direction on the inner side of the housing, a second circumferential limiting portion is spaced in the circumferential direction on the clutch assembly, the first circumferential limiting portion and the second circumferential limiting portion are circumferentially limited and can slide axially relative to each other, and the main drive shaft can be pressed to axially slide the second circumferential limiting portion away from the first circumferential limiting portion;

[0017] And, a plurality of first transmission portions are spaced in the circumferential direction on the clutch assembly, a plurality of second transmission portions are spaced in the circumferential direction on the transmission seat, the first transmission portion and the second transmission portion are always circumferentially limited when the main drive shaft slides axially, and the first transmission portion can slide axially relative to the second transmission portion.

[0018] According to some embodiments of the present invention, the clutch assembly includes:

[0019] A clutch base, sleeved on the main drive shaft, and the second circumferential limiting portion is spaced in the circumferential direction on the clutch base;

[0020] A clutch member, sleeved on the main drive shaft, a first clutch tooth is spaced in the circumferential direction on the main drive shaft, a second clutch tooth is provided in the circumferential direction on the clutch member, and the first clutch tooth meshes with the second clutch tooth;

[0021] An elastic member, one end of which abuts against the clutch base and the other end abuts against the clutch member to keep the first clutch tooth and the second clutch tooth meshed;

[0022] A connecting seat, connected to the clutch member and rotatably connected to the main drive shaft, and the first transmission portion is spaced in the circumferential direction on the connecting seat.

[0023] According to some embodiments of the present utility model, the second engaging teeth of the engaging member and the positioning tooth portion of the limiting sleeve are provided in equal numbers.

[0024] According to some embodiments of the present utility model, for the first circumferential limiting portion, the angle θ1 in the circumferential direction, for the second circumferential limiting portion, the angle θ2 in the circumferential direction, and for the first engaging tooth, the angle θ3 in the circumferential direction, θ1 = mθ3, θ2 = mθ3, where m is a positive integer greater than 0;

[0025] And / or, for the first transmission portion, the angle θ4 in the circumferential direction, for the second transmission portion, the angle θ5 in the circumferential direction, and for the first engaging tooth, the angle θ3 in the circumferential direction, θ4 = mθ3, θ5 = mθ3, where m is a positive integer greater than 0.

[0026] According to some embodiments of the present utility model, the injection device includes:

[0027] A transmission sleeve, rotatably disposed inside the housing and circumferentially restricted with the main drive shaft so as to be able to rotate synchronously with the main drive shaft;

[0028] A scale sleeve, disposed inside the housing and threadedly connected to the inner side of the housing. The scale sleeve is slidably sleeved outside the transmission sleeve and circumferentially restricted so as to be able to rotate synchronously with the transmission sleeve. An observation port is provided on the side wall of the housing for observing the scale of the scale sleeve.

[0029] According to some embodiments of the present utility model, a fixed sleeve is integrally provided inside the housing. The fixed sleeve is sleeved outside the torsion spring. The first circumferential limiting portion is circumferentially spaced at one end of the fixed sleeve close to the engaging assembly. The transmission sleeve is rotatably sleeved on the fixed sleeve, and the front end portion of the torsion spring is connected to the main drive shaft, and the rear end portion is connected to the fixed sleeve.

[0030] According to some embodiments of the present utility model, a fixed sleeve is axially inserted and fixed inside the housing. The fixed sleeve is sleeved outside the torsion spring. The first circumferential limiting portion is circumferentially spaced at one end of the fixed sleeve close to the engaging assembly. The transmission sleeve is rotatably sleeved on the fixed sleeve, and the front end portion of the torsion spring is connected to the main drive shaft, and the rear end portion is connected to the fixed sleeve.

[0031] According to some embodiments of the present utility model, a third circumferential limiting portion is provided on the inner circumferential surface of the housing, and a fourth circumferential limiting portion is provided on the side portion of the fixed sleeve. The third circumferential limiting portion and the fourth circumferential limiting portion are axially inserted and matched.

[0032] As can be seen from the above technical solutions, the embodiments of the present application have the following advantages: In the dose adjustment stage, the driving seat keeps the extrusion screw stationary. During the reverse rotation adjustment of the main drive shaft, the main drive shaft drives the limit sleeve to rotate in the same reverse direction. Also, since the extrusion screw remains stationary and is threadedly connected to the limit sleeve, when the main drive shaft drives the limit sleeve to rotate, the limit sleeve slides along the axial hole towards the limit surface until the end of the limit sleeve abuts against the limit surface, at which point the limit sleeve stops sliding and the dose adjustment of the injection device is completed. In the injection stage, the main drive shaft is in transmission connection with the driving seat, and the main drive shaft drives the driving seat to rotate forward. The driving seat drives the extrusion screw to rotate forward synchronously. Also, because the extrusion screw is threadedly connected to the housing, when the driving seat drives the extrusion screw to rotate, the extrusion screw moves outward along the axial hole, and the head of the extrusion screw abuts against the tail of the reagent bottle, thereby injecting the reagent for the patient. When the end of the limit sleeve abuts against the driving seat, the injection of the reagent in the reagent bottle is completed.

[0033] Among them, a plurality of positioning tooth portions are spaced apart on the outer peripheral surface of the limit sleeve, usually 20 or 24 positioning tooth portions are provided. With such a setting, when the limit sleeve is assembled into the axial hole, the guiding tooth portions on the inner peripheral surface of the axial hole can easily slide into the tooth grooves between adjacent positioning tooth portions, thereby facilitating the staff to assemble the limit sleeve into the axial hole, and further reducing the working intensity of the staff. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic cross-sectional structure diagram of the main components of the injection device according to the embodiment of the present utility model;

[0035] Figure 2 is an exploded structure diagram of the main drive shaft, the extrusion screw and the limit sleeve according to the embodiment of the present utility model;

[0036] Figure 3 is a schematic axial cross-sectional structure diagram of the main drive shaft according to the embodiment of the present utility model;

[0037] Figure 4 is an exploded structure diagram of the main components of the injection device according to the embodiment of the present utility model;

[0038] Figure 5 is an exploded structure diagram of the clutch assembly according to the embodiment of the present utility model;

[0039] Figure 6 is Figure 1 the axial exploded view of

[0040] Figure 7 is an exploded structure diagram of the injection device according to the embodiment of the present utility model;

[0041] Figure 8Exploded structural schematic diagram of the fixed sleeve, transmission sleeve, scale sleeve and rear shell of the embodiment of the present utility model;

[0042] Figure 9 Cross-sectional structural schematic diagram of the rear shell, main drive shaft and torsion spring of the embodiment of the present utility model;

[0043] Figure 10 Overall structural schematic diagram of the injection device of the embodiment of the present utility model.

[0044] Among them, the meanings of the reference numerals are as follows:

[0045] 100, housing; 110, front shell; 120, rear shell; 121, observation port; 122, third circumferential limiting portion; 130, knob; 140, button; 200, main drive shaft; 210, axial hole; 211, limiting surface; 212, guiding port; 220, guiding tooth portion; 230, annular flange; 231, first clutch tooth; 232, annular groove; 300, extrusion screw; 310, guiding groove; 400, transmission seat; 410, guiding protrusion; 420, second transmission portion; 430, second elastic arm; 440, second protrusion portion; 500, limiting sleeve; 510, positioning tooth portion; 600, torsion spring; 700, clutch assembly; 710, clutch base; 711, second circumferential limiting portion; 712, first tooth portion; 720, clutch member; 721, second clutch tooth; 722, first elastic arm; 723, first protrusion portion; 730, elastic member; 740, connecting seat; 741, first transmission portion; 800, fixed seat; 810, second tooth portion; 910, transmission sleeve; 920, scale sleeve; 930, fixed sleeve; 931, inner cylinder portion; 932, front ring portion; 933, rear ring portion; 934, fourth circumferential limiting portion; 935, first circumferential limiting portion. Detailed implementation manners

[0046] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the drawings, in which the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present utility model and should not be construed as a limitation to the present utility model.

[0047] In the description of the present utility model, it should be understood that the orientation descriptions, such as up, down, front, back, upper, lower, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model.

[0048] In the description of the present utility model, the meaning of "several" is more than one, the meaning of "multiple" is more than two, and understandings such as "greater than", "less than", "exceeding", etc. do not include the corresponding number, while understandings such as "above", "below", "within", etc. include the corresponding number. If there is a description of "first" and "second", it is only for the purpose of distinguishing technical features and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0049] In the description of the present utility model, unless otherwise clearly defined, terms such as "set", "installed", "connected", etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present utility model in combination with the specific content of the technical solution.

[0050] In the description of the present utility model, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0051] The present utility model will be further described in detail below with reference to the accompanying drawings.

[0052] Please refer to Figures 1 to 3, an injection device provided by an embodiment of the present utility model, comprising a housing 100, a main drive shaft 200, an extrusion screw 300, a transmission seat 400 and a limit sleeve 500. Among them, the main drive shaft 200 is arranged inside the housing 100. An axial hole 210 is formed along the central axis of the main drive shaft 200. A guiding port 212 is formed at the end of the main drive shaft 200 for the axial hole 210. The inner wall of the axial hole 210 has a limiting surface 211 arranged facing the guiding port 212. A guiding tooth portion 220 is arranged along the axial direction of the inner wall of the axial hole 210. One end of the guiding tooth portion 220 extends towards the guiding port 212, and the other end extends towards the limiting surface 211; the extrusion screw 300 is threadedly connected to the inside of the housing 100. The tail of the extrusion screw 300 is arranged in the axial hole 210, and the head of the extrusion screw 300 is used for extruding the tail of the medicine bottle; the transmission seat 400 is rotatably arranged on the housing 100. The transmission seat 400 is circumferentially restricted and axially slidably arranged with the extrusion screw 300. The main drive shaft 200 is used for driving connection with the transmission seat 400 to drive the extrusion screw 300 to rotate through the transmission seat 400; the limit sleeve 500 is threadedly connected to the extrusion screw 300. A plurality of positioning tooth portions 510 are arranged at intervals on the outer peripheral surface of the limit sleeve 500. The guiding tooth portion 220 is embedded in the tooth groove between adjacent positioning tooth portions 510.

[0053] Among them, the transmission seat 400 is circumferentially restricted and axially slidably arranged with the extrusion screw 300, that is, the transmission seat 400 and the extrusion screw 300 can only slide relative to each other and cannot rotate relative to each other. Similarly, the positioning tooth portions 510 are arranged at intervals in the circumferential direction on the outer peripheral surface of the limit sleeve 500, and the guiding tooth portion 220 is axially extended on the inner peripheral surface of the axial hole 210. The guiding tooth portion 220 is embedded in the tooth groove between adjacent positioning tooth portions 510. Thus, the main drive shaft 200 and the limit sleeve 500 can only slide relative to each other and cannot rotate relative to each other.

[0054] In the specific application process, during the dose adjustment stage, the driving seat 400 keeps the extrusion screw 300 stationary. During the reverse rotation adjustment of the main drive shaft 200, the main drive shaft 200 drives the limit sleeve 500 to rotate synchronously in the reverse direction. Also, because the extrusion screw 300 remains stationary and is threadedly connected to the limit sleeve 500, when the main drive shaft 200 drives the limit sleeve 500 to rotate, the limit sleeve 500 slides along the axial hole 210 towards the limit surface 211 until the end of the limit sleeve 500 abuts against the limit surface 211, and the limit sleeve 500 stops sliding, completing the dose adjustment of the injection device. During the injection stage, the main drive shaft 200 is in driving connection with the driving seat 400, and the main drive shaft 200 drives the driving seat 400 to rotate forward. The driving seat 400 drives the extrusion screw 300 to rotate forward synchronously. Also, since the extrusion screw 300 is threadedly connected to the housing 100, when the driving seat 400 drives the extrusion screw 300 to rotate, the extrusion screw 300 moves outward along the axial hole 210, and the head of the extrusion screw 300 abuts against the tail of the reagent bottle, thereby injecting the reagent for the patient. When the end of the limit sleeve 500 abuts against the driving seat 400, the injection of the reagent in the reagent bottle is completed.

[0055] It can be understood that a plurality of positioning tooth portions 510 are arranged at intervals on the outer peripheral surface of the limit sleeve 500, usually 20 or 24 positioning tooth portions 510 are arranged. With such an arrangement, when the limit sleeve 500 is assembled into the axial hole 210, the guiding tooth portions 220 on the inner peripheral surface of the axial hole 210 can easily slide into the tooth grooves between adjacent positioning tooth portions 510, thereby facilitating the staff to assemble the limit sleeve 500 into the axial hole 210, and further reducing the working intensity of the staff.

[0056] In a specific embodiment, the cross-sections of the positioning tooth portions 510 and the guiding tooth portions 220 are triangular. With such an arrangement, when the limit sleeve 500 slides into the axial hole 210 from the guiding port 212, the interference area between the guiding tooth portions 220 and the positioning tooth portions 510 in the circumferential direction is small, thereby further ensuring that when the limit sleeve 500 slides into the guiding hole from the guiding port 212, the guiding tooth portions 220 and the positioning tooth portions 510 are not likely to interfere, and further ensuring that the limit sleeve 500 can be conveniently assembled into the axial hole 210.

[0057] Of course, the cross-sections of the positioning tooth portions 510 and the guiding tooth portions 220 are not limited to only triangular. For example, the cross-sections of the positioning tooth portions 510 and the guiding tooth portions 220 can also be rectangular or other shapes.

[0058] In some embodiments, referring to Figures 1 to 4, the injection device further includes a torsion spring 600 and a clutch assembly 700. Among them, a circumferential flange 230 protrudes outward from the front end of the main drive shaft 200. The torsion spring 600 is sleeved outside the main drive shaft 200. The front end of the torsion spring 600 is hooked in the hooking hole of the circumferential flange 230, and the other end is connected to the inner side of the housing 100, so as to enable the main drive shaft 200 to have a reset rotational force after rotational adjustment. The clutch assembly 700 is connected to the housing 100 and the main drive shaft 200, and is used to maintain the position of the main drive shaft 200 after rotational adjustment. One of the clutch assembly 700 and the main drive shaft 200 is used for driving connection with the transmission seat 400.

[0059] Among them, a first circumferential limiting portion 935 is spaced in the circumferential direction on the inner side of the housing 100. The end of the clutch assembly 700 away from the transmission seat 400 is provided with a second circumferential limiting portion 711 at intervals in the circumferential direction. The first circumferential limiting portion 935 and the second circumferential limiting portion 711 are axially inserted and matched, and the first circumferential limiting portion 935 and the second circumferential limiting portion 711 are circumferentially limited. Thus, the housing 100 restricts the relative rotation of the clutch assembly 700 through the first circumferential limiting portion 935, thereby restricting the rotation of the main drive shaft 200. At the same time, the first circumferential limiting portion 935 and the second circumferential limiting portion 711 are circumferentially limited, and the main drive shaft 200 can slide relative to the housing 100 along the axial direction of the housing 100. Thus, the main drive shaft 200 can be pressed so that the first circumferential limiting portion 935 and the second circumferential limiting portion 711 are separated in the axial direction.

[0060] Specifically, in the energy storage stage, the first circumferential limiting portion 935 and the second circumferential limiting portion 711 are in a circumferentially restricted state in the circumferential direction. The staff reversely rotates and adjusts the main drive shaft 200, and the torsion spring 600 is energized. After the rotational adjustment of the main drive shaft 200 is completed, the clutch assembly 700 locks the main drive shaft 200, and the clutch assembly 700 remains in the adjusted position, and the torsion spring 600 is energized. In the driving stage, overcoming the elastic force of the torsion spring 600 in the axial direction, the staff axially presses the main drive shaft 200 forward, and the main drive shaft 200 drives the clutch assembly 700 to move forward synchronously. The first circumferential limiting portion 935 and the second circumferential limiting portion 711 are axially separated. At this time, the housing 100 releases the restriction on the clutch assembly 700, and the clutch assembly 700 loses the restricting effect on the main drive shaft 200. Therefore, under the action of the torsion spring 600, the clutch assembly 700 and the main drive shaft 200 rotate forward synchronously, thereby driving the transmission seat 400 to rotate forward, and the extrusion screw 300 axially moves forward relative to the housing 100, thereby extruding the tail of the reagent bottle.

[0061] In a further possible embodiment, referring to Figures 4 to 6, the clutch assembly 700 includes a clutch base 710, a clutch member 720, an elastic member 730 and a connection seat 740. Among them, the clutch base 710 is sleeved on the main drive shaft 200, and the second circumferential limiting portion 711 as described above is provided at intervals in the circumferential direction at one end of the clutch base 710 away from the transmission seat 400. An annular flange 230 is provided at the end of the main drive shaft 200 close to the transmission seat 400, and the first clutch teeth 231 are provided at intervals in the circumferential direction at the end of the annular flange 230 away from the transmission seat 400. The clutch member 720 is sleeved on the outside of the main drive shaft 200 and is located between the clutch base 710 and the annular flange 230. The second clutch teeth 721 are provided in the circumferential direction at one end of the clutch member 720 close to the annular flange 230, and the first clutch teeth 231 are engaged with the second clutch teeth 721. The elastic member 730 is sleeved on the main drive shaft 200, one end of which abuts against the clutch base 710, and the other end abuts against the clutch member 720. Thus, the elastic member 730 keeps the first clutch teeth 231 and the second clutch teeth 721 engaged. The connection seat 740 is connected to the clutch base 710, for example, by snap connection. The connection seat 740 is rotatably connected to the main drive shaft 200. For example, an annular groove 232 is provided in the circumferential direction on the annular flange 230, and an annular flange 230 is provided on the inner circumferential surface of the connection seat 740, and the annular flange 230 is rotatably embedded in the annular groove 232. Among them, one of the connection seat 740 and the main drive shaft 200 is used for rotatably connecting to the transmission seat 400.

[0062] Furthermore, a plurality of first tooth portions 712 are provided at intervals in the circumferential direction on the inner side of the clutch base 710. A first elastic arm 722 extends circumferentially on the side of the clutch member 720. A first protrusion 723 protrudes outward at the end of the first elastic arm 722, and the first protrusion 723 is embedded in the tooth groove between adjacent first tooth portions 712 and can slide axially along the tooth groove. Among them, in the reverse direction of the main drive shaft 200, more precisely, in the opposite direction of the torsion of the torsion spring 600, the resistance between the first clutch teeth 231 and the second clutch teeth 721 is less than the resistance between the first protrusion 723 and the first tooth portions 712; in the forward direction of the main drive shaft 200, more precisely, in the torsion direction of the torsion spring 600, the resistance between the first clutch teeth 231 and the second clutch teeth 721 is greater than the resistance between the first protrusion 723 and the first tooth portions 712.

[0063] Specifically, when the user reversely rotates the adjustment main drive shaft 200, the resistance between the first clutch tooth 231 and the second clutch tooth 721 is less than the resistance between the first protrusion 723 and the first tooth portion 712. Thus, the clutch member 720 overcomes the elastic force of the elastic member 730 and moves in a direction away from the first clutch tooth 231. Therefore, the first clutch tooth 231 rotates relative to the second clutch tooth 721. When the rotation of the main drive shaft 200 stops, each second clutch tooth 721 switches to other tooth grooves, so that the main drive shaft 200 is maintained at the rotated position. When it is necessary to correct the position of the main drive shaft 200 after adjustment, the user forwards rotates the adjustment main drive shaft 200, and the resistance between the first clutch tooth 231 and the second clutch tooth 721 is greater than the resistance between the first protrusion 723 and the first tooth portion 712. Thus, the relative position between the clutch member 720 and the main drive shaft 200 remains unchanged, the first elastic arm 722 deforms inwards, and the first protrusion 723 switches positions in the tooth grooves between adjacent first tooth portions 712, so that the main drive shaft 200 is maintained at the adjusted position.

[0064] Furthermore, a plurality of first transmission portions 741 are provided at intervals in the circumferential direction at the end of the connecting seat 740 close to the transmission seat 400, and a plurality of second transmission portions 420 are provided at intervals in the circumferential direction at the end of the transmission seat 400 close to the connecting seat 740. The first transmission portions 741 and the second transmission portions 420 are axially inserted and connected. Thus, the first transmission portions 741 and the second transmission portions 420 are circumferentially limited, and the first transmission portions 741 and the second transmission portions 420 are axially slidably arranged and always remain circumferentially limited.

[0065] Specifically, the lengths of the first transmission portions 741 and the second transmission portions 420 in the axial direction are relatively large, and the first transmission portions 741 and the second transmission portions 420 always remain circumferentially limited. That is, when the first circumferential limiting portion 935 and the second circumferential limiting portion 711 are in a circumferentially limited state, the first transmission portions 741 and the second transmission portions 420 remain in a circumferentially limited state, that is, they are inserted and matched with each other. When the first circumferential limiting portion 935 and the second circumferential limiting portion 711 are axially separated from each other, the first transmission portions 741 and the second transmission portions 420 still remain circumferentially fixed, that is, they are inserted and matched with each other.

[0066] It can be understood that the first transmission portions 741 and the second transmission portions 420 always remain circumferentially limited. With such a setting, when the main drive shaft 200 drives or stops driving the transmission seat 400 through the clutch assembly 700, the main drive shaft 200 and the transmission seat 400 can be kept consistent, so as to ensure that the main drive shaft 200 can accurately control the dosage of medicine injected by the injection device to the patient.

[0067] In addition, during the dose adjustment process, the first transmission part 741 and the second transmission part 420 are circumferentially restricted. With this arrangement, the clutch assembly 700 can restrict the rotation of the transmission seat 400, and the transmission seat 400 restricts the rotation of the main drive shaft 200. Thus, during the rotation of the main drive shaft 200, the main drive shaft 200 can drive the limiting sleeve 500 to move along the extrusion screw 300 towards the limiting surface 211.

[0068] It should be noted that during the assembly process of the injection device, the transmission seat 400 and the limiting sleeve 500 are pre-installed on the extrusion screw 300, and the extrusion screw 300 is installed on the main drive shaft 200. The staff needs to align the limiting sleeve 500 with the axial hole 210 and align the second transmission part 420 with the first transmission part 741, so as to complete the simultaneous installation of the limiting sleeve 500 and the transmission seat 400. In this application, a plurality of positioning tooth parts 510 are arranged at intervals on the outer peripheral surface of the limiting sleeve 500, and the limiting sleeve 500 can easily slide into the tooth grooves between adjacent positioning tooth parts 510, thus facilitating the assembly of the transmission seat 400 to the connecting seat 740.

[0069] In some embodiments, the number of the second clutch teeth 721 of the clutch member 720 is the same as that of the positioning tooth parts 510 of the limiting sleeve 500. For example, both the second clutch teeth 721 of the clutch member 720 and the positioning tooth parts 510 of the limiting sleeve 500 are provided with 20 or 24. It can be understood that 24 teeth on the circumference of the limiting sleeve 500 are preferably corresponding to the equally divided numbers of the dose scale. The angle of each set measurement unit is synchronous. When assembling, there is no interference caused by inconsistent angles between the protruding ratchet teeth or convex keys and the concave ratchet teeth or protruding key grooves (i.e., the above-mentioned guiding tooth parts 220 and positioning tooth parts 510). When the number of the mutually cooperating protruding teeth or grooves is the minimum number, the position needs to be aligned during assembly. If it is less than 24 equal divisions, the assembly position needs to be aligned when assembling in place. Of course, for the mating structure with more than 24 equal divisions, although it is more precise and can also achieve assembly without interference or jamming, considering the product size and the fineness that the component materials can be processed to, more and more precise equal division structures are not particularly preferred structures.

[0070] In some embodiments, the angle θ1 of the first circumferential limiting portion 935 in the circumferential direction, the angle θ2 of the second circumferential limiting portion 711 in the circumferential direction, and the angle θ3 of the first clutch tooth 231 in the circumferential direction satisfy θ1 = mθ3 and θ2 = mθ3, where m is a positive integer greater than 0. Specifically, the dose setting mechanism is equally divided into 24 parts in one circle. If the equal division numbers of the clutch assembly 700 and the housing 100 are inconsistent, an angular difference will occur. For example, when equally divided into 24 in one circle, when setting a single injection dose, the rotated angle is 15 degrees. If the docking position of the housing 100 is 30, then the angle of the mating teeth of the housing 100 is 12 degrees, resulting in an angular difference, and the meshing teeth will interfere due to inconsistent angles. Therefore, in principle, it is preferred that the subsequent structures for the scaled dose be kept consistent.

[0071] In some embodiments, the angle θ4 of the first transmission portion 741 in the circumferential direction, the angle θ5 of the second transmission portion 420 in the circumferential direction, and the angle θ3 of the first clutch tooth 231 in the circumferential direction satisfy θ4 = mθ3 and θ5 = mθ3, where m is a positive integer greater than 0. Specifically, the dose setting mechanism is equally divided into 24 parts in one circle. If the equal division numbers of the clutch assembly 700 and the housing 100 are inconsistent, an angular difference will occur. For example, when equally divided into 24 in one circle, when setting a single injection dose, the rotated angle is 15 degrees. If the docking position of the housing 100 is 30, then the angle of the mating teeth of the housing 100 is 12 degrees, resulting in an angular difference, and the meshing teeth will interfere due to inconsistent angles. Therefore, in principle, it is preferred that the subsequent structures for the scaled dose be kept consistent.

[0072] In some embodiments, the injection device further includes a fixed seat 800. The extrusion screw 300 passes through the inner ring body of the fixed seat 800 and is threadedly connected to the fixed seat 800. Thus, the extrusion screw 300 is threadedly connected to the housing 100 through the fixed seat 800. The front end portion of the transmission seat 400 is rotatably provided at the rear end portion of the inner ring body of the fixed seat 800. Thus, relative positioning between the fixed seat 800 and the transmission seat 400 is achieved. The housing 100 includes a front shell 110 and a rear shell 120 (refer to Figure 10 ), the front end portion of the rear shell 120 is assembled on the outside of the fixed seat 800, the front shell 110 is assembled at one end of the fixed seat 800 away from the rear shell 120. Components such as the main drive shaft 200 and the transmission seat 400 are assembled on the rear shell 120. The inner side of the front shell 110 is used to accommodate the reagent bottle. The acting end of the extrusion screw 300 extends to the inner side of the front shell 110 to act on the tail of the reagent bottle. In addition, the rear shell 120 is provided with a button 140 and a knob 130. The button 140 facilitates pressing of the main drive shaft 200, and the knob 130 facilitates rotation of the main drive shaft 200.

[0073] Further, refer to Figures 4 to 6, on the inner circumferential surface of the outer ring body of the fixed seat 800, a second tooth portion 810 is provided at intervals. On the side portion of the transmission seat 400, a second elastic arm 430 extends circumferentially. At the end of the second elastic arm 430, a second protrusion 440 protrudes outward. The second protrusion 440 is embedded in the tooth groove between adjacent second tooth portions 810. During the rotation of the transmission seat 400, the second elastic arm 430 and the second protrusion 440 also rotate circumferentially. The second elastic arm 430 undergoes elastic deformation, and the second protrusion 440 jumps into each tooth groove in sequence, so that the injection device makes a sound and / or generates a slight vibration during the drug injection process to remind medical staff that the injection device is injecting drugs into the patient normally.

[0074] In some embodiments, referring to Figure 7 and Figure 8 , the injection device includes a transmission sleeve 910 and a scale sleeve 920. Among them, the transmission sleeve 910 is rotatably arranged inside the housing 100 and is fixedly arranged circumferentially with the main drive shaft 200 so as to be able to rotate synchronously with the main drive shaft 200. For example, on the outer circumferential surface of the rear end portion of the main drive shaft 200, strip-shaped grooves are provided at intervals. On the inner circumferential surface of the transmission sleeve 910, strip-shaped protrusions are provided at intervals. The strip-shaped protrusions are slidably embedded in the strip-shaped grooves. Thus, the transmission sleeve 910 and the main drive shaft 200 are circumferentially restricted. The scale sleeve 920 is at least partially sleeved outside the transmission sleeve 910 and is circumferentially restricted so as to be able to rotate synchronously with the transmission sleeve 910. For example, on the outer circumferential surface of the transmission sleeve 910, strip-shaped grooves are provided along its axial direction. On the inner circumferential surface of the scale cylinder, strip-shaped protrusions are provided along its axial direction. The strip-shaped protrusions are slidably embedded in the strip-shaped grooves. Thus, the transmission sleeve 910 and the scale sleeve 920 are circumferentially restricted and can slide relative to the axis. Among them, an observation port 121 is provided on the side wall of the rear end portion of the housing 100, and the user observes the scale of the scale cylinder through the observation port 121.

[0075] Specifically, during the dose adjustment stage of the injection device, the main drive shaft 200 drives the transmission sleeve 910 to rotate in the reverse direction, and the transmission sleeve 910 drives the scale cylinder to rotate circumferentially. Also, because the scale cylinder and the transmission sleeve 910 are axially slidably arranged and are threadedly connected to the inside of the housing 100, when the transmission sleeve 910 drives the scale sleeve 920 to rotate, the scale sleeve 920 rotates backward spirally inside the housing 100, thereby adjusting the scale of the scale cylinder; at the same time, during the reverse rotation of the main drive shaft 200, the main drive shaft 200 simultaneously adjusts the position of the limit sleeve 500 in the axial hole 210 and adjusts the energy storage condition of the torsion spring 600, so as to achieve the consistency of the adjustment of the scale cylinder, the adjustment of the limit sleeve 500, and the adjustment of the torsion spring 600, thereby ensuring that the adjusted scale of the scale cylinder is consistent with the injection volume of the injection device.

[0076] During the injection phase of the injection device, the user presses the main drive shaft 200 forward, the housing 100 releases the restriction on the clutch assembly 700, and the torsion spring 600 drives the main drive shaft 200 to rotate forward. During the forward rotation of the main drive shaft 200, the main drive shaft 200 drives the scale cylinder to rotate in the reverse direction through the transmission sleeve 910, and the scale rotates forward spirally on the inner side of the housing 100, thereby determining the injection condition of the injection device.

[0077] In a possible embodiment, a fixed sleeve 930 is axially inserted and fixed inside the housing 100. The fixed sleeve 930 is sleeved outside the torsion spring 600, and the front end of the fixed sleeve 930 is connected to the clutch assembly 700 and the inner side of the housing 100. Specifically, the fixed sleeve 930 includes an inner cylinder part 931, a front ring part 932 and a rear ring part 933. Among them, the inner cylinder part 931 is located outside the torsion spring 600 and is spaced. The front ring part 932 is connected to the front end of the inner cylinder part 931 and protrudes radially outward. The front ring part 932 is axially inserted and connected to the inner peripheral surface of the housing 100. The first circumferential limiting part 935 is arranged at the end of the front ring part 932 to be circumferentially limited with the second circumferential limiting part 711 on the rear end of the clutch base 710. The rear ring part 933 is connected to the rear end of the inner cylinder part 931 and protrudes radially inward. The rear ring part 933 is provided with a second hook hole, and the rear end of the torsion spring 600 is hooked on the second hook hole, so as to be connected to the inner side of the housing 100, and the transmission sleeve 910 is sleeved outside the inner cylinder part 931.

[0078] In other possible embodiments, refer to Figure 9 , a fixed sleeve 930 is integrally provided inside the housing 100. The fixed sleeve 930 is sleeved outside the torsion spring 600. A first circumferential limiting part 935 is arranged at intervals in the circumferential direction at one end of the fixed sleeve 930 close to the clutch assembly 700. The transmission sleeve 910 is rotatably sleeved on the fixed sleeve 930, and the front end of the torsion spring 600 is connected to the main drive shaft 200, and the rear end is connected to the fixed sleeve 930.

[0079] It can be understood that a fixed sleeve 930 is axially inserted and fixed inside the housing 100, as compared with the fixed sleeve 930 being integrally provided inside the housing 100. During the assembly process of the injection device, the main drive shaft 200, the clutch assembly 700, the torsion spring 600 and the transmission sleeve 910 can be installed on the fixed sleeve 930, and then the fixed sleeve 930 is installed inside the housing 100, so as to conveniently assemble the main drive shaft 200, the clutch assembly 700, the torsion spring 600 and the transmission sleeve 910 inside the housing 100. With this setting, when assembling the injection device, the staff can conveniently complete the assembly of the injection device, thus ensuring the production efficiency of the injection device.

[0080] Further, with reference to Figures 7 to 8 , a plurality of third circumferential limiting portions 122 are arranged at intervals in the circumferential direction on the inner circumferential surface of the housing 100, and a plurality of fourth circumferential limiting portions 934 are arranged at intervals in the circumferential direction at the end of the front ring portion 932 away from the clutch assembly 700. The third circumferential limiting portion 122 is in plug-in fit with the fourth circumferential limiting portion 934. Thus, when the first circumferential limiting portion 935 is in axial plug-in fit with the second circumferential limiting portion 711, the fixed sleeve 930 and the housing 100 are circumferentially restricted and cannot rotate relative to each other, so that the rotation of the clutch assembly 700 can be limited. Moreover, with the above connection method between the fixed sleeve 930 and the housing 100, the fixed sleeve 930 can be conveniently assembled inside the housing 100, which is convenient for the installation of the main drive shaft 200, the clutch assembly 700, the torsion spring 600 and the transmission sleeve 910.

[0081] The technical means disclosed in the solution of the present utility model are not limited to the technical means disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present utility model, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present utility model.

Claims

1. An injection device, characterized in that, Comprising: A housing; A main drive shaft, disposed inside the housing, an axial hole is formed along the central axis of the main drive shaft, a guiding port is formed at the end of the main drive shaft for the axial hole, a limiting surface facing the guiding port is provided on the inner wall of the axial hole, a guiding tooth portion is arranged along the axial direction of the inner wall of the axial hole, one end of the guiding tooth portion extends towards the guiding port, and the other end extends towards the limiting surface; An extrusion screw, threadedly connected to the inside of the housing, the tail of the extrusion screw is disposed in the axial hole, and the head of the extrusion screw is used to extrude the tail of the medicine bottle; A transmission seat, rotatably arranged on the housing, the transmission seat is circumferentially restricted and axially slidably arranged with the extrusion screw, and the main drive shaft is used to be in transmission connection with the transmission seat to drive the extrusion screw to rotate through the transmission seat; A limiting sleeve, threadedly connected to the extrusion screw, a plurality of positioning tooth portions are spaced on the outer peripheral surface of the limiting sleeve, and the guiding tooth portion is embedded in the tooth groove between adjacent positioning tooth portions.

2. The injection device according to claim 1, characterized in that, The cross section of the positioning tooth portion and the guiding tooth portion is triangular.

3. An injection device according to claim 1, characterized in that, The injection device further comprises: A torsion spring, sleeved outside the main drive shaft and connected to the housing and the main drive shaft; A clutch assembly, used to maintain the position of the main drive shaft after rotational adjustment; Wherein, a first circumferential limiting portion is spaced in the circumferential direction inside the housing, a second circumferential limiting portion is spaced in the circumferential direction on the clutch assembly, the first circumferential limiting portion and the second circumferential limiting portion are circumferentially restricted and can axially slide relative to each other, and the main drive shaft can be pressed to axially slide the second circumferential limiting portion away from the first circumferential limiting portion; And, a plurality of first transmission portions are spaced in the circumferential direction on the clutch assembly, a plurality of second transmission portions are spaced in the circumferential direction on the transmission seat, the first transmission portion and the second transmission portion are always circumferentially restricted when the main drive shaft axially slides, and the first transmission portion can axially slide relative to the second transmission portion.

4. An injection device according to claim 3, characterized in that, The clutch assembly includes: A clutch base, sleeved on the main drive shaft, and the second circumferential limiting portion is spaced in the circumferential direction on the clutch base; A clutch member, sleeved on the main drive shaft, a first clutch tooth is spaced in the circumferential direction on the main drive shaft, a second clutch tooth is arranged in the circumferential direction on the clutch member, and the first clutch tooth meshes with the second clutch tooth; An elastic member, one end of the elastic member abuts against the clutch base, and the other end abuts against the clutch member to keep the first clutch tooth and the second clutch tooth meshed; A connecting seat, connected to the clutch member and rotatably connected to the main drive shaft, and the first transmission portion is spaced in the circumferential direction on the connecting seat.

5. An injection device according to claim 4, characterized in that, The number of the second clutch teeth of the clutch member is the same as that of the positioning tooth portions of the limiting sleeve.

6. An injection device according to claim 4, characterized in that, The angle θ1 of the first circumferential limiting portion in the circumferential direction, the angle θ2 of the second circumferential limiting portion in the circumferential direction, the angle θ3 of the first clutch tooth in the circumferential direction, θ1 = mθ3, θ2 = mθ3, where m is a positive integer greater than 0; And / or, the angle θ4 of the first transmission portion in the circumferential direction, the angle θ5 of the second transmission portion in the circumferential direction, the angle θ3 of the first clutch tooth in the circumferential direction, θ4 = mθ3, θ5 = mθ3, where m is a positive integer greater than 0.

7. An injection device according to claim 3, characterized in that, The injection device includes: A transmission sleeve, rotatably arranged inside the housing and circumferentially restricted with the main drive shaft so as to be able to rotate synchronously with the main drive shaft; A scale sleeve, arranged inside the housing and threadedly connected to the inner side of the housing. The scale sleeve is slidably sleeved outside the transmission sleeve and circumferentially restricted so as to be able to rotate synchronously with the transmission sleeve. An observation port is provided on the side wall of the housing for observing the scale of the scale sleeve.

8. An injection device according to claim 7, characterized in that, A fixed sleeve is integrally provided inside the housing. The fixed sleeve is sleeved outside the torsion spring. The first circumferential limiting portion is circumferentially spaced at one end of the fixed sleeve close to the clutch assembly. The transmission sleeve is rotatably sleeved on the fixed sleeve, and the front end of the torsion spring is connected to the main drive shaft, and the rear end is connected to the fixed sleeve.

9. An injection device according to claim 7, characterized in that, A fixed sleeve is axially inserted and fixed inside the housing. The fixed sleeve is sleeved outside the torsion spring. The first circumferential limiting portion is circumferentially spaced at one end of the fixed sleeve close to the clutch assembly. The transmission sleeve is rotatably sleeved on the fixed sleeve, and the front end of the torsion spring is connected to the main drive shaft, and the rear end is connected to the fixed sleeve.

10. An injection device according to claim 9, characterized in that, A third circumferential limiting portion is provided on the inner circumferential surface of the housing, and a fourth circumferential limiting portion is provided on the side of the fixed sleeve. The third circumferential limiting portion and the fourth circumferential limiting portion are axially inserted and matched.

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