Dose adjusting mechanism of injection device and injection device

Abstract

The invention relates to the technical field of medical instruments, in particular to a dose adjusting mechanism of an injection device and the injection device. The push rod part penetrates through the holding part and is in threaded connection; the push rod part is sleeved with the transmission tooth part and limited in the circumferential direction, and the push rod part can move in the axial direction relative to the transmission tooth part. The transmission tooth part comprises a driven ratchet; the driving rod part can be switched from an initial position to an end position, and at the initial position, the driving ratchet and the driven ratchet are spaced in the axial direction and staggered by a preset angle in the circumferential direction; at the ending position, the driving ratchet is meshed with the driven ratchet, and the transmission tooth part rotates by an angle of one driving ratchet; the reset part drives the driving rod part to return to the initial position when the pressing force is released. The rotation angle of the transmission tooth part corresponds to the axial displacement of the push rod part, rotation of the transmission tooth part is discretized through one-by-one meshing of the driving ratchets and the driven ratchets, the single displacement of the push rod part is smaller, and the small-dose injection requirement is met.

Description

Technical Field

[0001] This application relates to the technical field of medical devices, and particularly to a dose adjustment mechanism and an injection device of an injection device. Background Art

[0002] The related art injection device includes an outer sleeve member, a push rod member, and a cartridge member. The surface of the push rod member has a concavo-convex structure continuously distributed along the axial direction. The push rod member is adapted to be sleeved with the outer sleeve member and move along the axial direction of the outer sleeve member. The concavo-convex structure is blocked by the cartridge member during the movement of the push rod member. The cartridge member is disposed at the opening of the first end where the push rod member is sleeved with the outer sleeve member, and is adapted to cooperate with the concavo-convex structure on the push rod member to block the movement of the push rod member during the axial movement of the push rod member along the outer sleeve member. The distance between adjacent concavo-convex structures has a corresponding relationship with the dose of the injection substance. With the cooperation of the concavo-convex structure and the cartridge member, by blocking the movement of the push rod member, the dose of the injection substance can be accurately controlled, and the accuracy of the injection amount of the injection substance can be improved.

[0003] In the related art injection device, the distance between adjacent concavo-convex structures determines the minimum dose unit. If a smaller dose is to be achieved, the distance between adjacent concavo-convex structures needs to be shortened. However, limited by processing precision such as machining ability, too small a distance may cause the concavo-convex structure to be unable to be stably formed or be easily worn, resulting in the related art injection device being only suitable for large-dose injections and unable to meet the requirements of small-dose injections. Summary of the Invention

[0004] The purpose of this application is to provide a dose adjustment mechanism and an injection device of an injection device to solve the problem of being unable to meet the requirements of small-dose injections.

[0005] To solve the above technical problems, this application provides a dose adjustment mechanism of an injection device, including a driving rod portion, a holding portion, a push rod portion, and a transmission gear portion. The driving rod portion is connected to the holding portion, and the driving rod portion is provided with driving ratchet teeth distributed along the circumferential direction; the push rod portion passes through the holding portion and is threadedly connected; the transmission gear portion is sleeved on the push rod portion and is circumferentially limited, and the push rod portion is axially movable relative to the transmission gear portion; the transmission gear portion further includes a driven ratchet tooth, and the front end surface of the driving ratchet tooth and the rear end surface of the driven ratchet tooth are matching inclined surfaces;

[0006] The driving rod portion has an initial position and a termination position. In the initial position, there is an axial distance between the driving ratchet tooth and the driven ratchet tooth, and the front end surface of one of the driving ratchet teeth and the rear end surface of the driven ratchet tooth are circumferentially offset by a preset angle;

[0007] In a state where the driving rod portion is under a pressing force, it can move axially and rotate circumferentially by a preset angle from the initial position to switch to the termination position. At the termination position, one of the active ratchets meshes with the driven ratchet, and the transmission tooth portion rotates by an angle of one active ratchet.

[0008] The dose adjustment mechanism further includes a reset portion configured to drive the driving rod portion back to the initial position in a state where the pressing force is released.

[0009] Optionally, the holding portion has a receiving cavity, and the circumferential wall surrounding the receiving cavity is provided with one-way card slots distributed circumferentially. The transmission tooth portion is located in the receiving cavity, and the transmission tooth portion further includes an elastic clamping portion that is clamped in any one of the one-way card slots.

[0010] When the driving rod portion moves from the initial position to the termination position, the elastic clamping portion can slide along the circumferential wall surrounding the receiving cavity to be clamped into one of the front-end one-way card slots.

[0011] Optionally, the circumferential wall surrounding the receiving cavity is provided with a plurality of ratchets distributed circumferentially, and a ratchet slot is formed between adjacent ratchets, and the ratchet slot is the one-way card slot.

[0012] Optionally, the holding portion has a receiving cavity, and a part of the driving rod portion is located in the receiving cavity. Among the outer circumferential wall of the driving rod portion and the inner circumferential wall surrounding the receiving cavity, one is provided with a guiding portion extending axially, and the other is provided with a guiding slot extending axially, and the guiding portion is slidably installed in the guiding slot.

[0013] Along the axial movement direction of the driving rod portion when it is under a pressing force, the rear side wall of the guiding slot includes a first wall portion, a second wall portion, and a third wall portion that are sequentially connected. The first wall portion and the third wall portion extend axially, and along the direction away from the first wall portion, the second wall portion extends obliquely toward the front side wall.

[0014] The reset portion includes an elastic member that is pre-compressed or pre-stretched circumferentially between the holding portion and the driving rod portion, so that the rear side wall of the guiding portion abuts against the rear side wall of the guiding slot. When the driving rod portion moves from the initial position to the termination position, the elastic member deforms axially and circumferentially to store energy.

[0015] Optionally, the elastic member includes:

[0016] An elastic arm, one end of the elastic arm is connected to the guiding portion, the other end of the elastic arm abuts against the front side wall of the guiding slot, and the elastic arm is pre-compressed circumferentially between the guiding portion and the front side wall of the guiding slot.

[0017] An axial spring is disposed axially between the holding portion and the drive rod portion.

[0018] Optionally, the elastic member includes:

[0019] A torsion spring, both ends of the torsion spring are connected to the holding portion and the drive rod portion.

[0020] Optionally, the elastic member further includes:

[0021] An axial spring is disposed axially between the holding portion and the drive rod portion.

[0022] Optionally, the holding portion includes:

[0023] A body portion, the body portion has a receiving groove, one end of the receiving groove close to the pressing end of the drive rod portion is an open end, and a one-way card slot is provided on the peripheral wall surrounding the receiving groove;

[0024] A cover plate portion, the cover plate portion is connected to the open end of the body portion, and the receiving groove forms at least part of the receiving cavity.

[0025] Optionally, the body portion includes a first cylinder disposed inside the receiving groove, a through hole communicating with the first cylinder is provided on the end wall surrounding the receiving groove, and the push rod portion passes through the first cylinder and is threadedly connected;

[0026] The transmission gear portion further includes a second cylinder, the second cylinder sleeved on the push rod portion is circumferentially limited and axially movable; the elastic clamping portion is connected to the outer peripheral wall of the second cylinder, a stepped portion is provided on the inner wall of the second cylinder, the second cylinder movably sleeved on the first cylinder, and the stepped portion and the opposite end of the first cylinder abut.

[0027] Optionally, the drive rod portion has a pressing end, and an installation groove is provided at the end of the holding portion facing away from the pressing end, and the installation groove is used for laterally limiting and installing a convex portion at the open end of the barrel of the injection device;

[0028] The dose adjustment mechanism further includes a blocking member, the blocking member is connected to the holding portion, and the blocking member is configured to abut against the end wall of the convex portion facing away from the pressing end to axially limit the convex portion.

[0029] Optionally, the blocking member includes at least two limiting protrusions, at least two of the limiting protrusions are arranged on relative wall portions surrounding the mounting groove, the limiting protrusions abut against the end wall facing the pressing end and the end wall of the protruding portion facing away from the pressing end to limit the axial position of the protruding portion, and from the connecting end of the limiting protrusion toward the free end of the limiting protrusion, the end wall of the limiting protrusion facing away from the pressing end extends obliquely toward the direction close to the pressing end.

[0030] The present application also provides an injection device, comprising:

[0031] A barrel having a pouring end and an opening end;

[0032] A sealing plug is slidably disposed inside the barrel, with the sealing plug as a boundary, and a storage cavity is formed in the area inside the barrel near the injection end, and the storage cavity is used to store the injection;

[0033] The aforementioned dose adjustment mechanism, the gripping portion of the dose adjustment mechanism is connected to the open end of the barrel, and the push rod portion of the dose adjustment mechanism is connected to the sealing plug.

[0034] The technical effects of this application are as follows:

[0035] In the dose adjustment mechanism of the present application, the push rod part and the transmission tooth part are connected in a circumferential limit direction, and the push rod part can move axially relative to the transmission tooth part, so that the transmission tooth part can rotate when subjected to force, and drive the push rod part to rotate synchronously, and the transmission tooth part will not hinder the axial movement of the push rod part. The push rod part and the grip part are threadedly matched. When the grip part is in a gripping state, when the push rod part rotates driven by the transmission tooth part, it can also move axially under the action of the thread cooperation. When the thread pitch of the push rod part and the grip part is fixed, the rotation angle of the transmission tooth part strictly corresponds to the axial displacement of the push rod part, thereby ensuring that the dose is controllable; at the same time, by the one-by-one engagement of the active ratchet teeth distributed circumferentially in the driving rod part and the driven ratchet teeth in the transmission tooth part, the rotational motion of the transmission tooth part is discretized into fixed angle steps. By matching the thread pitch with the number of active ratchets, the single-step axial displacement of the push rod part can be controlled to a lower level to meet the needs of small-dose injection. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a schematic structural diagram of a first specific embodiment of a dose adjustment mechanism of an injection device provided in the present application;

[0037] Figure 2 for Figure 1 A schematic diagram of a partial structure of a dosage adjustment mechanism of an injection device in an initial position;

[0038] Figure 3 for Figure 1Partial structural schematic diagram of the dose adjustment mechanism of the injection device in the end position;

[0039] Figure 4 For Figure 1 Partial structural schematic diagram of the dose adjustment mechanism of the injection device returning to the initial position;

[0040] Figure 5 Structural schematic diagram of a specific embodiment of the injection device provided by this application;

[0041] Figure 6 For Figure 1 Structural schematic diagram of the holding part and the transmission gear part in the dose adjustment mechanism of the injection device;

[0042] Figure 7 Structural schematic diagram of the second specific embodiment of the dose adjustment mechanism of the injection device provided by this application;

[0043] Figure 8 For Figure 7 Partial enlarged view of the driving rod part, the holding part and the elastic part in;

[0044] Figure 9 Structural schematic diagram of the third specific embodiment of the dose adjustment mechanism of the injection device provided by this application;

[0045] Figure 10 For Figure 9 Structural schematic diagram of the holding part and the axial spring in;

[0046] Figure 11 For Figure 9 Structural schematic diagram of the driving rod part and the axial spring in;

[0047] Figure 12 For Figure 1 Structural schematic diagram of the body part in the dose adjustment mechanism of the injection device;

[0048] Figure 13 For Figure 1 Structural schematic diagram of the cover plate part in the dose adjustment mechanism of the injection device;

[0049] Figure 14 For Figure 1 Structural schematic diagram of the transmission gear part in the dose adjustment mechanism of the injection device;

[0050] Figure 15 For Figure 1 Structural schematic diagram of the push rod part and the transmission gear part in the dose adjustment mechanism of the injection device;

[0051] Figure 16 For Figure 12 Structural schematic diagram of the body part at the second angle;

[0052] Figure 17 is Figure 5 a schematic structural view of the connection between the main body part and the cylinder body in

[0053] Among them, Figures 1 - 17 the reference numerals in

[0054] 100 - dose adjustment mechanism;

[0055] 101 - driving rod part; 1011 - active ratchet tooth; 1011' - first active ratchet tooth; 1011'' - second active ratchet tooth; 1012 - guiding part; 1013 - first connecting column;

[0056] 102 - holding part; 102a - accommodating cavity; 102b - one - way card slot; 1021 - ratchet tooth; 1022 - ratchet tooth groove; 1023 - second connecting column; 1024 - buckle; 1025 - mounting part; 1025a - notch part; 102c - guiding groove; 102c - 1 - first wall part; 102c - 2 - second wall part; 102c - 3 - third wall part; 102c - 4 - front side wall; 102 - 1 - main body part; 102 - 1a - accommodating groove; 102 - 11 - first cylinder body; 102 - 12 - protrusion; 102 - 2 - cover plate part; 102d - mounting groove;

[0057] 103 - push rod part; 103a - limiting groove;

[0058] 104 - transmission gear part; 1041 - driven ratchet tooth; 1042 - elastic clamping part; 1043 - second cylinder body; 1043a - step part; 1044 - limiting protrusion;

[0059] 105 - elastic arm;

[0060] 106 - axial spring;

[0061] 107 - torsion spring;

[0062] 108 - washer;

[0063] 109 - pressing part;

[0064] 110 - blocking part; 1101 - limiting convex block;

[0065] 200 - cylinder body; 200a - storage cavity; 201 - protruding part;

[0066] 300 - sealing plug;

[0067] a - inclined plane; b - spacing. Specific embodiments

[0068] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0069] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of the same category, and the number of objects is not limited. For example, the first object can be one or multiple. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally means an "or" relationship between the related objects before and after.

[0070] It should be understood that "some embodiments" mentioned throughout the specification means that specific features, structures, or characteristics related to the embodiments are included in at least one embodiment of the present application. Therefore, the "in some embodiments" that appears throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures, or characteristics can be combined in one or more embodiments in any suitable manner.

[0071] In the description herein, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this article can be understood according to specific circumstances.

[0072] Please refer to Figures 1 - 5 , Figure 1 which is a schematic structural diagram of the first specific embodiment of the dose adjustment mechanism of the injection device provided by the present application; Figure 2 is Figure 1 a partial structural diagram of the dose adjustment mechanism of the injection device in the initial position; Figure 3 is Figure 1 a partial structural diagram of the dose adjustment mechanism of the injection device in the termination position; Figure 4 is Figure 1 a partial structural diagram of the dose adjustment mechanism of the injection device returning to the initial position; Figure 5Schematic structural diagram of a specific embodiment of the injection device provided by the present application.

[0073] The present application provides a dose adjustment mechanism 100 for an injection device, including a driving rod portion 101, a holding portion 102, a push rod portion 103, and a transmission gear portion 104. The driving rod portion 101 is connected to the holding portion 102, and the driving rod portion 101 is provided with active ratchet teeth 1011 distributed circumferentially; the push rod portion 103 passes through the holding portion 102 and is threadedly connected; the transmission gear portion 104 is sleeved on the push rod portion 103 and is circumferentially limited, and the push rod portion 103 is axially movable relative to the transmission gear portion 104; the transmission gear portion 104 further includes a driven ratchet tooth 1041, and the front end surface of the active ratchet tooth 1011 and the rear end surface of the driven ratchet tooth 1041 are matching inclined surfaces a.

[0074] The driving rod portion 101 has an initial position and a terminal position. In the initial position, there is an axial distance between the active ratchet tooth 1011 and the driven ratchet tooth 1041, and the front end surface of one of the active ratchet teeth 1011 and the rear end surface of the driven ratchet tooth 1041 are circumferentially offset by a preset angle.

[0075] When the driving rod portion 101 is under a pressing force, it can move axially from the initial position and rotate circumferentially by a preset angle to switch to the terminal position. In the terminal position, one of the active ratchet teeth 1011 and the driven ratchet tooth 1041 are engaged, and the transmission gear portion 104 rotates by an angle of one active ratchet tooth 1011.

[0076] The dose adjustment mechanism 100 further includes a reset portion, and the reset portion is configured to drive the driving rod portion 101 back to the initial position when the pressing force is released.

[0077] As Figure 5 shown, the injection device generally further includes a barrel 200 and a sealing plug 300. The barrel 200 has an injection end and an open end. The sealing plug 300 is slidably disposed inside the barrel 200. Taking the sealing plug 300 as a boundary, the area inside the barrel 200 near the injection end forms a storage cavity 200a for storing the injection material. When the dose adjustment mechanism 100 of the present application is applied to the injection device, the holding portion 102 is connected to the open end of the barrel 200, and the holding portion 102 can be held by an operator, so that the holding portion 102 and the barrel 200 are in a fixed state. One end of the push rod portion 103 near the injection end is connected to the sealing plug 300. When the push rod portion 103 drives the sealing plug 300 to move towards the injection end, part of the injection material in the storage cavity 200a is extruded.

[0078] The transmission tooth portion 104 is fitted over the push rod portion 103 and limited in the circumferential direction. The push rod portion 103 is movable in the axial direction relative to the transmission tooth portion 104, that is, the transmission tooth portion 104 can rotate when subjected to force, and drive the push rod portion 103 to rotate synchronously, and the transmission tooth portion 104 will not hinder the axial movement of the push rod portion 103. The push rod portion 103 passes through the grip portion 102 and is threadedly connected, that is, when the grip portion 102 is in a gripping state, when the push rod portion 103 is driven by the transmission tooth portion 104 to rotate, it can also be threadedly matched. Under the action, the push rod portion 103 moves axially; when the thread pitch of the push rod portion 103 and the grip portion 102 is fixed, the rotation angle of the push rod portion 103 strictly corresponds to the axial displacement of the push rod portion 103, that is, the rotation angle of the transmission tooth portion 104 strictly corresponds to the axial displacement of the push rod portion 103. For example, if the thread pitch of the push rod portion 103 and the grip portion 102 is 1mm, when the push rod portion 103 (transmission tooth portion 104) rotates 360°, the push rod portion 103 moves 1mm axially, thereby ensuring that the dosage is controllable.

[0079] Please combine Figure 2 It is understood that the driving rod portion 101 is provided with active ratchet teeth 1011 distributed along the circumferential direction, and the transmission tooth portion 104 also includes a driven ratchet tooth 1041, and the front end surface of the active ratchet tooth 1011 and the rear end surface of the driven ratchet tooth 1041 are matched inclined surfaces a, and in the initial position, the active ratchet tooth 1011 and the driven ratchet tooth 1041 have a spacing along the axial direction, and the front end surface of one active ratchet tooth 1011 and the rear end surface of the driven ratchet tooth 1041 are staggered by a preset angle along the circumferential direction; definition Figure 2 One of the active ratchet teeth 1011 is a first active ratchet tooth 1011', the active ratchet tooth 1011 located at the front end adjacent to the first active ratchet tooth 1011' is a second active ratchet tooth 1011'', and the front end surface of the first active ratchet tooth 1011' and the rear end surface of the driven ratchet tooth 1041 are staggered at a preset angle along the circumferential direction. Figure 2 The direction of the dotted arrow is the pressing direction of the driving rod 101, and the direction of the solid arrow is the rotation direction of the driving rod 101 when it is subjected to the pressing force. In this article, the end to which the driving rod 101 points when it is subjected to the pressing force is the front end.

[0080] When the driving rod 101 is pressed, the driving rod 101 can move axially from the initial position and rotate circumferentially by a preset angle, so that the first active ratchet 1011' and the driven ratchet 1041 gradually mesh; when the driving rod 101 moves from the initial position to the terminal position, Figure 3As shown in the figure, the first driving ratchet 1011' meshes with the driven ratchet 1041. Under the pushing action of the first driving ratchet 1011', the transmission tooth part 104 rotates by an angle of one driving ratchet 1011. Since the transmission tooth part 104 is sleeved on the push rod part 103 and is circumferentially limited, the push rod part 103 also rotates by an angle of one driving ratchet 1011. Also, since the push rod part 103 passes through the holding part 102 and is threadedly connected, the push rod part 103 can also axially move a fixed distance under the action of the thread fit. In the state where the pressing force is released, the reset part drives the driving rod part 101 back to the initial position, as Figure 4 shown. The driving ratchet 1011 and the driven ratchet 1041 have an axial spacing. Since the transmission tooth part 104 rotates by an angle of one driving ratchet 1011, the front end face of the second driving ratchet 1011'' adjacent to the front end of the first driving ratchet 1011' and the rear end face of the driven ratchet 1041 are circumferentially staggered by a preset angle.

[0081] In the state where the driving rod part 101 is again subjected to a pressing force, the second driving ratchet 1011'' and the driven ratchet 1041 gradually mesh with the movement of the driving rod part 101. When the driving rod part 101 moves from the initial position to the end position, the second driving ratchet 1011'' and the driven ratchet 1041 mesh. Under the pushing action of the second driving ratchet 1011'', the transmission tooth part 104 rotates by an angle of one driving ratchet 1011, and drives the push rod part 103 to rotate by an angle of one driving ratchet 1011. The push rod part 103 axially moves a fixed distance under the action of the thread fit.

[0082] It can be seen that each driving ratchet 1011 corresponds to one gear position. By designing the number of driving ratchets 1011, the dose unit corresponding to each pressing of the driving rod part 101 can be made clear. For example, if the thread pitch between the push rod part 103 and the holding part 102 is 1 mm, and the driving rod part 101 is provided with 12 driving ratchets 1011, and the adjacent driving ratchets 1011 are spaced 30° apart, each time the driving rod part 101 is pressed, the moving distance of the push rod part 103 is the ratio between the thread pitch and the number of driving ratchets 1011, that is, approximately 0.0833 mm, breaking through the single - injection minimum limit of the traditional axial concave - convex structure and meeting the small - dose injection requirements.

[0083] In summary, the dose adjustment mechanism 100 of the embodiment of the present application discretizes the rotational motion of the transmission tooth part 104 into fixed - angle gradings through the sequential meshing of the driving ratchets 1011 circumferentially distributed in the driving rod part 101 and the driven ratchets 1041 in the transmission tooth part 104. By matching the thread pitch with the number of driving ratchets 1011, the single - time displacement of the push rod part 103 is reduced to a lower level, breaking through the single - injection minimum limit of the traditional axial concave - convex structure and meeting the small - dose injection requirements.

[0084] Combined with Figure 3 It is understood that a ratchet groove is formed between two adjacent active ratchets 1011. A ratchet groove is formed between the first active ratchet 1011' and the second active ratchet 1011'' located at its front end. The engagement between the first active ratchet 1011' and the driven ratchet 1041 means that the driven ratchet 1041 is inserted into the ratchet groove between the first active ratchet 1011' and the second active ratchet 1011'' located at its front end, and the front end face of the first active ratchet 1011' is completely attached to the rear end face of the driven ratchet 1041.

[0085] From Figure 1 It can be seen that in the embodiment of the present application, the driving rod portion 101 includes a cylindrical structure, which serves to partially accommodate the push rod portion 103.

[0086] From Figure 2 It can be seen that in the embodiment of the present application, the height direction (engagement depth direction) of the active ratchet 1011 and the driven ratchet 1041 is set to be consistent with the axial direction of the driving rod portion 101. When the driving rod portion 101 moves axially, the active ratchet 1011 pushes the driven ratchet 1041 along its height direction, that is, the direction of the force is consistent with the direction of movement, which is beneficial to the efficient transmission of force; at the same time, it is also beneficial to reduce the radial dimension of the driving rod portion 101, reduce the radial space occupation, and make the structure of the dose adjustment mechanism 100 in the embodiment of the present application more compact.

[0087] Please refer to Figure 6 , Figure 6 For Figure 1 A schematic structural diagram of the holding portion and the transmission gear portion in the dose adjustment mechanism of the injection device.

[0088] In the embodiment of the present application, the holding portion 102 has a receiving cavity 102a, and the peripheral wall surrounding the receiving cavity 102a is provided with circumferentially distributed one-way card slots 102b. The transmission gear portion 104 is located in the receiving cavity 102a, and the transmission gear portion 104 further includes an elastic clamping portion 1042, and the elastic clamping portion 1042 is clamped in any one of the one-way card slots 102b;

[0089] When the driving rod portion 101 moves from the initial position to the termination position, the elastic clamping portion 1042 can slide along the peripheral wall surrounding the receiving cavity 102a to be clamped into one of the one-way card slots 102b at the front end.

[0090] The aforementioned one-way slot 102b means that when the driving rod portion 101 is subjected to pressing force, the elastic clamping portion 1042 can only slide one-way along the peripheral wall surrounding the accommodating cavity 102a to be clamped into the one-way slot 102b at the front end, but cannot slide in the opposite direction, that is, to ensure that the transmission tooth portion 104 can only rotate one-way, but not in the opposite direction, and further ensure that the push rod portion 103 and the sealing plug 300 can only move in the direction close to the injection end under the action of pressing force, but cannot move in the opposite direction. On the one hand, the position accuracy of the transmission tooth portion 104 is improved, the transmission tooth portion 104 is avoided from shifting, the accuracy of the injection amount is improved, and injection errors are avoided as much as possible; on the other hand, the secondary use of the dosage adjustment mechanism 100 is avoided, the anti-reuse requirements of disposable medical devices are met, the risk of cross infection is reduced, and safety is improved.

[0091] By designing the number of the one-way slots 102b, it is possible to make the elastic clamping portion 1042 pass over at least one one-way slot 102b each time the driving rod 101 is pressed. For example, when the driving rod 101 is pressed once and the elastic clamping portion 1042 passes over one one-way slot 102b, when the driving rod 101 is pressed, the elastic clamping portion 1042 gradually slides out of the current one-way slot 102b, the elastic clamping portion 1042 is squeezed and deformed, and the elastic clamping portion 1042 gradually accumulates energy. When passing over the current one-way slot 102b, the elastic potential energy of the elastic clamping part 1042 is released, and the elastic clamping part 1042 instantly bounces into the next one-way slot 102b. The collision between the elastic clamping part 1042 and the surrounding wall of the accommodating cavity 102a will produce a "click" sound, or cause the driving rod part 101 to produce a slight vibration. When the user hears the "click" sound or senses the vibration, it indicates that the injection of one dosage unit is completed. The user can accurately control the total injection volume by counting the number of "click" sounds or vibrations to avoid injection errors as much as possible.

[0092] Taking the example that the elastic clamping part 1042 passes over two one-way clamping slots 102b each time the driving rod 101 is pressed, when the driving rod 101 is pressed, the elastic clamping part 1042 gradually slides out of the current one-way clamping slot 102b, the elastic clamping part 1042 is squeezed and deformed, and the elastic clamping part 1042 gradually accumulates energy; when the elastic clamping part 1042 passes over the current one-way clamping slot 102b, the elastic potential energy of the elastic clamping part 1042 is released, and the elastic clamping part 1042 instantly bounces into the lower one-way clamping slot 102b. A one-way slot 102b, the elastic clamping portion 1042 and the surrounding wall surrounding the accommodating chamber 102a will collide to produce a "click" sound, or cause the driving rod 101 to produce a slight vibration, and this is repeated twice. When the driving rod 101 moves to the end position, the user hears two "click" sounds or senses two vibrations, indicating that the injection of one dosage unit is completed. The user can accurately control the total injection volume by counting the number of "click" sounds or vibrations to avoid injection errors as much as possible.

[0093] Please continue to refer to Figure 6 In the embodiment of the present application, a plurality of ratchets 1021 distributed circumferentially are provided on the peripheral wall enclosing the accommodation cavity 102a, and a ratchet groove 1022 is formed between adjacent ratchets 1021. The ratchet groove 1022 is the aforementioned one-way clamping groove 102b.

[0094] The wall surface of the ratchet 1021 has a blocking surface and an inclined surface, and the inclined surface also forms a guiding surface. When the driving rod portion 101 moves from the initial position to the terminal position under the pressing force, the elastic clamping portion 1042 can slide along the inclined surface, so as to smoothly slide over the top of the current ratchet 1021 and fall into the next ratchet groove 1022. The inclined surface can reduce the resistance of the forward operation and improve the operation convenience; when the elastic clamping portion 1042 slides over the top of the current ratchet 1021 and falls into the next ratchet groove 1022, a clear "click" sound and / or operation feeling (such as slight vibration) is usually generated, giving the user a clear feedback; during the reverse operation, the blocking surface of the ratchet 1021 will block the elastic clamping portion 1042, ensuring that the push rod portion 103 and the sealing plug 300 cannot move in the reverse direction, avoiding injection errors as much as possible, and preventing the dose adjustment mechanism 100 from being reused, improving safety. Moreover, the shape of the ratchet 1021 is relatively standard, which is convenient for manufacturing by means of machining, stamping, casting or injection molding, etc., improving the forming convenience and reducing the production cost.

[0095] As described above, in the state where the driving rod portion 101 is under the pressing force, the driving rod portion 101 can move axially from the initial position and rotate circumferentially by a preset angle to switch to the terminal position. Specifically, please combine with Figures 1 - 3 Understand that in the embodiment of the present application, a part of the driving rod portion 101 is located in the accommodation cavity 102a. Among the outer peripheral wall of the driving rod portion 101 and the inner peripheral wall enclosing the accommodation cavity 102a, one is provided with a guiding portion 1012 extending axially, and the other is provided with a guiding groove 102c extending axially. The guiding portion 1012 is slidably installed in the guiding groove 102c;

[0096] Along the axial movement direction of the driving rod portion 101 when it is under the pressing force, the rear side wall of the guiding groove 102c includes a first wall portion 102c-1, a second wall portion 102c-2 and a third wall portion 102c-3 connected in sequence. The first wall portion 102c-1 and the third wall portion 102c-3 extend axially. Along the direction away from the first wall portion 102c-1, the second wall portion 102c-2 extends obliquely towards the front side wall 102c-4 of the guiding groove 102c;

[0097] The reset part includes an elastic member, which is pre-compressed or pre-stretched circumferentially between the holding part 102 and the driving rod part 101, so that the rear side wall of the guiding part 1012 abuts against the rear side wall of the guiding groove 102c. When the driving rod part 101 moves from the initial position to the terminal position, the elastic member deforms axially and circumferentially to store energy.

[0098] With the above arrangement, when the driving rod part 101 is in the initial position, as Figure 2 shown, the rear side wall of the guiding part 1012 abuts against the rear side wall of the first wall part 102c-1. There is a spacing between the driving ratchet 1011 and the driven ratchet 1041 axially. The front end face of the first driving ratchet 1011' and the rear end face of the driven ratchet 1041 are circumferentially staggered by a preset angle. When the driving rod part 101 is under a pressing force, the guiding part 1012 can first slide along the first wall part 102c-1, and the driving ratchet 1011 gradually approaches the driven ratchet 1041, and the elastic member stores energy axially; then, the guiding part 1012 can slide along the second wall part 102c-2. Since the second wall part 102c-2 extends obliquely towards the front side wall 102c-4 of the guiding groove 102c in the direction away from the first wall part 102c-1, therefore, the driving rod part 101 can also rotate circumferentially by a preset angle under the guiding action of the second wall part 102c-2, so that the front end face of the first driving ratchet 1011' contacts the rear end face of the driven ratchet 1041, and the elastic member stores energy further axially and further stores energy circumferentially; then, the guiding part 1012 can slide along the third wall part 102c-3, and the elastic member stores energy further axially; when the driving rod part 101 moves to the Figure 3 shown terminal position, the first driving ratchet 1011' and the driven ratchet 1041 are engaged, and the driving rod part 101 cannot move further. Under the pushing action of the first driving ratchet 1011', the transmission gear part 104 rotates by an angle of one driving ratchet 1011.

[0099] When the pressing force applied to the driving rod part 101 is released, under the restoring force of the elastic member, the guiding part 1012 can move in the reverse direction, and the rear side wall of the guiding part 1012 always abuts against the rear side wall of the guiding groove 102c, that is, the guiding part 1012 slides along the third wall part 102c-3, the second wall part 102c-2 and the first wall part 102c-1 in sequence. When the guiding part 1012 slides along the second wall part 102c-2, the guiding part 1012 rotates circumferentially in the reverse direction by a preset angle and finally returns to the initial position.

[0100] It can be seen that in the dose adjustment mechanism 100 of the embodiment of the present application, through the above settings of the guiding portion 1012, the guiding groove 102c and the elastic member, the driving rod portion 101 can be reliably switched between the initial position and the end position, improving the position accuracy of the driving rod portion 101 and ensuring that the dose adjustment mechanism 100 of the embodiment of the present application can work reliably.

[0101] Of course, the guiding groove is not limited to the above setting method. For example, in some other embodiments of the present application, along the axial movement direction of the driving rod portion 101 when a pressing force is applied, the rear side wall of the guiding groove 102c includes a first wall and a second wall connected in sequence. The second wall extends axially. Along the direction close to the second wall, the first wall extends obliquely towards the front side wall 102c-4 of the guiding groove 102c. In this way, when the driving rod portion 101 is in the initial position, the rear side wall of the guiding portion 1012 abuts against the rear side wall of the first wall, and there is an axial distance between the driving ratchet 1011 and the driven ratchet 1041. The front end face of the first driving ratchet 1011' and the rear end face of the driven ratchet 1041 are circumferentially offset by a preset angle. When the driving rod portion 101 is in a state of being subjected to a pressing force, the guiding portion 1012 can first slide along the first wall, and the driving ratchet 1011 gradually approaches the driven ratchet 1041. At the same time, under the guiding action of the first wall, the driving rod portion 101 rotates circumferentially by a preset angle, so that the front end face of the first driving ratchet 1011' and the rear end face of the driven ratchet 1041 come into contact, and the elastic member stores energy axially and circumferentially; then, the guiding portion 1012 slides along the second wall, and the elastic member stores more energy axially; when the driving rod portion 101 moves to the end position, the first driving ratchet 1011' and the driven ratchet 1041 are engaged, and the driving rod portion 101 cannot move further. Under the pushing action of the first driving ratchet 1011', the transmission tooth portion 104 rotates by an angle of one driving ratchet 1011.

[0102] When the pressing force applied to the driving rod portion 101 is released, under the restoring force of the elastic member, the guiding portion 1012 can move in the reverse direction, and the rear side wall of the guiding portion 1012 always abuts against the rear side wall of the guiding groove 102c, that is, the guiding portion 1012 slides along the second wall and the first wall in sequence. When the guiding portion 1012 slides along the first wall, the guiding portion 1012 rotates circumferentially in the reverse direction by a preset angle at the same time and finally returns to the initial position.

[0103] Among them, the elastic member can be implemented in various ways. In some embodiments, such as Figure 1 and Figure 2 shown, the elastic member includes:

[0104] The elastic arm 105, one end of the elastic arm 105 is connected to the guiding portion 1012, the other end of the elastic arm 105 abuts against the front side wall 102c-4 of the guiding groove 102c, and the elastic arm 105 is pre-compressed circumferentially between the guiding portion 1012 and the front side wall 102c-4 of the guiding groove 102c:

[0105] The axial spring 106 is arranged axially between the holding portion 102 and the driving rod portion 101.

[0106] It is defined that a first groove portion is formed between the first wall portion 102c-1 and the front side wall 102c-4 of the guiding groove 102c, a second groove portion is formed between the second wall portion 102c-2 and the front side wall 102c-4 of the guiding groove 102c, and a third groove portion is formed between the third wall portion 102c-3 and the front side wall 102c-4 of the guiding groove 102c; the width of the third groove portion is smaller than the width of the first groove portion, and along the direction away from the first groove portion, the width of the second groove portion gradually decreases; when the driving rod portion 101 is in the initial position, the guiding portion 1012 is located in the first groove portion, and under the squeezing force of the first wall portion 102c-1 and the front side wall 102c-4 of the guiding groove 102c, the elastic arm 105 is pre-compressed so that the rear side wall of the guiding portion 1012 abuts against the rear side wall of the first wall portion 102c-1; when the driving rod portion 101 is pressed, when the guiding portion 1012 enters the second groove portion, the width of the second groove portion gradually decreases, the squeezing force received by the elastic arm 105 gradually increases, and the elastic arm 105 is further deformed to store energy, so that the rear side wall of the guiding portion 1012 abuts against the rear side wall of the second wall portion 102c-2; when the guiding portion 1012 enters the third groove portion, the width of the third groove portion is not greater than the minimum width of the second groove portion, and the elastic arm 105 maintains the deformed energy storage state so that the rear side wall of the guiding portion 1012 can abut against the rear side wall of the third wall portion 102c-3.

[0107] It can be seen that the setting of the elastic arm 105 in the embodiment of the present application can make the rear side wall of the guiding portion 1012 always abut against the rear side wall of the guiding groove 102c, so that the guiding portion 1012 can rotate a preset angle circumferentially under the guiding action of the rear side wall of the guiding groove 102c, ensuring that the dose adjustment mechanism 100 in the embodiment of the present application can work normally.

[0108] At the same time, the axial spring 106 is arranged axially between the holding portion 102 and the driving rod portion 101. When the driving rod portion 101 is axially moved from the initial position under the pressing force, the axial spring 106 is compressed to store energy. Thus, in the state where the pressing force is released, the axial spring 106 can drive the driving rod portion 101 to move axially in the reverse direction. Under the cooperative action of the axial spring 106 and the elastic arm 105, the driving rod portion 101 can reliably switch between the initial position and the end position, ensuring the normal operation of the dose adjustment mechanism 100 in the embodiment of the present application.

[0109] As can be seen, in the embodiment of the present application, the axial spring 106 and the elastic arm 105 respectively achieve the axial reset and circumferential reset of the driving rod portion 101. This independent design enables the circumferential and axial reset behaviors of the driving rod portion 101 to be more precisely controlled.

[0110] Among them, as Figure 2 and Figure 3 shown, in the embodiment of the present application, there is a spacing b between the guiding portion 1012 and the opposite side wall of the elastic arm 105.

[0111] With the above setting, this spacing b can provide a deformation space for the elastic arm 105 when the elastic arm 105 is compressed and deformed, and as much as possible avoid the interference of the guiding portion 1012 on the deformation of the elastic arm 105, ensuring that the elastic arm 105 can be deformed normally.

[0112] Please continue to refer to Figure 2 , in the embodiment of the present application, the elastic arm 105 includes an axially extending section and a bent section connected to each other. The axially extending section extends along the axis of the dose adjustment mechanism 100. One end of the axially extending section far from the bent section is connected to the guiding portion 1012. Along the direction away from the axially extending section, the bent section bends towards the front side wall 102c-4 of the guiding groove 102c, so that one end of the bent section far from the axially extending section abuts against the front side wall 102c-4 of the guiding groove 102c.

[0113] Please refer to Figures 7 - 8 , Figure 7 which is a schematic structural diagram of the second specific embodiment of the dose adjustment mechanism of the injection device provided by the present application; Figure 8 is Figure 7 a partial enlarged view of the driving rod portion, the holding portion and the elastic member in

[0114] In some other embodiments of the present application, the elastic member includes:

[0115] a torsion spring 107, and both ends of the torsion spring 107 are connected to the holding portion 102 and the driving rod portion 101.

[0116] With the above setting, when the driving rod portion 101 moves from the initial position to the end position under the pressing force, the torsion spring 107 deforms both circumferentially and axially to store energy at the same time; in the state where the pressing force is released, the torsion spring 107 drives the driving rod portion 101 back to the initial position under the action of the restoring force. As can be seen, in the embodiment of the present application, the torsion spring 107 simultaneously achieves the axial reset and circumferential reset of the driving rod portion 101, which can reduce the number of parts and lower the cost.

[0117] As Figure 8As shown, in the embodiment of the present application, the driving rod portion 101 has a first connecting column 1013. The first connecting column 1013 has a first abutting wall facing the discharging end of the dose adjusting mechanism 100. One end of the torsion spring 107 is wound around the first connecting column 1013 and abuts against the first abutting wall. The holding portion 102 has a second connecting column 1023. The second connecting column 1023 has a second abutting wall facing away from the discharging end of the dose adjusting mechanism 100. The other end of the torsion spring 107 is wound around the second connecting column 1023 and abuts against the second abutting wall.

[0118] With the above arrangement, when the driving rod portion 101 moves axially under the pressing force, under the abutting action of the first abutting wall, one end of the torsion spring 107 will be stably wound around the first connecting column 1013 and move axially along with the driving rod portion 101. And under the abutting action of the second abutting wall, the other end of the torsion spring 107 will be stably wound around the second connecting column 1023 and be in a fixed state. Thus, the torsion spring 107 will deform axially to store energy and reliably exert the axial resetting effect on the driving rod portion 101 in the state where the pressing force is released.

[0119] In addition, one end of the torsion spring 107 can surround the first connecting column 1013 for one circle, and the other end of the torsion spring 107 can surround the second connecting column 1023 for one circle. Thus, the two ends of the torsion spring 107 can be stably connected to the first connecting column 1013 and the second connecting column 1023. When the driving rod portion 101 rotates circumferentially, the torsion spring 107 can deform circumferentially to store energy and reliably exert the circumferential resetting effect on the driving rod portion 101 in the state where the pressing force is released.

[0120] Or, as Figure 8 shown, one end of the torsion spring 107 is wound around at least a partial area on the front side of the first connecting column 1013, and the other end of the torsion spring 107 is wound around at least a partial area on the rear side of the second connecting column 1023. In this way, when the driving rod portion 101 rotates, the first connecting column 1013 can reliably drive one end of the torsion spring 107 to twist and deform, and the second connecting column 1023 can reliably maintain the fixed state of the other end of the torsion spring 107, as much as possible avoiding the torsion spring 107 from detaching from the first connecting column 1013 and the second connecting column 1023. Thus, the torsion spring 107 will deform circumferentially to store energy.

[0121] Please refer to Figure 9 , Figure 9 which is a schematic structural diagram of the third specific embodiment of the dose adjusting mechanism of the injection device provided by the present application.

[0122] In some other embodiments of the present application, on the basis of the torsion spring 107, an axial spring 106 is added to the elastic member. The axial spring 106 is axially arranged between the holding portion 102 and the driving rod portion 101.

[0123] With the above settings, when the driving rod portion 101 is subjected to a pressing force and moves axially from the initial position, the axial spring 106 is compressed to store energy. Thus, in the state where the pressing force is released, the axial spring 106 can also drive the driving rod portion 101 to move axially in the reverse direction, realizing the axial reset of the driving rod portion 101.

[0124] In this way, in the embodiment of the present application, the axial spring 106 is added on the basis of the torsion spring 107, which plays a role in sharing the axial burden of the torsion spring 107, thereby improving the reliability of the reset function of the torsion spring 107 and ensuring the normal operation of the dose adjustment mechanism 100 in the embodiment of the present application.

[0125] In some other embodiments of the present application, the elastic member includes a compression spring. The two ends of the compression spring are respectively connected to the driving rod portion 101 and the holding portion 102. During installation, the compression spring is twisted by a certain angle to store energy. When the driving rod portion 101 is subjected to a pressing force and moves from the initial position to the end position, the compression spring is deformed both circumferentially and axially to store energy; in the state where the pressing force is released, the compression spring drives the driving rod portion 101 back to the initial position under the action of the restoring force.

[0126] Please refer to Figure 10 and Figure 11 , Figure 10 For Figure 1 and Figure 9 the schematic structural diagrams of the holding portion and the axial spring in Figure 11 For Figure 1 and Figure 9 the schematic structural diagrams of the driving rod portion and the axial spring in

[0127] In the embodiment of the present application, the holding portion 102 has a receiving cavity 102a. The peripheral wall surrounding the receiving cavity 102a is provided with a plurality of ratchet teeth 1021 distributed circumferentially. The axial spring 106 is located in the receiving cavity 102a. Part of the axial spring 106 is sleeved on the outer peripheral wall of the driving rod portion 101. One end of the axial spring 106 abuts against the guiding portion 1012, and the other end of the axial spring 106 abuts against the end wall of the ratchet tooth 1021.

[0128] With the above settings, part of the axial spring 106 is sleeved on the outer peripheral wall of the driving rod portion 101. The outer peripheral wall of the driving rod portion 101 can play a guiding role for the axial spring 106, so that the axial spring 106 always moves along the axis of the driving rod portion 101 during the compression or restoration process, and as much as possible prevents the axial spring 106 from being distorted and laterally unstable; one end of the axial spring 106 abuts against the guiding portion 1012, and the other end of the axial spring 106 abuts against the end wall of the ratchet tooth 1021. Thus, the axial spring 106 is axially arranged between the holding portion 102 and the driving rod portion 101, playing an axial resetting role for the driving rod portion 101.

[0129] Please continue to refer to Figure 10 , in the embodiment of the present application, the dose adjustment mechanism 100 further includes a washer 108, and the washer 108 is disposed between the corresponding end of the axial spring 106 and the end wall of the ratchet 1021.

[0130] With the above arrangement, the washer 108 is disposed as a buffer member between the corresponding end of the axial spring 106 and the end wall of the ratchet 1021, which can reduce the wear of the corresponding end of the axial spring 106 and the end wall of the ratchet 1021; at the same time, during installation, by increasing or decreasing washers 108 with different thicknesses, the initial installation position of the axial spring 106 can be conveniently adjusted to make its height meet the requirements.

[0131] Please refer to Figures 12 - 13 , Figure 12 For Figure 1 a schematic structural view of the body part in the dose adjustment mechanism of the injection device; Figure 13 For Figure 1 a schematic structural view of the cover part in the dose adjustment mechanism of the injection device.

[0132] In the embodiment of the present application, the holding part 102 includes:

[0133] a body part 102-1, the body part 102-1 has a receiving groove 102-1a, one end of the receiving groove 102-1a close to the pressing end of the driving rod part 101 is an open end, and the circumferential wall of the receiving groove 102-1a is provided with the aforementioned one-way card slot 102b;

[0134] a cover part 102-2, the cover part 102-2 is connected to the open end of the body part 102-1, and the receiving groove 102-1a forms at least part of the receiving cavity 102a.

[0135] With the above arrangement, the holding part 102 adopts a split structure including the body part 102-1 and the cover part 102-2. During assembly, after installing the driving rod part 101, the push rod part 103, the transmission gear part 104, etc. on the body part 102-1, then connect the cover part 102-2 to the open end of the body part 102-1 to improve the assembly convenience.

[0136] Among them, the connection method between the cover part 102-2 and the body part 102-1 is not limited. For example, the two can be fixed by welding, snap connection, threaded connection parts, etc.

[0137] Among them, the pressing end of the driving rod part 101 is the end where the operator presses the driving rod part 101.

[0138] In some embodiments of the present application, one of the cover plate portion 102-2 and the main body portion 102-1 is provided with a buckle 1024, and the other is provided with a clamping groove. The cover plate portion 102-2 and the main body portion 102-1 are fixed through the clamping cooperation of the buckle 1024 and the clamping groove.

[0139] Please refer to Figure 12 and Figure 14 , Figure 14 is Figure 1 a schematic structural diagram of a transmission gear portion in a dose adjustment mechanism of an injection device.

[0140] In an embodiment of the present application, the main body portion 102-1 includes a first cylinder 102-11 disposed inside the accommodation groove 102-1a. The end wall surrounding the accommodation groove 102-1a has a through hole communicating with the first cylinder 102-11. The push rod portion 103 passes through the first cylinder 102-11 and is threadedly connected;

[0141] The transmission gear portion 104 further includes a second cylinder 1043. The second cylinder 1043 is sleeved on the push rod portion 103 and is circumferentially limited and axially movable; the elastic clamping portion 1042 is connected to the outer peripheral wall of the second cylinder 1043. The inner wall of the second cylinder 1043 has a stepped portion 1043a. The second cylinder 1043 is movably sleeved on the first cylinder 102-11, and the opposite end portions of the stepped portion 1043a and the first cylinder 102-11 are in contact.

[0142] With the above arrangement of the first cylinder 102-11, on the one hand, it can play a positioning role for the second cylinder 1043, improving the installation convenience and positioning accuracy of the transmission gear portion 104; on the other hand, the opposite end portions of the stepped portion 1043a and the first cylinder 102-11 are in contact, playing an axial limiting role for the transmission gear portion 104, preventing the axial movement of the transmission gear portion 104, ensuring that the elastic clamping portion 1042 and the one-way clamping groove 102b are always in a reliable clamping state, and improving the position accuracy of the transmission gear portion 104.

[0143] As Figure 12 shown, in order to reduce the friction force when the transmission gear portion 104 rotates, the end of the first cylinder 102-11 is provided with circumferentially distributed protrusions 102-12. The stepped portion 1043a is in contact with the protrusions 102-12, reducing the contact area between the opposite end portions of the stepped portion 1043a and the first cylinder 102-11, reducing the friction force when the transmission gear portion 104 rotates, and making the rotation of the transmission gear portion 104 smoother.

[0144] The protrusion 102-12 may be a hemispherical structure, further reducing the contact area between the step portion 1043a and the opposite end of the first cylinder 102-11, and further reducing the friction force when the transmission tooth portion 104 rotates. In other embodiments of the present application, the protrusion 102-12 may also be a columnar, pointed structure, etc.

[0145] In the embodiment of the present application, the end of the first cylinder 102-11 is provided with protrusions 102-12 distributed along the circumferential direction. In other embodiments, it is also feasible to provide protrusions on the step portion 1043a, which can also play a role in reducing the friction force when the transmission tooth portion 104 rotates.

[0146] like Figure 14 As shown, in the embodiment of the present application, the transmission tooth portion 104 has two elastic clamping portions 1042, and the two elastic clamping portions 1042 are arranged at intervals along the circumferential direction. The two elastic clamping portions 1042 cooperate with the ratchet 1021 to achieve one-way locking, which is conducive to dispersing the load, improving the bearing capacity of the dose adjustment mechanism 100 of the embodiment of the present application, and improving the locking accuracy of the push rod portion 103 and the sealing plug 300. In some other embodiments of the present application, the transmission tooth portion 104 has at least one elastic clamping portion 1042.

[0147] The elastic clamping portion 1042 is made of a material capable of producing elastic deformation, such as plastic with a certain elasticity.

[0148] Please refer to Figure 15 , Figure 15 for Figure 1 A schematic diagram of the structure of the push rod portion and the transmission gear portion in the dose adjustment mechanism of the injection device.

[0149] As mentioned above, the transmission tooth portion 104 is mounted on the push rod portion 103 and limited in the circumferential direction. The push rod portion 103 is movable in the axial direction relative to the transmission tooth portion 104. Specifically, a limiting groove 103a is provided on the outer peripheral wall of the push rod portion 103. The limiting groove 103a extends along the axial direction of the push rod portion 103. The transmission tooth portion 104 is provided with a limiting protrusion 1044, and at least a part of the limiting protrusion 1044 is slidably inserted in the corresponding limiting groove 103a.

[0150] As configured above, the limiting groove 103a can play a role in limiting and guiding the limiting protrusion 1044, and the two side walls in the width direction of the limiting protrusion 1044 and the two side walls in the width direction of the limiting groove 103a can adopt a transition fit. On the one hand, the limiting groove 103a can reliably limit the limiting protrusion 1044 along the width direction, and avoid relative shaking of the push rod part 103 and the transmission tooth part 104 along the circumferential direction as much as possible, thereby improving the injection accuracy; on the other hand, the limiting protrusion 1044 can slide more smoothly along the extension direction of the limiting groove 103a, thereby reducing the operating resistance and improving the operating convenience.

[0151] In addition, the limiting groove 103a is arranged on the push rod part 103, and the limiting protrusion 1044 is arranged on the transmission gear part 104, which can also avoid interfering with the threaded fit between the push rod part 103 and the holding part 102, and ensure the normal operation of the dose adjustment mechanism 100 in the embodiment of the present application.

[0152] From Figure 14 It can be seen that in the embodiment of the present application, the transmission gear part 104 includes two oppositely arranged limiting protrusions 1044; correspondingly, the push rod part 103 includes two oppositely arranged limiting grooves 103a. Through the insertion fit of the two groups of limiting protrusions 1044 and limiting grooves 103a, it is beneficial to disperse the load and further improve the limiting reliability of the transmission gear part 104 on the push rod part 103.

[0153] In some other embodiments of the present application, the transmission gear part 104 has at least one limiting protrusion 1044, and the push rod part 103 has at least one limiting groove 103a.

[0154] Please refer to Figure 16 and Figure 17 , Figure 16 For Figure 12 a schematic structural view of the second angle of the main body part; Figure 17 For Figure 5 a schematic structural view of the connection part between the main body part and the cylinder body in

[0155] In the embodiment of the present application, the driving rod part 101 has a pressing end, and an installation groove 102d is arranged on the end wall of the holding part 102 facing away from the pressing end. The installation groove 102d is used to limit and install the protruding part 201 at the opening end of the cylinder body 200 of the injection device in the transverse direction;

[0156] The dose adjustment mechanism 100 further includes a blocking part 110. The blocking part 110 is connected to the holding part 102, and the blocking part 110 is configured to abut against the end wall of the protruding part 201 facing away from the pressing end to axially limit the protruding part 201.

[0157] Wherein, the axial direction is defined as the extending direction of the driving rod part 101 and the cylinder body 200, and the transverse direction is the direction perpendicular to the axial direction.

[0158] With the above settings, when assembling the barrel 200 and the dose adjustment mechanism 100, the convex portion 201 can be inserted into the interior of the installation groove 102d to achieve the lateral limit connection between the holding portion 102 and the barrel 200; the blocking member 110 abuts against the end wall of the convex portion 201 facing away from the pressing end to axially limit the convex portion 201, achieving the axial limit connection between the holding portion 102 and the barrel 200, thereby fixing the holding portion 102 and the barrel 200 together to ensure the reliable connection between the barrel 200 and the dose adjustment mechanism 100; this setting method of the connection structure is also conducive to reducing the installation difficulty of the holding portion 102 and the barrel 200, improving the assembly convenience of the holding portion 102 and the barrel 200, and improving the production efficiency.

[0159] As Figure 16 shown, in the embodiment of the present application, the blocking member 110 includes at least two limiting bumps 1101, and the at least two limiting bumps 1101 are arranged on the opposite two wall portions surrounding the installation groove 102d. The end wall of the limiting bump 1101 facing the pressing end abuts against the end wall of the convex portion 201 facing away from the pressing end to axially limit the convex portion 201. From the connection end of the limiting bump 1101 to the free end of the limiting bump 1101, the end wall of the limiting bump 1101 facing away from the pressing end extends obliquely towards the direction close to the pressing end.

[0160] With the above settings, the end wall of the limiting bump 1101 facing away from the pressing end forms an obliquely extending guiding wall. When assembling the barrel 200 and the dose adjustment mechanism 100, the convex portion 201 can slide along the guiding wall. When the convex portion 201 crosses the guiding wall, the end wall of the limiting bump 1101 facing the pressing end abuts against the end wall of the convex portion 201 facing away from the pressing end to axially limit the convex portion 201, and the convex portion 201 is installed in place, realizing the reliable connection between the blocking member 110 and the holding portion 102. It can be seen that the structure of the blocking member 110 in the present application is simple, which is conducive to reducing the structural cost, simplifying the assembly steps of the barrel 200, and improving the assembly convenience.

[0161] Please continue to refer to Figure 16 and Figure 17 , in the embodiment of the present application, the end portion of the holding portion 102 facing away from the pressing end includes two spaced-apart mounting portions 1025, and the aforementioned installation groove 102d is formed between the two mounting portions 1025. The at least two limiting bumps 1101 are arranged on the opposite wall portions of the two mounting portions 1025.

[0162] With the above settings, the two mounting portions 1025 are spaced apart, and both ends in the length direction of the installation groove 102d are also open ends. When assembling the barrel 200 and the dose adjustment mechanism 100, the mounting portion 1025 is more likely to be deformed under the extrusion force of the convex portion 201, improving the assembly convenience of the barrel 200.

[0163] As Figure 16 andFigure 17 As shown, two mounting portions 1025 are respectively provided with notch portions 1025a near the limit bump 1101. The notch portions 1025a can reduce the stiffness of the surrounding area, so that when assembling the cylinder body 200 and the dose adjustment mechanism 100, the area near the limit bump 1101 is more likely to deform, further improving the assembly convenience of the cylinder body 200.

[0164] Of course, the blocking member 110 is not limited to the structural form of the above-mentioned limit bump 1101. For example, in some other embodiments of the present application, the holding portion 102 is further provided with mounting holes that penetrate the two mounting portions 1025 transversely. The mounting holes are communicated with the mounting grooves 102d, and both ends of the blocking member 110 are fixedly installed in the mounting holes. Before assembling the cylinder body 200 and the dose adjustment mechanism 100, the blocking member 110 and the holding portion 102 are in a separated state. When assembling the cylinder body 200 and the dose adjustment mechanism 100, first insert the protruding portion 201 of the cylinder body 200 into the inside of the mounting groove 102d to realize the transverse limit connection between the holding portion 102 and the cylinder body 200; then, insert the blocking member 110 into the mounting holes to realize the fixed connection between the blocking member 110 and the holding portion 102. The blocking member 110 abuts against the end wall of the protruding portion 201 opposite to the pressing end to axially limit the protruding portion 201, realizing the axial limit connection between the holding portion 102 and the cylinder body 200, thereby fixing the holding portion 102 and the cylinder body 200 together and ensuring the reliable connection between the cylinder body 200 and the dose adjustment mechanism 100. In some embodiments, the blocking member 110 and the mounting holes can adopt an interference fit method, which has reliable connection and convenient operation.

[0165] Furthermore, Figure 1 It can be seen that in order to enable the driving rod portion 101 to move axially and rotate a preset angle circumferentially under the pressing force, in some embodiments of the present application, the dose adjustment mechanism 100 further includes a pressing portion 109, and the pressing portion 109 is rotatably connected to the pressing end of the driving rod portion 101.

[0166] In this way, the operator can apply a pressing force to the driving rod portion 101 by pressing the pressing portion 109 as described above. The cross-sectional area of the pressing portion 109 can be set to be larger than the cross-sectional area of the driving rod portion 101, which is convenient for the operator to apply force and improves the operation convenience; the pressing portion 109 is rotatably connected to the pressing end of the driving rod portion 101, so that the driving rod portion 101 can rotate circumferentially without obstruction when receiving the pressing force, ensuring the normal operation of the dose adjustment mechanism 100 of the present application.

[0167] Among them, the connection manner between the pressing portion 109 and the driving rod portion 101 is not limited. For example, in some embodiments of the present application, the pressing end of the driving rod portion 101 has a spherical connection groove. The pressing portion 109 includes a panel portion, a connecting rod portion, and a spherical connection portion. The connecting rod portion is connected between the panel portion and the spherical connection portion. The spherical connection portion is installed inside the spherical connection groove. The spherical connection portion can rotate inside the spherical connection groove to realize the rotational connection between the pressing portion 109 and the driving rod portion 101. The diameter of the open end of the spherical connection groove is smaller than the diameter of the spherical connection portion. Therefore, the spherical connection portion can be reliably installed inside the spherical connection groove without coming out, ensuring the reliable axial connection between the pressing portion 109 and the driving rod portion 101.

[0168] An embodiment of the present application further provides an injection device, including:

[0169] A barrel 200 having an injection end and an open end;

[0170] A sealing plug 300 slidably disposed inside the barrel 200. Taking the sealing plug 300 as a boundary, the area inside the barrel 200 close to the injection end forms a storage cavity 200a for storing an injection substance.

[0171] The dose adjustment mechanism 100 of the aforementioned injection device, the holding portion 102 of the dose adjustment mechanism 100 is connected to the open end of the barrel 200, and the push rod portion 103 of the dose adjustment mechanism 100 is connected to the sealing plug 300.

[0172] The injection device of the embodiment of the present application includes the aforementioned dose adjustment mechanism 100, and thus has the same technical effects as the aforementioned dose adjustment mechanism 100, which will not be elaborated herein.

[0173] Among them, the connection manner between the push rod portion 103 and the sealing plug 300 is not limited. For example, the push rod portion 103 and the sealing plug 300 can be connected by interference fit. Specifically: the end wall of the sealing plug 300 facing the open end has a connection groove, the outer diameter of the connection end of the push rod portion 103 is larger than the inner diameter of the connection groove, and at least part of the connection end of the push rod portion 103 is inserted into the connection groove.

[0174] The above are only the preferred embodiments of the present application. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present application, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present application.

Claims

1. A dose adjustment mechanism of an injection device, characterized in that, It comprises a driving rod portion, a gripping portion, a push rod portion and a transmission tooth portion, wherein the driving rod portion is connected to the gripping portion, and the driving rod portion is provided with active ratchets distributed along the circumferential direction; the push rod portion passes through the gripping portion and is threadedly connected; the transmission tooth portion is sleeved on the push rod portion and limited in the circumferential direction, and the push rod portion is movable in the axial direction relative to the transmission tooth portion; the transmission tooth portion further comprises a driven ratchet, and the front end surface of the active ratchet and the rear end surface of the driven ratchet are matching inclined surfaces; The driving rod has an initial position and a terminal position. In the initial position, the active ratchet and the driven ratchet have a spacing in the axial direction, and the front end face of one of the active ratchet and the rear end face of the driven ratchet are staggered by a preset angle in the circumferential direction. The driving rod is capable of moving axially from the initial position and rotating circumferentially by a preset angle when subjected to a pressing force, so as to switch to the terminal position, in which one of the active ratchet teeth is meshed with the driven ratchet teeth, and the transmission tooth portion rotates by an angle of the active ratchet teeth; The dose adjustment mechanism further includes a reset portion configured to drive the drive rod portion to return to the initial position in a state where the pressing force is released.

2. The dose adjustment mechanism according to claim 1, characterized in that, The gripping portion has a receiving cavity, and the peripheral wall surrounding the receiving cavity is provided with one-way slots distributed along the circumferential direction, the transmission tooth portion is located in the receiving cavity, and the transmission tooth portion further includes an elastic clamping portion, and the elastic clamping portion is clamped in any one of the one-way slots; When the driving rod moves from the initial position to the terminal position, the elastic clamping portion can slide along the peripheral wall surrounding the accommodating cavity to be clamped into one of the one-way clamping grooves at the front end.

3. The dose adjustment mechanism according to claim 2, characterized in that, The peripheral wall surrounding the accommodating cavity is provided with a plurality of ratchet teeth distributed along the circumferential direction, and ratchet grooves are formed between adjacent ratchet teeth, and the ratchet grooves are the one-way clamping grooves.

4. The dose adjustment mechanism according to any one of claims 1-3, characterized in that The gripping portion has a receiving cavity, part of the driving rod portion is located in the receiving cavity, one of the outer peripheral wall of the driving rod portion and the inner peripheral wall surrounding the receiving cavity is provided with a guide portion extending in the axial direction, and the other is provided with a guide groove extending in the axial direction, and the guide portion is slidably mounted in the guide groove; Along the axial movement direction of the driving rod portion when the pressing force is applied, the rear side wall of the guide groove includes a first wall portion, a second wall portion and a third wall portion connected in sequence, the first wall portion and the third wall portion extend in the axial direction, and along the direction away from the first wall portion, the second wall portion extends obliquely toward the direction close to the front side wall; The reset portion includes an elastic member, which is pre-compressed or pre-stretched in the circumferential direction and arranged between the holding portion and the driving rod portion, so that the rear side wall of the guide portion and the rear side wall of the guide groove are in contact with each other. When the driving rod portion moves from the initial position to the terminal position, the elastic member is deformed in the axial and circumferential directions to store energy.

5. The dose adjustment mechanism according to claim 4, characterized in that, The elastic member comprises: An elastic arm, one end of which is connected to the guide portion, the other end of which is in contact with the front side wall of the guide groove, and the elastic arm is pre-compressed between the guide portion and the front side wall of the guide groove in the circumferential direction; An axial spring is arranged axially between the holding part and the driving rod part.

6. The dose adjustment mechanism according to claim 4, characterized in that, The elastic member includes: A torsion spring, with both ends of the torsion spring connected to the holding part and the driving rod part.

7. The dose adjustment mechanism according to claim 6, characterized in that, The elastic member further includes: An axial spring, arranged axially between the holding part and the driving rod part.

8. The dose adjustment mechanism according to claim 2 or 3, characterized in that, The holding part includes: A body part, which has a receiving groove. One end of the receiving groove close to the pressing end of the driving rod part is an open end, and a one-way card slot is arranged on the peripheral wall surrounding the receiving groove; A cover plate part, which is connected to the open end of the body part, and the receiving groove forms at least part of the receiving cavity.

9. The dose adjustment mechanism according to claim 8, characterized in that, The body part includes a first cylinder arranged inside the receiving groove. The end wall surrounding the receiving groove has a through hole communicating with the first cylinder, and the push rod part passes through the first cylinder and is threadedly connected; The transmission gear part further includes a second cylinder. The second cylinder sleeves the push rod part and is circumferentially limited and axially movable; the elastic clamping part is connected to the outer peripheral wall of the second cylinder. The inner wall of the second cylinder has a stepped part. The second cylinder movably sleeves the first cylinder, and the stepped part abuts against the opposite end part of the first cylinder.

10. The dose adjustment mechanism according to any one of claims 1-3, characterized in that, The driving rod part has a pressing end. An installation groove is arranged at the end of the holding part facing away from the pressing end. The installation groove is used for laterally limiting and installing a convex part at the open end of the cylinder of the injection device; The dose adjustment mechanism further includes a blocking member, which is connected to the holding part. The blocking member is configured to abut against the end wall of the convex part facing away from the pressing end to axially limit the convex part.

11. The dose adjustment mechanism according to claim 10, wherein The blocking member includes at least two limiting protrusions. At least two of the limiting protrusions are arranged on the opposite two wall parts surrounding the installation groove. The end wall of the limiting protrusion facing the pressing end abuts against the end wall of the convex part facing away from the pressing end to axially limit the convex part. From the connecting end of the limiting protrusion to the free end of the limiting protrusion, the end wall of the limiting protrusion facing away from the pressing end extends obliquely towards the pressing end.

12. An injection device, characterized in that, It includes: A cylinder, which has an injection end and an open end; A sealing plug, slidably arranged inside the cylinder. Taking the sealing plug as a boundary, the area inside the cylinder close to the injection end forms a storage cavity, and the storage cavity is used for storing the injection substance; The dose adjustment mechanism according to any one of claims 1-11, the holding part of the dose adjustment mechanism is connected to the open end of the cylinder, and the push rod part of the dose adjustment mechanism is connected to the sealing plug.

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