Dose adjustment mechanism of injection device and injection device

Abstract

The present application relates to the field of medical device technology, and more specifically to a dose adjustment mechanism for an injection device and an injection device, wherein a drive rod is provided with an active ratchet; a push rod passes through a grip portion and is threadedly connected; a transmission tooth portion is fitted over the push rod portion and circumferentially limited, and the push rod portion is axially movable relative to the transmission tooth portion; the transmission tooth portion includes a driven ratchet; the drive rod is capable of switching from an initial position to a final position, wherein in the initial position, the active ratchet and the driven ratchet are spaced axially and staggered circumferentially by a preset angle; in the final position, the active ratchet and the driven ratchet engage, and the transmission tooth portion rotates by an angle of the active ratchet; and a reset portion drives the drive rod portion back to the initial position when the pressing force is released. In the present application, the rotation angle of the transmission tooth portion corresponds to the axial displacement of the push rod portion. The one-by-one engagement of the active ratchet and the driven ratchet discretizes the rotation of the transmission tooth portion, resulting in a smaller single displacement of the push rod portion, thereby meeting the requirements of small-dose injections.

Description

Technical Field

[0001] The present application relates to the technical field of medical devices, and in particular to a dosage adjustment mechanism of an injection device and an injection device. Background Art

[0002] Related technology injection device includes a coat component, a push rod component and a clasp component. The surface of the push rod component has a concave-convex structure distributed continuously along the axial direction. The push rod component is suitable for being connected with the coat component and moving along the axial direction of the coat component. The concave-convex structure is blocked by the clasp component during the movement of the push rod component. The clasp component is arranged at the opening of the first end where the push rod component is connected to the coat component. It is suitable for cooperating with the concave-convex structure on the push rod component during the axial movement of the push rod component along the coat component to block the movement of the push rod component. The distance between adjacent concave-convex structures has a corresponding relationship with the dosage of the injection. Under the cooperation of the concave-convex structure and the clasp component, the dosage of the injection can be accurately controlled by blocking the movement of the push rod component, thereby improving the accuracy of the injection amount of the injection.

[0003] The spacing between adjacent concave-convex structures in the related technology injection device determines the minimum dosage unit. If a smaller dosage is to be achieved, the spacing between adjacent concave-convex structures needs to be shortened. However, due to limitations in processing precision such as machining capabilities, an excessively small spacing may cause the concave-convex structure to be unable to form stably or to be easily worn, resulting in the related technology injection device being only suitable for large-dose injections and unable to meet small-dose injection requirements. Summary of the Invention

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

[0005] To solve the above technical problems, the present application provides a dose adjustment mechanism for an injection device, comprising a drive rod, a gripping portion, a push rod, and a transmission tooth portion, wherein the drive rod is connected to the gripping portion and is provided with active ratchets distributed along a circumferential direction; the push rod passes through the gripping portion and is threadedly connected; the transmission tooth portion is fitted over the push rod portion and is circumferentially limited, and the push rod portion is axially movable 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;

[0006] The driving rod has an initial position and an end position. In the initial position, the active ratchet and the driven ratchet are spaced apart in the axial direction, and a front end face of one of the active ratchet and a rear end face of the driven ratchet are staggered in the circumferential direction by a preset angle.

[0007] When the driving rod is subjected to a pressing force, it can move axially from the initial position and rotate circumferentially by a preset angle to switch to the terminal position. At the terminal position, one of the active ratchet teeth is engaged with the driven ratchet teeth, and the transmission tooth portion rotates by an angle of the active ratchet teeth.

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

[0009] Optionally, the gripping portion has an accommodating cavity, and the peripheral wall surrounding the accommodating cavity is provided with one-way clamping grooves distributed along the circumferential direction. The transmission tooth portion is located in the accommodating 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 clamping grooves.

[0010] 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 slots at the front end.

[0011] Optionally, a 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.

[0012] Optionally, the gripping portion has an accommodating cavity, a portion of the driving rod portion is located in the accommodating cavity, and one of an outer peripheral wall of the driving rod portion and an inner peripheral wall surrounding the accommodating cavity is provided with an axially extending guide portion, and the other is provided with an axially extending guide groove, and the guide portion is slidably mounted in the guide groove;

[0013] 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 extending in the axial direction, and the second wall portion extending obliquely in a direction away from the first wall portion toward the front side wall;

[0014] The reset portion includes an elastic member, which is pre-compressed or pre-stretched in the circumferential direction and is arranged between the gripping 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.

[0015] Optionally, the elastic member includes:

[0016] an elastic arm, one end of the elastic arm being connected to the guide portion, the other end of the elastic arm being in contact with the front side wall of the guide groove, and the elastic arm being pre-compressed in the circumferential direction between the guide portion and the front side wall of the guide groove;

[0017] An axial spring is axially arranged between the gripping portion and the driving rod portion.

[0018] Optionally, the elastic member includes:

[0019] A torsion spring, two ends of which connect the gripping portion and the driving rod portion.

[0020] Optionally, the elastic member further includes:

[0021] An axial spring is axially arranged between the gripping portion and the driving rod portion.

[0022] Optionally, the gripping portion includes:

[0023] A main body portion, wherein the main body portion has a receiving groove, an end of the receiving groove close to the pressing end of the driving rod portion is an open end, and a peripheral wall surrounding the receiving groove is provided with the one-way clamping groove;

[0024] A cover portion is connected to the open end of the main body portion, and the accommodating groove forms at least a portion of the accommodating cavity.

[0025] Optionally, the main body includes a first cylinder disposed inside the accommodating groove, an end wall surrounding the accommodating groove has a through hole communicating with the first cylinder, and the push rod passes through the first cylinder and is threadedly connected;

[0026] The transmission gear portion also includes a second cylinder, which is fitted over the push rod portion and limited in the circumferential direction and movable in the axial direction; the elastic clamping portion is connected to the outer circumferential wall of the second cylinder, and the inner wall of the second cylinder has a step portion, and the second cylinder is movably fitted over the first cylinder, and the step portion and the opposite end of the first cylinder are in conflict.

[0027] Optionally, the driving rod has a pressing end, and the end of the gripping portion facing away from the pressing end is provided with a mounting groove, and the mounting groove is used for mounting the protrusion located at the open end of the barrel of the injection device in a transverse limited manner;

[0028] The dose adjustment mechanism further includes a blocking member connected to the grip portion, and the blocking member is configured to abut against an end wall of the protrusion facing away from the pressing end to limit the axial position of the protrusion.

[0029] Optionally, the blocking member includes at least two limiting protrusions, and at least two of the limiting protrusions are arranged on opposite wall portions that surround the mounting groove. The limiting protrusions face the end wall of the pressing end and abut against the end wall of the protrusion portion facing away from the pressing end to limit the axial position of the protrusion portion. 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 discharge end and an open end;

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

[0033] The aforementioned dose adjustment mechanism, wherein 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 along the circumferential limit, 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 threaded together. When the grip part is in the 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, ensuring that the dose is controllable; at the same time, by the one-by-one engagement of the active ratchet teeth distributed along the circumference of the drive 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 and 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 the dose adjustment mechanism of the injection device provided in this application;

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

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

[0039] Figure 4 for Figure 1 A schematic diagram of the partial structure of the dose adjustment mechanism of the injection device returning to the initial position;

[0040] Figure 5 This is a schematic structural diagram of a specific embodiment of the injection device provided in this application;

[0041] Figure 6 for Figure 1 A schematic diagram of the structure of the grip portion and transmission gear portion of the dose adjustment mechanism of the injection device;

[0042] Figure 7 This is a schematic structural diagram of a second specific embodiment of the dose adjustment mechanism of the injection device provided in this application;

[0043] Figure 8 for Figure 7 A partial enlarged view of the middle driving rod, the gripping portion, and the elastic member;

[0044] Figure 9 This is a schematic structural diagram of a third specific embodiment of the dose adjustment mechanism of the injection device provided in this application;

[0045] Figure 10 for Figure 9 Schematic diagram of the structure of the middle grip and axial spring;

[0046] Figure 11 for Figure 9 Schematic diagram of the structure of the middle driving rod and axial spring;

[0047] Figure 12 for Figure 1 A schematic diagram of the structure of the main body of the dose adjustment mechanism of the injection device;

[0048] Figure 13 for Figure 1 A schematic diagram of the structure of the cover portion of the dose adjustment mechanism of the injection device;

[0049] Figure 14 for Figure 1 A schematic diagram of the structure of the transmission gear portion in the dose adjustment mechanism of the injection device;

[0050] Figure 15 for Figure 1 A schematic diagram of the structure of the push rod and transmission gear in the dose adjustment mechanism of the injection device;

[0051] Figure 16 for Figure 12 A schematic diagram of the structure of the main body at the second angle;

[0052] Figure 17 for Figure 5 A schematic diagram of the structure of the connection between the middle body and the cylinder;

[0053] in, Figures 1-17 The reference numerals in the figures are as follows:

[0054] 100-dose adjustment mechanism;

[0055] 101 - driving rod; 1011 - active ratchet; 1011' - first active ratchet; 1011'' - second active ratchet; 1012 - guide portion; 1013 - first connecting column;

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

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

[0058] 104 - transmission tooth portion; 1041 - driven ratchet; 1042 - elastic clamping portion; 1043 - second cylinder; 1043a - step portion; 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 member; 1101-limiting protrusion;

[0065] 200-cylinder; 200a-storage chamber; 201-protrusion;

[0066] 300-sealing plug;

[0067] a- inclined surface; b- spacing. DETAILED DESCRIPTION

[0068] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0069] The terms "first," "second," and the like in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of this application can be implemented in an order other than that illustrated or described herein, and that the objects distinguished by "first," "second," and the like are generally of the same type, and do not limit the number of objects; for example, the first object can be one or more. In addition, the term "and / or" in the specification and claims refers to at least one of the connected objects, and the character " / " generally indicates that the objects connected are in an "or" relationship.

[0070] It should be understood that references throughout this specification to "some embodiments" mean that a particular feature, structure, or characteristic associated with an embodiment is included in at least one embodiment of the present application. Therefore, the appearance of "in some embodiments" throughout this specification does not necessarily refer to the same embodiment. Furthermore, these particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0071] In the description herein, unless otherwise expressly specified or limited, the terms "connected," "connect," and "fixed" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this disclosure in specific contexts.

[0072] Please refer to Figure 1-Figure 5 , Figure 1 This is a schematic structural diagram of a first specific embodiment of the dose adjustment mechanism of the injection device provided in this application; Figure 2 for Figure 1 A schematic diagram of the partial structure of the dose adjustment mechanism of the injection device in the initial position; Figure 3 for Figure 1 A schematic diagram of the partial structure of the dose adjustment mechanism of the injection device in the end position; Figure 4 for Figure 1 A schematic diagram of the partial structure of the dose adjustment mechanism of the injection device returning to the initial position; Figure 5This is a schematic structural diagram of a specific embodiment of the injection device provided in this application.

[0073] The present embodiment provides a dose adjustment mechanism 100 for an injection device, comprising a drive rod 101, a grip 102, a push rod 103, and a transmission tooth portion 104. The drive rod 101 is connected to the grip 102 and is provided with circumferentially distributed active ratchet teeth 1011. The push rod 103 passes through the grip 102 and is threadedly connected thereto. The transmission tooth portion 104 is fitted over the push rod 103 and is circumferentially position-limited. The push rod 103 is axially movable relative to the transmission tooth portion 104. The transmission tooth portion 104 further comprises a driven ratchet 1041. The front end surface of the active ratchet 1011 and the rear end surface of the driven ratchet 1041 are matched inclined surfaces a.

[0074] The driving rod 101 has an initial position and an end position. In the initial position, the active ratchet 1011 and the driven ratchet 1041 are spaced apart in the axial direction, and the front end surface of one active ratchet 1011 and the rear end surface of the driven ratchet 1041 are staggered by a preset angle in the circumferential direction.

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

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

[0077] like Figure 5 As 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 arranged inside the barrel 200. The area inside the barrel 200 near the injection end is bounded by the sealing plug 300 to form a storage chamber 200a. The storage chamber 200a is used to store the injection material. When the dose adjustment mechanism 100 of the embodiment of the present application is applied to the injection device, the gripping portion 102 is connected to the open end of the barrel 200. The gripping portion 102 can be gripped by the operator so that the gripping portion 102 and the barrel 200 are in a fixed state. The 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 toward the injection end, part of the injection material in the storage chamber 200a is squeezed out.

[0078] The transmission tooth portion 104 is fitted around 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, the push rod portion 103 rotates driven by the transmission tooth portion 104 and can also rotate in the threaded engagement. Under the action of the push rod portion 103 and the grip portion 102, 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 in the axial direction, 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 further includes a driven ratchet tooth 1041. The front end face of the active ratchet tooth 1011 and the rear end face of the driven ratchet tooth 1041 are matched inclined surfaces a. 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 face of one active ratchet tooth 1011 and the rear end face 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 ′, and the active ratchet tooth 1011 located adjacent to the front end of the first active ratchet tooth 1011 ′ is a second active ratchet tooth 1011 ″. 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 subjected to a pressing force, 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 engage with each other; when the driving rod 101 moves from the initial position to the end position, as shown in FIG. Figure 3As shown, the first active ratchet 1011' and the driven ratchet 1041 are engaged. Under the pushing action of the first active ratchet 1011', the transmission tooth portion 104 rotates by an angle of the active ratchet 1011; because the transmission tooth portion 104 is fitted on the push rod portion 103 and is limited in the circumferential direction, the push rod portion 103 also rotates by an angle of the active ratchet 1011; and because the push rod portion 103 passes through the grip portion 102 and is threadedly connected, the push rod portion 103 can also move a fixed distance in the axial direction under the action of the threaded fit; when the pressing force is released, the reset portion drives the driving rod portion 101 back to the initial position, as shown in FIG. Figure 4 As shown, the active ratchet 1011 and the driven ratchet 1041 are spaced apart in the axial direction. Since the transmission tooth portion 104 rotates by an angle of the active ratchet 1011, the front end face of the second active ratchet 1011'' located adjacent to the front end of the first active ratchet 1011' and the rear end face of the driven ratchet 1041 are staggered by a preset angle in the circumferential direction.

[0081] When the driving rod 101 is subjected to pressing force again, the second active ratchet 1011'' and the driven ratchet 1041 gradually engage with the movement of the driving rod 101; when the driving rod 101 moves from the initial position to the terminal position, the second active ratchet 1011'' and the driven ratchet 1041 engage with each other, and under the pushing action of the second active ratchet 1011'', the transmission tooth portion 104 rotates through an angle of the active ratchet 1011, and drives the push rod portion 103 to rotate through an angle of the active ratchet 1011, and the push rod portion 103 moves a fixed distance in the axial direction under the action of the threaded fit.

[0082] It can be seen that each active ratchet 1011 corresponds to a gear position. By designing the number of active ratchets 1011, each pressing of the drive rod 101 can correspond to a clear dosage unit. For example, the thread pitch of the push rod 103 and the gripping portion 102 is 1 mm, and the drive rod 101 is provided with 12 active ratchets 1011. The interval between adjacent active ratchets 1011 is 30°. Each time the drive rod 101 is pressed, the movement distance of the push rod 103 is the ratio of the thread pitch to the number of active ratchets 1011, that is, approximately 0.0833 mm. This breaks through the single minimum injection volume limit of the traditional axial concave-convex structure and meets the needs of small-dose injection.

[0083] To sum up, the dose adjustment mechanism 100 of the embodiment of the present application discretizes the rotational motion of the transmission tooth portion 104 into fixed angle steps by engaging the active ratchet teeth 1011 distributed circumferentially in the driving rod portion 101 with the driven ratchet teeth 1041 in the transmission tooth portion 104 one by one. By matching the thread pitch with the number of active ratchets 1011, the single displacement of the push rod portion 103 is reduced to a lower level, breaking through the single minimum injection volume limit of the traditional axial concave-convex structure and meeting the needs of small-dose injection.

[0084] Combine Figure 3 It is understood that a ratchet groove is formed between two adjacent active ratchet teeth 1011, a ratchet groove is formed between the first active ratchet tooth 1011' and the second active ratchet tooth 1011'' located at the front end thereof, and the engagement of the first active ratchet tooth 1011' and the driven ratchet tooth 1041 means that the driven ratchet tooth 1041 is sunk into the ratchet groove between the first active ratchet tooth 1011' and the second active ratchet tooth 1011'' located at the front end thereof, and the front end face of the first active ratchet tooth 1011' and the rear end face of the driven ratchet tooth 1041 are completely fitted together.

[0085] Depend on 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] Depend on 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 drive rod 101. When the drive rod 101 moves in the axial direction, the active ratchet 1011 pushes the driven ratchet 1041 along its height direction, that is, the direction of force is consistent with the direction of movement, which is conducive to achieving efficient force transmission; at the same time, it is also conducive to reducing the radial size of the drive rod 101 and reducing the radial space occupied, so that the structure of the dose adjustment mechanism 100 in the embodiment of the present application is more compact.

[0087] Please refer to Figure 6 , Figure 6 for Figure 1 Schematic diagram of the structure of the grip part and transmission gear part in the dose adjustment mechanism of the injection device.

[0088] In the embodiment of the present application, the grip portion 102 has an accommodating cavity 102a. The peripheral wall surrounding the accommodating cavity 102a is provided with circumferentially distributed one-way slots 102b. The transmission tooth portion 104 is located in the accommodating cavity 102a. The transmission tooth portion 104 further includes an elastic engaging portion 1042. The elastic engaging portion 1042 engages with any one-way slot 102b.

[0089] When the driving rod 101 moves from the initial position to the final position, the elastic engaging portion 1042 can slide along the peripheral wall surrounding the accommodating cavity 102 a to be engaged with one of the one-way engaging slots 102 b at the front end.

[0090] The aforementioned one-way slot 102b means that when the driving rod portion 101 is subjected to pressing pressure, the elastic clamping portion 1042 can only slide in one direction along the peripheral wall surrounding the accommodating cavity 102a to be clamped into the one-way slot 102b at the front end, and cannot slide in the opposite direction, that is, to ensure that the transmission tooth portion 104 can only rotate in one direction, and cannot rotate 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 pressure, and 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 volume is improved, and injection errors are avoided as much as possible; on the other hand, the secondary use of the dose 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] Among them, 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 the elastic clamping portion 1042 When passing the current one-way slot 102b, the elastic potential energy of the elastic clamping portion 1042 is released, and the elastic clamping portion 1042 instantly bounces into the next one-way slot 102b. The collision between the elastic clamping portion 1042 and the surrounding wall of the accommodating cavity 102a will produce a "click" sound, or cause the driving rod portion 101 to vibrate slightly. 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 of the elastic clamping portion 1042 crossing over the two one-way clamping slots 102b each time the driving rod 101 is pressed once, when the driving rod 101 is pressed, the elastic clamping portion 1042 gradually slides out of the current one-way clamping slot 102b, the elastic clamping portion 1042 is squeezed and deformed, and the elastic clamping portion 1042 gradually accumulates energy; when the elastic clamping portion 1042 crosses the current one-way clamping slot 102b, the elastic potential energy of the elastic clamping portion 1042 is released, and the elastic clamping portion 1042 instantly springs into the lower A one-way slot 102b, the elastic clamping portion 1042 and the surrounding wall of the accommodating chamber 102a collide to produce a "click" sound, or cause the driving rod 101 to vibrate slightly, and this is repeated twice. When the driving rod 101 moves to the end position, the user hears two "clicks" 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 "clicks" or vibrations, thereby avoiding injection errors as much as possible.

[0093] Please continue to refer to Figure 6 In the embodiment of the present application, the peripheral wall surrounding the accommodating cavity 102a is provided with a plurality of ratchet teeth 1021 distributed along the circumferential direction, and ratchet grooves 1022 are formed between adjacent ratchet teeth 1021, and the ratchet grooves 1022 are the aforementioned one-way slots 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 is pressed and moves from the initial position to the end position, the elastic clamping portion 1042 can slide along the inclined surface, thereby smoothly sliding over the top of the current ratchet 1021 and falling into the next ratchet groove 1022. The inclined surface can reduce the resistance of the forward operation and improve the convenience of operation; when the elastic clamping portion 1042 slides over the top of the current ratchet 1021 and falls into the next ratchet groove 1022, it usually produces a clear "click" sound and / or an operating feel (such as a slight vibration), giving the user clear feedback; and 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 opposite direction, avoiding injection errors as much as possible, and preventing the dose adjustment mechanism 100 from being reused, thereby improving safety. Moreover, the shape of the ratchet 1021 is relatively standard, and is easy to manufacture by machining, stamping, casting or injection molding, thereby improving molding convenience and reducing production costs.

[0095] As mentioned above, 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 to switch to the end position. Figure 1-Figure 3 It is understood that in the embodiment of the present application, a portion of the driving rod portion 101 is located in the accommodating cavity 102a, and an outer peripheral wall of the driving rod portion 101 and an inner peripheral wall surrounding the accommodating cavity 102a are provided with a guide portion 1012 extending in the axial direction, and the other is provided with a guide groove 102c extending in the axial direction, and the guide portion 1012 is slidably installed in the guide groove 102c;

[0096] Along the axial movement direction of the driving rod portion 101 when the pressing force is applied, the rear side wall of the guide 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 in the axial direction. In the direction away from the first wall portion 102c-1, the second wall portion 102c-2 extends obliquely toward the front side wall 102c-4 of the guide groove 102c.

[0097] The reset part includes an elastic member, which is pre-compressed or pre-stretched in the circumferential direction and is arranged between the gripping part 102 and the driving rod part 101, so that the rear side wall of the guide part 1012 and the rear side wall of the guide groove 102c are in conflict with each other. When the driving rod part 101 moves from the initial position to the terminal position, the elastic member deforms in the axial and circumferential directions to store energy.

[0098] As described above, when the driving rod 101 is in the initial position, Figure 2 As shown, the rear side wall of the guide portion 1012 conflicts with the rear side wall of the first wall portion 102c-1, the active ratchet 1011 and the driven ratchet 1041 have a spacing along the axial direction, the front end face of the first active ratchet 1011' and the rear end face of the driven ratchet 1041 are staggered at a preset angle along the circumferential direction, and when the driving rod portion 101 is subjected to a pressing force, the guide portion 1012 can first slide along the first wall portion 102c-1, the active ratchet 1011 gradually approaches the driven ratchet 1041, and the elastic member accumulates energy along the axial direction; then, the guide portion 1012 can slide along the second wall portion 102c-2, and due to the movement along the far In the direction away from the first wall portion 102c-1, the second wall portion 102c-2 extends obliquely toward the front side wall 102c-4 close to the guide groove 102c. Therefore, the driving rod portion 101 can also rotate circumferentially by a preset angle under the guidance of the second wall portion 102c-2, so that the front end face of the first active ratchet 1011' and the rear end face of the driven ratchet 1041 are in contact, and the elastic member further accumulates energy in the axial direction and further accumulates energy in the circumferential direction; then, the guide portion 1012 can slide along the third wall portion 102c-3, and the elastic member further accumulates energy in the axial direction; when the driving rod portion 101 moves to the position as shown in FIG. Figure 3 At the end position shown, the first active ratchet 1011 ′ and the driven ratchet 1041 are engaged, and the driving rod 101 cannot move further. Under the pushing action of the first active ratchet 1011 ′, the transmission tooth portion 104 rotates by an angle of the active ratchet 1011 .

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

[0100] It can be seen that the dose adjustment mechanism 100 of the embodiment of the present application, through the arrangement of the guide portion 1012, the guide groove 102c and the elastic member as described above, enables the drive rod portion 101 to reliably switch between the initial position and the end position, thereby improving the position accuracy of the drive 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 guide groove is not limited to the above-mentioned setting method. For example, in some other embodiments of the present application, along the axial movement direction when the driving rod 101 is subjected to pressing force, the rear side wall of the guide groove 102c includes a first wall and a second wall connected in sequence, the second wall extends axially, and along the direction close to the second wall, the first wall extends obliquely in the direction close to the front side wall 102c-4 of the guide groove 102c. In this way, when the driving rod 101 is in the initial position, the rear side wall of the guide portion 1012 and the rear side wall of the first wall collide with each other, the active ratchet 1011 and the driven ratchet 1041 have a spacing along the axial direction, the front end face of the first active ratchet 1011' and the rear end face of the driven ratchet 1041 are staggered at a preset angle along the circumferential direction, and when the driving rod 101 is subjected to pressing force, the guide portion 1012 can first slide along the first wall, and the active ratchet 1011 gradually approaches the driven ratchet 1041, while the driving rod 101 is guided by the first wall. The preset angle of rotation in the circumferential direction causes the front end face of the first active ratchet 1011' to contact the rear end face of the driven ratchet 1041, and the elastic member stores energy in the axial and circumferential directions; then, the guide portion 1012 slides along the second wall, and the elastic member further stores energy in the axial direction; when the driving rod portion 101 moves to the terminal position, the first active ratchet 1011' and the driven ratchet 1041 engage, and the driving rod portion 101 cannot move further. Under the pushing action of the first active ratchet 1011', the transmission tooth portion 104 rotates through an angle of the active ratchet 1011.

[0102] When the pressing force applied to the driving rod 101 is released, the guide portion 1012 can move in the reverse direction under the action of the restoring force of the elastic member, and the rear side wall of the guide portion 1012 always conflicts with the rear side wall of the guide groove 102c, that is, the guide portion 1012 slides along the second wall and the first wall in sequence. When the guide portion 1012 slides along the first wall, the guide portion 1012 simultaneously rotates in the reverse direction by a preset angle along the circumferential direction and finally returns to the initial position.

[0103] The elastic member can be implemented in a variety of ways. In some embodiments, for example, Figure 1 and Figure 2 As shown, the elastic member includes:

[0104] The elastic arm 105 has one end connected to the guide portion 1012, and the other end of the elastic arm 105 abuts against the front side wall 102c-4 of the guide groove 102c. The elastic arm 105 is pre-compressed in the circumferential direction between the guide portion 1012 and the front side wall 102c-4 of the guide groove 102c.

[0105] The axial spring 106 is axially arranged between the gripping 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 guide groove 102c, a second groove portion is formed between the second wall portion 102c-2 and the front side wall 102c-4 of the guide 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 guide groove 102c; the width of the third groove portion is smaller than the width of the first groove portion, and the width of the second groove portion gradually decreases in the direction away from the first groove portion; when the driving rod portion 101 is in the initial position, the guide portion 1012 is located in the first groove portion, and under the extrusion force of the first wall portion 102c-1 and the front side wall 102c-4 of the guide groove 102c, the elastic arm 1 05 is pre-compressed, so that the rear side wall of the guide part 1012 conflicts with the rear side wall of the first wall part 102c-1; when the driving rod part 101 is subjected to pressing force and the guide part 1012 enters the second groove part, the width of the second groove part gradually decreases, and the extrusion force exerted on the elastic arm 105 gradually increases, and the elastic arm 105 further deforms and stores energy, so that the rear side wall of the guide part 1012 conflicts with the rear side wall of the second wall part 102c-2; when the guide part 1012 enters the third groove part, the width of the third groove part is not greater than the minimum width of the second groove part, and the elastic arm 105 maintains the deformation and energy storage state, so that the rear side wall of the guide part 1012 can conflict with the rear side wall of the third wall part 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 guide part 1012 always contact the rear side wall of the guide groove 102c, thereby making the guide part 1012 able to rotate circumferentially by a preset angle under the guidance of the rear side wall of the guide groove 102c, thereby ensuring that the dose adjustment mechanism 100 in the embodiment of the present application can work normally.

[0108] At the same time, an axial spring 106 is axially disposed between the grip portion 102 and the drive rod 101. When the drive rod 101 is subjected to a compressive force and moves axially from its initial position, the axial spring 106 compresses and accumulates energy. Consequently, when the compressive force is released, the axial spring 106 can drive the drive rod 101 to move axially in the opposite direction. Under the coordinated action of the axial spring 106 and the elastic arm 105, the drive rod 101 can reliably switch between the initial position and the final position, ensuring the normal operation of the dose adjustment mechanism 100 of the embodiment of the present application.

[0109] It can be seen that in the embodiment of the present application, the axial spring 106 and the elastic arm 105 respectively realize the axial reset and circumferential reset of the driving rod 101. This independent design allows the circumferential and axial reset behavior of the driving rod 101 to be more accurately controlled.

[0110] Among them, such as Figure 2 and Figure 3 As shown, in the embodiment of the present application, there is a distance b between the guide portion 1012 and the opposite side walls of the elastic arm 105 .

[0111] As configured above, the spacing b can provide deformation space for the elastic arm 105 when the elastic arm 105 is deformed under pressure, thereby avoiding interference of the guide portion 1012 with the deformation of the elastic arm 105 as much as possible, thereby ensuring that the elastic arm 105 can deform normally.

[0112] Please continue to refer to Figure 2 In the embodiment of the present application, the elastic arm 105 includes an axial extension section and a curved section that are connected to each other. The axial extension section extends along the axial direction of the dose adjustment mechanism 100, and one end of the axial extension section away from the curved section is connected to the guide portion 1012. Along the direction away from the axial extension section, the curved section bends toward the front side wall 102c-4 of the guide groove 102c, so that the end of the curved section away from the axial extension section contacts the front side wall 102c-4 of the guide groove 102c.

[0113] Please refer to Figure 7-Figure 8 , Figure 7 This is a schematic structural diagram of a second specific embodiment of the dose adjustment mechanism of the injection device provided in this application; Figure 8 for Figure 7 A partial enlarged view of the middle driving rod, gripping part and elastic member.

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

[0115] The torsion spring 107 has two ends connecting the gripping portion 102 and the driving rod 101 .

[0116] As described above, when the drive rod 101 is subjected to a pressing force and moves from its initial position to its final position, the torsion spring 107 simultaneously deforms in both the circumferential and axial directions to store energy. When the pressing force is released, the torsion spring 107, under the action of its restoring force, drives the drive rod 101 back to its initial position. Thus, in this embodiment of the present application, the torsion spring 107 simultaneously achieves both axial and circumferential repositioning of the drive rod 101, thereby reducing the number of parts and lowering costs.

[0117] like Figure 8As shown, in the embodiment of the present application, the drive rod portion 101 has a first connecting column 1013, the first connecting column 1013 has a first abutting wall facing the discharge end of the dose adjustment mechanism 100, and one end of the torsion spring 107 is wound around the first connecting column 1013 and abuts against the first abutting wall; the grip portion 102 has a second connecting column 1023, the second connecting column 1023 has a second abutting wall facing away from the discharge end of the dose adjustment mechanism 100, and the other end of the torsion spring 107 is wound around the second connecting column 1023 and abuts against the second abutting wall.

[0118] As configured above, when the driving rod 101 moves axially under the pressing force, one end of the torsion spring 107 will be stably wound around the first connecting column 1013 under the abutting action of the first abutting wall, and move axially with the driving rod 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, so that the torsion spring 107 will deform axially to store energy, and reliably play the axial resetting role of the driving rod 101 when the pressing force is released.

[0119] In addition, one end of the torsion spring 107 can wrap around the first connecting column 1013, and the other end of the torsion spring 107 can wrap around the second connecting column 1023, so that 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 101 rotates circumferentially, the torsion spring 107 can deform and store energy in the circumferential direction, and reliably play the circumferential reset role of the driving rod 101 when the pressing force is released.

[0120] Or, as Figure 8 As shown, one end of the torsion spring 107 is wound around at least a portion of the front side of the first connecting post 1013, and the other end of the torsion spring 107 is wound around at least a portion of the rear side of the second connecting post 1023. In this way, when the drive rod 101 is rotated, the first connecting post 1013 can reliably drive one end of the torsion spring 107 to twist and deform, while the second connecting post 1023 can reliably maintain the other end of the torsion spring 107 in a fixed state, minimizing the possibility of the torsion spring 107 being separated from the first connecting post 1013 and the second connecting post 1023. As a result, the torsion spring 107 deforms circumferentially and stores energy.

[0121] Please refer to Figure 9 , Figure 9 This is a schematic structural diagram of a third specific embodiment of the dose adjustment mechanism of the injection device provided in this application.

[0122] In some other embodiments of the present application, the elastic member is provided with an axial spring 106 in addition to the torsion spring 107 , and the axial spring 106 is axially arranged between the gripping portion 102 and the driving rod portion 101 .

[0123] As configured above, when the driving rod 101 is subjected to a pressing force and moves axially from the initial position, the axial spring 106 is compressed to store energy, so that when the pressing force is released, the axial spring 106 can also drive the driving rod 101 to move axially in the opposite direction, thereby realizing the axial reset of the driving rod 101.

[0124] In this way, the embodiment of the present application adds an axial spring 106 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 of the embodiment of the present application.

[0125] In some other embodiments of the present application, the elastic member includes a compression spring, and the two ends of the compression spring are respectively connected to the driving rod 101 and the holding portion 102. When installed, the compression spring is twisted by a certain angle to store energy. When the driving rod 101 is subjected to pressing pressure and moves from the initial position to the end position, the compression spring deforms circumferentially and axially at the same time to store energy; when the pressing pressure is released, the compression spring drives the driving rod 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 Schematic diagram of the structure of the middle grip and axial spring; Figure 11 for Figure 1 and Figure 9 Schematic diagram of the structure of the middle drive rod and axial spring.

[0127] In the embodiment of the present application, the holding portion 102 has a accommodating cavity 102a, and the peripheral wall surrounding the accommodating cavity 102a is provided with a plurality of ratchet teeth 1021 distributed along the circumferential direction. The axial spring 106 is located in the accommodating cavity 102a, and part of the axial spring 106 is mounted on the outer peripheral wall of the driving rod portion 101. One end of the axial spring 106 abuts against the guide portion 1012, and the other end of the axial spring 106 abuts against the end wall of the ratchet teeth 1021.

[0128] As configured above, part of the axial spring 106 is sleeved on the outer peripheral wall of the driving rod 101. The outer peripheral wall of the driving rod 101 can guide the axial spring 106, so that the axial spring 106 always moves along the axis of the driving rod 101 during compression or recovery, thereby preventing the axial spring 106 from twisting and lateral instability as much as possible; one end of the axial spring 106 abuts against the guide portion 1012, and the other end of the axial spring 106 abuts against the end wall of the ratchet 1021, so that the axial spring 106 is axially arranged between the gripping portion 102 and the driving rod 101, thereby playing an axial resetting role on the driving rod 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 , which is disposed between the corresponding end of the axial spring 106 and the end wall of the ratchet 1021 .

[0130] As set above, the washer 108 is arranged as a buffer component 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 adding or removing washers 108 of different thicknesses, the initial installation position of the axial spring 106 can be easily adjusted so that its height meets the requirements.

[0131] Please refer to Figure 12-13 , Figure 12 for Figure 1 A schematic diagram of the structure of the main body of the dose adjustment mechanism of the injection device; Figure 13 for Figure 1 Schematic diagram of the structure of the cover part of the dose adjustment mechanism of the injection device.

[0132] In the embodiment of the present application, the grip portion 102 includes:

[0133] The main body 102-1 has a receiving groove 102-1a. The end of the receiving groove 102-1a close to the pressing end of the driving rod 101 is an open end. The peripheral wall of the receiving groove 102-1a is provided with the aforementioned one-way locking groove 102b.

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

[0135] As configured above, the gripping portion 102 adopts a split structure including a main body portion 102-1 and a cover portion 102-2. During assembly, after the driving rod portion 101, the push rod portion 103, the transmission gear portion 104, etc. are installed on the main body portion 102-1, the cover portion 102-2 is connected to the open end of the main body portion 102-1 to improve assembly convenience.

[0136] There is no limitation on the connection method between the cover portion 102 - 2 and the main body portion 102 - 1 . For example, the two can be fixed by welding, clamping, or threaded connection.

[0137] The pressing end of the driving rod 101 is the end at which the operator presses the driving rod 101 .

[0138] In some embodiments of the present application, one of the cover portion 102-2 and the main body portion 102-1 is provided with a snap 1024, and the other is provided with a snap groove, and the cover portion 102-2 and the main body portion 102-1 are fixed by snapping together the snap 1024 and the snap groove.

[0139] Please refer to Figure 12 and Figure 14 , Figure 14 for Figure 1 Schematic diagram of the structure of the transmission gear part in the dose adjustment mechanism of the injection device.

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

[0141] The transmission gear portion 104 also includes a second cylinder 1043, which is fitted onto the push rod portion 103 and limited circumferentially and movable axially; the elastic clamping portion 1042 is connected to the outer circumferential wall of the second cylinder 1043, and the inner wall of the second cylinder 1043 has a step portion 1043a. The second cylinder 1043 is movably fitted onto the first cylinder 102-11, and the step portion 1043a and the relative end of the first cylinder 102-11 are in conflict.

[0142] As shown above, the setting of the first cylinder 102-11 can, on the one hand, play a role in positioning the second cylinder 1043, thereby improving the installation convenience and positioning accuracy of the transmission tooth portion 104; on the other hand, the step portion 1043a and the relative end portion of the first cylinder 102-11 collide with each other, thereby playing a role in axially limiting the transmission tooth portion 104, preventing the axial movement of the transmission tooth portion 104, ensuring that the elastic clamping portion 1042 and the one-way clamping groove 102b are always in a reliable clamping state, thereby improving the positioning accuracy of the transmission tooth portion 104.

[0143] like Figure 12 As shown, in order to reduce the friction force when the transmission tooth portion 104 rotates, the end of the first cylinder 102-11 is provided with a protrusion 102-12 distributed along the circumferential direction, and the step portion 1043a is in contact with the protrusion 102-12, thereby reducing the contact area between the step portion 1043a and the opposite end of the first cylinder 102-11, reducing the friction force when the transmission tooth portion 104 rotates, and making the transmission tooth portion 104 rotate more smoothly.

[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, 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 cylindrical, 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 engaging portions 1042, which are spaced apart along the circumference. The two elastic engaging portions 1042 cooperate with the ratchet teeth 1021 to achieve one-way locking, which helps to distribute the load, improve the load-bearing capacity of the dose adjustment mechanism 100 of the embodiment of the present application, and enhance the locking accuracy of the push rod portion 103 and the sealing plug 300. In other embodiments of the present application, the transmission tooth portion 104 has at least one elastic engaging portion 1042.

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

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

[0149] As mentioned above, the transmission tooth portion 104 is fitted onto 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. At least part of the limiting protrusion 1044 is slidably inserted into 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. 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 be transitionally matched. 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 provided on the push rod portion 103, and the limiting protrusion 1044 is provided on the transmission tooth portion 104, which can also avoid interference with the threaded fit between the push rod portion 103 and the grip portion 102, thereby ensuring the normal operation of the dose adjustment mechanism 100 of the embodiment of the present application.

[0152] Depend on Figure 14 It can be seen that in the embodiment of the present application, the transmission tooth portion 104 includes two oppositely arranged limiting protrusions 1044; correspondingly, the push rod portion 103 includes two oppositely arranged limiting grooves 103a. The plug-in cooperation of the two sets of limiting protrusions 1044 and the limiting grooves 103a is conducive to dispersing the load and further improving the limiting reliability of the transmission tooth portion 104 on the push rod portion 103.

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

[0154] Please refer to Figure 16 and Figure 17 , Figure 16 for Figure 12 A schematic diagram of the structure of the main body at the second angle; Figure 17 for Figure 5 Schematic diagram of the structure of the connection between the middle body and the cylinder.

[0155] In the embodiment of the present application, the driving rod 101 has a pressing end, and the end wall of the gripping portion 102 facing away from the pressing end is provided with a mounting groove 102d. The mounting groove 102d is used to install the protrusion 201 at the open end of the barrel 200 of the injection device in a transverse limited manner;

[0156] The dose adjustment mechanism 100 further includes a blocking member 110 connected to the grip portion 102 . The blocking member 110 is configured to abut against an end wall of the protrusion 201 facing away from the pressing end to limit the axial position of the protrusion 201 .

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

[0158] As configured above, when assembling the barrel 200 and the dose adjustment mechanism 100, the protrusion 201 can be inserted into the interior of the mounting groove 102d to achieve a lateral limit connection between the gripping portion 102 and the barrel 200; the blocking member 110 abuts against the end wall of the protrusion 201 facing away from the pressing end to axially limit the protrusion 201, thereby achieving an axial limit connection between the gripping portion 102 and the barrel 200, thereby fixing the gripping portion 102 and the barrel 200 as one, and ensuring a reliable connection between the barrel 200 and the dose adjustment mechanism 100; this connection structure arrangement is also conducive to reducing the difficulty of installing the gripping portion 102 and the barrel 200, improving the assembly convenience of the gripping portion 102 and the barrel 200, and improving production efficiency.

[0159] like Figure 16 As shown, in the embodiment of the present application, the blocking member 110 includes at least two limiting protrusions 1101, and the at least two limiting protrusions 1101 are arranged on the two opposite wall portions that surround the mounting groove 102d. The end wall of the limiting protrusion 1101 facing the pressing end abuts against the end wall of the protrusion 201 facing away from the pressing end to limit the axial position of the protrusion 201. From the connecting end of the limiting protrusion 1101 to the direction of the free end of the limiting protrusion 1101, the end wall of the limiting protrusion 1101 facing away from the pressing end extends obliquely toward the direction close to the pressing end.

[0160] As configured above, the end wall of the limiting protrusion 1101 facing away from the pressing end forms an inclined guide wall. When the barrel 200 and the dose adjustment mechanism 100 are assembled, the protrusion 201 can slide along the guide wall. When the protrusion 201 passes over the guide wall, the end wall of the limiting protrusion 1101 facing the pressing end abuts against the end wall of the protrusion 201 facing away from the pressing end to axially limit the protrusion 201. The protrusion 201 is installed in place, achieving a reliable connection between the blocking member 110 and the gripping portion 102. It can be seen that the structure of the blocking member 110 of the present application is simple, which helps reduce structural costs, simplifies the assembly steps of the barrel 200, and improves assembly convenience.

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

[0162] As configured above, the two mounting portions 1025 are spaced apart, and both ends of the mounting groove 102d in the length direction are also open ends. When assembling the barrel 200 and the dose adjustment mechanism 100, the mounting portion 1025 is more easily deformed under the squeezing force of the protrusion 201, thereby improving the assembly convenience of the barrel 200.

[0163] like Figure 16 and Figure 17 As shown, the two mounting portions 1025 are provided with corresponding notches 1025a at positions close to the limiting protrusions 1101. The notches 1025a can reduce the rigidity of the surrounding areas, so that when the barrel 200 and the dose adjustment mechanism 100 are assembled, the areas close to the limiting protrusions 1101 are more easily deformed, further improving the assembly convenience of the barrel 200.

[0164] Of course, the blocking member 110 is not limited to the structure of the aforementioned limiting protrusion 1101. As in some other embodiments of the present application, the grip portion 102 is further provided with a mounting hole that extends transversely through the two mounting portions 1025, the mounting hole being connected to the mounting groove 102d, and the two ends of the blocking member 110 being fixedly mounted in the mounting hole. Before assembling the barrel 200 and the dose adjustment mechanism 100, the blocking member 110 and the grip portion 102 are in a separate state. When assembling the barrel 200 and the dose adjustment mechanism 100, the raised portion 201 of the barrel 200 is first inserted into the mounting groove 102d to achieve a transversely limited connection between the grip portion 102 and the barrel 200. Then, the blocking member 110 is inserted into the mounting hole to securely connect the blocking member 110 and the grip portion 102. The blocking member 110 abuts against the end wall of the raised portion 201 facing away from the pressing end to axially limit the raised portion 201, thereby achieving an axially limited connection between the grip portion 102 and the barrel 200. This secures the grip portion 102 and the barrel 200 together, ensuring a secure connection between the barrel 200 and the dose adjustment mechanism 100. In some embodiments, the blocking member 110 and the mounting hole can be fitted with an interference fit, providing a secure connection and convenient operation.

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

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

[0167] There is no restriction on the connection method between the pressing portion 109 and the driving rod portion 101. For example, in some embodiments of the present application, the pressing end of the driving rod portion 101 has a spherical connecting groove, the pressing portion 109 includes a panel portion, a connecting rod portion and a spherical connecting portion, the connecting rod portion is connected between the panel portion and the spherical connecting portion, the spherical connecting portion is installed inside the spherical connecting groove, and the spherical connecting portion can rotate inside the spherical connecting groove to achieve a rotational connection between the pressing portion 109 and the driving rod portion 101; and the diameter of the open end of the spherical connecting groove is smaller than the diameter of the spherical connecting portion, so that the spherical connecting portion can be reliably installed inside the spherical connecting groove without falling out, thereby ensuring a reliable axial connection between the pressing portion 109 and the driving rod portion 101.

[0168] The present application also provides an injection device, comprising:

[0169] The barrel 200 has an outlet end and an open end;

[0170] The sealing plug 300 is slidably disposed inside the barrel 200. The area inside the barrel 200 near the discharge end is bounded by the sealing plug 300 to form a storage cavity 200a for storing the injection;

[0171] In the dose adjustment mechanism 100 of the aforementioned injection device, the gripping 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 described in detail here.

[0173] Among them, there is no restriction on the connection method between the push rod part 103 and the sealing plug 300. For example, the push rod part 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 connecting groove, the outer diameter of the connecting end of the push rod part 103 is larger than the inner diameter of the connecting groove, and at least part of the connecting end of the push rod part 103 is inserted into the connecting groove.

[0174] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A dose adjustment mechanism of an injection device, characterized in that: The invention 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 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 fitted over the push rod portion and is limited in the circumferential direction, and the push rod portion is movable axially 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 an end position. In the initial position, the active ratchet and the driven ratchet are spaced apart in the axial direction, and a front end face of one of the active ratchet and a rear end face of the driven ratchet are staggered in the circumferential direction by a preset angle. When the driving rod is subjected to a pressing force, it can move axially from the initial position and rotate circumferentially by a preset angle to switch to the terminal position. At the terminal position, one of the active ratchet teeth is engaged 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 back to the initial position when the pressing force is released.

2. The dosage adjustment mechanism according to claim 1, characterized in that: The grip portion has a receiving cavity, and the peripheral wall surrounding the receiving cavity is provided with one-way clamping grooves 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 clamping grooves; 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 slots at the front end.

3. The dosage 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 dosage adjustment mechanism according to any one of claims 1 to 3, characterized in that: The grip portion has a receiving cavity, a portion of the drive rod portion is located in the receiving cavity, an outer peripheral wall of the drive rod portion and an inner peripheral wall surrounding the receiving cavity are provided with a guide portion extending in the axial direction on one side, and a guide groove extending in the axial direction on the other side, the guide portion being 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 extending in the axial direction, and the second wall portion extending obliquely in a direction away from the first wall portion toward the front side wall; The reset portion includes an elastic member, which is pre-compressed or pre-stretched in the circumferential direction and is arranged between the gripping 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 dosage adjustment mechanism according to claim 4, characterized in that: The elastic member comprises: an elastic arm, one end of the elastic arm being connected to the guide portion, the other end of the elastic arm being in contact with the front side wall of the guide groove, and the elastic arm being pre-compressed in the circumferential direction between the guide portion and the front side wall of the guide groove; An axial spring is axially arranged between the gripping portion and the driving rod portion.

6. The dosage adjustment mechanism according to claim 4, characterized in that: The elastic member comprises: A torsion spring, two ends of which connect the gripping portion and the driving rod portion.

7. The dosage adjustment mechanism according to claim 6, characterized in that: The elastic member further comprises: An axial spring is axially arranged between the gripping portion and the driving rod portion.

8. The dosage adjustment mechanism according to claim 2 or 3, characterized in that: The gripping portion comprises: A main body portion, wherein the main body portion has a receiving groove, an end of the receiving groove close to the pressing end of the driving rod portion is an open end, and a peripheral wall surrounding the receiving groove is provided with the one-way clamping groove; A cover portion is connected to the open end of the main body portion, and the accommodating groove forms at least a portion of the accommodating cavity.

9. The dosage adjustment mechanism according to claim 8, characterized in that: The main body includes a first cylinder disposed inside the receiving groove, an end wall surrounding the receiving groove has a through hole communicating with the first cylinder, and the push rod passes through the first cylinder and is threadedly connected; The transmission gear portion also includes a second cylinder, which is fitted over the push rod portion and limited in the circumferential direction and movable in the axial direction; the elastic clamping portion is connected to the outer circumferential wall of the second cylinder, and the inner wall of the second cylinder has a step portion, and the second cylinder is movably fitted over the first cylinder, and the step portion and the opposite end of the first cylinder are in conflict.

10. The dosage adjustment mechanism according to any one of claims 1 to 3, characterized in that: The driving rod has a pressing end, and the end of the grip portion facing away from the pressing end is provided with a mounting groove, and the mounting groove is used for mounting the protrusion located at the open end of the barrel of the injection device in a transverse limited manner; The dose adjustment mechanism further includes a blocking member connected to the grip portion, and the blocking member is configured to abut against an end wall of the protrusion facing away from the pressing end to limit the axial position of the protrusion.

11. The dosage adjustment mechanism according to claim 10, characterized in that: The blocking member includes at least two limiting protrusions, and at least two of the limiting protrusions are arranged on two opposite wall portions that surround the mounting groove. The end wall of the limiting protrusion facing the pressing end abuts against the end wall of the protrusion facing away from the pressing end to limit the axial position of the protrusion. From the connecting end of the limiting protrusion to the direction of 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.

12. An injection device, characterized in that: include: a barrel having a discharge end and an open end; A sealing plug is slidably disposed inside the barrel, with the sealing plug as the boundary, and an area inside the barrel near the discharge end forms a storage cavity, wherein the storage cavity is used to store the injection; The dose adjustment mechanism according to any one of claims 1 to 11, wherein 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.

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