Dose adjusting mechanism of injection device and injection device

Abstract

The invention relates to the technical field of medical instruments, in particular to a dosage adjusting mechanism of an injection device and the injection device. A push rod part penetrates through a holding part and is in circumferential limiting connection with the holding part, the push rod part can move in the axial direction relative to the holding part, and the push rod part is sleeved with a sounding tooth part and is in threaded connection with the sounding tooth part; one-way clamping grooves distributed in the circumferential direction are formed in the circumferential wall defining the containing cavity, the sound tooth part is located in the containing cavity, the sound tooth part is provided with an elastic clamping part, and the elastic clamping part is clamped into any one of the one-way clamping grooves; when the push rod part is pressed, the push rod part can move in the axial direction, the sound tooth part can rotate under the action of the threads, and the elastic clamping part slides along the peripheral wall of the defined containing cavity so as to be clamped into one of the one-way clamping grooves in the front end. Axial displacement control is converted into rotary motion control, rotary motion of the sound tooth part is discretized into fixed angle grading, single-time grading axial displacement of the push rod part is extremely small, and the small-dose injection requirement is met.

Description

Technical Field

[0001] The present 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] In related art, an injection device includes an outer sleeve component, a push rod component, and a cartridge component. The surface of the push rod component has concavo-convex structures continuously distributed along the axial direction. The push rod component is adapted to be sleeved with the outer sleeve component and move along the axial direction of the outer sleeve component. The concavo-convex structures are blocked by the cartridge component during the movement of the push rod component. The cartridge component is arranged at the opening of the first end where the push rod component is sleeved with the outer sleeve component, and is adapted to cooperate with the concavo-convex structures on the push rod component to block the movement of the push rod component during the axial movement of the push rod component along the outer sleeve component. 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 structures and the cartridge component, by blocking the movement of the push rod component, 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 accuracy such as machining ability, too small a distance may cause the concavo-convex structures 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 the present 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, the present application provides a dose adjustment mechanism of an injection device, including a push rod part, a holding part, and a click part. The push rod part passes through the holding part and is circumferentially limited and connected. The push rod part can move axially relative to the holding part. The click part is sleeved on the push rod part and is threadedly connected. The holding part has a receiving cavity, and the circumferential wall enclosing the receiving cavity is provided with one-way card slots distributed circumferentially. The click part is located in the receiving cavity, and the click part has an elastic clamping part, and the elastic clamping part is snapped into any one of the one-way card slots.

[0006] In a state where the push rod part is under a pressing force, the push rod part can move axially, and the click part can rotate under the action of the thread, so that the elastic clamping part slides along the circumferential wall enclosing the receiving cavity to be snapped into one of the front one-way card slots.

[0007] Optionally, the circumferential wall enclosing the receiving cavity is provided with a plurality of ratchet teeth distributed circumferentially. A ratchet tooth groove is formed between adjacent ratchet teeth, and the ratchet tooth groove is the one-way card slot.

[0008] Optionally, a limiting groove is provided on the outer peripheral wall of the push rod portion, the limiting groove extends along the axial direction of the push rod portion, a limiting protrusion is provided on the holding portion, and at least a part of the limiting protrusion is slidably inserted into the corresponding limiting groove.

[0009] Optionally, the push 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 protruding portion at the opening end of the barrel of the injection device;

[0010] 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 protruding portion facing away from the pressing end to axially limit the protruding portion.

[0011] Optionally, the end of the holding portion facing away from the pressing end includes two oppositely arranged mounting portions, the opposite end walls of the two mounting portions form part of the inner wall of the mounting groove, and the holding portion is further provided with a mounting hole that penetrates the two mounting portions laterally, the mounting hole communicates with the mounting groove, and both ends of the blocking member are fixedly installed in the mounting hole.

[0012] Optionally, the blocking member includes a blocking member body, the blocking member body is provided with a notch groove with an open first end and at least one avoidance opening, the blocking member further includes at least one elastic member, the first end of the elastic member is connected to the inner wall surrounding the avoidance opening, and in the non-loaded state, the second end of the elastic member extends obliquely away from the pressing end, and the length of the elastic member is not greater than the length between the first end and the second end of the avoidance opening;

[0013] In the connection state of the dose adjustment mechanism and the barrel, both ends of the blocking member are inserted into the mounting hole, the barrel passes through the notch groove, the closed end wall surrounding the notch groove abuts against the outer wall of the barrel, and the end wall of the second end of the elastic member abuts against the wall portion surrounding the mounting groove.

[0014] Optionally, the portions of the blocking member body on both sides in the width direction of the notch groove are blocking arms, among the two mounting portions, the mounting portion close to the first end is the first mounting portion, and the mounting portion close to the second end is the second mounting portion;

[0015] The mounting hole includes two first holes provided in the first mounting portion and a second hole provided in the second mounting portion, the first end of the blocking arm is inserted into the corresponding first hole, and the second end of the blocking member body is inserted into the second hole.

[0016] Optionally, the holding portion includes:

[0017] The body part, the body part has a receiving groove, one end of the receiving groove close to the pressing end of the push rod part is an open end, and the circumferential wall surrounding the receiving groove is provided with the one-way clamping groove;

[0018] The cover plate part, the cover plate part is connected to the open end of the body part, and the receiving groove forms at least part of the receiving cavity.

[0019] Optionally, annular protrusions are oppositely arranged on the end wall surrounding the receiving groove and the inner wall of the cover plate part, and the push rod part passes through the inside of the annular protrusion;

[0020] The rattling tooth part includes a cylindrical body part, the cylindrical body part is sleeved on the push rod part and is threadedly connected, the elastic clamping part is connected to the outer peripheral wall of the cylindrical body part, both axial ends of the cylindrical body part are partially located inside the corresponding annular protrusion, and the end wall surrounding the receiving groove abuts against the opposite end of the cylindrical body part.

[0021] The present application also provides an injection device, including:

[0022] A cylinder, having an injection end and an open end;

[0023] 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;

[0024] The dose adjustment mechanism of the aforementioned injection device, 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.

[0025] The technical effects of the present application are as follows:

[0026] In the present application, the axial displacement control of the push rod part is converted into the rotational motion control of the rattling tooth part through the precise thread fit between the push rod part and the rattling tooth part. At the same time, the rotational motion of the rattling tooth part is discretized into fixed-angle grading through the clamping fit of the circumferentially distributed one-way clamping grooves and the elastic clamping parts. By matching the thread pitch and the number of one-way clamping grooves, the single-step grading axial displacement of the push rod part is extremely small, meeting the small-dose injection requirements. Description of the Drawings

[0027] Figure 1 It is a schematic structural diagram of a specific embodiment of the dose adjustment mechanism of the injection device provided by the present application;

[0028] Figure 2 is Figure 1 The schematic structural diagram of the dose adjustment mechanism when the cover plate part is removed;

[0029] Figure 3 It is an axial sectional view of a specific embodiment of the injection device provided by the present application;

[0030] Figure 4 is Figure 1 Schematic diagram of the body part in the dose adjustment mechanism;

[0031] Figure 5 is Figure 1 Schematic diagram of the ratchet part in the dose adjustment mechanism;

[0032] Figure 6 is Figure 1 Schematic diagram of the gripping part in the dose adjustment mechanism;

[0033] Figure 7 is Figure 3 Schematic diagram of the gripping part, the blocking member and the barrel in the injection device;

[0034] Figure 8 is Figure 7 Schematic diagram of the gripping part and the blocking member in;

[0035] Figure 9 is Figure 8 Schematic diagram of the gripping part in;

[0036] Figure 10 is Figure 8 Schematic diagram of the blocking member in;

[0037] Figure 11 is Figure 1 Exploded view of the gripping part in the dose adjustment mechanism;

[0038] Figure 12 is Figure 1 Partial cross-sectional view of the dose adjustment mechanism;

[0039] Figure 13 is Figure 5 Schematic diagram of the ratchet part at a second angle;

[0040] Figure 14 is Figure 1 Schematic diagram of the push rod part and the pressing part in the dose adjustment mechanism;

[0041] Among them, Figures 1 - 14 the reference numerals in are as follows:

[0042] 100 - dose adjustment mechanism;

[0043] 101 - push rod part;

[0044] 102 - Holding part; 102-1 - Body part; 102-1a - Accommodating groove; 102-2 - Cover plate part; 102-A - Annular protrusion; 102a - Accommodating cavity; 102b - One-way card slot; 102c - Mounting groove; 102d - Mounting hole; 102d-1 - First hole; 102d-2 - Second hole; 1021 - Ratchet teeth; 1022 - Ratchet tooth groove; 1023 - Mounting part; 1023-1 - First mounting part; 1023-2 - Second mounting part;

[0045] 103 - Rattling part; 1031 - Elastic clamping part; 1032 - Cylindrical part; 1033 - Protrusion;

[0046] 104 - Blocking part; 1041 - Blocking part body; 1041a - Notch groove; 1041b - Avoidance opening; 10411 - Blocking arm; 1042 - Elastic part;

[0047] 105 - Pressing part;

[0048] a - Limit groove; b - Limit protrusion; c - Snap; d - Clamping groove; e - Positioning hole; f - Positioning post;

[0049] 200 - Cylinder; 201 - Protrusion part; 200a - Storage cavity;

[0050] 300 - Sealing plug. Detailed implementation mode

[0051] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0052] 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 used 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 type, 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 represents an "or" relationship between the associated objects before and after.

[0053] It should be understood that "some embodiments" mentioned throughout the specification mean that specific features, structures, or characteristics related to the embodiments are included in at least one embodiment of the present application. Therefore, "in some embodiments" that appears throughout the specification does not necessarily refer to the same embodiments. In addition, these specific features, structures, or characteristics can be combined in one or more embodiments in any suitable manner.

[0054] In the description herein, unless otherwise clearly specified 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 components or the interaction relationship between two components. 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.

[0055] Please refer to Figures 1 - 3 , Figure 1 which is a schematic structural diagram of a specific embodiment of the dose adjustment mechanism of the injection device provided by the present application; Figure 2 is Figure 1 a schematic structural diagram of the dose adjustment mechanism when the cover part is removed; Figure 3 an axial sectional view of a specific embodiment of the injection device provided by the present application.

[0056] The dose adjustment mechanism 100 of an injection device provided by an embodiment of the present application includes a push rod part 101, a holding part 102, and a ratchet part 103. The push rod part 101 passes through the holding part 102 and is circumferentially limited and connected. The push rod part 101 can move axially relative to the holding part 102. The ratchet part 103 is sleeved on the push rod part 101 and is threadedly connected. The holding part 102 has a receiving cavity 102a. The peripheral wall surrounding the receiving cavity 102a is provided with circumferentially distributed one-way card slots 102b. The ratchet part 103 is located in the receiving cavity 102a. The ratchet part 103 has an elastic clamping part 1031, and the elastic clamping part 1031 is snapped into any one of the one-way card slots 102b;

[0057] In a state where the push rod part 101 is subjected to a pressing force, the push rod part 101 can move axially, and the ratchet part 103 can rotate under the action of the thread, so that the elastic clamping part 1031 slides along the peripheral wall surrounding the receiving cavity 102a to be snapped into one of the one-way card slots 102b at the front end.

[0058] Figure 2 The direction of the arrow shown is the rotation direction of the ratchet part 103, that is, the sliding direction of the elastic clamping part 1031 along the peripheral wall surrounding the receiving cavity 102a. The front end mentioned here refers to the end pointed by the sliding direction of the elastic clamping part 1031. From Figure 3It can be seen that 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 chamber 200a for storing the injection substance. When the dose adjustment mechanism 100 of the embodiment 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 can be held by an operator, so that the holding portion 102 and the barrel 200 are in a fixed state. The push rod portion 101 passes through the holding portion 102 and is connected to the sealing plug 300. The push rod portion 101 and the holding portion 102 are circumferentially limited and connected. The push rod portion 101 can axially move relative to the holding portion 102. That is, when the holding portion 102 is held by the operator and the push rod portion 101 is under a pressing force, the push rod portion 101 can axially move but cannot rotate. The ratchet portion 103 is sleeved on the push rod portion 101 and is threadedly connected. The holding portion 102 has a receiving chamber 102a, and the ratchet portion 103 is located in the receiving chamber 102a. Thus, when the push rod portion 101 is under a pressing force, the push rod portion 101 axially moves, and the ratchet portion 103 rotates under the action of the thread. When the thread pitch between the push rod portion 101 and the ratchet portion 103 is fixed, the rotation angle of the ratchet portion 103 strictly corresponds to the axial displacement of the push rod portion 101. For example, when the thread pitch between the push rod portion 101 and the ratchet portion 103 is 1 mm and the ratchet portion 103 rotates 360°, the push rod portion 101 axially moves 1 mm, thereby ensuring controllable dosage. The peripheral wall surrounding the receiving chamber 102a is provided with circumferentially distributed one-way card slots 102b, and the ratchet portion 103 has an elastic clamping portion 1031 that is snapped into any one of the one-way card slots 102b. Thus, the circumferentially distributed one-way card slots 102b discretize the circular motion of the ratchet portion 103. When the push rod portion 101 is under a pressing force, the push rod portion 101 axially moves, and the ratchet portion 103 is forced to rotate due to screw drive. The elastic clamping portion 1031 gradually slides out of the current one-way card slot 102b along the peripheral wall surrounding the receiving chamber 102a and snaps into the next one-way card slot 102b. Each time the elastic clamping portion 1031 slides past a one-way card slot 102b, the push rod portion 101 moves a fixed distance. It can be seen that each one-way card slot 102b corresponds to one gear. By designing the number of one-way card slots 102b, each one-way card slot 102b can correspond to a clear dosage unit. For example, when the thread pitch between the push rod portion 101 and the ratchet portion 103 is 1 mm and the peripheral wall surrounding the receiving chamber 102a is provided with 12 one-way card slots 102b with an interval of 30° between adjacent one-way card slots 102b, when the ratchet portion 103 slides past a one-way card slot 102b, the moving distance of the push rod portion 101 is the ratio of the thread pitch to the number of one-way card slots, that is, approximately 0.0833 mm, breaking through the single-shot minimum injection volume limit of the traditional axial concave-convex structure and meeting the small-dose injection requirements.

[0059] Among them, in the process of the elastic clamping part 1031 gradually sliding out of the current one-way clamping slot 102b, the elastic clamping part 1031 is squeezed and deformed, and the elastic clamping part 1031 gradually accumulates energy; when the elastic clamping part 1031 passes over the current one-way clamping slot 102b, the elastic potential energy of the elastic clamping part 1031 is released, and the elastic clamping part 1031 instantly bounces into the next one-way clamping slot 102b. The collision between the elastic clamping part 1031 and the surrounding wall of the accommodating cavity 102a will produce a "click" sound, or cause the push rod part 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, thereby avoiding injection errors as much as possible.

[0060] The aforementioned one-way slot 102b means that when the push rod portion 101 is subjected to pressing pressure, the elastic clamping portion 1031 can only slide one-way along the peripheral wall surrounding the accommodating cavity 102a to engage with the one-way slot 102b at the front end, and cannot slide in the opposite direction, that is, to ensure that the tooth portion 103 can only rotate one-way and cannot rotate in the opposite direction, thereby ensuring that the push rod portion 101 and the sealing plug 300 can only move one-way under the action of pressing pressure and cannot move in the opposite direction. On the one hand, 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.

[0061] To sum up, the dose adjustment mechanism 100 of the embodiment of the present application converts the axial displacement control of the push rod part 101 into the rotational motion control of the tooth part 103 through the precise threaded cooperation between the push rod part 101 and the tooth part 103, and at the same time, the rotational motion of the tooth part 103 is discretized into fixed angle steps through the snap cooperation of the circumferentially distributed one-way slots 102b and the elastic snap-fitting part 1031. By matching the thread pitch and the number of one-way slots, the single-step axial displacement of the push rod part 101 can be controlled to below an extremely small level, thereby meeting the needs of small-dose injection.

[0062] Please refer to Figure 2 and Figure 4 , Figure 4 for Figure 1 Schematic diagram of the structure of the main body of the dose adjustment mechanism.

[0063] In some embodiments 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. The ratchet grooves 1022 are the aforementioned one-way slots 102b.

[0064] Depend on Figure 4It can be seen that the wall surface of the ratchet 1021 has a blocking surface and an inclined surface, and the inclined surface also forms a guiding surface. In a state where the push rod portion 101 is under a pressing force, the elastic clamping portion 1031 can slide along the inclined surface, so as to smoothly slide over the top end 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 1031 slides over the top end 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 that the unit metering injection is completed; during the reverse operation, the blocking surface of the ratchet 1021 will block the elastic clamping portion 1031, ensuring that the push rod portion 101 and the sealing plug 300 cannot move in the reverse direction, as much as possible avoiding injection errors, 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.

[0065] Please refer to Figure 5 , Figure 5 is Figure 1 a schematic structural view of the ratchet portion in the dose adjustment mechanism.

[0066] In the embodiment of the present application, the ratchet portion 103 has two elastic clamping portions 1031, and the two elastic clamping portions 1031 are circumferentially spaced apart. The one-way locking is realized by the cooperation of the two elastic clamping portions 1031 and the ratchets 1021 distributed circumferentially, which is beneficial to dispersing the load, improving the bearing capacity of the dose adjustment mechanism 100 in the embodiment of the present application, and enhancing the locking accuracy of the push rod portion 101 and the sealing plug 300.

[0067] In some other embodiments of the present application, the ratchet portion 103 has at least one elastic clamping portion 1031.

[0068] Among them, the elastic clamping portion 1031 is made of a material that can generate elastic deformation, such as plastic with a certain elasticity.

[0069] As described above, the push rod portion 101 passes through the holding portion 102 and is circumferentially limited and connected. The push rod portion 101 can axially move relative to the holding portion 102. Specifically, in the embodiment of the present application, as Figure 2 shown, a limiting groove a is provided on the outer peripheral wall of the push rod portion 101, and the limiting groove a extends along the axial direction of the push rod portion 101. The holding portion 102 is provided with a limiting protrusion b, and at least a part of the limiting protrusion b is slidably inserted into the corresponding limiting groove a.

[0070] As set up above, the limiting groove a can play a role in limiting and guiding the limiting protrusion b, and the two side walls in the width direction of the limiting protrusion b and the two side walls in the width direction of the limiting groove a can adopt a transition fit. On the one hand, the limiting groove a can reliably limit the limiting protrusion b along the width direction, and avoid the relative shaking of the push rod part 101 and the holding part 102 along the circumferential direction as much as possible, thereby improving the injection accuracy; on the other hand, the limiting protrusion b can slide more smoothly along the extension direction of the limiting groove a, thereby reducing the operating resistance and improving the operating convenience.

[0071] In addition, the limiting groove a is provided on the push rod portion 101, and the limiting protrusion b is provided on the grip portion 102, which can also avoid interference with the threaded fit between the push rod portion 101 and the tooth portion 103, thereby ensuring the normal operation of the dose adjustment mechanism 100 of the embodiment of the present application.

[0072] Please refer to Figure 6 , Figure 6 for Figure 1 Schematic diagram of the structure of the grip part in the dose adjustment mechanism.

[0073] In an embodiment of the present application, the holding portion 102 includes two oppositely arranged limiting protrusions b; correspondingly, the push rod portion 101 includes two back-to-back limiting grooves a. The circumferential limiting connection between the holding portion 102 and the push rod portion 101 is realized through the plug-in cooperation of the two sets of limiting protrusions b and the limiting grooves a, which is beneficial to dispersing the load and further improving the limiting reliability of the holding portion 102 on the push rod portion 101.

[0074] In some other embodiments of the present application, the gripping portion 102 has at least one limiting protrusion b, and the push rod portion 101 has at least one limiting groove a.

[0075] Please refer to Figure 7 and Figure 8 , Figure 7 for Figure 3 Schematic diagram of the structure of the gripping part, blocking member and barrel in the injection device; Figure 8 for Figure 7 Schematic diagram of the structure of the middle grip and the blocking member.

[0076] In the embodiment of the present application, the push rod portion 101 has a pressing end, and the end of the grip portion 102 facing away from the pressing end is provided with a mounting groove 102c, which is used to install the protrusion 201 located at the open end of the barrel 200 of the injection device in a transverse limited manner;

[0077] The dose adjustment mechanism 100 further includes a blocking member 104 connected to the grip portion 102 . The blocking member 104 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 .

[0078] With the above settings, when assembling the barrel 200 and the dose adjustment mechanism 100, the convex portion 201 can be inserted into the inside of the installation groove 102c to achieve the lateral limit connection between the holding portion 102 and the barrel 200; the blocking member 104 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 beneficial to reducing the installation difficulty between 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.

[0079] Please refer to Figure 8 and Figure 9 , Figure 9 is Figure 8 the structural schematic diagram of the holding portion in

[0080] In some embodiments, the connection manner between the blocking member 104 and the holding portion 102 is as follows:

[0081] The end of the holding portion 102 facing away from the pressing end includes two oppositely arranged mounting portions 1023. The opposite end walls of the two mounting portions 1023 form part of the inner wall of the mounting groove 102c. The holding portion 102 is further provided with a mounting hole 102d that penetrates the two mounting portions 1023 transversely. The mounting hole 102d communicates with the mounting groove 102c, and both ends of the blocking member 104 are fixedly installed in the mounting hole 102d.

[0082] With the above settings, before assembling the barrel 200 and the dose adjustment mechanism 100, the blocking member 104 and the holding portion 102 are in a split state. When assembling the barrel 200 and the dose adjustment mechanism 100, first insert the convex portion 201 into the inside of the installation groove 102c to achieve the lateral limit connection between the holding portion 102 and the barrel 200; then, insert both ends of the blocking member 104 into the mounting hole 102d to achieve the fixed connection between the blocking member 104 and the holding portion 102. The blocking member 104 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.

[0083] Both ends of the blocking member 104 are fixedly installed in the mounting hole 102d. Specifically, in some embodiments, the blocking member 104 and the mounting hole 102d can adopt an interference fit manner, which has reliable connection and convenient operation.

[0084] Please refer to Figures 7 - 10 , Figure 10 is Figure 8Structural schematic diagram of the middle blocking member.

[0085] In the embodiment of the present application, the blocking member 104 includes a blocking member body 1041. The blocking member body 1041 is provided with a notch groove 1041a having an opening at one end, and at least one avoidance opening 1041b. The blocking member 104 further includes at least one elastic member 1042. The first end of the elastic member 1042 is connected to the inner wall surrounding the avoidance opening 1041b. In the unloaded state, the second end of the elastic member 1042 extends obliquely away from the pressing end. The length of the elastic member 1042 is not greater than the length between the first end and the second end of the avoidance opening 1041b, so that the elastic member 1042 can enter the avoidance opening 1041b after being stressed.

[0086] In the connected state of the dose adjustment mechanism 100 and the cylinder 200, both ends of the blocking member 104 are inserted into the mounting holes 102d. The cylinder 200 passes through the notch groove 1041a. The closed end wall surrounding the notch groove 1041a abuts against the outer wall of the cylinder 200. The end wall of the second end of the elastic member 1042 abuts against the wall portion surrounding the mounting groove 102c.

[0087] Wherein, Figure 7 The direction of the arrow shown is the installation direction of the blocking member 104. The end of the blocking member 104 that first enters the mounting hole 102d during installation is the first end, and the end that finally enters the mounting hole 102d is the second end.

[0088] With the above settings, when installing the blocking member 104, the first end of the blocking member 104 first enters the mounting hole 102d. Under the constraint of the inner wall of the mounting hole 102d, the elastic member 1042 deforms and enters the inside of the avoidance opening 1041b. The cylinder 200 enters the inside of the notch groove 1041a from the open end of the notch groove 1041a. When the blocking member 104 is installed in place, both ends of the blocking member 104 are inserted into the mounting holes 102d. The closed end wall surrounding the notch groove 1041a abuts against the outer wall of the cylinder 200. Under the limiting action of the cylinder 200, the blocking member 104 cannot move further. At the same time, the elastic member 1042 passes through the inner wall of the mounting hole 102d, thereby releasing the constraint of the inner wall of the mounting hole 102d on the elastic member 1042. The elastic member 1042 returns to the unloaded state under the restoring force, that is, the second end of the elastic member 1042 extends obliquely away from the pressing end and abuts against the wall portion surrounding the mounting groove 102c. Under the limiting action of the wall portion surrounding the mounting groove 102c, the blocking member 104 cannot move in the reverse direction either. In this way, the fixed connection between the blocking member 104 and the holding portion 102 is realized, ensuring the reliable connection between the two, and further ensuring the reliable axial limitation of the cylinder 200 by the blocking member 104 and the reliable connection between the cylinder 200 and the dose adjustment mechanism 100.

[0089] From Figure 7It can be seen that in the embodiment of the present application, the blocking member 104 includes two elastic members 1042, and the two elastic members 1042 are located on both sides of the width direction of the notch groove 1041a. In this way, the elastic members 1042 on both sides can abut against the wall portion that surrounds the installation groove 102c, so that the blocking member 104 is subjected to balanced force along the width direction of the notch groove 1041a and is reliably installed.

[0090] In some other embodiments, the blocking member 104 may include at least one elastic member 1042. When the blocking member 104 includes one elastic member 1042, the elastic member 1042 may be located at the end of the second end of the notch 1041a to minimize uneven force on the blocking member 104 in the width direction and improve the installation stability of the blocking member 104.

[0091] Of course, the blocking member 104 and the gripping portion 102 are not limited to the above-mentioned connection method. For example, in some other embodiments of the present application, the blocking member 104 includes two limiting protrusions, which are relatively arranged on the wall portion surrounding the mounting groove 102c, and the end wall of the two limiting protrusions 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; the end walls of the two limiting protrusions facing away from the pressing end form an inclined guide wall, and the distance between the two guide walls gradually increases in the direction away from the pressing end. 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 protrusion 201 is installed in place to achieve a fixed connection between the blocking member 104 and the gripping portion 102.

[0092] Please continue to refer to Figures 7 - 10 In some embodiments of the present application, the portions of the blocking member body 1041 located on both sides of the notch 1041a in the width direction are blocking arms 10411, and the mounting portion 1023 closer to the first end of the two mounting portions 1023 is a first mounting portion 1023-1, and the mounting portion 1023 closer to the second end is a second mounting portion 1023-2.

[0093] The mounting hole 102d includes two first holes 102d-1 set in the first mounting part 1023-1, and a second hole 102d-2 set in the second mounting part 1023-2. The first end of the blocking arm 10411 is inserted into the corresponding first hole 102d-1, and the second end of the blocking member body 1041 is inserted into the second hole 102d-2.

[0094] With the above settings, the blocking member body 1041 of the embodiment of the present application is approximately U-shaped, and the two first holes 102d-1 provided in the first mounting portion 1023-1 and the second hole 102d-2 provided in the second mounting portion 1023-2 can achieve three-point positioning of the blocking member body 1041, making the connection between the blocking member 104 and the holding portion 102 more reliable, and the axial limit of the blocking member 104 on the cylinder body 200 more reliable.

[0095] Please refer to Figure 11 , Figure 11 For Figure 1 exploded view of the holding portion in the dose adjustment mechanism.

[0096] In some embodiments of the present application, the holding portion 102 includes:

[0097] A main body portion 102-1, the main body portion 102-1 has a receiving groove 102-1a, one end of the receiving groove 102-1a close to the pressing end of the push rod portion 101 is an open end, and a one-way card slot 102b is provided on the peripheral wall surrounding the receiving groove 102-1a;

[0098] A cover portion 102-2, the cover portion 102-2 is connected to the open end of the main body portion 102-1, and the receiving groove 102-1a forms at least part of the receiving cavity 102a.

[0099] With the above settings, the holding portion 102 adopts a split structure including the main body portion 102-1 and the cover portion 102-2. During the assembly process of the dose adjustment mechanism 100, the rattling tooth portion 103 can be first installed in the receiving groove 102-1a, and then the cover portion 102-2 is connected to the open end of the main body portion 102-1, improving the assembly convenience.

[0100] Among them, the connection method between the cover portion 102-2 and the main body portion 102-1 is not limited. For example, the two can be fixed by welding, snap connection, threaded connection, etc.

[0101] Such as Figure 11 shown, 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 buckle c, and the other is provided with a snap groove d. The cover portion 102-2 and the main body portion 102-1 are fixed through the snap fit of the buckle c and the snap groove d.

[0102] At the same time, one of a positioning hole e and a positioning post f is provided on the open end wall of the main body portion 102-1, and the other of the positioning hole e and the positioning post f is provided on the inner wall of the cover portion 102-2. During the connection process of the cover portion 102-2 and the main body portion 102-1, the positioning hole e and the positioning post f can play a positioning role, enabling the buckle c and the snap groove d to quickly find the right position for snap connection and improving the operation convenience.

[0103] Please refer to Figure 12 , Figure 12 the Figure 1 partial cross-sectional view of the dose adjustment mechanism.

[0104] In some embodiments of the present application, annular protrusions 102-A are oppositely arranged on the end wall enclosing the accommodation groove 102-1a and the inner wall of the cover plate portion 102-2, and the push rod portion 101 passes through the inside of the annular protrusion 102-A;

[0105] The rattling tooth portion 103 includes a cylindrical body portion 1032, the cylindrical body portion 1032 is sleeved on the push rod portion 101 and is threadedly connected, the elastic clamping portion 1031 is connected to the outer peripheral wall of the cylindrical body portion 1032, both axial end portions of the cylindrical body portion 1032 are located inside the corresponding annular protrusion 102-A, and the end wall enclosing the accommodation groove 102-1a abuts against the opposite end portion of the cylindrical body portion 1032.

[0106] With the above arrangement, the two annular protrusions 102-A can play a role in positioning the cylindrical body portion 1032, improving the installation convenience and positioning accuracy of the rattling tooth portion 103; the end wall enclosing the accommodation groove 102-1a abuts against the opposite end portion of the cylindrical body portion 1032. In the state where the push rod portion 101 is subjected to a pressing force, the end wall enclosing the accommodation groove 102-1a can play an axial limiting role on the rattling tooth portion 103, preventing the axial movement of the rattling tooth portion 103, and further enabling the rattling tooth portion 103 to rotate under the action of the threaded fit.

[0107] Among them, in some embodiments, the elastic clamping portion 1031 and the cylindrical body portion 1032 can be an integrally formed structure, improving the connection strength between the elastic clamping portion 1031 and the cylindrical body portion 1032.

[0108] Please refer to Figures 12 - 13 , Figure 13 the Figure 5 structural schematic diagram of the second angle of the rattling tooth portion.

[0109] In order to reduce the friction force when the rattling tooth portion 103 rotates, a circumferentially distributed protrusion 1033 is provided at the end of the cylindrical body portion 1032 away from the cover plate portion 102-2, and the end wall enclosing the accommodation groove 102-1a contacts the protrusion 1033, reducing the contact area between the end wall enclosing the accommodation groove 102-1a and the cylindrical body portion 1032, reducing the friction force when the rattling tooth portion 103 rotates, and making the rattling tooth portion 103 rotate more smoothly.

[0110] Among them, the protrusion 1033 can be a hemispherical structure, further reducing the contact area between the end wall enclosing the accommodation groove 102-1a and the cylindrical body portion 1032, and further reducing the friction force when the rattling tooth portion 103 rotates.

[0111] Of course, in some other embodiments, it is also feasible to provide protrusions on the end walls enclosing the accommodation groove 102-1a. The end walls enclosing the accommodation groove 102-1a abut against the corresponding ends of the cylinder part 1032 through the protrusions, which can also reduce the friction when the rattling tooth part 103 rotates.

[0112] In addition, in the dose adjustment mechanism 100 of the embodiment of the present application, the push rod part 101 can only move unidirectionally under the action of pressing force and cannot move reversely. Therefore, the rattling tooth part 103 has no tendency to move reversely either. Thus, there can be a gap between the inner wall of the cover plate part 102-2 and the corresponding end of the cylinder part 1032 to minimize the friction when the rattling tooth part 103 rotates and improve the smoothness of the rotation of the rattling tooth part 103.

[0113] Please refer to Figure 14 , Figure 14 For Figure 1 Schematic structural diagram of the push rod part and the pressing part in the dose adjustment mechanism.

[0114] In some embodiments of the present application, the push rod part 101 has a pressing end. The dose adjustment mechanism 100 further includes a pressing part 105. The pressing part 105 is fixedly connected to the pressing end of the push rod part 101. The cross-sectional area of the pressing part 105 is larger than that of the push rod part 101, which is convenient for the operator to apply force and improves the operation convenience.

[0115] Among them, the connection manner between the pressing part 105 and the push rod part 101 is not limited. For example, it can be fixed by welding, snap connection, interference fit, etc. Alternatively, in some other embodiments, the pressing part 105 and the push rod part 101 are integrally formed.

[0116] The embodiment of the present application further provides an injection device, including:

[0117] A cylinder 200 having an injection end and an open end;

[0118] A sealing plug 300 is slidably disposed inside the cylinder 200. Taking the sealing plug 300 as a boundary, a storage cavity 200a is formed in the area of the cylinder 200 near the injection end inside the cylinder 200. The storage cavity 200a is used to store the injection substance;

[0119] The dose adjustment mechanism 100 of the aforementioned injection device. The holding part 102 of the dose adjustment mechanism 100 is connected to the open end of the cylinder 200, and the push rod part 101 of the dose adjustment mechanism 100 is connected to the sealing plug 300.

[0120] 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.

[0121] Among them, the connection method between the push rod part 101 and the sealing plug 300 is not limited. For example, the push rod part 101 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 part 101 is larger than the inner diameter of the connection groove, and at least part of the connection end of the push rod part 101 is inserted into the connection groove.

[0122] 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 for an injection device, characterized in that, It includes a push rod part, a holding part and a ratchet part. The push rod part passes through the holding part and is circumferentially limited and connected. The push rod part can move axially relative to the holding part. The ratchet part is sleeved on the push rod part and is threadedly connected. The holding part has a receiving cavity, and the circumferential wall enclosing the receiving cavity is provided with one-way clamping grooves distributed circumferentially. The ratchet part is located in the receiving cavity, and the ratchet part has an elastic clamping part, and the elastic clamping part is snapped into any one of the one-way clamping grooves; In a state where the push rod part is subjected to a pressing force, the push rod part can move axially, and the ratchet part can rotate under the action of the thread, so that the elastic clamping part slides along the circumferential wall enclosing the receiving cavity to be snapped into one of the one-way clamping grooves at the front end.

2. The dose adjustment mechanism according to claim 1, wherein The circumferential wall enclosing the receiving cavity is provided with a plurality of ratchet teeth distributed circumferentially. An ratchet tooth groove is formed between adjacent ratchet teeth, and the ratchet tooth groove is the one-way clamping groove.

3. The dose adjustment mechanism according to claim 1, characterized in that, A limiting groove is provided on the outer peripheral wall of the push rod part, and the limiting groove extends along the axial direction of the push rod part. The holding part is provided with a limiting protrusion, and at least part of the limiting protrusion is slidably inserted into the corresponding limiting groove.

4. The dose adjustment mechanism according to any one of claims 1-3, characterized in that, The push rod part has a pressing end, and an installation groove is provided at the end of the holding part facing away from the pressing end. The installation groove is used for laterally limiting and installing a protrusion at the opening end of the barrel of the injection device; The dose adjustment mechanism further includes a blocking member, and the blocking member is connected to the holding part. The blocking member is configured to abut against the end wall of the protrusion facing away from the pressing end to axially limit the protrusion.

5. The dose adjustment mechanism according to claim 4, wherein, The end of the holding part facing away from the pressing end includes two oppositely arranged installation parts. The opposite end walls of the two installation parts form part of the inner wall of the installation groove. The holding part is also provided with an installation hole that penetrates the two installation parts laterally. The installation hole communicates with the installation groove, and both ends of the blocking member are fixedly installed in the installation hole.

6. The dose adjustment mechanism according to claim 5, characterized in that, The blocking member includes a blocking member body. The blocking member body is provided with a notch groove with an opening at the first end and at least one avoidance opening. The blocking member further includes at least one elastic member. The first end of the elastic member is connected to the inner wall enclosing the avoidance opening. In an unloaded state, the second end of the elastic member extends obliquely in a direction away from the pressing end, and the length of the elastic member is not greater than the length between the first end and the second end of the avoidance opening; In a state where the dose adjustment mechanism is connected to the barrel, both ends of the blocking member are inserted into the installation hole, the barrel passes through the notch groove, the closing end wall enclosing the notch groove abuts against the outer wall of the barrel, and the end wall of the second end of the elastic member abuts against the wall part enclosing the installation groove.

7. The dose adjustment mechanism according to claim 6, wherein, The parts of the blocking member body located on both sides in the width direction of the notch groove are blocking arms. Among the two installation parts, the installation part close to the first end is the first installation part, and the installation part close to the second end is the second installation part; The mounting holes include two first holes provided in the first mounting portion and a second hole provided in the second mounting portion. The first end of the blocking arm is inserted into the corresponding first hole, and the second end of the blocking member body is inserted into the second hole.

8. The dose adjustment mechanism according to any one of claims 1-3, characterized in that, The holding portion includes: A body portion having a receiving groove. One end of the receiving groove close to the pressing end of the push rod portion is an open end, and a one-way card slot is provided on the peripheral wall surrounding the receiving groove; A cover portion connected to the open end of the body portion, and the receiving groove forms at least part of the receiving cavity.

9. The dose adjustment mechanism according to claim 8, characterized in that, Circular protrusions are provided opposite to each other on the end wall surrounding the receiving groove and the inner wall of the cover portion, and the push rod portion passes through the inside of the circular protrusion; The rattling tooth portion includes a cylindrical body portion. The cylindrical body portion is sleeved on the push rod portion and is threadedly connected. The elastic clamping portion is connected to the outer peripheral wall of the cylindrical body portion. Both axial ends of the cylindrical body portion are partially located inside the corresponding circular protrusion, and the end wall surrounding the receiving groove abuts against the opposite end of the cylindrical body portion.

10. An injection device, characterized in that: It includes: A cylinder having a pouring end and an open end; A sealing plug slidably disposed inside the cylinder. Taking the sealing plug as a boundary, a storage cavity is formed in the area inside the cylinder close to the pouring end, and the storage cavity is used for storing the injection substance; The dose adjustment mechanism of the injection device according to any one of claims 1-9, wherein the holding portion of the dose adjustment mechanism is connected to the open end of the cylinder, and the push rod portion of the dose adjustment mechanism is connected to the sealing plug.

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