Drive worm and dose accumulation mechanism

Abstract

The utility model relates to a driving worm and a dose accumulation mechanism, the driving worm comprises a rod body and a driving rib, the rod body can rotate around a first axis, the driving rib extends on the rod body around the first axis, the driving rib is provided with a first end and a second end opposite to each other in the extending direction of the driving rib, and the first end and the second end are arranged in the extending direction of the driving rib. The surrounding angle formed by the first end and the second end based on the first axis is smaller than or equal to 360 degrees, and the driving rib is used for being meshed with a meshing groove in an integral worm gear. According to the driving worm, the axially-collided mold cores can be adopted to form the two axially-opposite side walls of the driving rib, demolding can be conveniently and rapidly achieved only by axially pulling away the axially-collided mold cores after injection molding, and the technical effect that the manufacturing process is convenient and rapid is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of injection devices, and in particular to a driving worm and a dose accumulation mechanism. Background Art

[0002] When injecting drugs, a specific injection device is used. This injection device is usually called a pen injector or injection pen. The user can adjust the dose based on needs and inject the adjusted dose; at the same time, the process of adjusting the dose and then injecting the adjusted dose is regarded as a complete injection.

[0003] During actual use, the injection device is equipped with a cartridge containing the drug. As the user injects the drug repeatedly, the remaining dose of the drug in the cartridge gradually decreases. As the remaining dose in the cartridge continues to decrease, the dose set by the user based on demand may be greater than the remaining dose of the drug. The injection device is usually also equipped with an accumulator for accumulating and recording the set dose value and a driving member for driving the accumulator to move. However, the manufacturing steps of the driving member are usually complex. Utility Model Content

[0004] On the one hand, in order to make the manufacturing process more convenient, the present application provides a driving worm, which can be used to drive the integral worm gear matched with it to move so as to record the dose setting value.

[0005] The present application provides a driving worm adopting the following technical solution:

[0006] A driving worm comprises a rod body and a driving rib, wherein the rod body is capable of rotating around a first axis, the driving rib extends on the rod body around the first axis, the driving rib has a first end and a second end opposite to each other along its extension direction, the surrounding angle formed by the first end and the second end based on the first axis is less than or equal to 360°, and the driving rib is used to engage with an engagement groove on an integral worm gear.

[0007] In order to achieve mass production, the driving worm is manufactured by injection molding. If the thread on the driving worm is set to a multi-turn spiral structure, it is usually necessary to use a mold core with a spiral groove for molding and use a spiral core pulling method to demold after molding. This will lead to complex manufacturing process, high cost and reduce a certain degree of production efficiency. By adopting the above technical scheme, the driving rib surrounds the rod body less than or equal to one circle, so that there is no overlapping area in the axial projection of the driving rib. Accordingly, when preparing the driving assembly and the driving ribs thereon by injection molding, axially opposed mold cores can be used to form the axially opposite side walls of the driving rib. After injection molding, it is only necessary to axially pull out the axially opposed mold cores for convenient demolding. Compared with allowing the driving rib to surround the rod body more than one circle and requiring spiral core pulling for demolding after injection molding, the driving worm of this scheme can be more convenient in the manufacturing process.

[0008] Furthermore, the driving rib includes a driving section and an engaging section at the end of the driving section. The process from the engagement section starting to engage into the engaging groove to the driving section starting to engage into the engaging groove is defined as the engagement process, and the process from the driving section completely disengaging from the engaging groove to the engagement section completely disengaging from the engaging groove is defined as the disengagement process. The integral worm gear remains stationary during the engagement process and the disengagement process.

[0009] Further, the central extension axis of the engaging segment is configured as an arc circumferentially arranged around the first axis.

[0010] Furthermore, the engagement section has a first side wall and a second side wall opposite to each other along a first axis, and the direction of the engagement section away from the driving section is defined as a moving away direction, and the axial distance between the first side wall and the second side wall remains unchanged along the moving away direction.

[0011] By adopting the above technical solution, the engaging section is configured as an arc section, which has a simple structure and is easy to prepare.

[0012] Furthermore, the engagement section has a first side wall and a second side wall opposite to each other along a first axis, and the direction of the engagement section away from the driving section is defined as a moving away direction, and the axial distance between the first side wall and the second side wall gradually decreases along the moving away direction.

[0013] By adopting the above technical solution, the engaging section with gradually decreasing axial size can play a guiding transition role in the process of engaging with the engaging groove.

[0014] Furthermore, the first end and the second end of the driving rib are both provided with transition chamfers.

[0015] By adopting the above technical solution, the transition chamfer can play a role in guiding the transition during the process of engaging into the engagement groove.

[0016] In a second aspect, the present application provides a dose accumulation mechanism.

[0017] The dose accumulation mechanism provided in this application adopts the following technical solution:

[0018] A dose accumulation mechanism, an integral worm gear and the above-mentioned driving worm, the integral worm gear can rotate around a second axis, the first axis and the second axis are arranged crosswise, the integral worm gear is provided with engagement grooves arranged at intervals along the circumferential direction of the second axis, the engagement grooves are used for the driving ribs to engage.

[0019] Furthermore, the central angle formed by the center points of two adjacent meshing grooves on the integral worm gear relative to the second axis is defined as a reference angle. When the driving worm rotates one circle relative to the integral worm gear, the rotation angle of the integral worm gear is a reference angle.

[0020] Furthermore, the dose adjusted by the driving worm rotating one circle around the first axis is defined as X, and the total set dose that can be accumulated by the dose accumulation mechanism is defined as Y, where Y is configured as an integer multiple of X.

[0021] Furthermore, the integral worm gear is arranged in the driving worm, and the driving rib is arranged on the inner side wall of the driving worm.

[0022] Furthermore, the integral worm gear is arranged outside the driving worm, and the driving rib is arranged on the outer side wall of the driving worm.

[0023] In summary, the present application includes the following beneficial technical effects: compared to allowing the driving rib to wrap around the rod body for more than one circle and requiring spiral core pulling for demolding after injection molding, the driving rib of this solution wraps around the rod body for less than one circle, so that there is no overlapping area in the axial projection of the driving rib. Therefore, when the drive assembly and the driving ribs thereon are prepared by injection molding, axially opposing mold cores can be used to form the axially opposite side walls of the driving rib, and after injection molding, the axially opposing mold cores only need to be axially pulled away for convenient demolding, which makes the driving worm more convenient in the manufacturing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of an injection device with a dose accumulation mechanism in an embodiment of the present application. Figure 1 ;

[0025] Figure 2 This is a schematic diagram of an injection device with a dose accumulation mechanism in an embodiment of the present application. Figure 2 ;

[0026] Figure 3This is a schematic diagram of an embodiment of the present application in which a portion of the side wall of the rod body is hidden to reveal the driving ribs;

[0027] Figure 4 This is a schematic diagram of the matching relationship between the integral worm gear and the matching components in the embodiment of the present application. Figure 1 ;

[0028] Figure 5 Schematic diagram of the matching relationship between the integral worm gear and the driving worm in the embodiment of the present application;

[0029] Figure 6 This is a schematic diagram of the matching relationship between the integral worm gear and the matching components in the embodiment of the present application. Figure 2 ;

[0030] Figure 7 This is a schematic diagram of an embodiment of the present application in which a portion of the side wall of the rod body is hidden to reveal the driving ribs and the integral worm gear;

[0031] Figure 8 This is a schematic diagram for showing the driving ribs in the embodiment of this application. Figure 1 ;

[0032] Figure 9 This is a schematic diagram for showing the driving ribs in the embodiment of this application. Figure 2 ;

[0033] Figure 10 is a schematic diagram for illustrating a reference angle of an integrating worm gear in an embodiment of the present application;

[0034] Figure 11 is a cross-sectional view for illustrating the dose accumulation mechanism and the clutch element in an embodiment of the present application;

[0035] Figure 12 is a schematic diagram for illustrating the axial gear ring on the mating component in an embodiment of the present application;

[0036] Figure 13 This is an exploded schematic diagram for illustrating the dose accumulation mechanism and the clutch element in the embodiment of the present application;

[0037] Figure 14 It is a schematic diagram used to illustrate the mating teeth on the clutch element in the embodiment of the present application.

[0038] Explanation of the accompanying reference numerals: 1. Driving worm; 11. Driving rib; 111. Driving section; 112. Engaging section; 1121. First side wall; 1122. Second side wall; 113. Transition chamfer; 12. Rod body; 13. Ratchet tooth ring; 2. Mating component; 21. Radial through groove; 22. Support seat; 23. Axial tooth ring; 3. Integral worm gear; 31. Engaging teeth; 32. Engaging groove; 33. Rotating shaft; 4. Clutch element; 41. Ratchet arm; 42. Mating teeth; 421. Right-angle surface; 422. Inclined surface; 5. Driving rod; 6. Push rod; 7. Housing; 8. Cartridge bottle; 81. Movable piston; 9. Button; 10. Spring. DETAILED DESCRIPTION

[0039] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0040] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention. In addition, features defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0041] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0042] Currently, a dose accumulation mechanism for cumulatively setting doses, based on the transmission principle of a worm gear, is conceived. The mechanism specifically includes a drive worm, a mating component, and an integrating worm gear. The drive worm and the mating component are rotatable relative to each other during dose setting, while forming a rotationally fixed coupling with the mating component during dose injection, allowing them to rotate synchronously. Furthermore, the integrating worm gear is rotatably mounted on the mating component, with its meshing groove meshing with the drive thread of the drive worm.

[0043] In the above solution, during dose adjustment, the drive thread on the drive worm drives the integrating worm gear to rotate relative to the mating component. During dose injection, the drive worm, mating component, and integrating worm gear remain relatively stationary. This allows the user to accumulate the dose set by the user through rotation of the integrating worm gear. Furthermore, in the above solution, the drive thread on the drive worm is designed as a conventional worm thread structure, which enables good power transmission between the drive worm and the integrating worm gear. However, this also makes the manufacturing process of the drive worm more complicated.

[0044] Reference Figure 1 and Figure 2 The dose accumulation mechanism includes a driving worm 1, a matching component 2 and an integral worm gear 3.

[0045] Among them, the driving worm 1 can rotate around a first axis, which is the central axis of the outer shell 7, and the driving worm 1 includes a rod body 12 and a driving rib 11 provided on the rod body 12, and the driving rib 11 extends on the rod body 12 around the first axis; the mating component 2 is socketed with the driving worm 1, and the mating component 2 can rotate around the first axis; the integral worm gear 3 is connected to the mating component 2, and the integral worm gear 3 can rotate around a second axis relative to the mating component 2, and the second axis is the central axis of the integral worm gear 3, and the second axis is arranged crosswise with the first axis; at the same time, the integral worm gear 3 is provided with a plurality of meshing teeth 31, and the plurality of meshing teeth 31 are arranged at intervals along the circumferential direction of the second axis, so that a meshing groove 32 for the driving rib 11 to engage is formed between two adjacent meshing teeth 31.

[0046] Specifically, during dose setting, the drive worm 1 and the mating component 2 are capable of rotating relative to each other, and dose setting includes both increasing and decreasing the dose. Accordingly, rotation of the drive worm 1 relative to the mating component 2 in a first direction is used to increase the dose, and rotation of the drive worm 1 relative to the mating component 2 in a second direction is used to decrease the dose, the first direction being opposite to the second direction. Simultaneously, throughout the dose setting period, the drive rib 11 is configured to engage with the meshing teeth 31 to drive the integral worm gear 3 to rotate. During dose injection, the drive worm 1 and the mating component 2 are non-rotatably connected, allowing the drive worm 1 and the mating component 2 to rotate or remain stationary in sync, during which time the integral worm gear 3 remains stationary relative to the drive worm 1 and the mating component 2.

[0047] It should be noted that the driving rib 11 extending on the rod body 12 around the first axis means that the driving rib 11 is provided on the rod body 12 of the driving worm 1 and extends in a circular manner along its axial direction with the first axis as the spiral axis; accordingly, for the convenience of description, the two opposite ends of the driving rib 11 along its extension direction are defined as the first end and the second end, and the first end and the second end have an axial spacing in the direction of the first axis. At the same time, combined with Figure 3 , the number of turns of the driving rib 11 on the driving worm 1 is less than or equal to one, that is, the angle formed by the first end and the second end based on the first axis is less than or equal to 360°. It can be understood that this ensures that the axial projection of the driving rib 11 along the first axis does not have any overlapping areas, that is, the axial projection appears as an arc with a gap or a complete circular ring; therefore, when the driving worm 1 and the driving rib 11 thereon are prepared by injection molding, axially opposing mold cores can be used to form the axially opposing side walls of the driving rib 11. After injection molding, the mold can be easily demolded by simply axially withdrawing the axially opposing mold cores.

[0048] It should also be noted that the intersecting arrangement of the first and second axes indicates that the first and second axes are not parallel, that is, the first and second axes are not in the same plane. Specifically, if the plane in which the first axis lies is defined as the first plane, then the second axis intersects the first plane at a point. In a specific embodiment, the first axis is configured to be perpendicular to the second axis to achieve better transmission efficiency in the transmission of driving force between the drive worm 1 and the integral worm gear 3.

[0049] It can be understood that the mating component 2 and the driving worm 1 are sleeved together in such a way that the driving worm 1 is sleeved outside the mating component 2 , or the mating component 2 is sleeved outside the driving worm 1 .

[0050] Reference Figure 1 and Figure 4In some embodiments, the driving worm 1 is sleeved on the outside of the mating component 2. The driving worm 1 is generally cylindrical, and the driving rib 11 is disposed on the inner sidewall of the rod body 12. The mating component 2 is generally cylindrical and at least partially accommodated within the driving worm 1. The integrating worm gear 3 is completely accommodated within the driving worm 1. The integrating worm gear 3 is rotationally connected to the mating component 2 via a rotating shaft 33. Accordingly, a clearance zone is provided on the mating component 2 to allow the integrating worm gear 3 to rotate unrestricted. In some specific embodiments, the mating component 2 is provided with a radial groove 21 perpendicular to the first and second axes. The integrating worm gear 3 is mounted in the radial groove 21, and the radial groove 21 serves as a clearance zone on the mating component 2 to allow the integrating worm gear 3 to rotate freely. Furthermore, the area of ​​the integrating worm gear 3 mounted in the radial groove 21, where the meshing groove 32 is provided, can protrude from a notch in the radial groove 21 and mesh with the driving rib 11 on the inner sidewall of the driving worm 1.

[0051] In the above embodiment, during dose setting, the drive worm 1 rotates about a first axis while the mating component 2 remains stationary. During dose injection, the drive worm 1 rotates synchronously with the mating component 2. It will be understood that if the drive worm 1 is defined as rotating clockwise when increasing the dose and counterclockwise when decreasing the dose, then rotation of the drive worm 1 relative to the mating component 2 in a first direction corresponds to clockwise rotation of the mating component 2 when the mating component 2 is stationary, and rotation of the drive worm 1 relative to the mating component 2 in a second direction corresponds to counterclockwise rotation of the mating component 2 when the mating component 2 is stationary. Furthermore, the first direction is the same as the clockwise rotation direction, and the second direction is the same as the counterclockwise rotation direction.

[0052] Reference Figure 2 、 Figure 5 and Figure 6 In other embodiments, the mating component 2 is sleeved on the outside of the driving worm 1. The mating component 2 is roughly cylindrical, and the integral worm wheel 3 is completely accommodated in the mating component 2 and outside the driving worm 1. At the same time, a support seat 22 is provided on the inside of the mating component 2, and the integral worm wheel 3 is rotatably mounted on the support seat 22 of the mating component 2; the driving worm 1 is at least partially accommodated in the mating component 2, and the driving rib 11 is arranged on the outer wall of the driving worm 1. Accordingly, a movable cavity for the free rotation of the integral worm wheel 3 is formed between the driving worm 1 and the mating component 2; in some specific embodiments, there is a gap between the inner wall of the mating component 2 and the outer wall of the driving worm 1 on which the driving rib 11 is provided, so that an annular cavity is formed between the driving worm 1 and the mating component 2, and the annular cavity serves as a movable cavity for the free rotation of the integral worm wheel 3.

[0053] In the above embodiment, during dose setting, the mating component 2 rotates about the first axis while the drive worm 1 remains stationary. During dose injection, the mating component 2 and the drive worm 1 rotate synchronously. If the mating component 2 is defined as rotating clockwise when adjusting the dose up and counterclockwise when adjusting the dose down, it can be understood that rotation of the drive worm 1 relative to the mating component 2 in the dose-increasing direction corresponds to the drive worm 1 being stationary while the mating component 2 rotates clockwise, and rotation of the drive worm 1 relative to the mating component 2 in the second direction corresponds to the drive worm 1 being stationary while the mating component 2 rotates counterclockwise, with the first direction being the same as the counterclockwise direction and the second direction being the same as the clockwise direction.

[0054] Further, refer to Figure 7 In some embodiments, both the first end and the second end of the driving rib 11 are provided with a transition chamfer 113 , and the transition chamfer 113 can guide the transition during the process of engaging with the engagement groove 32 .

[0055] Further, refer to Figure 3 In some specific embodiments, the driving rib 11 includes a driving section 111 and two engaging sections 112 at the ends of the driving section 111, that is, the driving rib 11 includes the engaging section 112, the driving section 111 and the engaging section 112 connected in sequence along its extension direction; wherein, the engaging section 112 is the part of the driving rib 11 that first engages with the engaging groove 32 on the integral worm gear 3, or the last to disengage from the engaging groove 32 on the integral worm gear 3, and the driving section 111 is the part of the driving rib 11 used to drive the integral worm gear 3 to rotate.

[0056] Similarly, for the convenience of subsequent description, the process from the engagement section 112 starting to engage into the engagement groove 32 to the drive section 111 starting to engage into the engagement groove 32 is defined as the engagement process, the process from the drive section 111 starting to engage into the engagement groove 32 to the drive section 111 completely disengaging from the engagement groove 32 is defined as the driving process, and the process from the drive section 111 completely disengaging from the engagement groove 32 to the engagement section 112 completely disengaging from the engagement groove 32 is defined as the disengagement process; accordingly, the integral worm gear 3 and the mating component 2 remain relatively stationary during the engagement process and the disengagement process.

[0057] If the driving rib 11 spirals around less than one turn, there is a possibility that the driving rib 11 will completely disengage from the meshing groove 32 on the integrating worm gear 3, that is, the first end may disengage from the meshing groove 32 while the second end has not yet engaged with another meshing groove 32. In this case, the integrating worm gear 3 remains stationary. If the driving rib 11 is configured as a continuous spiral segment, the end of the driving rib 11 may not be fully aligned with the meshing groove 32 when it reengages the integrating worm gear 3. This may cause the integrating worm gear 3 to rotate excessively, thereby resulting in cumulative errors in the integrating worm gear 3. By adopting the above solution, the driving rib 11 can only drive the integrating worm gear 3 to rotate during the driving process of the driving segment 111, while the integrating worm gear 3 remains stationary during the engagement and disengagement processes of the engagement segment 112. This ensures that the end of the driving rib 11 remains aligned with the meshing groove 32 when it reengages the integrating worm gear 3, thereby avoiding the situation in which the integrating worm gear 3 rotates excessively and thus resulting in cumulative errors in the integrating worm gear 3.

[0058] Further, refer to Figure 8 and Figure 9 In some embodiments where the driving rib 11 includes a driving segment 111 and an engaging segment 112, the central extension axis of the engaging segment 112 is configured as an arc circumferentially disposed about the first axis. For ease of description, the opposite side walls of the engaging segment 112 along the first axis are defined as a first side wall 1121 and a second side wall 1122, respectively. The direction of the engaging segment 112 away from the driving segment 111 is defined as a moving away direction.

[0059] Reference Figure 8 In some specific embodiments, the axial distance between the first side wall 1121 and the second side wall 1122 remains unchanged along the moving away direction, that is, the engaging section 112 is configured as a circular arc segment. It should be noted that the driving rib 11 includes two engaging sections 112, both of which are circular arc segments, but the two engaging sections 112 are located at different axial positions on the first axis. Figure 9 In some other specific embodiments, the axial distance between the first side wall 1121 and the second side wall 1122 gradually decreases along the away direction, that is, the engaging section 112 is configured as a tapered section with a gradually decreasing width.

[0060] Furthermore, in other embodiments where the driving rib 11 includes a driving section 111 and an engaging section 112, the driving section 111 is configured as a spiral section spirally arranged around a first axis; the spiral section is used to engage with the engaging groove 32, and is used to drive the integral worm gear 3 to rotate when the spiral section rotates synchronously with the driving worm 1.

[0061] Furthermore, in some embodiments, the dose adjusted by the drive worm 1 rotating one circle around the first axis is defined as X, and the total set dose that can be accumulated by the dose accumulation mechanism is defined as Y, then Y is configured as an integer multiple of X, that is, when the maximum set dose is reached, the drive worm 1 has accumulated an integer number of rotations relative to the mating component 2 in the direction of increasing the dose.

[0062] Further, refer to Figure 7 and 10 In some embodiments, when the driving worm 1 rotates one circle relative to the mating component 2, the integral worm wheel 3 is driven to rotate one tooth angle; specifically, the central angle formed by the center points of two adjacent meshing grooves 32 on the integral worm wheel 3 relative to the second axis is defined as the reference angle a. When the driving worm 1 and the mating component 2 rotate one circle relative to each other, that is, 360°, the rotation angle of the integral worm wheel 3 is a reference angle a.

[0063] The embodiment of the present application further discloses an injection device that can ensure that the set dose is less than or equal to the remaining dose of the drug that can be injected, so that the actual injection dose is consistent with the set dose.

[0064] Reference Figure 1 The injection device includes a housing 7, a clutch element 4, the aforementioned dose accumulation mechanism, a drive rod 5, and a push rod 6. The clutch element 4, dose accumulation mechanism, drive rod 5, and push rod 6 are all disposed within the housing 7. Furthermore, during dose setting, at least one of the drive worm 1 and the mating component 2 is capable of relative rotation with the clutch element 4. During dose injection, the clutch element 4 is non-rotatably coupled to the drive worm 1 and the mating component 2 in the dose injection direction. The drive worm 1, the mating component 2, the drive rod 5, and the push rod 6 are sleeved together from the outside inward. The drive rod 5 is axially fixed and rotatably disposed within the housing 7 and non-rotatably coupled to the mating component 2. The push rod 6 is threadedly coupled to the drive rod 5 and forms an axially guided engagement with the housing 7. Therefore, during dose injection, the drive worm 1 drives the mating component 2 and the drive rod 5 to rotate in the dose injection direction, thereby driving the push rod 6 axially. Accordingly, the distal end of the injection device is connected to a cartridge 8 containing a drug, a movable piston 81 is provided at the proximal end of the cartridge 8, and a needle assembly is connected to the distal end. The axially fed push rod 6 is used to push the movable piston 81 of the cartridge 8 toward the distal end, thereby expelling the drug in the cartridge 8 through the needle assembly.

[0065] Specifically, refer to Figures 11 to 13The proximal end of the mating component 2 is accommodated in the proximal end of the drive worm 1. At the same time, the clutch element 4 is located at the proximal end of the drive worm 1 and presses against the proximal end of the mating component 2. At the same time, when the dose is increased, the drive worm 1 rotates in a third direction. When the dose is decreased, the drive worm 1 rotates in a fourth direction opposite to the third direction. When the dose is injected, both the drive worm 1 and the mating component 2 rotate in the fourth direction. Specifically, the third direction is clockwise, and the fourth direction is counterclockwise. At the same time, the injection device also includes a button 9 and a spring 10, wherein the button 9 and the proximal end of the drive worm 1 form an anti-slip structure, the spring 10 is located between the button 9 and the clutch element 4, and the spring 10 is used to maintain the clutch element 4 pressed against the proximal end of the mating component 2.

[0066] Correspondingly, a ratchet tooth ring 13 is provided on the inner wall of the proximal end of the driving worm 1, and a ratchet arm 41 is provided which cooperates with the ratchet tooth ring 13. The ratchet tooth ring 13 and the ratchet arm 41 cooperate to form a first connection, which allows the driving worm 1 to rotate in a third direction relative to the clutch element 4, while preventing the driving worm 1 from rotating in a fourth direction relative to the clutch element 4.

[0067] The proximal end of the mating component 2 is provided with an axially protruding axial toothed ring 23, and the clutch element 4 is provided with mating teeth 42 that mesh with the axial toothed ring 23. Under the elastic force of the spring 10, the axial toothed ring 23 cooperates with the mating teeth 42 to form a second connection. This second connection prevents the clutch element 4 from rotating in the third direction relative to the mating component 2, while allowing relative axial movement between the clutch element 4 and the mating component 2, thereby rotating in the fourth direction relative to the mating component 2. Simultaneously, during dose injection, the clutch element 4 is pressed against the proximal end of the mating component 2 by the axial force transmitted by the button 9. At this time, the clutch element 4 and the mating component 2 cannot undergo axial movement, and the clutch element 4 and the mating component 2 remain relatively stationary.

[0068] Combine Figure 14 It should be noted that the axial gear ring 23 and the mating teeth 42 are configured as inclined teeth with a cross-section similar to a right-angled triangle, and the inclined teeth have a right-angled surface 421 and an inclined surface 422. During dose setting, when the right-angled surface 421 of the inclined tooth on the axial gear ring 23 abuts against the right-angled surface 421 of the mating tooth 42, the clutch element 4 is prevented from rotating in the third direction relative to the mating component 2. When the inclined surface 422 of the inclined tooth on the axial gear ring 23 abuts against the inclined surface 422 of the mating tooth 42, the clutch element 4 and the mating component 2 experience relative axial movement and "tooth jumping" occurs under the action of the elastic force of the spring 10, that is, the tooth jumps from one groove to an adjacent groove.

[0069] In summary, when the drive worm 1 rotates in the third direction to increase the dose, the clutch element 4 and the mating component 2 remain stationary, and the drive worm 1 rotates relative to the mating component 2 and the clutch element 4. When the drive worm 1 rotates in the fourth direction to decrease the dose, the drive worm 1 drives the clutch element 4 to rotate in the fourth direction, and the mating component 2 remains stationary. At this time, the drive worm 1 and the clutch element 4 rotate relative to the mating component 2. During dose injection, the drive worm 1, the clutch element 4, and the mating component 2 rotate synchronously in the fourth direction.

[0070] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the illustrative use of the above terms does not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0071] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and purpose of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A driving worm, characterized in that: It includes a rod body and a driving rib, the rod body can rotate around a first axis, the driving rib extends on the rod body around the first axis, the driving rib has a first end and a second end opposite to each other along its extension direction, the first end and the second end form a surrounding angle based on the first axis less than or equal to 360°, and the driving rib is used to engage with the meshing groove on the integral worm gear.

2. The driving worm according to claim 1, characterized in that The driving rib includes a driving section and an engaging section at the end of the driving section. The process from the engagement section starting to engage and enter the engaging groove to the driving section starting to engage and enter the engaging groove is defined as the engagement process, and the process from the driving section completely disengaging from the engaging groove to the engagement section completely disengaging from the engaging groove is defined as the disengagement process. The integral worm gear remains stationary during the engagement process and the disengagement process.

3. The driving worm according to claim 2, characterized in that The central extension axis of the engagement segment is configured as an arc of a circle circumferentially disposed about the first axis.

4. The driving worm according to claim 3, characterized in that The engaging section has a first side wall and a second side wall opposite to each other along a first axis. The direction in which the engaging section moves away from the driving section is defined as a moving away direction. The axial distance between the first side wall and the second side wall remains unchanged along the moving away direction.

5. The driving worm according to claim 3, characterized in that The engaging section has a first side wall and a second side wall opposite to each other along a first axis. The direction in which the engaging section moves away from the driving section is defined as a moving away direction. The axial distance between the first side wall and the second side wall gradually decreases along the moving away direction.

6. The driving worm according to claim 1, characterized in that The first end and the second end of the driving rib are both provided with transition chamfers.

7. A dose accumulation mechanism, characterized in that: It includes an integral worm wheel and a driving worm according to any one of claims 1 to 6, the integral worm wheel is capable of rotating around a second axis, the first axis and the second axis are arranged crosswise, the integral worm wheel is provided with engagement grooves arranged at intervals along the circumferential direction of the second axis, the engagement grooves are used for the driving ribs to engage.

8. The dose accumulation mechanism according to claim 7, characterized in that: The dose adjusted by the driving worm rotating one circle around the first axis is defined as X, and the total set dose that can be accumulated by the dose accumulation mechanism is defined as Y, where Y is configured as an integer multiple of X.

9. The dose accumulation mechanism according to claim 7, characterized in that: The integral worm wheel is arranged in the driving worm, and the driving rib is arranged on the inner side wall of the driving worm.

10. The dose accumulation mechanism according to claim 7, characterized in that: The integral worm wheel is arranged outside the driving worm, and the driving rib is arranged on the outer side wall of the driving worm.

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