Injection device

Abstract

The invention discloses an injection device, comprising: a guide; the measuring sleeve is connected with the guide piece in a sleeving manner and is connected with the guide piece through a spiral guide structure; the transmission rod is arranged in the proportioning sleeve in a penetrating manner; the connecting piece is arranged between the metering sleeve and the transmission rod, a first connecting structure is arranged between the connecting piece and the metering sleeve, and a second connecting structure and a third connecting structure are arranged between the connecting piece and the transmission rod; the first coupling structure is configured to allow the dosing sleeve to rotate relative to the coupling piece in a first rotation direction and to prevent the dosing sleeve from rotating relative to the coupling piece in a second rotation direction opposite to the first rotation direction; the second connecting structure is configured to enable the transmission rod and the connecting piece to be connected into a synchronously moving whole when the transmission rod is subjected to axial pressure to push and inject liquid; the third connecting structure is configured to allow the connecting piece to rotate relative to the transmission rod in the second rotation direction and prevent the connecting piece from rotating relative to the transmission rod in the first rotation direction.

Description

Technical Field

[0001] The present invention relates to the technical field of medical equipment, and in particular to an injection device. Background Art

[0002] When injecting drugs subcutaneously, a specific injection device is usually used. This injection device usually includes a guide sleeve, a metering sleeve and a transmission rod. The metering sleeve is sleeved outside the guide sleeve and is threadedly connected to the guide sleeve. By rotating the metering sleeve in a first rotation direction, the metering sleeve can drive the transmission rod to move axially in the first direction to adjust the dose. By rotating the metering sleeve in a second rotation direction, the metering sleeve can drive the transmission rod to move axially in the second direction to adjust the dose. By pressing the transmission rod, the metering sleeve and the transmission rod can be spirally moved in the second direction together to inject the liquid.

[0003] In order to achieve the above three functions, a corresponding clutch structure needs to be provided on the injection device, so that when adjusting or calling back the dose, the transmission rod is ensured not to rotate with the metering sleeve, and when the liquid is pushed, the transmission rod is ensured to rotate together with the metering sleeve. In the related art, such a clutch structure is fully integrated on the metering sleeve and the transmission rod, which makes the structure of the metering sleeve and the transmission rod more complicated. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems in the prior art. To this end, the present invention provides an injection device that can simplify the structure of a metering sleeve and a transmission rod.

[0005] According to some embodiments of the present invention, the injection device comprises: a guide member; a measuring sleeve, which is sleeved with the guide member and connected with the guide member through a spiral guide structure; a transmission rod, which is inserted into the metering sleeve; a coupling member, which is arranged between the metering sleeve and the transmission rod, wherein a first coupling structure is provided between the coupling member and the metering sleeve, and a second coupling structure and a third coupling structure are provided between the coupling member and the transmission rod;

[0006] The first coupling structure is configured to allow the metering sleeve to rotate relative to the coupling member in a first rotation direction and to prevent the metering sleeve from rotating relative to the coupling member in a second rotation direction opposite to the first rotation direction; wherein, when the metering sleeve is rotated relative to the guide member in the first rotation direction to adjust the dose, the metering sleeve rotates relative to the coupling member in the first rotation direction and generates a first acoustic signal and / or a first tactile signal; the second coupling structure is configured to connect the transmission rod and the coupling member into a synchronously movable whole when the transmission rod is subjected to axial pressure to push the liquid; the third coupling structure is configured to allow the coupling member to rotate relative to the transmission rod in the second rotation direction and to prevent the coupling member from rotating relative to the transmission rod in the first rotation direction; wherein, when the metering sleeve is rotated relative to the guide member in the second rotation direction to call back the dose, the coupling member is driven so that the coupling member rotates relative to the transmission rod in the second rotation direction and generates a second acoustic signal and / or a second tactile signal.

[0007] The injection device according to the embodiment of the present invention has at least the following beneficial effects:

[0008] In the injection device of the present invention, when the metering sleeve is operated to rotate relative to the guide member in the first rotation direction to adjust the dose, the metering sleeve is not connected to the coupling member. At this time, the metering sleeve will rotate relative to the coupling member. Naturally, the metering sleeve will not drive the transmission rod to rotate with the metering sleeve through the coupling member. When the metering sleeve is operated to rotate relative to the guide member in the second rotation direction to adjust the dose, the metering sleeve is connected to the coupling member. At this time, the coupling member will rotate with the metering sleeve, but the coupling member is not connected to the transmission rod. Therefore, although the coupling member rotates with the metering sleeve, it will not drive the metering sleeve to rotate together. When the end of the transmission rod away from the guide piece is subjected to axial pressure to push the liquid, the transmission rod and the connecting piece are connected to form a synchronously movable whole, and at this time, the metering sleeve rotates relative to the guide piece along the second rotation direction under the action of the guide piece, so that the metering sleeve and the connecting piece are connected together, so that the metering sleeve, the transmission rod and the connecting piece form a synchronously rotating and axially moving whole.

[0009] In the injection device of the present invention, by integrating part of the clutch structure into the coupling member, it is beneficial to simplify the structure of the metering sleeve and the transmission rod. In addition, when the metering sleeve rotates in the first rotation direction relative to the guide member to adjust the dosage, it rotates in the first rotation direction relative to the coupling member and generates a first acoustic signal and / or a first tactile signal. When the metering sleeve rotates in the second rotation direction relative to the guide member to call back the dosage, it drives the coupling member so that the coupling member rotates in the second rotation direction relative to the transmission rod and generates a second acoustic signal and / or a second tactile signal, which can improve the user's experience during operation.

[0010] According to some embodiments of the present invention, the first coupling structure includes a first gear ring disposed on the inner wall of the metering sleeve, and a first elastic arm disposed on the outer peripheral side of the coupling member, and the first elastic arm cooperates with the first gear ring to form a ratchet mechanism;

[0011] Wherein, when the first gear ring rotates relative to the first elastic arm, a first acoustic signal and / or a first tactile signal is generated.

[0012] According to some embodiments of the present invention, the second coupling structure includes a clamping portion disposed on the outer peripheral side of the transmission rod, and a second gear ring disposed on the inner side of the coupling member, and the clamping portion is disposed toward the second gear ring;

[0013] Wherein, the clamping portion can extend into the tooth groove of the second gear ring when the transmission rod is subjected to axial pressure to push the liquid.

[0014] According to some embodiments of the present invention, the third coupling structure comprises a second elastic arm disposed on an outer side wall of the transmission rod, and a third gear ring disposed on an inner side of the coupling member, and the second elastic arm cooperates with the third gear ring to form a ratchet mechanism;

[0015] Wherein, when the second elastic arm rotates relative to the third gear ring, a second acoustic signal and / or a second tactile signal is generated.

[0016] According to some embodiments of the present invention, the injection device further comprises a driving rod penetrating the transmission rod, and an axial guiding structure is provided between the driving rod and the guide member;

[0017] The driving rod is connected to the guide member via a fourth coupling structure, and the fourth coupling structure is configured to: allow the driving rod to rotate relative to the guide member along the second rotation direction, and prevent the driving rod from rotating relative to the guide member along the first rotation direction;

[0018] The fourth coupling structure includes a fourth gear ring arranged on the guide member, and a third elastic arm arranged on the drive rod, and the third elastic arm cooperates with the fourth gear ring to form a ratchet mechanism.

[0019] According to some embodiments of the present invention, the third elastic arm generates a third acoustic signal and / or a third tactile signal when the third elastic arm rotates relative to the fourth ring gear.

[0020] According to some embodiments of the present invention, the transmission rod is provided with a vent hole communicating with the interior thereof.

[0021] According to some embodiments of the present invention, the guide member is configured as a guide sleeve, the guide sleeve is inserted into the metering sleeve from a first end of the metering sleeve, and the transmission rod is inserted into the metering sleeve from a second end of the metering sleeve and into the guide sleeve;

[0022] The spiral guide structure includes a first spiral structure arranged on the inner wall of the metering sleeve and a second spiral structure arranged on the outer wall of the guide sleeve, and the second spiral structure is threadedly matched with the first spiral structure.

[0023] According to some embodiments of the present invention, the first helical structure or the second helical structure is configured to have two separate single helical portions;

[0024] A plane perpendicular to the axis of the metering sleeve is defined as a reference plane, the central angle of the projection of the single spiral portion on the reference plane is less than or equal to 180°, and the projections of the two single spiral portions on the reference plane are symmetrically arranged.

[0025] According to some embodiments of the present invention, the injection device further comprises a metering member, the metering member is sleeved outside the transmission rod and located inside the metering sleeve;

[0026] Wherein, one of the transmission rod and the metering sleeve is threadedly connected to the metering member, and the other is axially slidingly matched with the metering member.

[0027] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0029] Figure 1 A schematic cross-sectional view of an injection device according to an embodiment of the present invention;

[0030] Figure 2 A partial cross-sectional view of an injection device according to an embodiment of the present invention Figure 1 ;

[0031] Figure 3A partial cross-sectional view of an injection device according to an embodiment of the present invention Figure 2 ;

[0032] Figure 4 A schematic diagram of the structure of a metering sleeve according to an embodiment of the present invention Figure 1 ;

[0033] Figure 5 A schematic diagram of the structure of a metering sleeve according to an embodiment of the present invention Figure 2 ;

[0034] Figure 6 A schematic structural diagram of a guide sleeve according to an embodiment of the present invention;

[0035] Figure 7 A schematic diagram of the structure of a transmission rod according to an embodiment of the present invention Figure 1 ;

[0036] Figure 8 A schematic diagram of the structure of a transmission rod according to an embodiment of the present invention Figure 2 ;

[0037] Fig. 9 A schematic diagram of the structure of a coupling member according to an embodiment of the present invention Figure 1 ;

[0038] Fig.10 A schematic diagram of the structure of a coupling member according to an embodiment of the present invention Figure 2 ;

[0039] Fig.11 A schematic diagram of the structure of a measuring element according to an embodiment of the present invention;

[0040] Fig.12 A schematic diagram of the structure of a driving rod according to an embodiment of the present invention;

[0041] Fig.13 The figure is a schematic structural diagram of a push rod according to an embodiment of the present invention.

[0042] Figure Number:

[0043] 11. Shell;

[0044] 12. metering sleeve; 121. first gear ring; 122. scale line; 123. axial guide bar; 124. first spiral structure; 1241. single spiral portion;

[0045] 13. guide sleeve; 131. first position limiting portion; 1311. first guide inclined surface; 132. fourth gear ring; 133. second spiral structure;

[0046] 14. Transmission rod; 141. Second limiting portion; 1411. First elastic arm; 1412. First limiting buckle; 1413. Second guiding inclined plane; 142. Threaded section; 143. Ventilation hole; 144. Second elastic arm; 145. Limit position limiting portion; 1451. First limit position limiting portion; 14511. Third guiding inclined plane; 1451a. Second elastic arm; 1451b. Second limiting buckle; 1452. Second limit position limiting portion; 146. Clamping portion; 147. Axial convex ridge;

[0047] 15, connecting member; 15a, first connecting structure; 15b, second connecting structure; 15c, third connecting structure; 151, first elastic arm; 152, second gear ring; 153, third gear ring;

[0048] 16. Button cap;

[0049] 17. Measuring piece; 171. Axial guide groove;

[0050] 21, driving rod; 21a, fourth connecting structure; 211, third elastic arm; 212, axial groove; 213, channel; 2131, first axial plane;

[0051] 22. push rod; 221. second axial plane;

[0052] 23. Nut;

[0053] Fig.14 The principle of injection molding metering sleeve of an embodiment of the present invention Figure 1 ;

[0054] Fig.15 The principle of injection molding metering sleeve of an embodiment of the present invention Figure 2 ;

[0055] Fig.16 The principle of injection molding metering sleeve of an embodiment of the present invention Figure 3 . DETAILED DESCRIPTION

[0056] Embodiments of the present invention are described in detail below, examples of which 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 only used to explain the present invention, and cannot be understood as limiting the present invention.

[0057] 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 positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0058] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] Figure 1 The injection device of some embodiments of the present invention is shown, which can inject liquid products such as medicines into a patient's body, wherein the injection device includes a guide, a metering sleeve 12, a transmission rod 14 and a connecting piece 15.

[0060] The guide piece is sleeved with the metering sleeve 12 , and the guide piece and the metering sleeve 12 are connected via a spiral guide structure, and the metering sleeve 12 can be screwed in or out relative to the guide piece.

[0061] Specifically, the spiral guide structure includes a first spiral structure 124 provided on the metering sleeve 12 and a second spiral structure 133 provided on the guide member, and the first spiral structure 124 and the second spiral structure 133 are threadedly matched.

[0062] In some embodiments, the guide member is a guide sleeve 13, the first spiral structure 124 is arranged on the inner wall of the metering sleeve 12, the second spiral structure 133 is arranged on the outer wall of the guide sleeve 13, the guide sleeve 13 is inserted into the metering sleeve 12, and the spiral structure 124 is threadedly connected to the second spiral structure 133.

[0063] Specifically, the metering sleeve 12 has a first end and a second end opposite to the first end. The guide sleeve 13 is inserted into the metering sleeve 12 from the first end of the metering sleeve 12 and the first spiral structure 124 is threadedly connected with the second spiral structure 133 .

[0064] In other embodiments, the guide member is a shell 11, the first spiral structure is arranged on the outer wall of the metering sleeve 12, the second spiral structure is arranged on the inner wall of the shell 11, the metering sleeve 12 is penetrated through the shell 11, and the first spiral structure is threadedly connected to the second spiral structure.

[0065] It can be understood that, since the metering sleeve 12 is threadedly connected to the guide member, when the metering sleeve 12 rotates relative to the guide member, the metering sleeve 12 can also move axially relative to the guide member.

[0066] Specifically, when the metering sleeve 12 rotates relative to the guide along the first rotation direction, the metering sleeve 12 can generate an axial displacement along the first direction relative to the guide and make the second end of the metering sleeve 12 gradually move away from the guide; when the metering sleeve 12 rotates relative to the guide along the second rotation direction, the metering sleeve 12 can generate an axial displacement along the second direction relative to the guide and make the second end of the metering sleeve 12 gradually approach the guide; wherein the first rotation direction is opposite to the second rotation direction. In other words, when the metering sleeve 12 rotates relative to the guide along the first rotation direction, the metering sleeve 12 is gradually screwed out, and when the metering sleeve 12 rotates relative to the guide along the second rotation direction, the metering sleeve 12 is gradually screwed in.

[0067] It should be noted that when adjusting the dose, the metering sleeve 12 rotates relative to the guide along the first rotation direction and moves axially along the first direction; when adjusting the dose or injecting liquid, the metering sleeve 12 rotates relative to the guide along the second rotation direction and moves axially along the second direction.

[0068] It should be further explained that if Figure 4 As shown, the outer surface of the metering sleeve 12 is provided with spiral scale lines 122, and the scale lines 122 can be real lines or virtual lines. In a specific embodiment, the scale values ​​of the identification scale are printed or pressed along the spiral direction of the spiral scale lines 122. In this way, by observing the scale values ​​arranged along the scale lines 122, the operator can easily understand the adjustment value of the dose.

[0069] like Figure 5 As shown, a plane perpendicular to the axis of the metering sleeve 12 is defined as a reference plane, and the first spiral structure 124 is configured to have at least one single spiral portion 1241, and the central angle of the projection of the single spiral portion 1241 on the reference plane is less than 360°.

[0070] It should be noted that the projection of the single spiral portion 1241 on the reference plane is less than 360°, indicating that the single spiral portion 1241 does not constitute a circle, and the single spiral portion 1241 can move spirally under the guidance of the second spiral structure 133, thereby realizing the function of the metering sleeve 12 rotating relative to the guide and moving axially, and the single spiral portion 1241 is shorter than the traditional spiral structure with a multi-turn structure.

[0071] Furthermore, the central angle of the projection of the single spiral portion 1241 on the reference plane is less than 360° and greater than or equal to 120°. In this way, a more stable cooperation between the single spiral portion 1241 and the second spiral structure 133 can be achieved.

[0072] Furthermore, the first helical structure 124 is configured to have two separated single helical portions 1241 , and the projections of the two single helical portions 1241 on the reference plane are symmetrically arranged.

[0073] It can be understood that by arranging the projections of the two single spiral portions 1241 on the reference plane symmetrically, when the two single spiral portions 1241 cooperate with the second spiral structure 133, the coaxiality between the metering sleeve 12 and the guide member can be improved.

[0074] The central angle of the projection of each single spiral portion 1241 on the reference plane is less than 180°, so that the length of each spiral portion 1241 can be reduced as much as possible.

[0075] In other embodiments, the second spiral structure 133 may be configured to have at least one single spiral portion, which can also realize the function of the metering sleeve 12 rotating relative to the guide member and moving axially.

[0076] Combination Figure 5 and Figure 6 The specific structures of the first helical structure 124 and the second helical structure 133 are further described below by way of example:

[0077] (1) In some embodiments, the first helical structure 124 is configured to have at least one single helical portion 1241 , the single helical portion 1241 is a single thread, and the second helical structure 133 is a helical groove, and the single thread is inserted into the helical groove.

[0078] (2) In some embodiments, the first helical structure 124 is a helical groove, and the second helical structure 133 is configured to have at least one single helical portion, where the single helical portion is a single thread, and the single thread is inserted into the helical groove.

[0079] (3) In some embodiments, the first helical structure 124 is a thread, and the second helical structure 133 is configured to have at least one single helical portion, the single helical portion is a single helical groove, and the thread is inserted into the single helical groove.

[0080] (4) In some embodiments, the first helical structure 124 is configured to have at least one single helical portion, the single helical portion is a single helical groove, and the second helical structure 133 is a thread, and the thread is inserted into the single helical groove.

[0081] In some embodiments, the first spiral structure 124 is configured to have at least one single spiral portion 1241, the single spiral portion 1241 is a single thread, the second spiral structure 133 is a spiral groove, the single thread is inserted into the spiral groove, and the projection of the single spiral portion 1241 on the reference plane does not overlap, nor does it overlap with the projection of any other single spiral portion 1241 on the reference plane.

[0082] It should be noted that the fact that the projections of the single spiral portion 1241 on the reference plane do not overlap means that the single spiral portion 1241 does not have two directly opposite parts in the axial direction of the metering sleeve 12 .

[0083] By ensuring that the projection of a single spiral portion 1241 on the reference plane does not overlap or overlap with the projection of any other single spiral portion 1241 on the reference plane, the metering sleeve 12 does not need to be subjected to a spiral core pulling operation after injection molding, thereby simplifying the process.

[0084] like Figures 14 to 16 As shown, the guide member is a guide sleeve 13, the first spiral structure 124 is arranged on the inner wall of the metering sleeve 12, the first spiral structure 124 is configured to have at least one single spiral portion 1241, and the single spiral portion 1241 is a single thread, and the second spiral structure 133 is an embodiment of a spiral groove:

[0085] During the process of injection molding of the metering sleeve 12, the inner wall structure of the metering sleeve 12 is formed with the help of the first mold core 24 and the second mold core 25, wherein one end of the first mold core 24 has a first half groove 241, and one end of the second mold core 251 has a second half groove 251. After the first mold core 24 and the second mold core 25 are connected, the first half groove 241 and the second half groove 251 can be pieced together to form a groove that can form a first spiral structure 124 after injection molding. In this way, when the injection molding is completed, it is only necessary to directly pull out the first mold core 24 and the second mold core 251 from both ends without the need for spiral core pulling, which makes the operation simpler.

[0086] It can also be understood that in an embodiment in which the guide member is used as the shell 11, the first spiral structure is arranged on the outer wall of the metering sleeve 12, the first spiral structure is configured to have at least one single spiral portion, and the single spiral portion is a single thread, and the second spiral structure is a spiral groove, in the process of injection molding the metering sleeve 12, the outer wall structure of the metering sleeve 12 can be formed with the help of the other two mold cores, and these two mold cores are also provided with two half grooves, and the half grooves of these two mold cores can piece together the grooves of the first spiral structure that can be formed after injection molding. In this way, when the injection molding is completed, it is only necessary to directly pull out the two mold cores from both ends, without the need for spiral core pulling, and the operation is simpler.

[0087] Similarly, it can be understood that in an embodiment where the second spiral structure 133 is configured to have at least one single spiral portion, the single spiral portion is a single thread, the first spiral structure is a spiral groove, the single thread is inserted into the spiral groove, and the projection of the single spiral portion on the reference plane does not overlap, nor does it overlap with the projection of any other single spiral portion on the reference plane, after the injection molding guide, the purpose of simplifying the operation can be achieved without the need for spiral core pulling.

[0088] like Figure 1 As shown, the transmission rod 14 is inserted into the metering sleeve 12 .

[0089] Specifically, the transmission rod 14 is inserted into the metering sleeve 12 from the second end of the metering sleeve 12 and then inserted into the guide sleeve 13 .

[0090] The transmission rod 14 is configured to: be able to move axially synchronously with the metering sleeve 12 and not rotate relative to the guide sleeve 13 when the metering sleeve 12 rotates along the first rotation direction relative to the guide sleeve 13 to adjust the dose, and be able to move axially synchronously with the metering sleeve 12 and not rotate relative to the guide sleeve 13 when the metering sleeve 12 rotates along the second rotation direction relative to the guide sleeve 13 to adjust the dose.

[0091] It should be noted that when the transmission rod 14 does not rotate relative to the guide sleeve 13, the injection device will not perform the push injection action. Therefore, when the metering sleeve 12 is rotated along the first rotation direction to adjust the dose or the metering sleeve 12 is rotated along the second rotation direction to call back the dose, it is necessary to ensure that the transmission rod 14 does not rotate relative to the guide sleeve 13.

[0092] Furthermore, the inner side wall of the guide sleeve 13 is provided with a first limiting portion 131, and the transmission rod 14 is provided with a second limiting portion 141. The first limiting portion 131 is located on the side of the second limiting portion 141 close to the second end of the metering sleeve 12, and the first limiting portion 131 is located on the moving path of the second limiting portion 141.

[0093] It can be understood that when the metering sleeve 12 is rotated in the first rotation direction to adjust the dose, the transmission rod 14 will move axially synchronously with the metering sleeve 12 so that the second limit portion 141 gradually approaches the first limit portion 131. When the second limit portion 141 abuts against the first limit portion 131, the metering sleeve 12 and the transmission rod 14 can be restricted from further axial movement relative to the guide sleeve 13. In this way, on the one hand, the transmission rod 14 can be restricted from coming out of the guide sleeve 13, and on the other hand, the maximum dose limit for a single adjustment can be achieved.

[0094] In the injection device of the present invention, by providing the first limiting portion 131 on the inner side wall of the guide sleeve 13 and the second limiting portion 141 on the transmission rod 14, the limiting of the guide sleeve 13 and the transmission rod 14 and the metering sleeve 12 can be achieved, which can prevent the metering sleeve 12 from coming out with the transmission rod 14, and has high reliability. In addition, compared with the solution of providing the relevant limiting structure between the metering sleeve 12 and the guide sleeve 13, there is no need to consider the threaded connection structure between the metering sleeve 12 and the guide sleeve 13, and the structure is simpler.

[0095] Combination Figure 1 and Figure 7 In some embodiments, the second limiting portion 141 is an elastic component, and the second limiting portion 141 can be compressed and deviate toward the axis of the transmission rod 14 to avoid the first limiting portion 131.

[0096] It can be understood that the second limiting portion 141 is elastic, can be deformed when subjected to an external force, and can be restored to its original position after the external force disappears.

[0097] When the second limiting portion 141 is in a normal state, the second limiting portion 141 and the first limiting portion 131 are in a relative state. When the metering sleeve 12 is rotated in the first rotation direction to adjust the dosage, the transmission rod 14 will move axially synchronously with the metering sleeve 12 to make the second limiting portion 141 close to the first limiting portion 131 until it abuts against the first limiting portion 131. In the process of assembling the transmission rod 14 and the guide sleeve 13, after the transmission rod 14 is inserted into the guide sleeve 13 from the end of the guide sleeve 13 close to the second end of the metering sleeve 12, the second limiting portion 141 can be forced to be subjected to pressure in the radial direction of the transmission rod 14, so that the second limiting portion 141 can avoid the first limiting portion 131, so that the second limiting portion 141 passes over the first limiting portion 131, so that the transmission rod 14 and the guide sleeve 13 are assembled.

[0098] Specifically, the first limiting portion 131 is arranged opposite to the second limiting portion 141, and the first limiting portion 131 has a first guide slope 1311 on the side away from the second limiting portion 141, and the second limiting portion 141 has a second guide slope 1413 on the side away from the first limiting portion 131. The first guiding slope 1311 and the second guiding slope 1413 are both gradually inclined toward the inner side wall of the guide sleeve 13 along the spacing direction from the second limiting portion 141 to the first limiting portion 131.

[0099] It can be understood that in the process of assembling the transmission rod 14 and the guide sleeve 13, after the transmission rod 14 is inserted into the guide sleeve 13 from one end of the guide sleeve 13 close to the second end of the metering sleeve 12, the first guide bevel 1311 and the second guide bevel 1413 will first contact, and as the transmission rod 14 continues to be inserted into the metering sleeve 12, under the extrusion of the first limiting portion 131, the second limiting portion 141 will be forced to be subjected to radial pressure along the transmission rod 14, so that the second limiting portion 141 passes over the first limiting portion 131, so that the transmission rod 14 and the guide sleeve 13 are completely assembled.

[0100] like Figure 7 As shown, further, the second limiting portion 141 is located at one end of the transmission rod 14 extending into the guide sleeve 13, and the second limiting portion 141 includes a first elastic arm 1411 and a first limiting buckle 1412 connected to the outer side wall of the first elastic arm 1411. Figure 1 The first limiting buckle 1412 is disposed opposite to the first limiting portion 131 . The second guiding inclined surface 1413 is disposed on a side of the first limiting buckle 1412 away from the first limiting portion 131 .

[0101] It can be understood that the first elastic arm 1411 is capable of elastic deformation. When the first limiting buckle 1412 is subjected to radial pressure along the transmission rod 14, the first elastic arm 1411 will shift toward the axis of the transmission rod 14, so that the first limiting buckle 1412 is shifted toward the axis of the transmission rod 14 to achieve the effect of avoiding the first limiting portion 131.

[0102] like Figure 7 As shown, there are multiple second limiting portions 141 , and the multiple second limiting portions 141 are arranged at intervals along the circumference of the transmission rod 14 .

[0103] It can be understood that there is a gap between every two adjacent second limiting portions 141 , and the gap can allow the first elastic arm 1411 of each second limiting portion 141 to deform.

[0104] like Figure 2As shown, a coupling member 15 is provided between the metering sleeve 12 and the transmission rod 14, and the coupling member 15 is configured to selectively couple or not couple the metering sleeve 12 and the transmission rod 14. In other words, the coupling member 15 can couple the metering sleeve 12 and the transmission rod 14 together, or not couple the metering sleeve 12 and the transmission rod 14 together.

[0105] Among them, the connecting piece 15 can not connect the metering sleeve 12 and the transmission rod 14 when the metering sleeve 12 rotates relative to the guide sleeve 13 to adjust or call back the dose, so that the metering sleeve 12 and the transmission rod 14 can rotate relative to each other; and the connecting piece 15 can connect the metering sleeve 12 and the transmission rod 14 into a synchronously movable whole when the transmission rod 14 is subjected to axial pressure to push the liquid.

[0106] It should be noted that when the metering sleeve 12 and the transmission rod 14 rotate relative to each other and the transmission rod 14 does not rotate relative to the guide sleeve 13, the injection device will not perform the push injection action. Therefore, when the metering sleeve 12 is rotated along the first rotation direction to adjust the dose or the metering sleeve 12 is rotated along the second rotation direction to call back the dose, it is necessary to ensure that the metering sleeve 12 and the transmission rod 14 rotate relative to each other and the transmission rod 14 does not rotate relative to the guide sleeve 13; and if the injection device needs to perform the push injection action, it is necessary to apply axial pressure to the end of the transmission rod 14 away from the guide sleeve 13, so that the coupling 15 combines the metering sleeve 12 and the transmission rod 14 into a synchronously movable whole, so that the transmission rod 14 and the metering sleeve 12 can both move axially together and rotate together.

[0107] The following is an explanation of the actions of the injection device in several different working modes:

[0108] (1) Dosage adjustment:

[0109] The metering sleeve 12 is operated to rotate along the first rotation direction relative to the guide sleeve 13, and the metering sleeve 12 is screwed outward. At this time, since the connecting piece 15 does not connect the metering sleeve 12 and the transmission rod 14, the transmission rod 14 moves out axially together with the metering sleeve 12 but does not rotate with the metering sleeve 12.

[0110] (2) Callback dose:

[0111] The metering sleeve 12 is operated to rotate along the second rotation direction relative to the guide sleeve 13, and the metering sleeve 12 is screwed inward. At this time, since the connecting piece 15 does not connect the metering sleeve 12 and the transmission rod 14, the transmission rod 14 moves axially inward under the drive of the metering sleeve 12 but does not rotate with the metering sleeve 12.

[0112] (3) Push injection of liquid:

[0113] Axial pressure is applied to the end of the transmission rod 14 away from the guide sleeve 13 so that the coupling 15 combines the metering sleeve 12 and the transmission rod 14 into a synchronously movable whole; wherein, in the process of applying axial pressure to the end of the transmission rod 14 away from the guide sleeve 13, since the metering sleeve 12 and the guide sleeve 13 are threadedly connected, at this time, the metering sleeve 12 and the transmission rod 14 will be screwed inward together.

[0114] It should be noted that, by controlling the thread lead angle of the spiral guide structure between the metering sleeve 12 and the guide sleeve 13, it is possible to achieve that when an axial pressure is applied to the end of the transmission rod 14 away from the guide sleeve 13, the metering sleeve 12 rotates relative to the guide sleeve 13 and moves axially. It is understandable that the larger the thread lead angle of the spiral guide structure between the metering sleeve 12 and the guide sleeve 13, the easier it is for the metering sleeve 12 to rotate relative to the guide sleeve 13 and move axially when an axial pressure is applied to the end of the transmission rod 14 away from the guide sleeve 13.

[0115] like Figure 2 As shown, in some embodiments, there is a first coupling structure 15a between the coupling member 15 and the metering sleeve 12, a second coupling structure 15b between the coupling member 15 and the transmission rod 14, and a third coupling structure 15c between the coupling member 15 and the transmission rod 14.

[0116] The first coupling structure 15a is configured to allow the metering sleeve 12 to rotate relative to the coupling member 15 in a first rotation direction, and to prevent the metering sleeve 12 from rotating relative to the coupling member 15 in a second rotation direction. In other words, the first coupling structure 15a enables the metering sleeve 12 and the coupling member 15 to rotate relative to each other when the metering sleeve 12 rotates relative to the guide sleeve 13 in the first rotation direction to adjust the dose, and enables the coupling member 15 to rotate synchronously with the metering sleeve 12 when the metering sleeve 12 rotates relative to the guide sleeve 13 in the second rotation direction to adjust the dose or when the transmission rod 14 is subjected to axial pressure to push the liquid.

[0117] The second coupling structure 15 b is configured to couple the transmission rod 14 and the coupling member 15 into a synchronously movable whole when the transmission rod 14 is subjected to axial pressure to push the liquid.

[0118] The third coupling structure 15c is configured to allow the coupling member 15 to rotate relative to the transmission rod 14 in the second rotation direction, and to prevent the coupling member 15 from rotating relative to the transmission rod 14 in the first rotation direction; in other words, the third coupling structure 15c can prevent the coupling member 15 and the transmission rod 14 from rotating relative to each other when the metering sleeve 12 is rotated relative to the guide sleeve 13 in the first rotation direction to adjust the dose, and can enable the coupling member 15 to rotate relative to the transmission rod 14 when the metering sleeve 12 is rotated relative to the guide sleeve 13 in the second rotation direction to adjust the dose.

[0119] It can be understood that when the metering sleeve 12 is operated to rotate relative to the guide sleeve 13 in the first rotation direction to adjust the dose, the metering sleeve 12 is not connected to the coupling member 15. At this time, the metering sleeve 12 will rotate relative to the coupling member 15. Naturally, the metering sleeve 12 will not drive the transmission rod 14 to rotate with the metering sleeve 12 through the coupling member 15. When the metering sleeve 12 is operated to rotate relative to the guide sleeve 13 in the second rotation direction to adjust the dose, the metering sleeve 12 is connected to the coupling member 15. At this time, the coupling member 15 will rotate with the metering sleeve 12, but the coupling member 15 is not connected to the transmission rod 14. Therefore, although the coupling member 15 rotates with the metering sleeve 12, it will not drive the metering sleeve 12 to rotate together. When the end of the transmission rod 14 away from the guide sleeve 13 is subjected to axial pressure to push the liquid, the transmission rod 14 and the connecting piece 15 are connected to form a synchronously movable whole, and at this time, the metering sleeve 12 rotates relative to the guide sleeve 13 along the second rotation direction under the action of the guide sleeve 13, so that the metering sleeve 12 and the connecting piece 15 are connected together, so that the metering sleeve 12, the transmission rod 14 and the connecting piece 15 form a synchronously rotating and axially moving whole.

[0120] In the injection device of the present invention, by integrating part of the clutch structure into the coupling member 15 , the structures of the metering sleeve 12 and the transmission rod 14 are simplified.

[0121] Combination Figure 2 , Figure 4 , Figure 5 and Fig.10 The connecting member 15 is sleeved on the outside of the transmission rod 14 and is located in the metering sleeve 12. The first connecting structure 15a includes a first gear ring 121 arranged on the inner wall of the metering sleeve 12, and a first elastic arm 151 arranged on the outer peripheral side of the connecting member 15. The first elastic arm 151 cooperates with the first gear ring 121 to form a ratchet mechanism.

[0122] It can be understood that the first elastic arm 151 is used as a pawl of the ratchet mechanism, and the first gear ring 121 is used as a ratchet of the ratchet mechanism. Under the action of the ratchet mechanism, the metering sleeve 12 can be rotated only in one direction relative to the coupling member 15. In this way, when the metering sleeve 12 rotates relative to the guide sleeve 13 along the first rotation direction to adjust the dose, the metering sleeve 12 and the coupling member 15 can be rotated relative to each other, and when the metering sleeve 12 rotates relative to the guide sleeve 13 along the second rotation direction to call back the dose or when the end of the transmission rod 14 away from the guide sleeve 13 is subjected to axial pressure to push the liquid, the coupling member 15 and the metering sleeve 12 can be rotated synchronously.

[0123] It should be noted that when the first ring gear 121 rotates relative to the first elastic arm 151, a first acoustic signal or a first tactile signal is generated, that is, when the operator rotates the metering sleeve 12 so that the metering sleeve 12 rotates relative to the guide sleeve 13 along the first rotation direction, the first ring gear 121 rotates relative to the first elastic arm 151, thereby emitting a first sound or allowing the operator to obtain a first tactile sensation.

[0124] Combination Figure 2 , Figure 7 , Figure 8 and Fig. 9 The second connecting structure 15b includes a clamping portion 146 arranged on the outer peripheral side of the transmission rod 14, and a second gear ring 152 arranged on the inner side of the connecting member 15, the clamping portion 146 is closer to the end of the transmission rod 14 away from the guide sleeve 13 than the second gear ring 152, and the tooth groove of the second gear ring 152 is arranged toward the end of the transmission rod 14 away from the guide sleeve 13; wherein the clamping portion 146 can extend into the tooth groove of the second gear ring 152 when the end of the transmission rod 14 away from the guide sleeve 13 is subjected to axial pressure to push the liquid.

[0125] It can be understood that when the clamping portion 146 does not extend into the tooth groove of the second gear ring 152, the transmission rod 14 and the coupling member 15 can rotate relative to each other, and when the clamping portion 146 extends into the tooth groove of the second gear ring 152, the transmission rod 14 and the coupling member 15 form a whole that can move synchronously. In this way, when the end of the transmission rod 14 away from the guide sleeve 13 is subjected to axial pressure to push the liquid, the transmission rod 14 and the coupling member 15 are connected to form a whole that moves synchronously, and at this time, the metering sleeve 12 rotates relative to the guide sleeve 13 along the second rotation direction under the action of the guide sleeve 13, so that the metering sleeve 12 and the coupling member 15 are connected together, so that the metering sleeve 12, the transmission rod 14 and the coupling member 15 form a whole that rotates synchronously and moves axially.

[0126] Combination Figure 2 , Figure 7 and Fig. 9 The third connecting structure 15c includes a second elastic arm 144 disposed on the outer wall of the transmission rod 14, and a third gear ring 153 disposed on the inner side of the connecting member 15, and the second elastic arm 144 cooperates with the third gear ring 153 to form a ratchet mechanism.

[0127] It can be understood that the second elastic arm 144 is used as a pawl of the ratchet mechanism, and the third gear ring 153 is used as a ratchet of the ratchet mechanism. Under the action of the ratchet mechanism, the transmission rod 14 can be rotated only in one direction relative to the coupling member 15. In this way, when the metering sleeve 12 rotates relative to the guide sleeve 13 along the first rotation direction to adjust the dose, the coupling member 15 and the transmission rod 14 cannot rotate relative to each other, and when the metering sleeve 12 rotates relative to the guide sleeve 13 along the second rotation direction to call back the dose, the coupling member 15 can rotate relative to the transmission rod 14.

[0128] It should be noted that when the second elastic arm 144 rotates relative to the third ring gear 153, a second acoustic signal or a second tactile signal is generated, that is, when the operator rotates the metering sleeve 12 so that the metering sleeve 12 rotates along the second rotation direction relative to the guide sleeve 13, the second elastic arm 144 rotates relative to the third ring gear 153, thereby emitting a second sound or allowing the operator to obtain a second tactile sensation.

[0129] The following is a further description of the actions of the injection device under several different working modes:

[0130] (1) Dosage adjustment:

[0131] The metering sleeve 12 is operated to rotate along the first rotation direction relative to the guide sleeve 13, and the metering sleeve 12 is screwed outward. At this time, the first connecting structure 15a makes the metering sleeve 12 and the connecting member 15 in a relatively rotatable relationship, and the transmission rod 14 is driven by the metering sleeve 12 to move out axially but does not rotate with the metering sleeve 12.

[0132] (2) Callback dose:

[0133] The metering sleeve 12 is operated to rotate along the second rotation direction relative to the guide sleeve 13, and the metering sleeve 12 is screwed inward. At this time, the first connecting structure 15a makes the metering sleeve 12 and the connecting member 15 in a connected state, and the second connecting structure 15b and the third connecting structure 15c make the connecting member 15 and the transmission rod 14 in a relatively rotatable relationship. The transmission rod 14 moves axially inward together with the metering sleeve 12 but does not rotate with the metering sleeve 12.

[0134] (3) Push injection of liquid:

[0135] When axial pressure is applied to the end of the transmission rod 14 away from the guide sleeve 13, the second connecting structure 15b connects the transmission rod 14 with the connecting piece 15, and the first connecting structure 15a connects the metering sleeve 12 with the connecting piece 15, so that the metering sleeve 12, the connecting piece 15 and the transmission rod 14 form a synchronously movable whole; wherein, in the process of applying axial pressure to the end of the transmission rod 14 away from the guide sleeve 13, since the metering sleeve 12 and the guide sleeve 13 are threadedly connected, at this time, the metering sleeve 12, the connecting piece 15 and the transmission rod 14 will be screwed inward together.

[0136] Combination Figure 1 and Figure 2 In some embodiments, a button cap 16 is connected to the second end of the metering sleeve 12, and the button cap 16 covers the end of the transmission rod 14 away from the guide sleeve 13, wherein axial pressure can be applied to the end of the transmission rod 14 away from the guide sleeve 13 by squeezing the button cap 16.

[0137] It should be noted that the button cap 16 is clamped with the second end of the metering sleeve 12, and the button cap 16 can drive the transmission rod 14 to move axially inward when the metering sleeve 12 rotates relative to the guide sleeve 13 along the second rotation direction, and the button cap 16 can rotate relative to the metering sleeve 12, and the button cap 16 can also make a smaller range of axial movement relative to the metering sleeve 12; in addition, the connecting piece 15 also drives the transmission rod 14 to move axially outward when the metering sleeve 12 rotates relative to the guide sleeve 13 along the first rotation direction.

[0138] The following is another explanation of the actions of the injection device under several different working modes:

[0139] (1) Dosage adjustment:

[0140] The metering sleeve 12 is operated to rotate along the first rotation direction relative to the guide sleeve 13, and the metering sleeve 12 is screwed outward and pushes the connecting piece 15 to drive the transmission rod 14 to move axially outward. However, in this process, due to the first connecting structure 15a, the metering sleeve 12 and the connecting piece 15 are in a relatively rotatable relationship, and the transmission rod 14 does not rotate with the metering sleeve 12.

[0141] (2) Callback dose:

[0142] The metering sleeve 12 is operated to rotate along the second rotation direction relative to the guide sleeve 13, and the metering sleeve 12 is screwed inward and drives the transmission rod 14 to move axially inward through the button cap 16. However, in this process, the first connecting structure 15a makes the metering sleeve 12 and the connecting member 15 in a connected state, and the second connecting structure 15b and the third connecting structure 15c make the connecting member 15 and the transmission rod 14 in a relatively rotatable relationship, and the transmission rod 14 does not rotate with the metering sleeve 12.

[0143] It should be noted that, in the process of calling back the dose, the metering sleeve 12 is directly operated to rotate relative to the guide sleeve 13 along the second rotation direction, and since the button cap 16 can perform a smaller range of axial movement and rotation relative to the metering sleeve 12, when the button cap 16 drives the transmission rod 14 to move axially inward, the button cap 16 will move and will not cause the second connecting structure 15b to connect the transmission rod 14 and the connecting member 15 together.

[0144] (3) Push injection of liquid:

[0145] Axial pressure is applied to the key cap 16, and the transmission rod 14 is connected to the coupling member 15 due to the second coupling structure 15b, while the metering sleeve 12 is connected to the coupling member 15 due to the first coupling structure 15a, so that the metering sleeve 12, the coupling member 15 and the transmission rod 14 form a synchronously movable whole; wherein, in the process of applying axial pressure to the key cap 16, since the metering sleeve 12 and the guide sleeve 13 are threadedly connected, at this time, the metering sleeve 12, the coupling member 15 and the transmission rod 14 will be screwed inward together.

[0146] It should be noted that after completing an action of pushing liquid, if it is necessary to adjust the dose again and then adjust the dose back, then in the process of adjusting the dose, that is, in the process of operating the metering sleeve 12 to rotate relative to the guide sleeve 13 along the second rotation direction: since the connecting member 15 and the metering sleeve 12 are connected together under the action of the first connecting structure 15a and can rotate with the metering sleeve 12, the connecting member 15 and the transmission rod 14 are not connected together under the action of the third connecting structure 15c, and since the button cap 16 is not subjected to axial pressure to squeeze the transmission rod 14, the clamping portion 146 in the second connecting structure 15b will be squeezed out of the tooth groove of the second gear ring 152, so that the second connecting structure 15b does not connect the connecting member 15 and the transmission rod 14, so that the transmission rod 14 does not rotate with the metering sleeve 12.

[0147] Next, the structure in which the transmission rod 14 does not rotate with the metering sleeve 12 when adjusting the dose and calling back the dose, but rotates together with the metering sleeve 12 when injecting the liquid is described:

[0148] Combination Figure 1 and Figure 2 The push injection device further includes a driving rod 21, which is inserted into the transmission rod 14, and the driving rod 21 and the transmission rod 14 can only move axially relative to each other but cannot rotate relative to each other.

[0149] Combination Figure 8 and Fig.12 Specifically, the transmission rod 14 is provided with an assembly channel, and the driving rod 21 is inserted into the assembly channel, wherein a first axial guide structure is provided between the transmission rod 14 and the driving rod 21, and the first axial guide structure is used to realize that the driving rod 21 and the transmission rod 14 can only move axially relative to each other but cannot rotate relative to each other.

[0150] More specifically, the first axial guiding structure includes an axial rib 147 arranged on the inner wall of the assembly channel, and an axial groove 212 arranged on the outer wall of the driving rod 21, and the axial rib 147 is penetrated in the axial groove 212, so that the driving rod 21 and the transmission rod 14 can only move axially relative to each other but cannot rotate relative to each other.

[0151] Combination Figure 3 , Figure 6 and Fig.12 Further, the driving rod 21 is connected to the guide member via a fourth coupling structure 21a, and the fourth coupling structure is configured to allow the driving rod 21 to rotate relative to the guide member in a second rotation direction and prevent the driving rod 21 from rotating relative to the guide member in a first rotation direction.

[0152] Specifically, the fourth connecting structure 21a includes a fourth gear ring 132 arranged on the inner wall of the guide sleeve 13, and a third elastic arm 211 arranged on the outer wall of the driving rod 21. The third elastic arm 211 cooperates with the fourth gear ring 132 to form a ratchet mechanism. The fourth connecting structure 21a is configured to only allow the driving rod 21 to rotate in the second rotation direction relative to the guide sleeve 13, but not allow the driving rod 21 to rotate in the first rotation direction relative to the guide sleeve 13.

[0153] During the process of adjusting the dose, the metering sleeve 12 is operated to rotate in the first rotation direction relative to the guide sleeve 13. At this time, under the action of the fourth coupling structure 21a, the drive rod 21 is not allowed to rotate relative to the guide sleeve 13. Since the transmission rod 14 cannot rotate relative to the drive rod 21 but can only move axially relative to it, the transmission rod 14 can only move axially outward under the drive of the metering sleeve 12.

[0154] During the process of calling back the dose, the metering sleeve 12 is operated to rotate in the second rotation direction relative to the guide sleeve 13. However, at this time, the torque indirectly applied by the metering sleeve 12 to the transmission rod 14 cannot overcome the resistance of the third elastic arm 211 in the fourth connecting structure 21a to escape from the fourth gear ring 132. Since the transmission rod 14 cannot rotate relative to the drive rod 21 but can only move axially relatively, the transmission rod 14 can only move axially inwardly driven by the metering sleeve 12.

[0155] During the process of pushing the liquid, axial pressure is applied to the button cap 16, and the connecting piece 15 makes the metering sleeve 12, the connecting piece 15 and the transmission rod 14 form a synchronously movable whole. During the process of applying axial pressure to the button cap 16, since the metering sleeve 12 and the guide sleeve 13 are threadedly connected, and at this time the fourth connecting structure 21a allows the drive rod 21 to rotate along the second rotation direction relative to the guide sleeve 13, and since the transmission rod 14 cannot rotate relative to the drive rod 21 but can only move axially relative to it, the metering sleeve 12, the connecting piece 15, the transmission rod 14 and the drive rod 21 will be screwed inward together.

[0156] It should be noted that when the third elastic arm 211 rotates relative to the fourth ring gear 132, a third acoustic signal or a third tactile signal will be generated, that is, when the operator applies axial pressure to the key cap 16, the third elastic arm 211 will rotate relative to the fourth ring gear 132, thereby emitting a third sound or allowing the operator to obtain a third tactile sensation.

[0157] The rotation of the driving rod 21 can realize the push injection of the liquid.

[0158] like Figures 1 to 3 As shown, specifically, the guide sleeve 13 is fixedly inserted into the shell 11, and the guide sleeve 13 will not move relative to the shell 11; the metering sleeve 12 is inserted into the shell 11 and the guide sleeve 13 is inserted from its first end, and the metering sleeve 12 can be screwed in or out; the transmission rod 14 is inserted into the metering sleeve 12 from the second end of the metering sleeve 12 and extends into the guide sleeve 13; a driving rod 21 is inserted into the transmission rod 14, and the driving rod 21 and the transmission rod 14 can only move axially relative to each other but cannot rotate relative to each other; a push rod 22 is inserted into the drive rod 21, and the push rod 22 and the transmission rod 14 can only move axially relative to each other but cannot rotate relative to each other; a nut 23 is also fixed in the shell 11, and the push rod 22 is inserted into the nut 23 and is threadedly connected with the nut 23.

[0159] Among them, the guide sleeve 13 is fixed to the shell 11; in some embodiments, the guide sleeve 13 and the shell 11 are an integrated cylindrical structure with an inner cylinder and an outer cylinder, wherein the inner cylinder serves as the guide sleeve 13, and the outer cylinder serves as the shell 11, and there is a distance between the two for the installation of the metering sleeve 12; in other embodiments, the guide sleeve 13 and the shell 11 are arranged separately, and can be relatively fixed by means of snap connection, threaded connection or welding.

[0160] When injecting liquid, the metering sleeve 12, the transmission rod 14, the drive rod 21 and the push rod 22 will rotate together. Since the push rod 22 and the nut 23 are threadedly connected, the push rod 22 will be screwed out when rotating relative to the nut 23 to push liquid. When adjusting the dose and calling back the dose, the transmission rod 14 and the drive rod 21 do not rotate with the metering sleeve 12. Therefore, the drive rod 21 will not drive the push rod 22 to rotate. Naturally, the push rod 22 will not move axially to push liquid.

[0161] like Fig.12 , Fig.13 As shown, it should be noted that there is a second axial guide structure between the driving rod 21 and the push rod 22, and the second axial guide structure enables the push rod 22 and the transmission rod 14 to only move axially relative to each other but not to rotate relative to each other.

[0162] Specifically, the driving rod 21 is provided with a channel 213 for the push rod 22 to pass through, and the second axial guiding structure includes a first axial plane 2131 provided on the side wall of the channel 213, and a second axial plane 221 provided on the outer wall of the push rod 22. The first axial plane 2131 is in contact with the second axial plane 221, so that the push rod 22 and the transmission rod 14 can only move axially relative to each other but cannot rotate relative to each other.

[0163] like Figure 2 As shown, in some embodiments, the transmission rod 14 is provided with a vent hole 143 connected to the interior thereof, and the vent hole 143 is used to connect the interior of the transmission rod 14 with the outside, so that holding of breath can be avoided, thereby reducing the resistance of push injection.

[0164] It should be noted that the vent hole 143 is opened at one end of the transmission rod 14 close to the key cap 16, and there is a gap between the key cap 16 and the metering sleeve 12. The gas inside the transmission rod 14 can be discharged through the vent hole 143 and the gap between the key cap 16 and the metering sleeve 12 in turn.

[0165] Combination Figure 1 and Figure 2In some embodiments, the injection device further includes a metering member 17, which is sleeved outside the transmission rod 14 and located inside the metering sleeve 12, and the metering member 17 is located on one side of the guide sleeve 13 close to the second end of the metering sleeve 12. The metering member 17 moves axially relative to the transmission rod 14 along the transmission rod 14 when adjusting or calling back the dose.

[0166] It should be noted that the metering member 17 is used to record the value of each dose adjustment or dose call-back. Specifically, each time the dose is adjusted, the metering member 17 moves in a first direction relative to the transmission rod 14, and each time the dose is called back, the metering member 17 moves in a second direction opposite to the first direction relative to the transmission rod 14.

[0167] An injection operation consists of adjusting the dose, calling back the dose (if such operation exists), and pushing the liquid. For each injection operation, the metering member 17 will move relative to the transmission rod 14 only when the dose is adjusted and called back. Therefore, after multiple injection operations, the movement of the metering member 17 will be accumulated.

[0168] It can be understood that if a total of 300 units of medicine are configured in the injection device, the movement stroke of the metering member 17 can be considered to be 300 movement amounts adapted to 300 units of medicine; during the first injection operation, the first injection amount is 20 units by adjusting the dose, at this time, the movement amount of the metering member 17 is 20, which can represent 20 units of medicine; during the second injection operation, the second injection amount is 30 units by adjusting the dose, at this time, the movement amount of the metering member 17 is 30, which can represent 30 units of medicine, and the total movement amount of the metering member 17 at this time is 50 movement amounts representing 50 units of medicine. By analogy, each injection amount adjusted will be gradually accumulated and recorded by the metering member 17. If the total movement amount of the metering member 17 has reached 290 movement amounts before the last dose adjustment, the last dose adjustment can only be adjusted to 10 units of medicine at most.

[0169] Furthermore, one of the transmission rod 14 and the metering sleeve 12 is threadedly connected to the metering member 17 , and the other is axially slidingly matched with the metering member 17 .

[0170] It is understandable that, in the process of adjusting or calling back the dosage, the metering sleeve 12 and the transmission rod 14 move axially synchronously, but the two move relative to each other. Therefore, by making one of the transmission rod 14 and the metering sleeve 12 threadedly connected to the metering member 17 and the other axially slidingly cooperating with the metering member 17, the metering member 17 can be moved along the axial direction of the transmission rod 14 relative to the transmission rod 14 during the process of adjusting or calling back the dosage. Since the metering sleeve 12 and the transmission rod 14 can not only move axially synchronously but also rotate together during the process of pushing the liquid, the metering member 17 will not move along the axial direction of the transmission rod 14 relative to the transmission rod 14 during this process. In this way, for multiple injection operations, the injection volume of each time will be gradually accumulated and recorded by the metering member 17.

[0171] like Figure 2 As shown, in some embodiments, the metering sleeve 12 is slidably matched with the metering member 17, and the transmission rod 14 is threadedly connected with the metering member 17.

[0172] Combination Figure 2 , Figure 4 and Fig.11 Specifically, one of the metering sleeve 12 and the metering piece 17 is provided with an axial guide groove 171, and the other is provided with an axial guide bar 123 passing through the axial guide groove 171; the transmission rod 14 has a threaded section 142 with an external thread, and the metering piece 17 is provided with a screw hole with an internal thread, and the threaded section 142 passes through the screw hole and threadedly connects the transmission rod 14 and the metering piece 17.

[0173] In other embodiments, the transmission rod 14 and the metering member 17 are slidably matched, and the metering sleeve 12 is threadedly connected to the metering member 17 .

[0174] Specifically, the transmission rod 14 and the metering piece 17 are slidably matched, one of the transmission rod 14 and the metering piece 17 is provided with an axial guide groove, and the other is provided with an axial guide strip passing through the axial guide groove 171; the metering sleeve 12 has a threaded section with an internal thread, and the metering piece 17 is provided with an external thread. The metering piece 17 is passed through the threaded section and the metering sleeve 12 and the metering piece 17 are threadedly connected.

[0175] like Figure 2 As shown, in some embodiments, the transmission rod 14 is provided with two extreme position limit portions 145 spaced apart along the axial direction of the transmission rod 14 , the two extreme position limit portions 145 are both located on the side of the guide sleeve 13 close to the second end of the metering sleeve 12 , and the metering element 17 is located between the two extreme position limit portions 145 .

[0176] In another embodiment, the two extreme position limiting portions 145 are both disposed on the inner wall of the metering sleeve 12 .

[0177] It can be understood that the two extreme position limit parts 145 are used to limit the two extreme positions of the measuring piece 17. When the measuring piece 17 is at the "0 scale" position, the measuring piece 17 is against one of the extreme position limit parts 145. When the measuring piece 17 is at the "highest scale" position, the measuring piece 17 is against the other extreme position limit part 145.

[0178] In the injection device of the present invention, by providing two extreme position limit portions 145, when assembling the metering member 17, it is only necessary to ensure that the metering member 17 is abutted against the extreme position limit portion 145 representing the "0 scale" position, thereby reducing the risk of deviation in the initial position of the metering member 17. In addition, by providing the two extreme position limit portions 145 on the same component (the metering sleeve 12 or the transmission rod 14), manufacturing is facilitated.

[0179] Combination Figure 2 and Figure 7 In some embodiments, two extreme position limit portions 145 are both arranged on the transmission rod 14; at least one extreme position limit portion 145 is an elastic component, which can be compressed and deviate toward the axis of the transmission rod 14 to avoid the metering member 17 so that the metering member 17 can pass over the elastic component.

[0180] It can be understood that the elastic component has elasticity, can be deformed when subjected to external force, and can be restored after the external force disappears.

[0181] For the limit position limiting part 145 which is an elastic member, when it is in a normal state, it is in a relative state with the metering member 17, and when the metering member 17 moves toward the limit position limiting part 145, the limit position limiting part 145 can block the metering member 17. In the process of assembling the metering member 17 and the transmission rod 14, after the metering member 17 is inserted into the transmission rod 14, the limit position limiting part 145 can be avoided by forcing the elastic limit position limiting part 145 to be subjected to the radial pressure of the transmission rod 14, so that the metering member 17 is assembled between the two limit position limiting parts 145.

[0182] Furthermore, among the two extreme position limiting portions 145, one of the extreme position limiting portions 145 is a first extreme position limiting portion 1451, and the other is a second extreme position limiting portion 1452. The first extreme position limiting portion 1451 is closer to the end of the transmission rod 14 extending into the guide sleeve 13 than the second extreme position limiting portion 1452. The first extreme position limiting portion 1451 is an elastic component, and the metering member 17 can be inserted into the transmission rod 14 from the end of the transmission rod 14 extending into the guide sleeve 13, and is assembled between the two extreme position limiting portions 145 after squeezing the first extreme position limiting portion 1451.

[0183] Specifically, the first extreme position limiting portion 1451 has a third guiding inclined surface 14511 , and the third guiding inclined surface 14511 gradually inclines toward the inner side wall of the metering sleeve 12 along the spacing direction from the first extreme position limiting portion 1451 to the second extreme position limiting portion 1452 .

[0184] It can be understood that in the process of assembling the metering piece 17 and the transmission rod 14, after the metering piece 17 is inserted into the transmission rod 14 from one end of the transmission rod 14 close to the guide sleeve 13, the metering piece 17 will first contact the third guide slope 14511, and as the metering piece 17 continues to move axially toward the transmission rod 14, under the extrusion of the metering piece 17, the first extreme position limit portion 1451 will be forced to be subjected to radial pressure along the transmission rod 14, so that the metering piece 17 passes over the first extreme position limit portion 1451, so that the metering piece 17 is assembled between the two extreme position limit portions 145.

[0185] Furthermore, the first extreme position limiting portion 1451 includes a second elastic arm 1451 a and a second limiting buckle 1451 b connected to an outer side wall of the second elastic arm 1451 a , and the second limiting buckle 1451 b is arranged opposite to the second extreme position limiting portion 1452 .

[0186] It can be understood that the second elastic arm 1451a is capable of elastic deformation. When the second limit buckle 1451b is subjected to radial pressure along the transmission rod 14, the second elastic arm 1451a will shift toward the axis of the transmission rod 14, so that the second limit buckle 1451b will shift toward the axis of the transmission rod 14 to achieve the effect of avoiding the measuring piece 17.

[0187] There are multiple first limit position limiting portions 1451 , and the multiple first limit position limiting portions 1451 are arranged at intervals along the circumference of the transmission rod 14 .

[0188] It can be understood that there is a gap between every two adjacent first extreme position limiting portions 1451 , and the gap can allow the second elastic arm 1451 a of each first extreme position limiting portion 1451 to deform.

[0189] Specifically in this embodiment, two extreme position limiting portions 145 are respectively arranged at the two ends of the thread segment 142. In this way, the metering member 17 can be restricted on the thread segment 142, ensuring that the metering member 17 can accurately measure the dosage.

[0190] The following is a description of the assembly method of the injection device:

[0191] like Figures 1 to 3As shown, first, the coupling member 15 is inserted into the transmission rod 14 from one end of the transmission rod 14 close to the second limit portion 141, and then the metering member 17 is screwed into the transmission rod 14 from one end of the transmission rod 14 close to the second limit portion 141, and then the transmission rod 14 is installed into the metering sleeve 12, and then the button cap 16 is pressed into the second end of the metering sleeve 12 to complete the assembly of the first component;

[0192] Then, the guide sleeve 13 is pressed into the housing 11, and then the drive rod 21 is installed into the guide sleeve 13. After that, the nut 23 is screwed into the push rod 22, and then the push rod 22 is pressed into the drive rod 21, and the assembly of the second component is completed.

[0193] Finally, the first component is assembled with the second assembly.

[0194] The injection device of the present invention is easy to assemble and can be assembled by only the hands of an operator without the aid of any tools.

[0195] The following are some different working modes of the injection device:

[0196] (1) Dosage adjustment:

[0197] The metering sleeve 12 is operated to rotate along the first rotation direction relative to the guide sleeve 13, and the metering sleeve 12 is screwed outward and pushes the connecting piece 15 to drive the transmission rod 14 to move axially outward. However, in this process, since the metering sleeve 12 and the connecting piece 15 are in a relatively rotatable relationship, the transmission rod 14 does not rotate with the metering sleeve 12.

[0198] (2) Callback dose:

[0199] The metering sleeve 12 is operated to rotate in the second rotation direction relative to the guide sleeve 13, and the metering sleeve 12 is screwed inward and drives the transmission rod 14 to move axially inward through the key cap 16. However, in this process, since the metering sleeve 12 and the connecting piece 15 are in a connected state, and the connecting piece 15 and the transmission rod 14 are in a relatively rotatable relationship, the transmission rod 14 does not rotate with the metering sleeve 12.

[0200] (3) Push injection of liquid:

[0201] Axial pressure is applied to the key cap 16, and the transmission rod 14 is connected to the connecting piece 15, and the metering sleeve 12 is connected to the connecting piece 15, so that the metering sleeve 12, the connecting piece 15 and the transmission rod 14 form a synchronously movable whole; wherein, in the process of applying axial pressure to the key cap 16, since the metering sleeve 12 and the guide sleeve 13 are threadedly connected, at this time, the metering sleeve 12, the connecting piece 15 and the transmission rod 14 will be screwed inward together, thereby driving the drive rod 21 to rotate but without axial movement, and since the push rod 22 and the nut 23 are threadedly connected, the push rod 22 will rotate relative to the nut 23 under the action of the drive rod 21 and screw out to push liquid.

[0202] In the description of this specification, the description with reference to the terms "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 the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0203] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An injection device, characterized in that: include: guides; A metering sleeve, which is sleeved with the guide member and connected with the guide member through a spiral guide structure; A transmission rod is inserted into the metering sleeve; A coupling member, arranged between the metering sleeve and the transmission rod, wherein a first coupling structure is provided between the coupling member and the metering sleeve, and a second coupling structure and a third coupling structure are provided between the coupling member and the transmission rod; The first coupling structure is configured to: allow the metering sleeve to rotate relative to the coupling member in a first rotation direction, and prevent the metering sleeve from rotating relative to the coupling member in a second rotation direction opposite to the first rotation direction; wherein, when the metering sleeve is rotated relative to the guide member in the first rotation direction to adjust the dose, the metering sleeve rotates relative to the coupling member in the first rotation direction and generates a first acoustic signal and / or a first tactile signal; The second coupling structure is configured to: when the transmission rod is subjected to axial pressure to push the liquid, the transmission rod and the coupling member are coupled to form a synchronously movable whole; The third coupling structure is configured to allow the coupling member to rotate relative to the transmission rod along the second rotation direction, and to prevent the coupling member from rotating relative to the transmission rod along the first rotation direction; wherein, when the metering sleeve rotates relative to the guide member along the second rotation direction to call back the dose, it drives the coupling member to rotate relative to the transmission rod along the second rotation direction and generate a second acoustic signal and / or a second tactile signal.

2. The injection device according to claim 1, characterized in that The first coupling structure comprises a first gear ring disposed on the inner wall of the metering sleeve, and a first elastic arm disposed on the outer peripheral side of the coupling member, and the first elastic arm cooperates with the first gear ring to form a ratchet mechanism; Wherein, when the first gear ring rotates relative to the first elastic arm, a first acoustic signal and / or a first tactile signal is generated.

3. The injection device according to claim 1, characterized in that The second coupling structure includes a clamping portion disposed on the outer peripheral side of the transmission rod, and a second gear ring disposed on the inner side of the coupling member, wherein the clamping portion is disposed toward the second gear ring; Wherein, the clamping portion can extend into the tooth groove of the second gear ring when the transmission rod is subjected to axial pressure to push the liquid.

4. The injection device according to claim 1, characterized in that The third coupling structure comprises a second elastic arm disposed on the outer side wall of the transmission rod, and a third gear ring disposed on the inner side of the coupling member, wherein the second elastic arm cooperates with the third gear ring to form a ratchet mechanism; Wherein, when the second elastic arm rotates relative to the third gear ring, a second acoustic signal and / or a second tactile signal is generated.

5. The injection device according to claim 1, characterized in that It also includes a driving rod passing through the transmission rod, and an axial guiding structure is provided between the driving rod and the guide member; The driving rod is connected to the guide member via a fourth coupling structure, and the fourth coupling structure is configured to: allow the driving rod to rotate relative to the guide member along the second rotation direction, and prevent the driving rod from rotating relative to the guide member along the first rotation direction; The fourth coupling structure includes a fourth gear ring arranged on the guide member, and a third elastic arm arranged on the driving rod, and the third elastic arm cooperates with the fourth gear ring to form a ratchet mechanism.

6. The injection device according to claim 5, characterized in that When the third elastic arm rotates relative to the fourth gear ring, a third acoustic signal and / or a third tactile signal is generated.

7. The injection device according to claim 5, characterized in that The transmission rod is provided with a vent hole communicated with the interior thereof.

8. The injection device according to claim 1, characterized in that The guide member is configured as a guide sleeve, the guide sleeve is inserted into the metering sleeve from a first end of the metering sleeve, and the transmission rod is inserted into the metering sleeve from a second end of the metering sleeve and into the guide sleeve; The spiral guide structure includes a first spiral structure arranged on the inner wall of the metering sleeve and a second spiral structure arranged on the outer wall of the guide sleeve, and the second spiral structure is threadedly matched with the first spiral structure.

9. The injection device according to claim 8, characterized in that The first helical structure or the second helical structure is configured to have two separate single helical portions; A plane perpendicular to the axis of the metering sleeve is defined as a reference plane, the central angle of the projection of the single spiral portion on the reference plane is less than or equal to 180°, and the projections of the two single spiral portions on the reference plane are symmetrically arranged.

10. The injection device according to claim 1, characterized in that It also includes a metering piece, which is sleeved outside the transmission rod and located inside the metering sleeve; Wherein, one of the transmission rod and the metering sleeve is threadedly connected to the metering member, and the other is axially slidingly matched with the metering member.

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