Prefilled drug injection device

Abstract

The utility model relates to the technical field of automatic injection, in particular to a preloaded medicine injection device which comprises a liquid pushing mechanism. The threaded sleeve is arranged in the fixed sleeve in a sleeving manner; the push rod is located in the threaded sleeve; a connecting part is arranged at one end, opposite to the needle inserting direction, of the push rod and is in threaded connection with the interior of the threaded sleeve; the connecting sleeve is connected to one end, facing the needle inserting direction, of the fixed sleeve; a connecting cavity is formed in the end, facing the needle inserting direction, of the connecting sleeve, a rotation stopping hole is formed in one end of the connecting sleeve, and one end of the push rod penetrates through the rotation stopping hole to be located in the connecting cavity. The push rod is in anti-rotation sliding fit with the anti-rotation hole; the liquid pushing motor is located at one end of the threaded sleeve. And the rotation of the rotating shaft and the axis of the push rod are on the same straight line, so that a torsion error possibly caused by a structure in the background technology is avoided, the accurate control of the liquid pushing motor on the push rod is further ensured, and finally accurate liquid injection is realized.

Description

Technical Field

[0001] The present application relates to the technical field of automated injection, and in particular to a pre-filled drug injection device. Background Art

[0002] Pre-filled medicine tubes are essential professional tools in the medical industry and can be used for injections, dispensing medicines, etc. Traditionally, they are usually operated by people holding the pre-filled medicine tubes. With the continuous development of science and technology and the medical industry, pre-filled medicine tubes are no longer operated by people holding them alone, but are combined with automated equipment such as needle insertion and liquid injection at a specific rate to ensure accuracy during the operation.

[0003] A traditional preloaded medicine tube includes a needle pushing mechanism and a liquid pushing mechanism. The liquid pushing mechanism is usually provided with a structure for clamping the preloaded medicine tube. In order to facilitate the independent clamping of the piston and the outer sleeve of the preloaded medicine tube, the axis of the entire preloaded medicine tube is usually not in the same straight line as the axis of the liquid pushing mechanism motor, so that the actual stroke of the liquid pushing mechanism cannot be highly unified with the driving stroke of the motor, which often leads to a certain liquid pushing error. Utility Model Content

[0004] In order to solve the above technical problems or partially solve the above technical problems, the present application provides a pre-filled drug injection device.

[0005] The present application provides a pre-filled drug injection device, including a liquid pushing mechanism, wherein the liquid pushing mechanism includes:

[0006] Fixed sleeve;

[0007] A threaded sleeve, wherein the threaded sleeve is sleeved inside the fixed sleeve and is coaxially rotated with the fixed sleeve;

[0008] A push rod, the push rod is located inside the threaded sleeve; a connecting portion is provided at one end of the push rod facing away from the needle insertion direction, and the connecting portion is threadedly connected to the inner wall of the threaded sleeve;

[0009] A connecting sleeve is connected to the end of the fixed sleeve facing the needle insertion direction; a connecting cavity is provided at the end of the connecting sleeve facing the needle insertion direction, a rotation-stopping hole is provided at the end of the connecting sleeve facing away from the needle insertion direction, and the end of the push rod facing the needle insertion direction passes through the rotation-stopping hole and is located in the connecting cavity; the push rod is in rotation-stopping sliding cooperation with the rotation-stopping hole;

[0010] A liquid pushing motor, the liquid pushing motor is located at one end of the threaded sleeve facing away from the needle insertion direction, and the transmission end of the liquid pushing motor is in transmission connection with the threaded sleeve;

[0011] A pre-loaded medicine tube, wherein one end of the pre-loaded medicine tube facing away from the needle insertion direction is detachably connected in the connecting cavity; one end of the push rod located in the connecting cavity is used to abut against the piston of the pre-loaded medicine tube.

[0012] Optionally, the fluid pushing motor is partially sleeved in a section of the fixed sleeve facing away from the needle insertion direction;

[0013] A connecting hole is provided at one end of the threaded sleeve facing away from the needle insertion direction, and the rotating shaft of the liquid pushing motor is inserted into the connecting hole and is in anti-rotation cooperation with the connecting hole.

[0014] Optionally, a bearing is sleeved on the outer peripheral wall of the threaded sleeve, and an outer ring of the bearing is sleeved inside the fixed sleeve.

[0015] Optionally, the radial cross section of the anti-rotation hole is in the shape of a straight slot;

[0016] And / or, a push block is provided at one end of the push rod facing the needle insertion direction.

[0017] Optionally, a zero-position protrusion is provided on a section of the push rod facing the needle insertion direction, a trigger switch is embedded in the inner wall of the stop hole, and a trigger pressing end of the trigger switch is located in the stop hole. When the zero-position protrusion abuts against the trigger pressing end during the movement of the push rod in the direction away from the needle insertion direction, the push rod is in a zero-position state.

[0018] Optionally, one end of the pre-filled medicine tube facing away from the needle insertion direction is threadedly connected to the connecting cavity.

[0019] Optionally, the end of the pre-filled medicine tube facing away from the needle insertion direction is plugged into the connecting cavity.

[0020] Optionally, it also includes a base plate and a push pin mechanism;

[0021] The pin-pushing mechanism comprises a pin-pushing motor, a lead screw and a sliding nut. The driving end of the pin-pushing motor is drivingly connected to the lead screw. The sliding nut is sleeved on the lead screw. The sliding nut and the base plate are slidably matched along the length direction of the lead screw.

[0022] Optionally, a bearing support is provided on the base plate, a linear bearing is sleeved inside the bearing support, an outer shell sleeve is sleeved outside the connecting sleeve and the fixing sleeve, and the outer shell sleeve is sleeved inside the linear bearing;

[0023] The sliding nut is connected to an end of the fixing sleeve facing away from the needle insertion direction.

[0024] Optionally, a support seat is provided on the base plate, and one end of the lead screw facing away from the pin-pushing motor passes through the support seat and rotates with the support seat;

[0025] A first bevel gear is provided at one end of the lead screw facing away from the needle pushing motor; an adjusting shaft is rotatably provided on the support seat, the axial direction of the adjusting shaft is perpendicular to the needle insertion direction, a second bevel gear is provided on the adjusting shaft, and the first bevel gear is in driving engagement with the second bevel gear.

[0026] Compared with the prior art, the technical solution provided by the embodiments of the present application has the following advantages:

[0027] The pre-filled injection device provided in the present application has a liquid pushing motor arranged at the end of the threaded sleeve facing away from the needle insertion direction, and the transmission end of the liquid pushing motor, that is, the axis of the rotating shaft and the axis of the push rod coincide with each other. The rotation of the rotating shaft and the axis of the push rod are on the same straight line, and there is no radial distance between the rotating shaft and the threaded sleeve, thereby avoiding the torque error that may be caused by the structure in the background technology, further ensuring the precise control of the push rod by the liquid pushing motor, and ultimately precise injection. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0029] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0030] Figure 1 It is a schematic diagram of the explosion structure of the liquid pushing structure in the pre-filled medicine injection device according to the embodiment of the present application;

[0031] Figure 2 This is a schematic diagram of the structure of the pre-filled drug injection device described in an embodiment of the present application;

[0032] Figure 3 This is a schematic structural diagram of the pre-filled drug injection device according to an embodiment of the present application from another perspective;

[0033] Figure 4 This is a schematic diagram of the top view of the pre-filled drug injection device according to an embodiment of the present application;

[0034] Figure 5 It is a cross-sectional view of the liquid pushing structure of the pre-filled injection device described in an embodiment of the present application.

[0035] in,

[0036] 10. Fixed sleeve; 100. Through hole; 11. Threaded sleeve; 110. Connecting hole; 12. Push rod; 120. Connecting part; 121. Push block; 122. Zero position protrusion; 13. Connecting sleeve; 130. Anti-rotation hole; 131. Trigger switch; 132. Press column; 133. Connecting chamber; 14. Liquid push motor; 15. Pre-loaded medicine tube; 16. Rotating shaft support; 17. Shell sleeve; 18. Bearing support; 19. Bearing; 20. Push needle motor; 21. Lead screw; 22. Sliding nut; 23. Sliding block; 24. Zero position switch; 25. Support; 3. Base plate; 30. Slide groove; 31. Sliding groove; 4. L-shaped plate; 5. Support seat; 50. First mounting plate; 51. Second mounting plate; 52. First bevel gear; 53. Adjusting shaft; 54. Second bevel gear. DETAILED DESCRIPTION

[0037] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the scheme of the present application will be further described below. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0038] In the following description, many specific details are set forth to facilitate a full understanding of the present application, but the present application may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only part of the embodiments of the present application, rather than all of the embodiments.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0040] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0041] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0042] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0043] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0044] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0045] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like 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 an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0046] Reference Figure 1 and Figure 5As shown, a pre-filled injection device provided in this embodiment includes a liquid pushing mechanism, which includes: a fixed sleeve 10; a threaded sleeve 11, the threaded sleeve 11 is sleeved inside the fixed sleeve 10, and is coaxially rotated with the fixed sleeve 10; a push rod 12, the push rod 12 is located inside the threaded sleeve 11; a connecting portion 120 is provided at one end of the push rod 12 facing away from the needle insertion direction, and the connecting portion 120 is threadedly connected to the inner wall of the threaded sleeve 11; a connecting sleeve 13, connected to one end of the fixed sleeve 10 facing the needle insertion direction; a connecting cavity 13 is provided at one end of the connecting sleeve 13 facing the needle insertion direction 3. A stop hole 130 is provided at one end of the connecting sleeve 13 facing away from the needle insertion direction, and one end of the push rod 12 facing the needle insertion direction passes through the stop hole 130 and is located in the connecting cavity 133; the push rod 12 and the stop hole 130 are in anti-rotation sliding cooperation; the liquid pushing motor 14 is located at one end of the threaded sleeve 11 facing away from the needle insertion direction, and the transmission end of the liquid pushing motor 14 is in transmission connection with the threaded sleeve 11; the pre-loaded medicine tube 15, the end of the pre-loaded medicine tube 15 facing away from the needle insertion direction is detachably connected in the connecting cavity 133; the end of the push rod 12 located in the connecting cavity 133 is used to abut the piston of the pre-loaded medicine tube 15.

[0047] The threaded sleeve 11 is entirely located inside the fixed sleeve 10, and can rotate concentrically relative to the fixed sleeve 10 under the action of external force; the push rod 12 is located inside the threaded sleeve 11, and with the cooperation of the connecting portion 120 and the threaded sleeve 11, the push rod 12 will move along the axial direction of the push rod 12 inside the threaded sleeve 11. Specifically, the radial dimension of the connecting portion 120 is larger than the radial dimension of the push rod 12, thereby avoiding interference between the push rod 12 and the inner wall of the threaded sleeve 11 during movement.

[0048] The connecting sleeve 13 is a columnar structure, and the connecting cavity 133 is open at one end face of the connecting sleeve 13 facing the needle insertion direction. One end of the anti-rotation hole 130 is open at one end face of the connecting sleeve 13 facing away from the needle insertion direction, and the other end of the anti-rotation hole 130 is connected to the connecting cavity 133; when the push rod 12 moves along its own axial direction, that is, the needle insertion direction, the push rod 12 will perform anti-rotation sliding motion with the connecting sleeve 13 through the anti-rotation hole 130 to push the piston of the pre-loaded medicine tube 15 or perform a zeroing motion.

[0049] In actual situations, the end of the connecting sleeve 13 facing away from the needle insertion direction is inserted into the end of the fixed sleeve 10 facing the needle insertion direction, and when the threaded sleeve 11 rotates, the driving force generated by the threaded sleeve 11 on the connecting part 120 to cause the push rod 12 to rotate is smaller than the rotational friction force generated by the cooperation between the connecting sleeve 13 and the thread, thereby avoiding the push rod 12 directly driving the connecting sleeve 13 to rotate relative to the threaded sleeve 11 and causing the cooperation between the connecting part 120 and the threaded sleeve 11 to fail.

[0050] In this embodiment, the liquid pushing motor 14 is arranged at the end of the threaded sleeve 11 that is opposite to the needle insertion direction. The transmission end of the liquid pushing motor 14, that is, the axis of the rotating shaft, coincides with the axis of the push rod 12. The axis of the rotating shaft is colinear with the axis of the push rod 12. There is no radial distance between the rotating shaft and the threaded sleeve 11, thereby avoiding the torque error that may be caused by the structure in the background technology, further ensuring the precise control of the push rod 12 by the liquid pushing motor 14, and ultimately precise injection.

[0051] The pre-loaded medicine tube 15 is a columnar structure, including an external tube shell and an internal piston. The end of the pre-loaded medicine tube 15 facing away from the needle insertion direction is open. Under the action of external force, a thrust can be applied to the piston from this position, thereby pressing the medicine inside the tube shell out from the needle head to complete the injection; in this embodiment, the end of the tube shell facing away from the needle insertion direction can be detachably connected to the connecting cavity 133. Compared with the device in the traditional way that additionally sets a structure for clamping the pre-loaded medicine tube 15, the pre-loaded medicine injection device in the present application has a simpler structure, and the installation of the pre-loaded medicine tube 15 is also more convenient. In the process of automated injection, the medicine liquid can be flexibly replaced or supplemented according to actual conditions, which is very convenient.

[0052] In a further embodiment, the liquid pushing motor 14 is partially sleeved inside a section of the fixed sleeve 10 facing away from the needle insertion direction; a connecting hole 110 is provided at one end of the threaded sleeve 11 facing away from the needle insertion direction, and the rotating shaft of the liquid pushing motor 14 is inserted into the connecting hole 110 and cooperates with the connecting hole 110 to prevent rotation.

[0053] A portion of the fluid pushing motor 14 facing the needle insertion direction is sleeved within a portion of the fixed sleeve 10 facing away from the needle insertion direction, so as to fully ensure the coaxiality of the rotating shaft and the threaded sleeve 11 .

[0054] The end of the threaded sleeve 11 facing away from the needle insertion direction is a solid part, and the connecting hole 110 is arranged on the end face of this end. The rotating shaft is inserted into the connecting hole 110 and realizes the anti-rotation movement with the threaded sleeve 11 by means of keyway cooperation to ensure the synchronous rotation of the threaded sleeve 11 and the rotating shaft. In some other embodiments, a anti-rotation plane can be provided on the outer peripheral wall of the rotating shaft, and at the same time, the radial cross-section of the connecting hole 110 and the cross-sectional profile of the rotating shaft are ensured to be compatible with each other, so as to achieve anti-rotation.

[0055] In some other further embodiments, a rotating shaft support 16 is provided inside the fixed sleeve 10 and is located between the threaded sleeve 11 and the push-pin motor 20. The rotating shaft support 16 is a disc-shaped structure, and the rotating shaft passes through the rotating shaft support 16 and rotates with the rotating shaft support 16; a pin hole is provided on the outer peripheral wall of the rotating shaft support 16, and a through hole 100 is provided on the outer peripheral wall of the fixed sleeve 10. In actual use, a pin can be used to pass through the through hole 100 and the pin hole in sequence to fix the rotating shaft support 16.

[0056] In a further embodiment, a bearing 19 is sleeved on the outer peripheral wall of the threaded sleeve 11 , and the outer ring of the bearing 19 is sleeved inside the fixed sleeve 10 .

[0057] In this embodiment, the relative rotation between the threaded sleeve 11 and the fixed sleeve 10 is achieved through the bearing 19. Specifically, two bearings 19 are sleeved on the outer periphery of the threaded sleeve 11, one of which is relatively located at one end of the threaded sleeve 11 facing the needle insertion direction, and the other is relatively located at one end of the threaded sleeve 11 facing away from the needle insertion direction, so that the two bearings 19 have a large distance relative to each other to ensure the stability of the threaded sleeve 11 when rotating relative to the fixed sleeve 10.

[0058] In a further embodiment, the inner walls at both ends of the fixed sleeve 10 can be set to a countersunk shape to form two annular steps. When the bearings 19 are set, the two bearings 19 can be placed into the fixed sleeve 10 from both ends respectively, thereby playing a certain limiting role.

[0059] In a further embodiment, the radial cross-section of the stop hole 130 is in the shape of a straight slot; the corresponding cross-sectional area of ​​the push rod 12 is adapted to the radial cross-section of the stop hole 130, and can only move axially relative to the stop hole 130; the radial cross-sectional shape of the stop hole 130 and the cross-sectional shape of the push rod 12 can also be rectangular with an arc-shaped transition, or a protrusion or groove can be provided on the push rod 12, and a corresponding groove or protrusion can be provided on the inner wall of the stop hole 130.

[0060] In some further embodiments, a push block 121 is provided at one end of the push rod 12 facing the needle insertion direction. The push block 121 is made of rubber material with relatively high hardness. The rubber has a certain elasticity and can be directly sleeved and clamped on the end of the push rod 12. After the push rod 12 with the push block 121 is provided, it can play a certain buffering role when it pushes the piston of the pre-loaded medicine tube 15. At the same time, the radial dimension of one end face of the push block 121 abutting against the piston is larger than that of the push rod 12, which can ensure stability during the abutment process with the piston; in addition, the push block 121 made of rubber material can adaptively deform under the action of external force, so that it is more convenient to disassemble and assemble with the push rod 12.

[0061] In some further embodiments, a zero-position protrusion 122 is provided on a section of the push rod 12 facing the needle insertion direction, a trigger switch 131 is embedded in the inner wall of the stop hole 130, and a trigger pressing end of the trigger switch 131 is located in the stop hole 130. When the zero-position protrusion 122 abuts against the trigger pressing end during the movement of the push rod 12 in the opposite direction to the needle insertion direction, the push rod 12 is in a zero-position state.

[0062] The zero position protrusion 122 is preferably arranged on the side wall of the end of the push rod 12 facing the needle insertion direction to ensure that the push rod 12 has a maximum pushing stroke in the zero position state; the trigger pressing end of the trigger switch 131 is located in the stop hole 130 when not pressed. During the sliding process of the push rod 12, if the zero position protrusion 122 is located outside the stop hole 130, the trigger pressing end of the trigger switch 131 is just not in contact with the side wall of the push rod 12. When the push rod 12 slides back to the needle insertion direction until the zero position switch 24 enters the stop hole 130, the zero position protrusion 122 abuts against the trigger pressing end of the trigger switch 131, the trigger switch 131 is triggered, and the liquid pushing motor 14 stops running. At this time, the push rod 12 is in the zero position state.

[0063] In other embodiments, in order to ensure the sensitivity of the push switch, a push column 132 may be provided in the installation groove where the trigger switch 131 is provided, and the push column 132 is located between the trigger switch and the push rod 12 .

[0064] In some further embodiments, one end of the preloaded medicine tube 15 facing away from the needle insertion direction is threadedly connected to the connecting cavity 133, and an outer peripheral wall of the tube shell of the preloaded medicine tube 15 facing away from the needle insertion direction is provided with an external thread, while an internal thread is provided on the inner wall of the connecting cavity 133. When the preloaded medicine tube 15 is installed, the installation and disassembly of the preloaded medicine tube 15 can be achieved through the mutual cooperation of the external thread and the internal thread, which is very convenient.

[0065] In some other embodiments, the end of the pre-loaded medicine tube 15 facing away from the needle insertion direction is plugged into the connecting cavity 133, and the tube shell of the pre-loaded medicine tube 15 is directly plugged into the connecting cavity 133. The two can be separated under the action of a certain external force, but the force required for separation must be greater than the friction force (reaction force) of the inner wall of the tube shell on the piston during the liquid pushing process to avoid the separation of the pre-loaded medicine tube 15 during the liquid pushing process.

[0066] Reference Figure 2 and Figure 3 As shown, in some further embodiments, a base plate 3 and a push-pin mechanism are also included; the push-pin mechanism includes a push-pin motor 20, a lead screw 21 and a sliding nut 22, the transmission end of the push-pin motor 20 is transmission-connected to the lead screw 21, the sliding nut 22 is sleeved on the lead screw 21, and the sliding nut 22 and the base plate 3 are slidably matched along the length direction of the lead screw 21.

[0067] The base plate 3 is used as a bearing part for installing the needle pushing mechanism and the liquid pushing mechanism.

[0068] The pin-pushing motor 20 is installed on the base plate 3 via a support 25 , and the transmission end of the pin-pushing motor 20 is connected to the lead screw 21 via a coupling.

[0069] The sliding nut 22 is sleeved on the lead screw 21, a slider 23 is arranged at the lower end of the sliding nut 22, and a slide groove 30 is arranged on the upper surface of the base plate 3 at a position corresponding to the slider 23. When the lead screw 21 rotates, the sliding nut 22 slides with the cooperation of the slider 23 and the slide groove 30.

[0070] A zero position switch 24 is provided on the substrate 3 at one end of the slide slot 30 close to the push-pin motor 20. When the sliding nut 22 moves toward the push-pin motor 20 driven by the lead screw 21, the sliding nut 22 or the slider 23 will abut against the zero position switch 24. At this time, the sliding nut 22 is in a zero position state.

[0071] In some other embodiments, a bearing support 18 is provided on the base plate 3, a linear bearing is sleeved inside the bearing support 18, an outer shell sleeve 17 is sleeved outside the connecting sleeve 13 and the fixed sleeve 10, and the outer shell sleeve 17 is sleeved inside the linear bearing; the sliding nut 22 is connected to the end of the fixed sleeve 10 facing away from the needle insertion direction.

[0072] The bearing support 18 is arranged on the base plate 3 and is arranged side by side with the needle pushing mechanism. The outer shell sleeve 17 and the bearing support 18 are slidably connected through a linear bearing; the sliding nut 22 and the fixed sleeve 10 are connected to each other through an L-shaped plate 4. When the sliding nut 22 moves along the screw 21, the entire liquid pushing mechanism will slide synchronously under the action of the L-shaped plate 4, thereby realizing the needle insertion movement of the liquid pushing mechanism.

[0073] In other embodiments, a sliding groove 31 is correspondingly arranged on the base plate 3, and a sliding block is provided corresponding to the sliding groove 31 below the end of the L-shaped plate 4 connected to the fixed sleeve 10. The sliding block slides in cooperation with the sliding groove 31. Under the action of the sliding block and the sliding groove 31, the operating stability of the liquid pushing mechanism can be better guaranteed.

[0074] Reference Figure 4 As shown, in some further embodiments, a support seat 5 is provided on the base plate 3, and the end of the lead screw 21 facing away from the needle pushing motor 20 is penetrated by the support seat 5 and rotatably cooperates with the support seat 5; the end of the lead screw 21 facing away from the needle pushing motor 20 is provided with a first bevel gear 52; an adjusting shaft 53 is rotatably provided on the support seat 5, and the axial direction of the adjusting shaft 53 is perpendicular to the needle insertion direction, and a second bevel gear 54 is provided on the adjusting shaft 53, and the first bevel gear 52 is in transmission meshing engagement with the second bevel gear 54.

[0075] The support seat 5 includes a first mounting plate 50 perpendicular to the needle insertion direction, the lead screw 21 and the first mounting plate 50 are rotatably arranged, and two second mounting plates 51 are spaced apart on the side of the first mounting plate 50 facing away from the needle pushing motor 20. The two ends of the adjusting shaft 53 are rotatably arranged on the two second mounting plates 51 respectively. When the adjusting shaft 53 is rotated, the second bevel gear 54 rotates, and at the same time drives the first bevel gear 52 to rotate, thereby driving the lead screw 21 to rotate. When an accident occurs to the needle pushing mechanism, the needle insertion and needle pushing operations can be manually controlled by adjusting the adjusting shaft 53.

[0076] Due to the meshing action of the first bevel gear 52 and the second bevel gear 54, the adjustment shaft 53 can be adjusted at the side position of the needle pushing mechanism without adjusting one end of the entire device in the needle insertion direction, thereby avoiding the gap formed between the injected object and the device from interfering with the operator's manual needle withdrawal and needle insertion.

[0077] The above is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features applied for herein.

Claims

1. A pre-filled injection device, characterized in that: It includes a liquid pushing mechanism, and the liquid pushing mechanism includes: A fixing sleeve (10); A threaded sleeve (11), wherein the threaded sleeve (11) is sleeved inside the fixed sleeve (10) and is coaxially rotatably matched with the fixed sleeve (10); A push rod (12), the push rod (12) being located inside the threaded sleeve (11); a connecting portion (120) is provided at one end of the push rod (12) facing away from the needle insertion direction, the connecting portion (120) being threadedly connected to the inner wall of the threaded sleeve (11); A connecting sleeve (13) is connected to the end of the fixed sleeve (10) facing the needle insertion direction; a connecting cavity (133) is provided at the end of the connecting sleeve (13) facing the needle insertion direction, a rotation-stopping hole (130) is provided at the end of the connecting sleeve (13) facing away from the needle insertion direction, and the end of the push rod (12) facing the needle insertion direction passes through the rotation-stopping hole (130) and is located in the connecting cavity (133); the push rod (12) and the rotation-stopping hole (130) are rotation-stopping and slidingly matched; A liquid pushing motor (14), the liquid pushing motor (14) is located at an end of the threaded sleeve (11) facing away from the needle insertion direction, and the transmission end of the liquid pushing motor (14) is in transmission connection with the threaded sleeve (11); A pre-loaded medicine tube (15), wherein one end of the pre-loaded medicine tube (15) facing away from the needle insertion direction is detachably connected in the connecting cavity (133); and one end of the push rod (12) located in the connecting cavity (133) is used to abut against the piston of the pre-loaded medicine tube (15).

2. The prefilled injection device according to claim 1, characterized in that: The liquid pushing motor (14) is partially sleeved in a section of the fixed sleeve (10) facing away from the needle insertion direction; A connecting hole (110) is provided at one end of the threaded sleeve (11) facing away from the needle insertion direction, and a rotating shaft of the liquid pushing motor (14) is inserted into the connecting hole (110) and is locked in rotation with the connecting hole (110).

3. The prefilled injection device according to claim 1, characterized in that: A bearing (19) is sleeved on the outer peripheral wall of the threaded sleeve (11), and the outer ring of the bearing (19) is sleeved inside the fixed sleeve (10).

4. The prefilled injection device according to claim 1, characterized in that: The radial cross section of the anti-rotation hole (130) is in the shape of a straight slot; And / or, a push block (121) is provided at one end of the push rod (12) facing the needle insertion direction.

5. The prefilled injection device according to claim 1, characterized in that: A zero-position protrusion (122) is provided on a section of the push rod (12) facing the needle insertion direction, a trigger switch (131) is embedded in the inner wall of the stop hole (130), and a trigger pressing end of the trigger switch (131) is located in the stop hole (130). When the zero-position protrusion (122) abuts against the trigger pressing end during the movement of the push rod (12) in the direction opposite to the needle insertion direction, the push rod (12) is in a zero-position state.

6. The prefilled injection device according to claim 1, characterized in that: One end of the pre-filled medicine tube (15) facing away from the needle insertion direction is threadedly connected to the connecting cavity (133).

7. The prefilled injection device according to claim 1, characterized in that: The end of the pre-filled medicine tube (15) facing away from the needle insertion direction is plugged into and matched with the connecting cavity (133).

8. The prefilled injection device according to claim 1, characterized in that: It also includes a base plate (3) and a pin pushing mechanism; The needle pushing mechanism comprises a needle pushing motor (20), a lead screw (21) and a sliding nut (22); the driving end of the needle pushing motor (20) is drivingly connected to the lead screw (21); the sliding nut (22) is sleeved on the lead screw (21); the sliding nut (22) and the base plate (3) are slidably matched along the length direction of the lead screw (21).

9. The prefilled injection device according to claim 8, characterized in that: The base plate (3) is provided with a bearing support (18), and a linear bearing is sleeved inside the bearing support (18); the connection sleeve (13) and the fixed sleeve (10) are sleeved outside with an outer sleeve (17), and the outer sleeve (17) is sleeved inside the linear bearing; The sliding nut (22) is connected to an end of the fixed sleeve (10) facing away from the needle insertion direction.

10. The prefilled injection device according to claim 9, characterized in that: A support seat (5) is provided on the base plate (3); an end of the lead screw (21) facing away from the needle pusher motor (20) passes through the support seat (5) and is rotatably matched with the support seat (5); A first bevel gear (52) is provided at one end of the lead screw (21) facing away from the needle pushing motor (20); an adjusting shaft (53) is rotatably provided on the support seat (5), the axial direction of the adjusting shaft (53) is perpendicular to the needle insertion direction, and a second bevel gear (54) is provided on the adjusting shaft (53), and the first bevel gear (52) is in transmission meshing engagement with the second bevel gear (54).

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