Needle-free injector body and needle-free injector
By introducing an auxiliary drug suction mechanism into the needle-free injector, and using an auxiliary pushing component and an actuation spring to push the reservoir piston, the problem of drug suction difficulties caused by increased friction between the piston and the inner wall of the bottle is solved, and a fast and stable drug suction process is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- BEIJING QS MEDICAL TECH
- Filing Date
- 2025-01-07
- Publication Date
- 2026-05-29
AI Technical Summary
In existing needle-free injectors, the increased friction between the piston of the reservoir and the inner wall of the reservoir or the piston getting stuck on the inner wall of the reservoir results in slow, unstable, or impossible drug intake.
A needleless injector body was designed, including an auxiliary drug suction mechanism, comprising an auxiliary pushing component and an actuating spring. The auxiliary pushing component engages with the piston of the reservoir before the drug suction operation, and the actuating spring pushes the piston during the drug suction process to assist its movement.
This allows the storage bottle piston to move smoothly and steadily under atmospheric pressure and the thrust of the auxiliary drug suction mechanism, completing a rapid and stable drug suction operation.
Smart Images
Figure CN224292305U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a medical device for injecting a substance. More specifically, this utility model relates to a needle-free injector body and a needle-free injector. Background Technology
[0002] A needle-free injector eliminates the need for a needle. Instead, it's a medical device that injects a drug into the patient's body by applying high pressure through a micro-orifice at its tip, thus sparing the patient the pain of needle pricks. A needle-free injector includes an injection head and a body. The injection head and a reservoir, such as a cartridge, are housed within the body, where the injection head draws the drug from the reservoir. After drawing, an actuator actuates the injection head to deliver the injection. The injection head includes a drug delivery tube and a piston rod located within the tube; the piston rod and the drug delivery tube are movable relative to each other.
[0003] The storage bottle consists of a body, a mouth, and a tail. The tail is a piston (e.g., a rubber piston) that can move along the inner wall of the body. A piston rod passes through the mouth of the storage bottle and enters the bottle. During drug aspiration, the piston rod and the drug tube move relative to each other, creating a space between them that serves as a drug-containing cavity. This cavity is under vacuum. The drug in the storage bottle is drawn into the cavity through the drug channel within the piston rod. Under the influence of atmospheric pressure, the piston overcomes friction with the inner wall of the bottle and moves towards the mouth as the drug moves, thus completing the drug aspiration process.
[0004] However, due to various reasons, such as the storage bottles being stored or left for a long time after leaving the factory before being used, or due to process or manufacturing tolerances, the friction between the piston and the inner wall of the storage bottle increases or the piston gets stuck on the inner wall of the bottle. This makes it difficult or even impossible for the piston to move under the action of external atmospheric pressure during drug aspiration, or the movement is not smooth or stable. This results in slow or stuck drug aspiration, instability, or even inability to start, or interruption in the middle, thus the drug aspiration operation fails and cannot be completed.
[0005] Therefore, there is a need to provide a needle-free injector body and a needle-free injector to at least partially solve the above problems. Utility Model Content
[0006] According to one aspect of the present invention, a needle-free injector body is provided, comprising: a base; an internal push rod assembly, at least partially disposed in the base and including a main push rod; a reservoir, spaced apart from the main push rod when installed in the internal push rod assembly and including a piston located at the reservoir adjacent to one end of the main push rod; wherein the needle-free injector body further includes an auxiliary drug suction mechanism for the reservoir, the auxiliary drug suction mechanism being disposed between the reservoir and the main push rod, the auxiliary drug suction mechanism comprising: an auxiliary pushing member configured to engage with the piston of the reservoir before drug suction operation; an actuation spring disposed between the auxiliary pushing member and the main push rod, wherein before drug suction operation, the actuation spring is in a compressed state, the piston of the reservoir remains stationary relative to the main push rod, and during drug suction operation, the piston of the reservoir moves forward relative to the main push rod, the auxiliary pushing member pushing the piston of the reservoir forward under the action of the actuation spring.
[0007] In one embodiment, the auxiliary actuating member includes an auxiliary actuating member body and an actuating column extending from the auxiliary actuating member body, the actuating column being configured to engage with the piston of the reservoir before the drug aspiration operation.
[0008] In one embodiment, the main push rod includes a main push rod end and a main push rod step spaced apart from the main push rod end, and the actuation spring is sleeved on the main push rod end and abuts against the main push rod step.
[0009] In one embodiment, the auxiliary pushing member body has a hollow interior forming a receiving cavity, which is configured to accommodate the actuation spring.
[0010] In one embodiment, the needleless injector body further includes a support member disposed on the internal push rod assembly and configured to support the reservoir and the auxiliary drug suction mechanism.
[0011] In one embodiment, the support member includes a support member body and a support member boss extending upward from the support member body. The support member is hollow to form a receiving cavity. An opening is formed at the top of the support member boss. The receiving cavity communicates with the opening to receive the auxiliary pushing member. The opening allows the pushing column to be inserted and moved.
[0012] In one embodiment, the support member includes a plurality of claws located on the outer peripheral edge of the support member body for clamping the storage bottle.
[0013] In one embodiment, the support member includes an annular wall that extends continuously in the circumferential direction on the outer peripheral edge of the support member body for clamping the storage bottle.
[0014] In one embodiment, a stop shoulder is formed between the push column and the auxiliary push member body, and an inner end face is provided in the receiving cavity, the inner end face being configured to engage with the stop shoulder.
[0015] In one embodiment, before the drug aspiration operation, the stop shoulder is spaced apart from the inner end face. During the drug aspiration operation, the push column moves forward through the opening to push the piston of the reservoir until the stop shoulder engages with the inner end face.
[0016] According to another aspect of the present invention, a needleless injector is provided, comprising a needleless injector body as described above and an injection head mounted on the front end of the needleless injector body.
[0017] This utility model provides an auxiliary drug suction mechanism. The auxiliary drug suction mechanism has a simple structure, low cost, and is easy to implement. It can assist in pushing the piston of the storage bottle during the drug suction step, so that the piston of the storage bottle can move smoothly and stably under the action of atmospheric pressure and the thrust of the auxiliary drug suction mechanism, thereby achieving rapid and stable drug suction. Attached Figure Description
[0018] To better understand the above and other objects, features, advantages, and functions of this utility model, reference can be made to the preferred embodiments shown in the accompanying drawings. The same reference numerals in the drawings refer to the same parts. Those skilled in the art should understand that the drawings are intended to schematically illustrate the preferred embodiments of this utility model and do not limit the scope of this utility model in any way; the parts in the drawings are not drawn to scale.
[0019] Figure 1 This is a perspective view of a needle-free injector according to one embodiment of the present invention.
[0020] Figure 2 This is a cross-sectional view of a needleless injector according to one embodiment of the present invention, taken along a longitudinally centrally symmetrical plane, showing the non-actuated position of the auxiliary pushing member.
[0021] Figure 3 yes Figure 2 A magnified view of part A shows the state of the auxiliary push member in the non-actuated position.
[0022] Figure 4 yes Figure 2 A magnified view of part A shows the state of the auxiliary pusher in the actuated position.
[0023] Figure 5 This is a perspective view of an auxiliary drug suction mechanism according to one embodiment of the present invention, showing its connection with the main push rod.
[0024] Figure 6 This is a perspective view of an auxiliary pushing component according to one embodiment of the present invention.
[0025] Figure 7 This is a bottom perspective view of an auxiliary pushing component according to one embodiment of the present invention.
[0026] Figure 8 This is a perspective view of a support member according to one embodiment of the present invention.
[0027] Figure 9 This is a bottom perspective view of a support member according to one embodiment of the present invention. Detailed Implementation
[0028] Now, with reference to the accompanying drawings, specific embodiments of the present invention will be described in detail. The embodiments described herein are merely preferred embodiments of the present invention. Those skilled in the art can conceive of other ways to implement the present invention based on these preferred embodiments, and such other ways also fall within the scope of the present invention.
[0029] First, it should be noted that the "axial direction" or "longitudinal direction" mentioned in this article can be understood as the direction of the axis of the needle-free injector. In this axial direction, the direction facing the patient when using the needle-free injector is called the "front side", and the opposite direction is called the "back side".
[0030] It should be noted that this document uses injectable pharmaceuticals, liquids, and other pharmaceutical substances as examples to describe the concept of this disclosure; however, this is merely an example and not intended to be limiting. The injectable substance can be of various other types, such as saline solution or glucose, as long as it can be injected into the human body using the needle-free injector of this disclosure, it falls within the scope of protection of this disclosure. Similarly, the storage bottle contains various injectable substances. The term "drug aspiration" is used only for descriptive convenience; in describing injectable pharmaceutical substances, "drug aspiration" should be understood as the act of drawing up the injectable substance.
[0031] refer to Figure 1 and Figure 2The needle-free injector 100 includes a needle-free injector body 20 and an injection head 10 mounted at the front end of the needle-free injector body 20. The injection head 10 includes a drug tube 11 and a piston rod 12 capable of pushing liquid medication forward within the drug tube 11. A cap is provided on the injection head 10 to close an injection micro-orifice located at the front end of the drug tube, communicating between the chamber of the drug tube and the outside. The needle-free injector body 20 includes a base 21, an outer housing 22, and an internal push rod assembly. The internal push rod assembly is at least partially disposed within the base 21 and includes a main push rod 23. The base 21 has a forward opening, and the outer housing 22 has a rearward opening and is mounted at the front end of the base 21 to form a receiving space between the base 21 and the outer housing 22. The outer housing 22 has a front opening for fixedly mounting the injection head and its drug tube. The internal push rod assembly is located within the receiving space and has a forward opening. A reservoir can be accommodated within the internal push rod assembly and moves with the internal push rod assembly.
[0032] Throughout the drug aspiration and injection process, the outer casing 22 is fixed relative to the drug tube 11, and the internal push rod assembly is fixed relative to the reservoir and piston rod 12. However, the outer casing 22, the internal push rod assembly, and the base 21 can all move relative to each other. Therefore, the outer casing 22 can drive the drug tube 11 to move, and the internal push rod assembly can drive the reservoir and piston rod 12 to move.
[0033] The following is a brief description of the drug aspiration and injection process, which includes the following main steps in sequence: installation, pressurization and energy storage, drug aspiration, and injection. First, in the installation step, the piston rod 12 of the injection head 10 is inserted into the reservoir. Then, the injection head and reservoir are installed as a whole into the needle-free injector body. When the reservoir enters the internal push rod assembly and moves backward until it can no longer move, the piston rod 12 and the internal push rod assembly are locked together, and the drug tube 11 and the outer shell 22 are also tightened together by threads.
[0034] The next step is to compress and store energy in the actuation spring. Specifically, the outer housing 22 is rotated to move rearward relative to the base 21 (achieved through a threaded engagement between the two), causing the outer housing 22 to move the internal push rod assembly rearward. When the outer housing 22 is threadedly tightened relative to the base 21, the internal push rod assembly is locked by a locking mechanism. During this process, the actuation spring is compressed and stores energy in preparation for the final injection step.
[0035] Next is the drug aspiration step. Specifically, the outer housing 22 is rotated to move forward relative to the base 21 (achieved through a threaded engagement between the two), while the internal push rod assembly remains fixed relative to the base 21 due to being locked by the locking mechanism. In other words, during this process, the outer housing 22 moves forward relative to the internal push rod assembly. Since the drug tube 11 is fixed relative to the outer housing 22, and the reservoir and piston rod 12 are fixed relative to the internal push rod assembly, the drug tube 11 moves forward relative to the reservoir and piston rod 12. Furthermore, since the injection orifice of the drug tube 11 is sealed by a cap, a drug-containing cavity appears inside the drug tube 11 when it moves forward relative to the piston rod 12. The pressure inside the drug-containing cavity is relatively low, thus allowing the liquid from the reservoir to be drawn into the drug-containing cavity through the drug channel in the piston rod 12, thereby completing the drug aspiration.
[0036] Finally, the injection step. In this step, the outer housing 22 and the drug tube 11 are fixed relative to the base 21, while the internal push rod assembly, reservoir, and piston rod 12 move forward relative to the base 21. Specifically, when injection is required, the injection actuator 30 at the rear end of the base 21 is pressed. The actuator 30 moves forward, releasing the locking mechanism from locking the internal push rod assembly. After being unlocked, the internal push rod assembly can move forward relative to the base 21. At this time, the pressurized and energy-storing actuator spring applies a large thrust to the internal push rod assembly, causing it to drive the piston rod 12 forward and squeeze the drug in the drug reservoir, thus ejecting the drug through the injection micro-orifice.
[0037] During the drug aspiration process, the piston of the storage bottle overcomes the friction with the inner wall of the bottle under the action of vacuum suction and moves towards the bottle opening as the liquid moves. As mentioned earlier, for example, when the storage bottle is used for the first time after being stored or placed for a long time, the piston may be difficult or even impossible to move smoothly and steadily under the action of vacuum suction alone.
[0038] Therefore, this utility model proposes an auxiliary drug suction mechanism that can push the piston with a certain force during the drug suction step, assisting the piston to move smoothly and steadily, thereby completing the drug suction operation.
[0039] The auxiliary drug aspiration mechanism is described in detail below with reference to the accompanying drawings. The auxiliary drug aspiration mechanism includes an auxiliary pushing member 40 and an actuating spring 50, which are installed between the reservoir 60 and the main push rod 23 of the internal push rod assembly. Specifically, the auxiliary pushing member 40 is positioned between the piston of the reservoir 60 and the actuating spring 50, and the actuating spring 50 is positioned between the auxiliary pushing member 40 and the main push rod 23. Therefore, the piston of the reservoir 60 is located at one end of the reservoir 60 adjacent to the main push rod 23. Throughout the drug aspiration and injection process, the reservoir 60 and the piston rod 12 are fixed relative to the main push rod 23 of the internal push rod assembly. Before the drug aspiration process, during the installation and pressurization steps, the piston of the storage bottle 60 is fixed relative to the main push rod 23. At this time, the auxiliary pushing component 40 is in contact with the piston, and the actuation spring 50 is in a compressed state, causing the auxiliary pushing component 40 to be pushed. Therefore, the piston of the storage bottle 60 is pushed by the auxiliary pushing component 40. Since the drug aspiration operation has not yet started, the biasing force generated by the actuation spring 50 cannot make the auxiliary pushing component 40 push the piston of the storage bottle 60.
[0040] When the medicine is inhaled, a liquid-containing cavity appears in the medicine tube 11, generating a vacuum negative pressure. The piston of the storage bottle 60 needs to overcome the frictional force with the inner wall of the bottle and move forward relative to the main push rod 23. The piston may be difficult to move or move unsmoothly under atmospheric pressure alone. However, at this time, the piston is also pushed by the auxiliary pushing component 40. The combined effect of the two is sufficient to make the piston move forward stably, especially the auxiliary pushing component 40 pushes the piston forward.
[0041] The thrust of the auxiliary pushing component 40 is the elastic force generated by the compression deformation of the actuation spring 50. Its magnitude can be set between 0 N and the piston's starting force, which is the frictional force between the piston and the inner wall of the bottle. The piston's starting force can vary depending on the specific type of bottle. For cartridge bottles, national standards (derived from ISO standards) have requirements for the frictional force of the cartridge bottle piston. Taking a 3 ml cartridge bottle as an example, the maximum starting force of the piston cannot exceed 30 N. Due to differences in manufacturing processes and equipment among manufacturers, some 3 ml cartridge bottles have a starting force of less than 10 N, while others are close to the standard upper limit. For example, the elastic force of the actuation spring 50 can be set between 0 and 30 N, for example, 10 to 20 N, such as 5 N, 10 N, 15 N, 20 N, and 30 N. The deformation (i.e., compression) of the actuation spring 50 can be set between 1 and 4 mm, for example, 2 to 3 mm, such as 1 mm, 2 mm, 3 mm, and 4 mm. Based on the elastic force and deformation of the actuation spring 50 listed in the example, its spring stiffness can be calculated. This is only an example and is not restrictive. The elastic force, deformation, and spring stiffness of the actuation spring 50 can be set and selected according to specific applications.
[0042] The auxiliary pushing member 40 and the actuating spring 50, and their connections with the reservoir and the main push rod, are described below. The end of the main push rod 23 near the reservoir 60 is the main push rod end 231, and a main push rod step 232 is spaced apart from the main push rod end 231. One end of the actuating spring 50 is fitted onto the main push rod end 231 and abuts against the main push rod step 232, thereby supporting, fixing, and positioning one end of the actuating spring 50. The auxiliary pushing member 40 includes an auxiliary pushing member body 41 and a pushing column 42 extending protruding from the auxiliary pushing member body 41. The size of the pushing column 42 is smaller than that of the auxiliary pushing member body 41, thus forming a stop shoulder 43 between them. The auxiliary pushing member body 41 and the pushing column 42 can be, for example, cylindrical, but this is only an example and not a limitation; they can have any other suitable form. The auxiliary pushing member body 41 is hollow inside and open at the bottom, forming a receiving cavity 44 within the auxiliary pushing member body 41 to accommodate the actuating spring 50. Thus, a portion of the actuation spring 50 is housed within the receiving cavity 44, while the other portion is fitted onto the end 231 of the main push rod. For example, a stop step or stop end face is provided within the receiving cavity 44, such that one end of the actuation spring 50 abuts against the stop step or stop end face, and the other end abuts against the step 232 of the main push rod, thereby achieving the support, fixation, and positioning of the entire actuation spring 50.
[0043] In addition, a support member 70 is provided to support the auxiliary push member 40 and the actuation spring 50 connected thereto. The support member 70 is disposed on the internal push rod assembly at the tail of the reservoir 60, supporting the reservoir. The support member 70 is fixedly connected to the internal push rod assembly, thus remaining fixed relative to the main push rod 23 and the reservoir. The support member 70 includes a support member body 71 and a support member boss 72 extending upward from the support member body 71. The support member body 71 may be disc-shaped, and the support member boss 72 may be a cylindrical structure with dimensions smaller than the support member body 71, thereby forming an annular step at the interface between the support member body 71 and the support member boss 72. An opening 73 is formed at the top of the support member boss 72 for the insertion and movement of the push rod 42.
[0044] Multiple claws 74 are provided on the outer peripheral edge of the support member body 71. The figure shows four claws 74 evenly spaced circumferentially along the outer peripheral edge; this is merely an example and not limiting. The support member body 71 may include more or fewer claws, which may be evenly or unevenly spaced, for example, two, three, five, six, seven, eight, or more claws. The purpose of the claws is to support the storage bottle 60. Specifically, the tail of the storage bottle 60 includes a cylindrical outer wall. The piston is located inside the cylindrical outer wall and can move forward along it. The piston is not aligned with the end face of the cylindrical outer wall but retracts within it. Thus, when the storage bottle 60 is installed in place, its cylindrical outer wall is fitted over the outside of the support member boss 72 and abuts against the annular step between the support member body 71 and the support member boss 72. Multiple claws 74 are clamped on the cylindrical outer wall of the storage bottle 60, thereby fixing the storage bottle 60.
[0045] It should be noted that the storage bottle 60 can be fixed by being fitted onto the support member boss 72 and abutting against the support member body 71. Therefore, the locking claw 74 is optional, and in one embodiment, the locking claw 74 may not be provided. In another embodiment, instead of multiple separate locking claws 74, the locking claw 74 can be set as an integral single component. For example, the multiple locking claws 74 can be modified into a ring-shaped boss or ring wall that extends continuously in the circumferential direction on the outer peripheral edge of the support member body 71.
[0046] The supporting member body 71 and the supporting member boss 72 are hollow and interconnected, with a receiving cavity 75 connected to the opening 73 for receiving the auxiliary pushing member 40. An inner end face 76 is provided within the receiving cavity 75. When the actuating spring 50 actuates the auxiliary pushing member 40, the auxiliary pushing member 40 moves until its stop shoulder 43 engages with the inner end face 76. That is, the inner end face 76 acts as a stop for the auxiliary pushing member 40, limiting its stroke. As mentioned earlier, the pushing force of the auxiliary pushing member 40 can be set between 0 and 30 N, for example, 10 to 20 N, such as 5 N, 10 N, 15 N, 20 N, or 30 N. The pushing stroke of the auxiliary pushing member 40 can be set to be the same as the deformation of the actuating spring 50, for example, 1 to 4 mm, such as 2 to 3 mm, such as 1 mm, 2 mm, 3 mm, or 4 mm.
[0047] Reference Figures 2 to 4 Describe the operation and status of the auxiliary drug inhalation device. See also Figure 2 system Figure 3The diagram shows the non-actuated state of the auxiliary drug delivery mechanism and the non-actuated position of the auxiliary push member. At this time, the needle-free injector is in the pressurization and energy storage step. The reservoir 60 is fixed in place within the support member 70. The auxiliary push member 40 is located in the receiving cavity 75 of the support member 70. The actuation spring 50 is compressed between the receiving cavity 44 and the main push rod 23. The push column 42 contacts the piston at the tail of the reservoir 60. Under the elastic force of the actuation spring 50, the push column 42 applies a thrust to the piston. At this time, the push column 42 protrudes from the opening 73 of the support member 70, and the stop shoulder 43 is spaced apart from the inner end face 76 of the support member 70.
[0048] See Figure 4 The actuation state of the auxiliary drug suction mechanism and the actuation position of the auxiliary pushing member are shown. At this time, the needle-free injector is in the drug suction step. As the drug tube 11 moves forward relative to the piston rod 12, a drug receiving cavity appears inside the drug tube 11. The liquid in the reservoir is drawn into the drug receiving cavity through the drug channel in the piston rod 12. It can be seen that the piston of the reservoir moves forward accordingly. Under the elastic force of the actuation spring 50, the pushing column 42 applies a thrust to the piston and moves forward with the piston. The stop shoulder 43 engages with the inner end face 76 of the support member 70, that is, the pushing stroke of the pushing column 42 is completed. The pushing column 42 remains in this actuation position until the reservoir is removed and a new reservoir is loaded onto the internal push rod assembly. Then, the rear piston of the new reservoir pushes the pushing column 42 backward, causing the pushing column 42 to partially retract into the receiving cavity 75 of the support member 70, while the pushing column 42 protrudes from the opening 73 of the support member 70. At this point, the auxiliary drug inhalation mechanism returns to the non-actuated state, and the auxiliary pushing component returns to the non-actuated position.
[0049] This utility model provides an auxiliary drug suction mechanism. The auxiliary drug suction mechanism has a simple structure, low cost, and is easy to implement. It can assist in pushing the piston of the storage bottle during the drug suction step, so that the piston of the storage bottle can move smoothly and stably under the action of atmospheric pressure and the thrust of the auxiliary drug suction mechanism, thereby achieving rapid and stable drug suction.
[0050] The above description of various embodiments of this utility model is provided for descriptive purposes to a person skilled in the art. It is not intended to exclude or limit the utility model to a single disclosed embodiment. As taught above, those skilled in the art will understand that various alternatives and variations of this utility model are possible. Therefore, although some alternative embodiments have been specifically described, those skilled in the art will understand or relatively easily develop other embodiments. This utility model is intended to include all alternatives, modifications, and variations of the utility model described herein, as well as other embodiments falling within the spirit and scope of the utility model described above.
[0051] Figure label:
[0052] 100 needle-free injectors
[0053] 10 injection heads
[0054] 11 Drug Management
[0055] 12 piston rods
[0056] 20 needle-free injector body
[0057] 21 bases
[0058] 22 Outer casing
[0059] 23 main putter
[0060] 231 Main push rod end
[0061] 232 main push rod step
[0062] 30 injection actuators
[0063] 40 Auxiliary Propulsion Components
[0064] 41 Auxiliary Propulsion Component Main Body
[0065] 42 push column
[0066] 43 Stop shoulder
[0067] 44 Reception Chamber
[0068] 50 Actuation Spring
[0069] 60 storage bottles
[0070] 70 Supporting Components
[0071] 71 Supporting Components Main Body
[0072] 72 Support Component Boss
[0073] 73 opening
[0074] 74 chucks
[0075] 75 receiving cavity
[0076] 76 inner end face
Claims
1. A needle-free injector body, comprising: Base (21); An internal push rod assembly is at least partially disposed in the base (21) and includes a main push rod (23); The reservoir (60), when installed into the internal push rod assembly, is spaced apart from the main push rod (23) and includes a piston located on the reservoir adjacent to one end of the main push rod; The needleless injector body is characterized by further including an auxiliary drug suction mechanism for the reservoir (60), the auxiliary drug suction mechanism being disposed between the reservoir (60) and the main push rod (23). The auxiliary drug inhalation mechanism includes: An auxiliary actuating member (40) is configured to engage with the piston of the reservoir (60) prior to the drug aspiration operation; An actuation spring (50) is disposed between the auxiliary pushing member (40) and the main push rod (23). Before the drug inhalation operation, the actuation spring (50) is in a compressed state, and the piston of the storage bottle (60) remains stationary relative to the main push rod (23). During the drug inhalation operation, the piston of the storage bottle (60) moves forward relative to the main push rod (23), and the auxiliary pushing member (40) pushes the piston of the storage bottle (60) forward under the action of the actuation spring (50).
2. The needleless injector body according to claim 1, characterized in that, The auxiliary actuating member (40) includes an auxiliary actuating member body (41) and an actuating column (42) extending from the auxiliary actuating member body (41), the actuating column (42) being configured to engage with the piston of the reservoir (60) prior to the drug aspiration operation.
3. The needleless injector body according to claim 2, characterized in that, The main push rod (23) includes a main push rod end (231) and a main push rod step (232) spaced apart from the main push rod end (231). The actuation spring (50) is sleeved on the main push rod end (231) and abuts against the main push rod step (232).
4. The needleless injector body according to claim 3, characterized in that, The auxiliary pushing component body (41) has a hollow cavity (44) inside, which is configured to accommodate the actuation spring (50).
5. The needleless injector body according to claim 4, characterized in that, The needleless injector body also includes a support member (70), which is disposed on the internal push rod assembly and configured to support the reservoir (60) and the auxiliary drug suction mechanism.
6. The needleless injector body according to claim 5, characterized in that, The support member (70) includes a support member body (71) and a support member boss (72) extending upward from the support member body (71). The support member (70) is hollow inside to form a receiving cavity (75). An opening (73) is formed on the top of the support member boss (72). The receiving cavity (75) communicates with the opening (73) to receive the auxiliary pushing member (40). The opening (73) allows the pushing column (42) to be inserted and moved.
7. The needleless injector body according to claim 6, characterized in that, The support member (70) includes a plurality of claws (74) located on the outer peripheral edge of the support member body (71) for clamping the storage bottle (60).
8. The needleless injector body according to claim 6, characterized in that, The support member (70) includes an annular wall that extends continuously in the circumferential direction on the outer peripheral edge of the support member body (71) for clamping the storage bottle (60).
9. The needleless injector body according to claim 6, characterized in that, A stop shoulder (43) is formed between the push column (42) and the auxiliary push component body (41). An inner end face (76) is provided in the receiving cavity (75), and the inner end face (76) is configured to engage with the stop shoulder (43).
10. The needleless injector body according to claim 9, characterized in that, Before the drug aspiration operation, the stop shoulder (43) is spaced apart from the inner end face (76). During the drug aspiration operation, the push column (42) moves forward through the opening (73) to push the piston of the reservoir (60) until the stop shoulder (43) engages with the inner end face (76).
11. A needle-free injector, characterized in that, It includes a needleless injector body according to any one of claims 1 to 10 and an injection head mounted on the front end of the needleless injector body.