An adjustable pressure needleless injector

Abstract

The utility model discloses a kind of needleless injectors of adjustable pressure, belong to needleless injector technical field, technical scheme is, including injection head casing, injection cavity is equipped in injection head casing inside, the front end of injection head casing has the aperture of the intercommunication outside and injection cavity;The rear end of injection head casing is provided with the injection push rod of inlaying injection cavity;Drive mechanism and injection push rod between are provided with transmission assembly, transmission assembly includes the first cylinder and the second cylinder that are parallel to each other, transmission push rod is slidably arranged in the first cylinder and the second cylinder, two transmission push rods are all sleeved with firing spring, two firing spring parameters are consistent but initial compression amount is different;Two transmission push rods are switched connection by detachable conversion piece and achieve two transmission push rods and injection push rod;Two transmission push rods are switched connection by detachable connecting piece and achieve two transmission push rods and drive mechanism.The beneficial effects of the utility model are as follows: provide a kind of needleless injector of adjustable pressure.

Description

Technical Field

[0001] This utility model belongs to the field of needleless injector technology, and specifically relates to an adjustable pressure needleless injector. Background Technology

[0002] Currently, the most common needle-free injectors on the market are mainly of two types: electrically driven and pneumatically driven. These devices often use a single pre-compression spring or a fixed pressure output structure, making them only suitable for specific types of vaccines or animals of specific sizes. In actual immunization operations on pig farms, it is often necessary to match needle-free injectors with different injection pressures based on vaccine properties (such as water-adjuvant vaccines versus oil-adjuvant vaccines) and the age and size of the pigs (such as sows, finishing pigs, and piglets). Therefore, multiple sizes of injection equipment are often required. This not only significantly increases equipment procurement and maintenance costs but also leads to frequent injector replacements during operation.

[0003] Therefore, an adjustable pressure needle-free injector was designed. Utility Model Content

[0004] The purpose of this invention is to provide an adjustable pressure needle-free injector.

[0005] This utility model is achieved through the following measures: an adjustable pressure needle-free injector, characterized in that it includes an injection head assembly, the injection head assembly includes an injection head housing, the injection head housing has an injection cavity inside, and the front end of the injection head housing has an opening communicating with the outside and the injection cavity; The rear end of the injection head housing is provided with an injection push rod that extends into the injection cavity; It also includes a drive mechanism, and a transmission assembly is provided between the drive mechanism and the injection push rod. The transmission assembly includes a first cylinder and a second cylinder that are parallel to each other. A transmission push rod is slidably provided inside the first cylinder and the second cylinder. A firing spring is sleeved on the outside of the two transmission push rods. The two firing springs have the same parameters but different initial compression. The two drive push rods are connected to the injection push rod via a detachable conversion component; The two drive push rods are connected to the drive mechanism via a detachable connector.

[0006] Furthermore, it also includes a front end plate and a rear base. The first cylinder and the second cylinder are respectively fixed at both ends on the front end plate and the rear base. A cylinder is concentrically arranged around the injection push rod. The rear end of the cylinder is fixed on the front end plate and the front end is fixed on the injection head housing. The rear end of the transmission push rod extends out of the rear base and is connected to the drive mechanism through the detachable connector; The rear end of the injection plunger extends out of the front end plate and is connected to the transmission plunger via the detachable conversion component.

[0007] Furthermore, one end of the detachable conversion component is sleeved on the rear end of the injection push rod, and the other end is symmetrically provided with arc-shaped clips. Both of the transmission push rods are provided with slots that cooperate with the arc-shaped clips. When one of the arc-shaped clips is inserted into a slot, the other arc-shaped clip is separated from the other slot; When any of the arc-shaped clips is inserted into the slot, the detachable conversion component moves along the axis of the cylinder.

[0008] Both the first and second cylinders have openings on their side walls that allow the arc-shaped clip to enter the slot, and strip openings on their side walls that allow the detachable conversion component to move. The strip openings are connected to the openings. By using two horizontally arranged cylinders, the openings and strip openings on the cylinders facilitate the switching of the conversion component.

[0009] Furthermore, it also includes a fastener that secures the arc-shaped clip within the slot. (The fastener is a nut, and the rear end of the injection push rod has a threaded section, on which the arc-shaped clip is fitted.) Furthermore, the injection head housing includes an adapter, within which an injection chamber is concentrically arranged. A one-way valve communicating with the injection chamber is located at the front end of the adapter (the adapter has a mounting groove for the one-way valve). A drug reservoir ring is located at the rear end of the adapter, and a groove for mounting the drug reservoir ring is provided on the adapter. A transition cavity is concentrically arranged within the drug reservoir ring. An annular groove is provided on the outer wall of the drug reservoir ring, forming a drug inlet channel between the annular groove and the sidewall of the groove. At least one through hole communicating with the drug inlet channel and the transition cavity is opened in the annular groove. A drug inlet tube communicating with the drug inlet channel is provided on the adapter. A connector for connecting the drug inlet tube is provided on the adapter. Sealing rings are provided at both ends of the drug reservoir ring, and a pressure cap for fixing the drug reservoir ring is provided at the outer end of the adapter.

[0010] The front end of the injection plunger is provided with a blind hole communicating with the injection cavity, and the outer wall of the injection plunger is provided with a liquid inlet hole communicating with the blind hole. The liquid inlet hole is used to connect the blind hole and the transition cavity.

[0011] The reciprocating movement of the injection plunger along the axial direction enables the connection and closure of the transition chamber and the injection chamber.

[0012] Furthermore, a trigger ring is concentrically sleeved on the outer front end of the adapter, the front end of the trigger ring protrudes from the adapter, a trigger spring is provided between the trigger ring and the adapter, a flange is provided at the rear end of the adapter, a limit ring is fixedly provided on the outer front wall of the trigger ring, the rear end of the trigger spring is fixed on the flange, the front end of the trigger spring is fixed on the limit ring, and a sensor for receiving the trigger ring signal is provided on the flange.

[0013] An injection head cap is fixedly mounted on the front end of the adapter. The injection head cap has a micro-injection hole, and the front end of the injection head cap does not protrude from the trigger ring. A rubber ring is provided between the injection head cap and the adapter.

[0014] Furthermore, retaining rings are provided at both ends of the interior of the first and second cylinders; A compression ring is provided at either end of the retaining ring and the firing spring, and the two compression rings have different thicknesses. The parameters of the two firing springs are the same, and the compression rings of different thicknesses are used to ensure that the two firing springs are initially at different pre-compression levels.

[0015] Furthermore, the drive mechanism includes a motor, a cylindrical cam connected to the motor shaft, and a follower that cooperates with the cylindrical cam, the follower being connected to the detachable connector; The motor is fixed on the rear base and the motor shaft extends out of the rear base and is connected to the cylindrical cam; the cylindrical cam includes a cylindrical cam body, and a cam profile is machined on the rear end face of the cam body. The cam profile is a spatial helical surface that extends from the starting position of the end face around the rotation axis of the cam body to the ending position; there is an axial height difference between the radial section at the starting position and the radial section at the ending position, and the cam body is concentrically connected to the motor shaft.

[0016] The spatial helical surface has a section of a plane parallel to the rear end face of the cam body at the termination position.

[0017] Furthermore, the detachable connector includes a drive block, and the driven member includes a roller disposed below the drive block, the sidewall of the roller abutting against the cam profile; Both of the transmission push rods have their rear ends extending out of the rear base and their extended ends extending into the drive block. The outer wall of each transmission push rod is provided with a guide structure that moves along the rear base. (The guide structure is generally a spline.) A slide plate is slidably provided on the rear base. Two detachable locking members are provided on the slide plate by threaded connection. The two locking members correspond one-to-one with the two transmission push rods and can pass through the drive block to connect with the corresponding transmission push rod.

[0018] The locking component is generally a screw, the slide plate is provided with a threaded hole that mates with the screw, and the drive block and the transmission push rod are both provided with a connecting hole that mates with the screw.

[0019] Furthermore, a trigger screw is fixedly provided on the cam body at a position corresponding to the termination position, and a sensor for receiving the signal from the trigger screw is provided on the rear base.

[0020] The system also includes a controller that receives signals from the two sensors. This controller enables automatic injection by receiving signals from the two sensors. A sensor located on the adapter is used to acquire the position of the trigger ring, ensuring the syringe is firmly pressed against the animal and preventing accidental triggering. A sensor located on the rear base is used to position the cylindrical cam, ensuring complete aspiration before injection.

[0021] How to use: In the initial position, the inlet tube is connected to the external liquid via the connector, and the liquid is close to the suction port. At this time, the injection push rod is in the injection position, and the injection push rod keeps the transition chamber and the injection chamber in a non-connected state, that is, the initial position on the cylindrical cam is in contact with the driven part (roller).

[0022] Before liquid aspiration is required, one of the two drive push rods is connected to the injection push rod by rotating the detachable conversion component so that the arc-shaped clip is engaged in the slot on the corresponding injection push rod and secured by fasteners. At this time, the other drive push rod is not connected to the injection push rod.

[0023] When liquid aspiration is required, the motor is activated. The motor's rotation drives the cylindrical cam to rotate, and the driven component (roller) moves along the cam profile, causing the transmission push rod and the injection push rod connected to the transmission push rod to move towards the rear end of the syringe. During this movement, the transition chamber and the injection chamber are connected, thus achieving liquid aspiration. Liquid aspiration stops when the driven wheel contacts the termination position.

[0024] When injection is required, the trigger ring comes into contact with the animal, the trigger spring is squeezed, and the trigger ring gradually approaches the sensor to realize the injection (at this time, the motor continues to rotate, and the follower falls from the end position to the starting position through the height difference). The firing spring is released instantly, and the injection push rod is launched instantly. During this process, the transition chamber and the injection chamber are sealed again, and the liquid is sprayed out in a mist.

[0025] In addition, the presence of the cylindrical cam also helps clean the injection chamber. The cleaning process is as follows: when cleaning fluid is drawn into the injection chamber, the reverse motor rotates slowly from the termination position back to the starting position along the spatial helical surface. The injection push rod moves forward, and the cleaning fluid opens the one-way valve and flows out slowly without forming a spray.

[0026] The beneficial effects of the technical solution provided by this utility model embodiment are as follows: using two firing springs with different pre-compression strokes, the firing springs can be switched through a detachable conversion component. The two different firing springs correspond to different pressures, realizing the switching injection of water adjuvant vaccines and oil adjuvant vaccines. When targeting pigs of different ages, the switching can better adapt to the pressure. The cylindrical cam is driven by a motor to rotate, thereby compressing a specific spring. The liquid is then injected by falling from the highest point of the cylindrical cam with the help of the firing spring pressure. Since the cylindrical cam has a helical curved surface, when the cylindrical cam reverses, the follower can move smoothly from the highest point to the lowest point, thus cleaning the injection chamber. Attached Figure Description

[0027] To more clearly illustrate the technical solution of this utility model, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings listed below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present utility model; Figure 2 This is a schematic diagram of the back-end structure of an embodiment of this utility model; Figure 3 Is with Figure 2 Schematic diagrams of structures at different angles; Figure 4 This is a structural diagram after removing the first cylinder, the second cylinder, and the cylinder body; Figure 5 This is a structural schematic diagram of the injection head assembly and its related components; Figure 6 This is a schematic diagram of the internal structure of the injection head assembly; Figure 7 This is a structural diagram of the motor and cylindrical cam; Figure 8 This is a structural schematic diagram of the first cylinder and the transmission push rod; Figure 9 This is a schematic diagram of the drug storage ring structure; Figure 10 This is a schematic diagram of the injection head assembly and the internal structure of the cylinder. Figure 11 yes Figure 10 A partial schematic diagram at point C.

[0029] The components represented by each number in the attached diagram are listed below: 1. Adapter; 2. Cylinder body; 3. Trigger ring; 4. First transmission push rod; 5. Second transmission push rod; 6. Front end plate; 7. Rear base; 8. Drive mechanism; 9. Detachable conversion part; 10. Drive block; 11. Slide plate; 12. Locking part; 13. Injection head cap; 14. Spline; 15. Connector; 16. Sensor 1; 17. Sealing ring; 18. Trigger spring; 19. Firing spring 1; 20. Firing spring 2; 21. Thick compression ring; 22. Thin compression ring; 23. Slot; 24. Trigger screw; 25. Sensor 2; 26. Opening; 27, Strip-shaped opening; 101, Flange; 102, Injection chamber; 103, Drug reservoir ring; 10301, Transition chamber; 10302, Through hole; 10304, Annular groove; 104, Check valve; 201, Injection push rod; 20101, Threaded section; 20102, Fastener; 20103, Blind hole; 20104, Liquid inlet; 401, First cylinder; 501, Second cylinder; 801, Motor; 802, Cylindrical cam; 80201, Cam body; 80202, Cam profile; 803, Roller; 901, Arc-shaped clamp; A, Starting position; B, Ending position. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with embodiments. Of course, the specific embodiments described herein are merely illustrative of this utility model and are not intended to limit its scope.

[0031] See Figures 1-11 An adjustable pressure needle-free injector, characterized in that it includes an injection head assembly, the injection head assembly including an injection head housing, an injection cavity 102 inside the injection head housing, and an opening at the front end of the injection head housing communicating with the outside and the injection cavity 102. An injection push rod 201 that extends into the injection chamber 102 is provided at the rear end of the injection head housing; It also includes a drive mechanism 8, and a transmission assembly is provided between the drive mechanism 8 and the injection push rod 201. The transmission assembly includes a first cylinder 401 and a second cylinder 501 that are parallel to each other. A transmission push rod is slidably provided in both the first cylinder 401 and the second cylinder 501, namely the first transmission push rod 4 and the second transmission push rod 5. A firing spring is sleeved on both transmission push rods, namely the first firing spring 19 and the second firing spring 20. The two firing springs have the same parameters but different initial compression amounts. Two transmission push rods are connected to the injection push rod 201 via a detachable conversion component 9; The two transmission push rods are connected to the drive mechanism 8 via a detachable connector.

[0032] It also includes a front end plate 6 and a rear base 7. The first cylinder 401 and the second cylinder 402 are fixed at both ends on the front end plate 6 and the rear base 7 respectively. A cylinder 2 is concentrically arranged around the injection push rod 201. The rear end of the cylinder 2 is fixed on the front end plate 6 and the front end is fixed on the injection head housing. The rear end of the transmission push rod extends out of the rear base 7 and is connected to the drive mechanism 8 via a detachable connector; The rear end of the injection push rod 201 extends out of the front end plate 6 and is connected to the transmission push rod via a detachable conversion part 9.

[0033] One end of the detachable conversion part 9 is sleeved on the rear end of the injection push rod 201, and the other end is symmetrically provided with an arc-shaped locking part 901. Both transmission push rods are provided with a slot 23 that cooperates with the arc-shaped locking part 901. When one of the arc-shaped clips 901 is inserted into a slot 23, the other arc-shaped clip 901 is separated from the other slot 23. When any arc-shaped clip 901 is inserted into the slot 23, the detachable conversion part 9 moves along the axis of the cylinder.

[0034] Both the first and second cylinders have openings 26 on their side walls that allow the arc-shaped clip 901 to enter the slot 23, and strip openings 27 on their side walls that allow the detachable conversion piece 9 to move. The strip openings 27 are connected to the openings 26. By using two horizontally arranged cylinders, the openings 26 and strip openings 27 on the cylinders facilitate the switching of the conversion piece.

[0035] It also includes a fastener 20102 that restricts the arc-shaped clip 901 within the slot 23. (The fastener 20102 is a nut, and the rear end of the injection push rod 201 is provided with a threaded section 20101, on which the arc-shaped clip 901 is sleeved.) The injection head housing includes an adapter 1, an injection chamber 102 concentrically arranged inside the adapter 1, a one-way valve 104 communicating with the injection chamber 102 at the front end of the adapter 1 (the adapter 1 is provided with a mounting groove for mounting the one-way valve 104); a drug storage ring 103 is provided at the rear end of the adapter 1, a groove for mounting the drug storage ring 103 is provided on the adapter 1, a transition cavity 10301 concentrically arranged inside the drug storage ring 103, an annular groove 10304 is provided on the outer wall of the drug storage ring 103, a drug inlet channel is formed between the annular groove 10304 and the side wall of the groove, at least one through hole 10302 is opened on the annular groove 10304 to connect the drug inlet channel and the transition cavity 10301, a drug inlet tube communicating with the drug inlet channel is provided on the adapter 1; a connector 15 for connecting the drug inlet tube is provided on the adapter 1. The drug storage ring 103 is provided with sealing rings 17 at both ends, and the outer end of the adapter 1 is provided with a pressure cap to fix the drug storage ring 103.

[0036] The front end of the injection push rod 201 is provided with a blind hole 20103 that communicates with the injection chamber 102. The outer wall of the injection push rod 201 is provided with a liquid inlet hole 20104 that communicates with the blind hole 20103. The liquid inlet hole 20104 is used to connect the blind hole 20103 and the transition chamber 10301.

[0037] The reciprocating movement of the injection plunger 201 along the axial direction enables the connection and closure of the transition cavity 10301 and the injection cavity 102.

[0038] A trigger ring 3 is concentrically sleeved on the outer front end of the adapter 1. The front end of the trigger ring 3 protrudes from the adapter 1. A trigger spring 18 is provided between the trigger ring 3 and the adapter 1. A flange 101 is provided at the rear end of the adapter 1. A limit ring is fixedly provided on the outer front end of the trigger ring 3. The rear end of the trigger spring 18 is fixed on the flange 101, and the front end of the trigger spring 18 is fixed on the limit ring. A sensor for receiving signals from the trigger ring 3 is provided on the flange 101.

[0039] An injection head cap 13 is fixedly mounted on the front end of the adapter 1. The injection head cap 13 has a micro injection hole, and the front end of the injection head cap 13 does not protrude from the trigger ring 3. A rubber ring is provided between the injection head cap 13 and the adapter 1.

[0040] Both ends of the first and second cylinders are equipped with retaining rings. A compression ring is provided at either end of the retaining ring and the firing spring. The two compression rings have different thicknesses, namely a thick compression ring 21 and a thin compression ring 22. The parameters of the two firing springs are the same. By using compression rings of different thicknesses, the two firing springs are initially at different pre-compression levels.

[0041] The drive mechanism 8 includes a motor 801, a cylindrical cam 802 connected to the shaft of the motor 801, and a follower that cooperates with the cylindrical cam 802. The follower is connected to a detachable connector. The motor 801 is fixed on the rear base 7 and the motor 801 shaft extends out of the rear base 7 and is connected to the cylindrical cam 802; the cylindrical cam 802 includes a cylindrical cam body 80201, and a cam profile 80202 is machined on the rear end face of the cam body 80201. The cam profile 80202 is a spatial helical surface that extends from the starting position A of the end face around the rotation axis of the cam body 80201 to the ending position B; there is an axial height difference between the radial section of the starting position A and the radial section of the ending position B. The cam body 80201 and the motor 801 shaft are concentrically connected.

[0042] The spatial helical surface at the termination position B has a plane parallel to the rear end face of the cam body 80201.

[0043] The detachable connector includes a drive block 10, and the driven component includes a roller 803 disposed below the drive block 10, the sidewall of the roller 803 abutting against the cam profile 80202; The rear ends of both transmission push rods extend out of the rear base 7 and the extended ends extend into the drive block 10. The outer wall of the transmission push rod is provided with a guide structure that moves along the rear base 7; (the guide structure is generally a spline 14) A slide plate 11 is slidably provided on the rear base 7. Two detachable locking parts 12 are provided on the slide plate 11 by threaded connection. The two locking parts 12 correspond one-to-one with the two transmission push rods and can pass through the drive block 10 to connect with the corresponding transmission push rods.

[0044] The locking element 12 is generally a screw. The slide plate 11 is provided with a threaded hole that mates with the screw. The drive block 10 and the transmission push rod are both provided with a connection hole that mates with the screw.

[0045] A trigger screw 24 is fixedly installed on the cam body 80201 at a position corresponding to the termination position B, and a sensor for receiving the signal from the trigger screw 24 is installed on the rear base 7.

[0046] It also includes a controller that receives signals from two sensors. The controller uses these signals to automate injection. The sensor on adapter 1 detects the position of trigger ring 3, ensuring the syringe is firmly pressed against the animal and preventing accidental triggering. The sensor on the rear base 7 detects the position of cylindrical cam 802, ensuring complete aspiration before injection. The controller uses an STM32ZET6 chip. Sensors 1 and 2 can be inductive metal proximity switches; the specific model can be determined based on the actual situation.

[0047] How to use: In the initial position, the inlet pipe is connected to the external liquid through the connector 15, and the liquid is close to the suction port. At this time, the injection push rod 201 is in the injection position. The injection push rod 201 keeps the transition chamber 10301 and the injection chamber 102 in a non-connected state, that is, the initial position on the cylindrical cam 802 is in contact with the follower (roller 803).

[0048] Before liquid aspiration is required, select one of the two drive push rods to connect with the injection push rod 201. That is, rotate the detachable conversion part 9 so that the arc-shaped clip 901 is inserted into the slot 23 on the corresponding injection push rod 201 and fastened by the fastener 20102. At this time, the other drive push rod is not connected to the injection push rod 201.

[0049] When liquid aspiration is required, motor 801 is started. The rotation of motor 801 drives the cylindrical cam 802 to rotate. The driven member (roller 803) moves along the cam profile 80202, driving the transmission push rod and the injection push rod 201 connected to the transmission push rod to move towards the rear end of the syringe. During the movement, the transition chamber 10301 and the injection chamber 102 are connected, thus realizing the aspiration of the liquid. When the driven wheel contacts the termination position B, liquid aspiration stops.

[0050] When injection is required, the trigger ring 3 comes into contact with the animal, the trigger spring 18 is squeezed, and the trigger ring 3 gradually approaches the sensor to realize the injection (at this time, the motor 801 continues to rotate, and the follower falls from the end position B to the starting position A through the height difference). The firing spring is released instantly, and the injection push rod 201 is triggered instantly. During this process, the transition chamber 10301 and the injection chamber 102 are closed again, and the liquid is sprayed out in a mist.

[0051] In addition, the presence of the cylindrical cam 802 also helps to clean the injection chamber 102. The cleaning process is as follows: when cleaning fluid is drawn into the injection chamber 102, the reverse motor 801 rotates slowly from the termination position B back to the starting position A along the spatial spiral surface, the injection push rod 201 moves forward, and the cleaning fluid opens the one-way valve 104 and flows out slowly without forming a spray.

[0052] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An adjustable pressure needle-free injector, characterized in that, The device includes an injection head assembly, which includes an injection head housing with an injection cavity inside. The front end of the injection head housing has an opening that connects to the outside and the injection cavity. The rear end of the injection head housing is provided with an injection push rod that extends into the injection cavity; It also includes a drive mechanism, and a transmission assembly is provided between the drive mechanism and the injection push rod. The transmission assembly includes a first cylinder and a second cylinder that are parallel to each other. A transmission push rod is slidably disposed in both the first cylinder and the second cylinder. A firing spring is sleeved on both of the transmission push rods. The two firing springs have the same parameters but different initial compressions. The two transmission push rods are switched to the injection push rod through a detachable conversion component. The two drive push rods are connected to the drive mechanism via a detachable connector.

2. The adjustable pressure needleless injector according to claim 1, characterized in that, It also includes a front end plate and a rear base. The first cylinder and the second cylinder are respectively fixed at both ends on the front end plate and the rear base. A cylinder is concentrically arranged around the injection push rod. The rear end of the cylinder is fixed on the front end plate and the front end is fixed on the injection head housing. The rear end of the transmission push rod extends out of the rear base and is connected to the drive mechanism through the detachable connector; The rear end of the injection plunger extends out of the front end plate and is connected to the transmission plunger via the detachable conversion component.

3. The adjustable pressure needleless injector according to claim 2, characterized in that, One end of the detachable conversion component is sleeved on the rear end of the injection push rod, and the other end is symmetrically provided with arc-shaped clips. Both of the transmission push rods are provided with slots that cooperate with the arc-shaped clips. When one of the arc-shaped clips is inserted into a slot, the other arc-shaped clip is separated from the other slot; When any of the arc-shaped clips is inserted into the slot, the detachable conversion component moves along the axis of the cylinder.

4. The adjustable pressure needleless injector according to claim 2, characterized in that, The injection head housing includes an adapter, an injection chamber concentrically arranged within the adapter, a one-way valve communicating with the injection chamber at the front end of the adapter, a drug reservoir ring at the rear end of the adapter, a groove for mounting the drug reservoir ring on the adapter, a transition cavity concentrically arranged within the drug reservoir ring, an annular groove on the outer wall of the drug reservoir ring, a drug inlet channel formed between the annular groove and the side wall of the groove, at least one through hole communicating with the drug inlet channel and the transition cavity on the annular groove, and a drug inlet tube communicating with the drug inlet channel on the adapter. The reciprocating movement of the injection plunger along the axial direction enables the connection and closure of the transition chamber and the injection chamber.

5. The adjustable pressure needleless injector according to claim 4, characterized in that, Both ends of the first and second cylinders are provided with retaining rings. A compression ring is provided at either end of the retaining ring and the spring, and the two compression rings have different thicknesses.

6. The adjustable pressure needleless injector according to claim 2, characterized in that, The drive mechanism includes a motor, a cylindrical cam connected to the motor shaft, and a follower that cooperates with the cylindrical cam. The follower is connected to the detachable connector. The motor is fixed on the rear base and the motor shaft extends out of the rear base and is connected to the cylindrical cam; the cylindrical cam includes a cylindrical cam body, and a cam profile is machined on the rear end face of the cam body. The cam profile is a spatial helical surface that extends from the starting position of the end face around the rotation axis of the cam body to the ending position; there is an axial height difference between the radial section at the starting position and the radial section at the ending position, and the cam body is concentrically connected to the motor shaft.

7. The adjustable pressure needleless injector according to claim 6, characterized in that, The detachable connector includes a drive block, and the driven member includes a roller disposed below the drive block, the sidewall of the roller abutting against the cam profile; Both of the transmission push rods have their rear ends extending out of the rear base and their extended ends extending into the drive block. The outer wall of each transmission push rod is provided with a guide structure that moves along the rear base. A slide plate is slidably provided on the rear base. Two detachable locking members are provided on the slide plate by threaded connection. The two locking members correspond one-to-one with the two transmission push rods and can pass through the drive block to connect with the corresponding transmission push rod.

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