Needle-free injection device

Abstract

Provided in the present utility model is a needle-free injection device, comprising: a pushing module, the pushing module comprising a plunger rod; and an ejection module, wherein the ejection module comprises a plunger sleeve, a cavitation bubble generator and a nozzle; a first liquid medicine cavity is formed in the plunger sleeve, and a head end of the first liquid medicine cavity is provided with a first liquid outlet; the cavitation bubble generator comprises a one-way liquid inlet, a second liquid outlet and a second liquid medicine cavity; an ejection hole is formed in the nozzle; the plunger rod is inserted into the first liquid medicine cavity from a tail end of the plunger sleeve; and the cavitation bubble generator is mounted between the plunger sleeve and the nozzle, the one-way liquid inlet of the cavitation bubble generator is connected to the first liquid outlet, and the second liquid outlet of the cavitation bubble generator is in communication with a tail end of the ejection hole. By means of the present utility model, liquid medicine ejected through the ejection hole in the nozzle is enabled to have a relatively high pressure and kinetic energy, thereby improving the success rate of injection of the liquid medicine.

Description

Needle-free injection device Technical Field

[0001] The utility model relates to the field of medical devices, and more particularly to a needle-free injection device. Background Art

[0002] In recent years, the proportion of large-scale farming of pigs, cattle, sheep, and poultry in China has steadily increased. These concentrated, large-scale farms are susceptible to various diseases, necessitating frequent injections of medications (vaccines, antibiotics, etc.) to prevent and control these diseases. Traditional needle injections are often ineffective at meeting the needs of large-scale farming operations for rapid, concentrated, and large-scale drug administration, due to their high operator trauma and slow drug absorption. Furthermore, these methods are labor-intensive and require a high workload.

[0003] Needle-free injectors are a new type of injector, unlike traditional ones that use needles to penetrate muscle for injection. They utilize a specially integrated power source and microfluidics to accelerate liquids, creating a high-pressure jet after the liquid passes through microfluidic holes. This jet can penetrate the skin without the aid of a traditional needle, enabling precise drug delivery. However, existing needle-free veterinary injectors have a relatively slow injection speed and, in some cases, may not deliver the drug to the intended location. Technical issues

[0004] The technical problem to be solved by the present invention is to provide a new needle-free injection device to address the problem that the injection speed of the liquid medicine of the needle-free syringe is relatively slow. Technical Solutions

[0005] The present invention solves the above-mentioned technical problems by providing a needle-free injection device, comprising:

[0006] A pushing module, comprising a piston rod;

[0007] A spray module, comprising a piston sleeve, a cavitation generator, and a nozzle; a first liquid chamber is formed in the piston sleeve, a first liquid outlet is provided at a head end of the first liquid chamber, and a radial dimension of the first liquid outlet is smaller than a radial dimension of the first liquid chamber; the cavitation generator comprises a one-way liquid inlet, a second liquid outlet, and a second liquid chamber formed between the one-way liquid inlet and the second liquid outlet, the second liquid chamber having a cavitation generating structure, and a radial dimension of the one-way liquid inlet is smaller than a radial dimension of the second liquid chamber and the second liquid outlet; a spray hole is formed on the nozzle, and a radial dimension of a head end of the spray hole is smaller than a radial dimension of a tail end of the spray hole;

[0008] The piston rod is inserted into the first liquid medicine chamber by the tail end of the piston sleeve, and pushes the liquid in the first liquid medicine chamber out of the first liquid outlet by moving toward the first liquid outlet; the cavitation generator is installed between the piston sleeve and the nozzle, the one-way liquid inlet of the cavitation generator is connected to the first liquid outlet, and the second liquid outlet is connected to the tail end of the injection hole, and the one-way liquid inlet opens when the pressure on the first liquid outlet side is greater than the pressure on the second liquid medicine chamber side, and closes when the pressure on the first liquid outlet side is less than or equal to the pressure on the second liquid medicine chamber side.

[0009] As a further improvement of the present invention, the needle-free injection device includes a main housing, a main mounting cavity is formed in the main housing, and an assembly port communicating with the main mounting cavity is formed at the front end of the main housing;

[0010] The main body of the pushing module is installed in the main installation cavity, and at least a part of the pushing module is exposed to the outside of the main shell through the assembly port; the nozzle is detachably assembled on the part of the pushing module exposed to the outside of the main shell, and the piston sleeve and cavitation generator assembled to the pushing module are locked and fixed.

[0011] As a further improvement of the present invention, the piston sleeve includes a valve cavity, the radial size of the valve cavity is adapted to the radial size of the cavitation generator, and the cavitation generator is installed in the valve cavity;

[0012] The first liquid medicine chamber and the valve chamber are respectively located at different axial positions on the piston sleeve, the opening of the valve chamber is located at the axial head end of the piston sleeve, the opening of the first liquid medicine chamber is located at the axial tail end of the piston sleeve, and the first liquid medicine chamber and the valve chamber are connected through the first liquid outlet.

[0013] As a further improvement of the present invention, the axial dimension of the valve cavity is larger than the axial dimension of the cavitation generator, and the second liquid outlet of the cavitation generator is connected to the injection hole of the nozzle through the valve cavity;

[0014] The inner wall of the valve cavity has an internal thread extending to the opening of the valve cavity, the side wall of the cavitation generator has an opening connecting the second liquid medicine cavity with the outside, and the cavitation generating structure is formed by the internal thread, the second liquid medicine cavity and the opening of the side wall of the cavitation generator.

[0015] As a further improvement of the present invention, the injection module includes a first spring, which is installed between the cavitation generator and the nozzle, and presses the one-way liquid inlet of the cavitation generator onto the first liquid outlet of the piston sleeve through elastic force.

[0016] As a further improvement of the present invention, the pushing module includes a first tubular portion exposed outside the main housing, and the first tubular portion has a first thread;

[0017] The nozzle includes a second tubular portion and a bottom wall portion located at the end of the second tubular portion, the injection hole is located at the bottom wall portion, the second tubular portion has a second thread, and the nozzle is fixed to the first tubular portion by locking the second thread with the first thread.

[0018] As a further improvement of the present invention, the piston sleeve is inserted into the first tubular part, and at least a part of the head end of the piston sleeve is exposed to the outside of the first tubular part, and the part of the piston sleeve exposed outside the first tubular part is sealed with the inner wall of the second tubular part.

[0019] As a further improvement of the present invention, the outer wall of the piston sleeve has a circumferential groove, and when the piston sleeve is inserted into the first tubular portion, the groove forms a third liquid medicine chamber; the bottom of the groove has a plurality of communication holes that connect the third liquid medicine chamber with the first liquid medicine chamber;

[0020] The needle-free injection device also includes a liquid medicine bottle, which is connected to the third liquid medicine chamber through a one-way valve and a catheter. When the piston rod moves away from the first liquid outlet, the liquid medicine in the liquid medicine bottle enters the first liquid medicine chamber through the catheter, the one-way valve, the third liquid medicine chamber and the connecting hole under the action of negative pressure.

[0021] As a further improvement of the present invention, the pushing module includes a push rod assembly, an elastic member and a driving assembly;

[0022] The elastic member is installed on the push rod assembly, and the push rod assembly is connected to the tail end of the piston rod. The elastic member is connected to the push rod assembly, and the push rod assembly pushes the piston rod for injection through the released stored energy; the driving assembly includes a motor and a reducer, and the motor drives the reducer to rotate when powered on, and the reducer drives the push rod assembly to compress the elastic member for energy storage.

[0023] As a further improvement of the present invention, the needle-free injection device includes a pressing piece, a second spring, a pressure sensor and a main control circuit board for controlling the operation of the motor. The pressing piece is mounted outside the injection module, and the front end surface of the pressing piece protrudes from the surface where the injection hole is located under the push of the second spring; the pressure sensor is installed at the rear end of the pressing piece and connected to the main control circuit board. Beneficial effects

[0024] The utility model has the following beneficial effects: three-stage acceleration of the medicinal liquid is achieved through the piston sleeve, the cavitation generator and the nozzle, so that the medicinal liquid sprayed through the spray hole of the nozzle has higher pressure and kinetic energy, and can instantly pierce the thicker skin of the animal, thereby improving the success rate of the medicinal liquid injection. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG1 is a schematic diagram of a needle-free injection device provided in an embodiment of the present invention;

[0026] FIG2 is a schematic diagram of the exploded structure of the injection module in the needle-free syringe provided in an embodiment of the present invention;

[0027] FIG3 is a schematic cross-sectional view of a needle-free syringe according to an embodiment of the present invention;

[0028] FIG4 is an enlarged structural diagram of portion A in FIG3 ;

[0029] FIG5 is a schematic structural diagram of a push module in a needle-free syringe provided by an embodiment of the present utility model;

[0030] FIG6 is a schematic diagram of a needle-free syringe according to an embodiment of the present invention performing liquid medicine injection;

[0031] FIG7 is another schematic diagram of the needle-free syringe provided in an embodiment of the present invention for spraying liquid medicine. Modes for Carrying Out the Invention

[0032] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0033] Those skilled in the art will understand that hardware manufacturers may use different names for the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in their functions. The term "including" as used throughout the specification and claims is an open-ended term and should be interpreted as "including but not limited to." "Substantially" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range and essentially achieve the technical effect.

[0034] In the description of the application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "horizontal", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are only used to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or elements referred to must have a specific direction, be constructed or operate in a specific direction. Therefore, they should not be understood as limiting the present invention.

[0035] In the description of this application, unless otherwise expressly specified or limited, the terms "first", "second", and "third" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance; the term "plurality" refers to two or more; unless otherwise specified or explained, the terms "connected" and "fixed" should be understood in a broad sense. For example, "connected" can mean a fixed connection, a detachable connection, an integral connection, or an electrical connection; "connected" can mean a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0036] As shown in Figures 1 and 3, there are schematic diagrams of the structure of a needle-free injection device provided in an embodiment of the present invention. This needle-free injection device can be used to inject liquid medicines, such as vaccines and antibiotics, into animals. The needle-free injection device of this embodiment includes a main housing 10, an injection module 20, and a push module 30. The main housing 10 can be made of metal or hard plastic. A main mounting cavity 11 is formed within the main housing 10, and an assembly port is formed at the front end of the main housing 10, communicating with the main mounting cavity 11. The push module 30 is mounted within the main mounting cavity 11 of the main housing 10, with at least a portion of the push module 30 exposed to the outside of the main housing 10 through the assembly port. The injection module 20 is mounted on the portion of the push module 30 exposed to the outside of the main housing 10. The injection module 20 and push module 30 are each assembled from multiple components and can cooperate to achieve needle-free injection of liquid medicines. In a specific implementation, the injection module 20 and push module 30 can be assembled together using any conventional method.

[0037] As shown in Figures 2 and 4, the above-mentioned pushing module 30 includes a piston rod 31, the front end of which forms a piston head with a conical or similar shape; the injection module 20 includes a piston sleeve 21, a cavitation generator 22 and a nozzle 23, wherein a first liquid chamber 211 is formed in the piston sleeve 21, and the head end of the first liquid chamber 211 has a first liquid outlet, the radial size of the first liquid chamber 211 is adapted to the radial size of the piston rod 31, and the radial size of the first liquid outlet is smaller than the radial size of the first liquid chamber 211, for example, the radial size of the first liquid outlet is less than one tenth of the radial size of the first liquid chamber 211; the cavitation generator 22 includes a one-way liquid inlet, a second liquid outlet and a nozzle. and a second liquid cavity formed between the one-way liquid inlet and the second liquid outlet, the second liquid cavity having a cavitation generating structure, and the radial dimension of the one-way liquid inlet is smaller than the radial dimension of the second liquid cavity and the second liquid outlet, for example, the radial dimension of the one-way liquid inlet is less than one tenth of the radial dimension of the second liquid cavity, and the radial dimension of the second liquid cavity and the second liquid outlet may be the same; an injection hole 231 is formed on the nozzle 23, and the radial dimension of the head end of the injection hole 231 (i.e., the end away from the cavitation generator 22) is smaller than the radial dimension of the tail end of the injection hole 231 (i.e., the end adjacent to the cavitation generator 22), for example, the radial dimension of the tail end of the injection hole 231 may be the same as the radial dimension of the second liquid outlet.

[0038] The piston rod 31 is inserted into the first liquid chamber 211 by the tail end of the piston sleeve 21, and pushes the liquid in the first liquid chamber 211 out of the first liquid outlet by moving toward the first liquid outlet; the cavitation generator 22 is installed between the piston sleeve 21 and the nozzle 23, and the one-way liquid inlet of the cavitation generator 22 is connected to the first liquid outlet, and the second liquid outlet is connected to the tail end of the injection hole 231, and the one-way liquid inlet opens when the pressure on the first liquid outlet side is greater than the pressure on the second liquid chamber side, and closes when the pressure on the first liquid outlet side is less than or equal to the pressure on the second liquid chamber side.

[0039] Specifically, when the piston rod 31 moves rapidly toward the first liquid outlet, the volume of the first liquid chamber 211 decreases sharply. When the radial dimension of the first liquid outlet is much smaller than that of the first liquid chamber 211, the liquid in the first liquid chamber 211 quickly enters the first liquid outlet under the action of huge pressure, thereby achieving first-stage acceleration. The one-way liquid inlet of the cavitation generator 22 is opened under the action of pressure on the first liquid outlet side, and tiny bubbles are mixed into the liquid from the first liquid outlet under the action of the cavitation generating structure. When the liquid in the second liquid chamber enters the injection hole 231 of the nozzle 23, since the radial dimension of the head end of the injection hole 231 is smaller than the radial dimension of its tail end, the liquid can achieve second-stage acceleration under the action of pressure. At the same time, during the second-stage acceleration process, due to the increase in the pressure of the liquid, the bubbles in the liquid burst, thereby producing a third-stage acceleration effect on the liquid.

[0040] In the above manner, the liquid medicine has very high pressure and kinetic energy when it is ejected from the injection hole 231, and can instantly pierce the skin, and can instantly pierce the thicker skin of animals, thereby improving the success rate of liquid medicine injection.

[0041] In one embodiment of the present invention, the piston sleeve 21 and the cavitation generator 22 can be sequentially mounted on the push module 30. For example, the piston sleeve 21 can be inserted into the mounting hole of the push module 30, and the piston rod 31 can be inserted into the first liquid chamber 211 of the piston sleeve 21. The nozzle 23 is detachably mounted on the portion of the push module 30 exposed outside the main housing 10, and the piston sleeve 21 and the cavitation generator 22 assembled to the push module 2 are locked and fixed.

[0042] Through the above structure, the injection module 20 can be disassembled and assembled without disassembling the main housing 10, which greatly facilitates the maintenance operation of the needle-free injection device.

[0043] In one embodiment of the present invention, the piston sleeve includes a valve cavity, the radial size of the valve cavity is adapted to the radial size of the cavitation generator 22, the cavitation generator 22 is installed in the valve cavity, and the cavitation generator 22 is coaxial with the valve cavity.

[0044] On the piston sleeve 21, the first liquid medicine chamber 211 and the valve chamber are located at different axial positions of the piston sleeve 21, with the valve chamber opening located at the axial leading end of the piston sleeve 21 and the first liquid medicine chamber 211 opening located at the axial trailing end of the piston sleeve 21. The first liquid medicine chamber 211 and the valve chamber are connected via the first liquid outlet. In particular, the end of the valve chamber that connects to the first liquid outlet is tapered to facilitate alignment of the one-way liquid inlet of the cavitation generator 22 with the first liquid outlet. This structure facilitates assembly of the cavitation generator 22, eliminating the need for additional components to secure the cavitation generator 22.

[0045] Specifically, the axial dimension of the valve cavity on the piston sleeve 21 is greater than the axial dimension of the cavitation generator 22, and the second liquid outlet of the cavitation generator 22 is connected to the injection hole of the nozzle 23 through the valve cavity. The inner wall of the valve cavity has an internal thread extending to the opening of the valve cavity, and the side wall of the cavitation generator 22 has an opening 221 that connects the second liquid chamber to the outside. The internal thread, the second liquid chamber, and the opening 221 on the side wall of the cavitation generator form the cavitation generating structure. Specifically, a portion of the liquid in the second liquid chamber can enter the internal thread of the valve core through the opening 221 on the side wall of the cavitation generator 22, causing tiny bubbles to be mixed into the liquid, thereby facilitating the acceleration of the liquid at the injection hole 231.

[0046] In one embodiment of the present invention, the injection module 20 further includes a first spring 24, which is installed between the cavitation generator 22 and the nozzle 23. The first spring 24 uses elastic force to pressurize the one-way liquid inlet of the cavitation generator 22 against the first liquid outlet of the piston sleeve 21. Furthermore, to ensure a more sealed connection between the one-way liquid inlet of the cavitation generator 22 and the first liquid outlet, an elastic gasket may be added to the bottom of the valve cavity (i.e., near the first liquid outlet). Of course, in actual applications, other structures may also be used to secure the cavitation generator 22 and ensure a sealed connection between the one-way liquid inlet and the first liquid outlet.

[0047] As shown in FIG4 , in one embodiment of the present invention, the push module 30 includes a first tubular portion 331 exposed outside the main housing 10 , and the outer periphery of the first tubular portion 331 has a first thread. Accordingly, the nozzle 23 includes a second tubular portion 232 and a bottom wall portion 132 located at the end of the second tubular portion 232 . The injection hole 231 is located in the bottom wall portion 232 . The inner wall of the second tubular portion 232 has a second thread, and the nozzle 23 is fixed to the first tubular portion via the second thread and the first thread. In actual application, the first thread can also be located on the inner wall of the first tubular portion 331 , and the second thread can correspondingly be located on the outer periphery of the second tubular portion 232 .

[0048] The piston sleeve 21 can be inserted into the first tubular portion 331, with at least a portion of the front end of the piston sleeve 21 exposed outside the first tubular portion 331. The portion of the piston sleeve 21 exposed outside the first tubular portion 331 is sealed to the inner wall of the second tubular portion 232. For example, an elastic gasket can be added between the piston sleeve 21 and the second tubular portion 232. In this way, the liquid from the second liquid outlet of the cavitation generator 22 can only be ejected from the injection hole 231 of the nozzle 23. When maintaining the needle-free injection device, the nozzle 23 can be first unscrewed from the active tubular portion 331, and then the piston sleeve 21, cavitation generator 22, etc. can be removed using tweezers or other tools.

[0049] Furthermore, the outer wall of the piston sleeve 21 may also have a circumferential groove 213. When the piston sleeve 21 is inserted into the first tubular portion 331, the groove 213 and the inner wall of the first tubular portion 331, which seals the groove 213, form a third drug liquid chamber. The bottom of the groove 213 has a plurality of connecting holes 214 that connect the third drug liquid chamber to the first drug liquid chamber. Accordingly, the needle-free injection device also includes a drug liquid bottle 50, which is connected to the third drug liquid chamber via a one-way valve 51 and a conduit. When the piston rod 31 moves away from the first liquid outlet, the drug liquid in the drug liquid bottle, under the action of negative pressure, enters the first drug liquid chamber 211 through the conduit, the one-way valve 51, the third drug liquid chamber, and the connecting holes 214. This structure enables automatic drug delivery, thus enabling the needle-free injection device to perform multiple injections.

[0050] As shown in Figures 5-7, in one embodiment of the present invention, the above-mentioned pushing module also includes a push rod assembly, an elastic member 32 and a driving assembly; wherein the elastic member 32 is installed on the push rod assembly, the push rod assembly is connected to the tail end of the piston rod 31, the elastic member 32 is connected to the push rod assembly, and the push rod assembly pushes the piston rod 31 for injection through the released stored energy.

[0051] The drive assembly includes a rotating shaft parallel to the central axis of the push rod assembly, and the rotating shaft can rotate and output torque when the drive assembly is powered on. Specifically, the drive assembly includes a motor 391 and a reducer 392. The free end of the reducer 392 has a power conversion member 393. The end of the power conversion member 393 away from the reducer 392 contacts the push rod assembly. When the motor 391 is powered on, the reducer 392 is driven to rotate. During the process of being driven to rotate by the reducer 392, the power conversion member 393 pushes the push rod assembly, causing the elastic member 32 to generate deformation energy. When the push rod assembly is released by the power conversion member 393, the stored energy released by the elastic member 32 pushes the tail end of the piston rod 31 to inject the liquid medicine.

[0052] When the needle-free injection device is in use (the push module 30 of the needle-free injection device is shown in FIG6 ), the motor 391 is first energized and rotated, and the reducer 392 and the power conversion member 393 are driven to rotate through the rotating shaft thereof. During the rotation of the power conversion member 393, the push rod assembly is pushed to the right to store energy in the elastic member 32. When the power conversion member 393 rotates to a preset position, the push rod assembly reaches the maximum stroke position, as shown in FIG7 , and the energy stored in the elastic member reaches the maximum value, at which time the electric assembly stops rotating. When triggered for injection, the motor 391 continues to rotate, and the power conversion member 393 releases the push rod assembly during the driven rotation process. The energy released by the elastic member 32 of the push rod assembly pushes the tail of the piston rod 31 to pressurize the liquid medicine in the first liquid medicine chamber 211, so that the liquid medicine in the first liquid medicine chamber 211 is instantly accelerated through the first liquid outlet, the cavitation generator 22 and the nozzle 23 in sequence to form a high-pressure jet, and pierces the skin of the animal to achieve liquid medicine injection.

[0053] In particular, the above-mentioned power conversion member 393 is composed of a cam, which has a curved surface at one end away from the electric component, and the curved surface gradually moves away from the reducer 392 from the first position to the second position in the circumferential direction of the cam, thereby converting the rotational motion of the reducer 392 into the linear motion of the push rod assembly.

[0054] In one embodiment of the present invention, the push rod assembly, in addition to the elastic member 32, further includes a sleeve 332, a sliding rod 34, and a push block 35. The sleeve 332 is fixedly disposed at the tail end of the piston rod 31 (e.g., connected to the tail end of the first tubular portion 331 and coaxial with the first tubular portion 331), and the sleeve 332 contains a sliding block 36 and a fixed block 37 fixedly connected to the tail end of the sleeve 332. The sliding rod 34 is mounted to the sleeve 332 in a manner that is fixedly connected to the sliding block 36 and slidably connected to the fixed block 37, and the sliding rod 34 is connected to the tail end of the piston rod 31. The push rod assembly is installed and fixed in the main mounting cavity 11 by the sleeve 332 passing through the first through hole of the vertical mounting plate 81. The sliding block 36 and the fixed block 37 are respectively columnar and adapted to the inner wall of the sleeve 332 (for example, when the cross-section of the sleeve 332 is circular, the sliding block 36 and the fixed block 37 are respectively cylindrical) and have mounting holes for the sliding rod 34 to pass through. The sliding rod 34 passes through the mounting holes of the sliding block 36 and the fixed block 37 and is fixed to the sliding block 36. The sliding block 36 is movably arranged in the sleeve 332 and, together with the inner wall of the sleeve 332 and the mounting hole of the fixed block 37, forms a sliding direction guide for the sliding rod 34.

[0055] The tail end of the sliding rod 34 is exposed outside the sleeve 332. The push block 35 is fixed to the tail end of the sliding rod 34. The power conversion member 393 pushes the push block 35 away from the sleeve 332 to store energy in the elastic member 32. That is, the push block 35 drives the sliding rod 34 to move axially relative to the sleeve 332, thereby storing energy in the elastic member 32. In particular, the sleeve 332, the sliding rod 34, and the piston rod 31 are coaxial, which makes the sliding rod 34 more direct in exerting force on the piston rod 31, thereby facilitating the piston rod 31 to generate instantaneous high pressure within the first liquid medicine chamber 211.

[0056] Specifically, the elastic member 32 may be comprised of a compression spring sleeved around the sliding rod 34, with its ends respectively abutting against the sliding block 36 and the fixed block 37. Consequently, when the sliding rod 34 moves rightward, the sliding block 36, fixed to the sliding rod 34, compresses the left end of the compression spring. Since the fixed block 37 is secured to the sleeve 332, the compression spring elastically deforms, increasing its elastic potential energy. When the push block 35 is released by the power conversion member 393, the sliding block 36 rapidly moves leftward under the elastic potential energy of the compression spring, driving the sliding rod 34 leftward. This, in turn, pushes the piston rod 31 leftward, squeezing the liquid within the first liquid chamber 211 to form a high-pressure jet.

[0057] In one embodiment of the present invention, the needle-free injection device includes a pressing member 381, a second spring 382, ​​a pressure sensor, and a main control circuit board 60 for controlling the operation of the motor. The pressing member 381 is mounted outside the injection module 20, and the front end of the pressing member 381 protrudes from the surface where the injection hole 231 is located under the push of the second spring 382. The pressure sensor is installed at the rear end of the pressing member 381 and is connected to the main control circuit board 60. During injection, the pressure sensor is triggered by pushing the pressing member 381 to generate an electrical signal. After receiving the electrical signal generated by the pressure sensor, the main control circuit board 60 controls the operation of the motor 391 to achieve liquid drug injection. In actual applications, liquid drug injection can also be triggered by other existing methods, such as switches, buttons, etc.

[0058] To facilitate holding, the main shell 10 further includes a grip portion, and a battery cavity 12 is formed in the grip portion. Accordingly, the needle-free injection device further includes a main control circuit board 60 installed in the main mounting cavity 11 and a battery 70 installed in the battery cavity 12. The battery 70 and the motor 391 are electrically connected to the main control circuit board 60, respectively, thereby realizing rotation control of the motor assembly.

[0059] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A needle-free injection device, characterized in that: include: A pushing module, the pushing module comprising a piston rod; A spray module, the spray module comprising a piston sleeve, a cavitation generator and a nozzle; a first liquid chamber is formed in the piston sleeve, the first liquid chamber has a first liquid outlet at the head end, and the radial dimension of the first liquid outlet is smaller than the radial dimension of the first liquid chamber; the cavitation generator comprises a one-way liquid inlet, a second liquid outlet and a second liquid chamber formed between the one-way liquid inlet and the second liquid outlet, the second liquid chamber has a cavitation generating structure, and the radial dimension of the one-way liquid inlet is smaller than the radial dimension of the second liquid chamber and the second liquid outlet; a spray hole is formed on the nozzle, and the radial dimension of the head end of the spray hole is smaller than the radial dimension of the tail end of the spray hole; The piston rod is inserted into the first liquid medicine chamber by the tail end of the piston sleeve, and pushes the liquid in the first liquid medicine chamber out of the first liquid outlet by moving toward the first liquid outlet; the cavitation generator is installed between the piston sleeve and the nozzle, the one-way liquid inlet of the cavitation generator is connected to the first liquid outlet, the second liquid outlet is connected to the tail end of the injection hole, and the one-way liquid inlet opens when the pressure on the first liquid outlet side is greater than the pressure on the second liquid medicine chamber side, and closes when the pressure on the first liquid outlet side is less than or equal to the pressure on the second liquid medicine chamber side.

2. The needle-free injection device according to claim 1, characterized in that: The needle-free injection device comprises a main housing, a main installation cavity is formed in the main housing, and an assembly port communicating with the main installation cavity is formed at the front end of the main housing; The main body of the pushing module is installed in the main installation cavity, and at least a part of the pushing module is exposed to the outside of the main shell through the assembly port; the nozzle is detachably assembled on the part of the pushing module exposed to the outside of the main shell, and the piston sleeve and the cavitation generator assembled to the pushing module are locked and fixed.

3. The needle-free injection device according to claim 2, characterized in that: The piston sleeve comprises a valve cavity, the radial dimension of the valve cavity is matched with the radial dimension of the cavitation generator, and the cavitation generator is installed in the valve cavity; The first medicine liquid chamber and the valve chamber are respectively located at different axial positions on the piston sleeve, the opening of the valve chamber is located at the axial head end of the piston sleeve, the opening of the first medicine liquid chamber is located at the axial tail end of the piston sleeve, and the first medicine liquid chamber and the valve chamber are connected through the first liquid outlet.

4. The needle-free injection device according to claim 3, characterized in that: The axial dimension of the valve cavity is larger than the axial dimension of the cavitation generator, and the second liquid outlet of the cavitation generator is connected with the injection hole of the nozzle through the valve cavity; The inner wall of the valve cavity has an internal thread extending to the opening of the valve cavity, the side wall of the cavitation generator has an opening connecting the second liquid medicine cavity with the outside, and the cavitation generating structure is formed by the internal thread, the second liquid medicine cavity and the opening of the side wall of the cavitation generator.

5. The needle-free injection device according to claim 3, characterized in that: The injection module includes a first spring, which is installed between the cavitation generator and the nozzle and presses the one-way liquid inlet of the cavitation generator onto the first liquid outlet of the piston sleeve through elastic force.

6. The needle-free injection device according to claim 3, characterized in that: The pushing module comprises a first tubular portion exposed outside the main housing, and the first tubular portion has a first thread; The nozzle comprises a second tubular portion and a bottom wall portion located at the end of the second tubular portion, the injection hole is located at the bottom wall portion, the second tubular portion has a second thread, and the nozzle is fixed to the first tubular portion by locking the second thread with the first thread.

7. The needle-free injection device according to claim 6, characterized in that: The piston sleeve is inserted into the first tubular portion, and at least a portion of the head end of the piston sleeve is exposed outside the first tubular portion. The portion of the piston sleeve exposed outside the first tubular portion is sealed and connected to the inner wall of the second tubular portion.

8. The needle-free injection device according to claim 7, characterized in that: The outer wall of the piston sleeve has a circumferential groove, and when the piston sleeve is inserted into the first tubular portion, a third liquid medicine chamber is formed by the groove; the bottom of the groove has a plurality of connecting holes that connect the third liquid medicine chamber with the first liquid medicine chamber; The needle-free injection device also includes a medicine liquid bottle, which is connected to the third medicine liquid chamber through a one-way valve and a catheter, and when the piston rod moves away from the first liquid outlet, the medicine in the medicine liquid bottle enters the first medicine liquid chamber through the catheter, the one-way valve, the third medicine liquid chamber and the connecting hole under the action of negative pressure.

9. The needle-free injection device according to any one of claims 1 to 8, characterized in that: The pushing module includes a push rod assembly, an elastic member and a driving assembly; The elastic member is mounted on the push rod assembly, the push rod assembly is connected to the tail end of the piston rod, the elastic member is connected to the push rod assembly, and the push rod assembly pushes the piston rod for injection through the released stored energy; the driving assembly includes a motor and a reducer, and the motor drives the reducer to rotate when powered on, and the reducer drives the push rod assembly to compress the elastic member for energy storage.

10. The needle-free injection device according to claim 9, characterized in that: The needle-free injection device includes a pressing piece, a second spring, a pressure sensor and a main control circuit board for controlling the operation of the motor. The pressing piece is mounted outside the injection module, and the front end surface of the pressing piece protrudes from the surface where the injection hole is located under the push of the second spring; the pressure sensor is installed at the rear end of the pressing piece and connected to the main control circuit board.

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