Needleless syringe

Abstract

A needleless syringe that dicharges a substance to be injected into a target area without the mediation of an injection needle. The needleless syringe comprises a syringe body that is formed from a resin member, an igniter, a housing part that contains the substance to be injected, and a piston that is configured so as to be propelled by discharge energy through a prescribed passage that communicates with a combustion chamber to pressurize the substance to be injected. A cylindrical, metal reinforcing member that surrounds at least the igniter and the combustion chamber and extends in the axial direction of the syringe body is provided inside the syringe body. The reinforcing member is arranged so as to be sandwiched by the syringe body in the radial direction of the syringe body. The present invention thereby provides a needleless syringe that uses an igniter as a pressurization source and avoids reductions in operability by a user while ensuring sufficient strength against the pressure generated by the igniter.

Description

[Technical field]

[0001] The present invention relates to a needleless syringe that delivers an injection target substance to a target area without using a needle. [Background technology]

[0002] Needle-free syringes, which do not have a needle, are an example of a device for injecting an injection target substance such as a medicinal liquid into a target area of ​​a living body, and in recent years, they have been developed with attention being paid to ease of handling and hygienic aspects. A needle-free syringe requires an actuator that can impart relatively large energy so that the medicinal liquid is injected toward the target area and delivered to the inside of the target area using the energy of the medicinal liquid. One example is a pyro actuator that uses the energy generated by the combustion of gunpowder.

[0003] For example, the pyro actuator described in Patent Document 1 is not applied to needleless syringes but to vehicle safety devices, but employs a mechanism in which an ignition part of an igniter is positioned inside a cylindrical metal case, a piston is disposed opposite the ignition part, and the piston is driven by the combustion energy generated when the ignition part is activated, and the case is covered with a resin housing. This structure ensures the heat resistance and pressure resistance of the combustion chamber in the pyro actuator. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6632437 Summary of the Invention [Problem to be solved by the invention]

[0005] A needle-free syringe requires a user to hold it and place the injection port on a place where a medicinal liquid or the like needs to be administered. Therefore, if the needle-free syringe becomes large and heavy, the operability of the user decreases. On the other hand, when an igniter capable of generating a relatively large amount of energy is applied to the needle-free syringe as a pressure source for the medicinal liquid or the like, the needle-free syringe must have sufficient strength against the generated pressure from the viewpoint of ensuring the safety of the user. However, in order to increase the strength, it is generally necessary to use a high-strength member such as a metal for the syringe body or to increase the size of the syringe body itself, which leads to a decrease in operability.

[0006] In view of the above problems, the disclosure of the present application aims to provide a technology that can ensure sufficient strength against the pressure generated by an igniter in a needleless syringe having an igniter as a pressure source while avoiding a decrease in operability for the user. [Means for solving the problem]

[0007] In order to solve the above problems, the needle-free syringe disclosed in the present application employs a structure in which a cylindrical reinforcing member made of a metal member is embedded inside a syringe body made of a resin member. This makes it possible to ensure sufficient strength against the pressure generated by the combustion of an ignition charge in an igniter by making the syringe body out of a composite material, and to reduce the weight ratio of the metal member to the syringe body as much as possible.

[0008] Specifically, the present disclosure relates to a needleless syringe for injecting an injection target substance into a target area without using an injection needle, the syringe body being made of a resin member, an igniter provided in the syringe body and emitting an injection energy for injecting the injection target substance into a combustion chamber in the syringe body by burning an ignition charge, a housing provided in the syringe body having a housing space for housing the injection target substance and defining a flow path so that the injection target substance is injected from an injection port into the target area, and a piston configured to propel a predetermined passage in the syringe body communicating with the combustion chamber by the injection energy in order to pressurize the injection target substance contained in the housing space. A reinforcing member is provided inside the syringe body, which is a cylindrical member made of a metal member and extends in the axial direction of the syringe body while surrounding at least the igniter and the combustion chamber, and the reinforcing member is disposed in a state of being sandwiched between the syringe body in the radial direction of the syringe body.

[0009] In the above needle-free syringe, an igniter releases injection energy into a combustion chamber to inject an injection target substance into a target area. This injection energy pressurizes a piston to propel the piston along a predetermined passage, and the injection target substance in the container is pressurized by the piston, causing the injection target substance to flow through a flow path in the container and be injected into the target area. In addition, the tip side of the needle-free syringe refers to the side relatively close to the injection port, and the base side refers to the side opposite to the tip side in the longitudinal direction (axial direction) of the needle-free syringe.

[0010] Here, examples of the injection target substance injected by the needleless syringe include a predetermined substance containing a component expected to be effective in the target area or a component expected to exert a predetermined function in the target area. Therefore, as long as it can be ejected at least by the above-mentioned ejection energy, the physical form of the injection target substance does not matter. For example, the injection target substance may be present in a state dissolved in a liquid, or may be in a state where it is simply mixed without being dissolved in the liquid. For example, the predetermined substance to be delivered may be a vaccine for antibody enhancement, a protein for beauty, cultured cells for hair regeneration, etc., and the injection target substance is formed by being contained in a liquid medium so that these can be ejected. Note that the above-mentioned medium is preferably a medium that does not inhibit the above-mentioned efficacy or function of the predetermined substance when injected into the target area. Alternatively, the above-mentioned medium may be a medium that exerts the above-mentioned efficacy or function by acting together with the predetermined substance when injected into the target area.

[0011] In addition, in order to eject the injection target substance from the needleless syringe toward the target area and deliver it into the inside, it is necessary to penetrate the surface of the target area with the ejected injection target substance. Therefore, in the initial stage of ejection, it is necessary to eject the injection target substance toward the target area at a relatively high speed. In consideration of this point, as an example, it is preferable that the igniter applies ejection energy by utilizing a combustion product released by the combustion of the ignition charge. Note that, as the ignition charge, any one of explosives containing zirconium and potassium perchlorate, explosives containing titanium hydride and potassium perchlorate, explosives containing titanium and potassium perchlorate, explosives containing aluminum and potassium perchlorate, explosives containing aluminum and bismuth oxide, explosives containing aluminum and molybdenum oxide, explosives containing aluminum and copper oxide, and explosives containing aluminum and iron oxide, or any combination of these explosives, can be used. A characteristic of the above-mentioned ignition charge is that although its combustion products are gaseous at high temperatures, they do not contain gaseous components at room temperature. As a result, the combustion products condense immediately after ignition, allowing the igniter to impart ejection energy in an extremely short period of time.

[0012] In the above-mentioned needleless syringe, the syringe body is formed of a resin material, and a cylindrical reinforcing member formed of a metal member is provided inside the syringe body. The reinforcing member is provided on the syringe body so that the reinforcing member surrounds at least the igniter and the combustion chamber, that is, so that at least the igniter and the combustion chamber are accommodated in the inner space of the reinforcing member. Here, the combustion chamber is a space in which the igniter itself is disposed, and is a space to which pressure generated by instantaneous combustion of the ignition charge is applied. Therefore, the above-mentioned arrangement configures the needleless syringe so that the pressure generated by the combustion can be favorably received by the reinforcing member having a relatively high strength. In addition, in the radial direction of the syringe body, the metallic reinforcing member is sandwiched between the syringe body made of a resin. Therefore, the syringe body made of a composite material of a resin material and a metal material is disposed against the pressure caused by the ejection energy that spreads in the radial direction of the syringe body around the igniter, and therefore the strength against the pressure can be effectively strengthened.

[0013] The reinforcing member may have a tubular shape that can accommodate at least the igniter and the combustion chamber in the internal space, and is preferably cylindrical. When the reinforcing member has a cylindrical shape, the pressure can be evenly received, and the strength of the syringe body can be more effectively increased. As an example, the reinforcing member may be formed from a single plate member, or alternatively, from a mesh member or a plate member processed with punching metal. of The reinforcing member may be formed from a member that has been subjected to a predetermined processing such as the above. The reinforcing member may be formed from a single cylindrical member, or may be formed by appropriately combining a plurality of cylindrical members. Furthermore, the reinforcing member may be a straight cylindrical member whose cross-sectional area does not change in the axial direction, or alternatively, may be a sleeve member whose cross-sectional area changes in the axial direction.

[0014] In this way, the needleless syringe of the present disclosure employs a structure in which a cylindrical reinforcing member made of a metal member is embedded inside the syringe body made of a resin member, thereby making it possible to reduce the weight ratio of the metal member in the syringe body as much as possible while ensuring sufficient strength against the pressure generated by the igniter. As a result, the needleless syringe can be suitably reduced in size and weight, and the deterioration of the user's operability can be avoided. In addition, in general, when a cylindrical member made of metal is used as the reinforcing member, the cylindrical member is relatively easy to obtain and process. As a result, it is also possible to keep the cost of manufacturing the needleless syringe low.

[0015] Here, in the above-mentioned needle-free syringe, the reinforcing member may extend in the axial direction of the syringe body, surrounding at least a part of the predetermined passage in addition to the igniter and the combustion chamber. The predetermined passage is a space propelled by the piston, and is also a space to which pressure is applied by the energy of combustion in the igniter because it communicates with the combustion chamber. Therefore, by having the reinforcing member extend so as to surround at least a part of the predetermined passage in this manner, it is possible to effectively increase the strength against the pressure.

[0016] In addition, in the syringe body of the above-mentioned needleless syringe, the thickness of the syringe body forming the combustion chamber may be set to be thinner than the thickness of the syringe body forming the predetermined passage. In that case, in the reinforcing member, the thickness of the first portion surrounding the igniter and the combustion chamber may be set to be thicker than the thickness of the second portion surrounding the predetermined passage. In order to collect energy from combustion in the igniter to the piston and efficiently propel the piston, the diameter of the predetermined passage may be made thinner than the diameter of the igniter or the combustion chamber. As a result, the thickness of the syringe body forming the combustion chamber may be thinner than the thickness of the syringe body forming the predetermined passage, and as a result, the former is more likely to have a lower strength than the latter. Therefore, by making the thickness of the first portion of the reinforcing member thicker than the thickness of the second portion as described above, it is easier to ensure sufficient strength against the pressure caused by combustion in the igniter.

[0017] In the above needle-free syringe, the reinforcing member may be formed by stacking a plurality of cylindrical metallic sub-members having different diameters. The number of stacked sub-members corresponding to the first portion may be greater than the number of stacked sub-members corresponding to the second portion. By adjusting the number of stacked sub-members in this manner, the thickness of the first portion of the reinforcing member can be made thicker than the thickness of the second portion.

[0018] In addition, in the above-mentioned needleless syringe, the syringe body may be configured to have a first housing in which the igniter is provided and a second housing in which the storage section is provided. Then, the first housing and the second housing may be attached to each other in a state in which the reinforcing member is arranged on the surface of the first housing or in a state in which the reinforcing member is arranged on the surface of the second housing, so that the reinforcing member is sandwiched between the first housing and the second housing. By configuring the syringe body with two housings in this way, it is possible to easily arrange the reinforcing member inside the syringe body. Note that any form can be adopted as the form of attachment of the first housing and the second housing, and for example, an attachment form by screwing, snap fastening, fastening using a bolt, etc. can be exemplified.

[0019] Here, in the above-mentioned needleless syringe, a surface of the syringe body forming the predetermined passage may be provided with an additional reinforcing member formed of a metal material in a cylindrical shape, which forms a sliding surface with the piston. By providing the additional reinforcing member in this manner, the predetermined passage can be suitably protected from the pressure caused by the combustion in the igniter, and since the sliding surface of the piston is formed of an additional reinforcing member made of metal, the frictional force acting on the piston can be reduced, making it possible to more efficiently inject the injection target substance. Effect of the Invention

[0020] According to the disclosure of the present application, in a needle-free syringe having an igniter as a pressure source, it is possible to ensure sufficient strength against the pressure generated by the igniter and to avoid a decrease in operability for the user. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a first diagram showing a schematic configuration of a needle-free syringe. [Figure 2A] 2 is a cross-sectional view taken along line AA of the needle-free syringe shown in FIG. 1. [Figure 2B] 2 is a cross-sectional view taken along line BB of the needle-free syringe shown in FIG. 1. [Diagram 3] FIG. 2 is a second diagram showing a schematic configuration of a needle-free syringe. [Figure 4] FIG. 3 is a third diagram showing a schematic configuration of a needle-free syringe. [Diagram 5] FIG. 4 is a fourth diagram showing a schematic configuration of a needle-free syringe. [Figure 6] 5 is a diagram showing attachment of a first housing and a second housing in the needle-free syringe shown in FIG. 4. FIG. [Figure 7] FIG. 5 is a fifth diagram showing a schematic configuration of a needle-free syringe. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The following describes, with reference to the drawings, an example of a needleless syringe 1 (hereinafter simply referred to as "syringe 1") disclosed in the present application. Note that the configurations and combinations thereof in the embodiments shown in the present application are merely examples, and additions, omissions, substitutions, and other modifications of the configurations are possible as appropriate within the scope of the present invention. The present disclosure is not limited by the embodiments, but is limited only by the scope of the claims.

[0023] <First embodiment> The syringe 1 is a needleless syringe that uses the combustion energy of explosives to inject an injection liquid corresponding to the injection target substance of the present application into a target area, that is, a device that performs an injection by injecting the injection liquid into a target area without using an injection needle. In this embodiment, the terms "tip side" and "base side" are used to indicate the relative positional relationship in the longitudinal direction (axial direction) of the syringe 1. The "tip side" refers to a position closer to the tip of the syringe 1, that is, closer to the injection port 77, which will be described later, and the "base side" refers to the direction opposite to the "tip side" in the longitudinal direction of the syringe 1, that is, the direction toward the igniter 22.

[0024] Here, FIG. 1 is a cross-sectional view of the syringe 1 to show a schematic configuration of the syringe 1. The syringe 1 includes an igniter 22, a syringe body 30, a container 70, a plunger 80, and the like. In the container 70 included in the syringe 1, a storage space 75 formed between the plunger 80 is filled with an ejection liquid in a preparation stage before the operation of the syringe 1. In the following description of the present application, the ejection liquid ejected by the syringe 1 into a target area is formed by containing a predetermined substance that exerts an expected efficacy or function in the target area in a liquid medium. In the ejection liquid, the predetermined substance may be dissolved in the liquid medium, or may be simply mixed without being dissolved.

[0025] Examples of the predetermined substance contained in the ejection liquid include, for example, a biological substance that can be ejected into a target area, which is a living body, and a substance that exhibits a desired physiological activity. For example, biological substances include DNA, RNA, nucleic acids, antibodies, cells, etc., and biologically active substances include medicines, vaccines, inorganic substances such as metal particles for thermotherapy and radiotherapy, and substances having various pharmacological and therapeutic effects, including carriers, which are made of low molecular weight, proteins, peptides, etc. In addition, the liquid that is the medium of the ejection liquid may be a substance suitable for administering these predetermined substances into the target area, and may be aqueous or oily. In addition, as long as the predetermined substance can be ejected by the syringe 1, the viscosity of the liquid that is the medium is not particularly limited.

[0026] In the syringe 1, an ignition current is supplied from an external power source to the igniter 22, which activates the igniter 22 and causes the syringe 1 to eject the injection liquid. The supply of the ignition current to the igniter 22 can be in various forms. For example, power for activating the igniter 22 may be supplied from the outside via a power cable (not shown). Alternatively, a battery for supplying the power may be provided inside the syringe 1.

[0027] The igniter 22 is an electric igniter that burns an ignition charge to generate energy for ejection. The igniter 22 has a cap 20 that is cleaved by the combustion products generated when the ignition charge is burned. When the igniter 22 is attached to the syringe body 30, the cap 20 is located in the combustion chamber 20a. When the igniter 22 is activated, the generated combustion products cleave the cap 20 and are released into the combustion chamber 20a.

[0028] Here, the combustion energy of the ignition charge used in the igniter 22 is the energy for the syringe 1 to eject the ejection liquid to the target area. The ignition charge is preferably an explosive containing zirconium and potassium perchlorate (ZPP), an explosive containing titanium hydride and potassium perchlorate (THPP), an explosive containing titanium and potassium perchlorate (TiPP), an explosive containing aluminum and potassium perchlorate (APP), an explosive containing aluminum and bismuth oxide (ABO), an explosive containing aluminum and molybdenum oxide (AMO), an explosive containing aluminum and copper oxide (ACO), an explosive containing aluminum and iron oxide (AFO), or an explosive consisting of a combination of a plurality of these explosives. These explosives generate high-temperature and high-pressure plasma during combustion immediately after ignition, but when the temperature becomes normal and the combustion products condense, the generated pressure drops rapidly because they do not contain gas components. Explosives other than these may be used as the ignition charge as long as they can eject an appropriate ejection liquid.

[0029] Here, the internal space of the syringe body 30, into which the combustion products are released from the igniter 22, is the combustion chamber 20a. The combustion chamber 20a is a cylindrical space, and has a diameter such that the igniter 22 having the cap 20 can be fitted into the combustion chamber 20a. The syringe body 30 is provided with an internal space 36 formed in a cylindrical shape and communicating with the combustion chamber 20a. The internal space 36 is arranged together with an O-ring 25, which is a sealing member, so that the piston 40 can slide, and the internal space 36 corresponds to the predetermined passage disclosed in the present application. When the piston 40 is arranged in the internal space 36 before the activation of the igniter 22, the flange surface 41 on the base end side of the piston 40, which is the pressure receiving surface of the pressure due to the combustion products from the igniter 22, is exposed to the combustion chamber 20a side, and the tip of the piston 40 is accommodated in an internal space 37 formed in a cylindrical shape and communicating with the internal space 36 at the tip side of the syringe body 30. The diameter of the interior space 37 is smaller than the diameter of the interior space 36 .

[0030] When the igniter 22 is activated and the combustion products are released into the combustion chamber 20a, the pressure there rises, and the flange surface 41 on the base end side of the piston 40 receives the pressure, and the piston 40 is propelled toward the tip end. That is, in the syringe 1, the piston 40 is driven by the igniter 22 as a pressure source. Note that, since the diameter of the expanded flange surface 41 of the piston 40 is larger than the diameter of the internal space 37, the movement amount of the piston 40 to press the plunger 80 is limited. Note that the piston 40 may be made of resin, and in that case, metal may be used in combination with resin for parts that require heat resistance and pressure resistance.

[0031] As another method for adjusting the pressure applied to the piston 40, a gas generating agent that burns with the combustion product from the igniter 22 and generates gas may be further disposed in the combustion chamber 20a facing the cap 20 of the igniter 22. The location of the gas generating agent is a location that can be exposed to the combustion product from the igniter 22. As another method, the gas generating agent may be disposed in the igniter 22, as disclosed in International Publication No. 01-031282 and Japanese Patent Application Laid-Open No. 2003-25950. An example of the gas generating agent is a single-base smokeless powder consisting of 98% by mass of nitrocellulose, 0.8% by mass of diphenylamine, and 1.2% by mass of potassium sulfate. It is also possible to use various gas generating agents used in gas generators for airbags and gas generators for seatbelt pretensioners. By adjusting the dimensions, size, shape, and particularly the surface shape, of the gas generating agent when it is placed in the combustion chamber 20a, etc., it is possible to change the time until combustion of the gas generating agent is completed, and thereby the pressure applied to the piston 40 can be adjusted to the desired pressure.

[0032] Here, the syringe body 30 is a component that becomes the main body of the syringe 1, to which the igniter 22, the plunger 80, the container 70, etc. are attached as shown in Fig. 1. For the syringe body 30, for example, a resin member such as known nylon 6-12, polyarylate, polybutylene terephthalate, polyphenylene sulfide, or liquid crystal polymer can be used. In addition, these resins may contain fillers such as glass fiber or glass filler, and polybutylene terephthalate may contain 20 to 80% by mass of glass fiber, polyphenylene sulfide may contain 20 to 80% by mass of glass fiber, and liquid crystal polymer may contain 20 to 80% by mass of mineral.

[0033] Furthermore, in the syringe body 30, an internal space 38 communicating with the internal space 37 is formed. The internal space 38 is a region in which the plunger 80 is generally disposed as shown in FIG. 1, and is a hollow region formed in a cylindrical shape along the axial direction of the syringe body 30. The diameter of the internal space 38 is larger than the diameter of the internal space 37, and is a diameter in which the plunger 80 can slide. The plunger 80 is a member that pressurizes the ejection liquid by the energy received from the piston 40, and has a plunger rod 50 that receives force from the piston 40 at its base end side, and a stopper part 60 that is formed of an elastic member such as rubber at its tip end side and presses the ejection liquid. Note that the syringe body 30 may have a through hole that penetrates from the outer surface of the side to the internal space 38. Through this through hole, the user can check the state of the plunger 80 in the syringe 1 from the outside (for example, whether the syringe 1 is before or after operation, etc.).

[0034] A female screw portion 39a for mounting a container 70 is formed on the inner wall of the tip portion 39 of the syringe body 30. The container 70 is mounted to the syringe body 30 via the female screw portion 39a using a container holder 71 described later. Here, the container 70 is a member that contains the injection liquid pressurized by the plunger 80 and defines a flow path 76 for ejecting the pressurized injection liquid from an ejection port to a target area, and corresponds to a storage portion. In consideration of this point, a resin material for forming the container 70 can be adopted, and for example, the same type of resin material as that of the syringe body 30 can be used.

[0035] The container 70 has a storage space 75 that is a space capable of storing the injection liquid and is formed so that the stopper portion 60 of the plunger 80 can be advanced, and has a flow path 76 that connects the storage space 75 and an ejection port 77 facing the outside of the container 70. The container 70 formed in this manner does not have a male screw portion that screws with the female screw portion 39a of the syringe body 30. Therefore, the container 70 is attached to the syringe body 30 by the container holder 71. The container holder 71 stores the container 70 so that the ejection port 77 of the container 70 is exposed through an opening on the tip side. At this time, the container 70 is in a state in which the injection target substance is filled in the storage space 75 and the plunger 80 is also loaded. Then, while the container 70 is stored in the container holder 71, the male screw of the container holder 71 and the female screw portion 39a of the syringe body 30 are screwed together until the end face on the base end side of the container 70 comes into contact with the end face of the syringe body 30. As a result, the container 70 is sandwiched between the container holder 71 and the syringe body 30 by the fastening force of the screw engagement. At this time, the plunger 80 is disposed across the storage space 75 in the container 70 and the internal space 38 in the syringe body 30.

[0036] The state in which the container 70 is attached to the syringe body 30 by the container holder 71 in this manner is shown in FIG. 1. When the igniter 22 is activated in this state, the piston 40 is pressurized by the combustion products generated there, and the plunger 80 slides in the internal space 38. As a result, the injection liquid contained in the accommodation space 75 is pressurized and is injected from the injection port 77 through the flow path 76. The inner diameter of the flow path 76 provided in the container 70 is formed to be smaller than the inner diameter of the accommodation space 75. With this configuration, the injection liquid pressurized to a high pressure is injected to the outside from the injection port 77.

[0037] The contour of the tip side of the stopper portion 60 of the plunger 80 is shaped to generally match the contour of the inner surface near the portion (the innermost portion of the storage space 75) where the storage space 75 and the flow path 76 are connected. This makes it possible to minimize the gap formed between the stopper portion 60 and the inner surface of the container 70 when the plunger 80 slides during ejection of the ejected liquid and reaches the innermost portion of the storage space 75, thereby preventing the ejected liquid from remaining in the storage space 75 and being wasted. However, the shape of the stopper portion 60 is not limited to a specific shape as long as the desired effect can be obtained in the syringe 1 of this embodiment.

[0038] Here, the syringe 1 employs an igniter 22 as a pressure source for ejecting the ejection liquid. Therefore, when the igniter 22 is activated, a relatively large pressure is instantaneously applied to the inner wall of the combustion chamber 20a exposed to the combustion products and the inner wall of the internal space 36 propelled by the piston 40. Inside the syringe body 30, the piston 40 is movably arranged when viewed in the axial direction of the syringe 1, but since there is no movable member in the radial direction, a corresponding stress acts inside the syringe body 30 as the pressure increases. Therefore, in order to suppress deformation and damage of the syringe body 30, a cylindrical reinforcing member 35 formed of a metal member is arranged inside the syringe body 30. As the metal material, for example, aluminum, iron, copper, steel, or an alloy thereof can be adopted. In the present disclosure, the reinforcing member 35 has a cylindrical shape, but other cylindrical shapes can also be adopted.

[0039] 1, in the syringe body 30, a portion where the reinforcing member 35 surrounds the igniter 22 and the combustion chamber 20a, i.e., a portion including the igniter 22 and the combustion chamber 20a arranged inside the reinforcing member 35 when the syringe body 30 is cut in the radial direction, is defined as a first portion 30a. Furthermore, in the syringe body 30, a portion where the reinforcing member 35 surrounds the internal space 36, i.e., a portion including the internal space 36 arranged inside the reinforcing member 35 when the syringe body 30 is cut in the radial direction, is defined as a second portion 30b. The reinforcing member 35 is formed so as to extend across the first portion 30a and the second portion 30b along the axial direction of the syringe 1.

[0040] FIG. 2A shows an AA cross-sectional view of the syringe 1 at the first portion 30a, and FIG. 2B shows a BB cross-sectional view of the syringe 1 at the second portion 30b. As can be understood from FIG. 2A and FIG. 2B, the syringe 1 is configured so that the pressure generated by the explosive combustion in the igniter 22 can be applied to the radial inner wall of the syringe body 30 at the first portion 30a and the second portion 30b, where the pressure can be applied to the radial inner wall of the syringe body 30, can be appropriately received by the metallic reinforcing member 35. In addition, in the radial direction of the syringe body 30, the metallic reinforcing member 35 is sandwiched between the syringe bodies 30 made of resin, so that the syringe body 30 made of a composite material of a resin material and a metal material is disposed against the pressure, and the strength against the pressure can be effectively strengthened. In addition, since the reinforcing member 35 has a cylindrical shape, the pressure can be evenly received, and the strength of the syringe body 30 can be more effectively increased.

[0041] Furthermore, when a cylindrical metal member is used as the reinforcing member 35, the member is generally a "metal pipe" and is very easy to obtain and process. That is, the reinforcing member 35 can be easily formed by preparing a ready-made metal pipe having a diameter dimension that accommodates the igniter 22 and the combustion chamber 20a, and cutting it to match the axial length of the first portion 30a and the second portion 30b. Then, in the manufacturing process of the syringe 1, the reinforcing member 35 is placed at a predetermined position in a mold for forming the syringe body 30, and a predetermined resin material is injected into the mold for insert molding, thereby forming the syringe body 30 shown in FIG. 1. At this time, the igniter 22 may also be insert molded.

[0042] 1, the syringe 1 shown in FIG. 1 has a configuration in which a metallic reinforcing member 35 is embedded in a resin syringe body 30, so that the syringe body 30 can be effectively protected against the pressure generated when the igniter 22 is activated. In particular, since the strength of the syringe body 30 can be effectively improved by combining a resin material with a metallic material, the ratio of metallic material in the syringe body 30 can be suppressed, and the syringe 1 can be made smaller and lighter, and a decrease in operability for the user can be avoided. In addition, as described above, the syringe 1 can be easily manufactured, and the cost advantage required for the manufacturing is also extremely large.

[0043] <Modification> In relation to the reinforcing member 35 in the syringe 1 disclosed in the present application, a modified example of this embodiment will be described with reference to FIG. 3. In the syringe 1 shown in FIG. 3, the reinforcing member 35 extends only to the first portion 30a in the syringe body 30. The radial thickness of the syringe body 30 in the second portion 30b is thicker than the radial thickness of the syringe body 30 in the first portion 30a. In addition, since the piston 40 propels the internal space 36 in the second portion 30b, the rate of increase in the pressure in the internal space 36 may be slower than the pressure in the combustion chamber 20a at the beginning of the operation of the igniter 22. Therefore, it is relatively easy to ensure the strength of the second portion 30b against pressure. Therefore, when the strength of the second portion 30b can be sufficiently ensured, the length of the reinforcing member 35 can be set to a length that extends only to the first portion 30a, as shown in FIG. 3.

[0044] <Second embodiment> A second embodiment of the syringe 1 of the present disclosure will be described with reference to Fig. 4. Fig. 4 is a diagram showing a schematic configuration of the syringe 1, similar to Fig. 1, and among the configurations shown in Fig. 4, those that are substantially the same as those shown in Fig. 1 are given the same reference numerals and detailed descriptions thereof will be omitted.

[0045] The reinforcing member 35 in the syringe 1 shown in FIG. 4 is formed by stacking two sub-members 35a, 35b. The sub-members 35a, 35b are both cylindrical members made of a metal material (e.g., aluminum, iron, copper, steel, or an alloy thereof). The inner diameter of the sub-member 35a is equal to or greater than the outer diameter of the sub-member 35b, and the sub-member 35b can be stacked and accommodated in the internal space of the sub-member 35a. The sub-member 35a has an axial length extending to the first portion 30a and the second portion 30b of the syringe body 30, and the sub-member 35b has an axial length extending only to the first portion 30a of the syringe body 30.

[0046] As described above, the strength of the second portion 30b against the pressure generated by the activation of the igniter 22 is easier to ensure than that of the first portion 30a. Therefore, the minimum reinforcement required for each of the first portion 30a and the second portion 30b of the syringe body 30 is different. By forming the reinforcing member 35 capable of providing the necessary strength for each portion by stacking sub-members of different diameters as described above, the amount of metal of the reinforcing member 35 required for reinforcing the entire syringe 1 can be adjusted to a minimum. As a result, the syringe 1 can be made smaller and lighter. In addition, since the reinforcing member 35 can be formed by stacking the sub-members 35a and 35b, which are cylindrical metal pipes, the manufacturing of the reinforcing member 35 can be made easier, and the manufacturing cost of the syringe 1 can be kept low.

[0047] 4, the number of layers of the sub-members is different between the first portion 30a and the second portion 30b, but if there is a portion of the first portion 30a that needs to be further reinforced, the strength of that portion may be improved by preparing a sub-member having a different diameter and increasing the number of layers. The same applies to the second portion 30b.

[0048] <Third embodiment> A third embodiment of the syringe 1 of the present disclosure will be described with reference to Fig. 5 and Fig. 6. Fig. 5 is a diagram showing a schematic configuration of the syringe 1, similar to Fig. 1, and among the configurations shown in Fig. 5, those that are substantially the same as those shown in Fig. 1 are given the same reference numerals and detailed descriptions thereof will be omitted. Fig. 6 is a diagram showing the procedure for assembling the syringe 1 shown in Fig. 5.

[0049] The reinforcing member 35 in the syringe 1 shown in FIG. 5 and FIG. 6 is a metallic cylindrical member having a length extending to the first portion 30a and the second portion 30b inside the syringe body 30, similar to the reinforcing member 35 in the syringe 1 shown in FIG. 1. Here, as shown in FIG. 6, the syringe body 30 is formed by screwing together the first housing 31 in which the igniter 22 is provided and the second housing 32 in which the container 70 is attached. The first housing 31 has a female cylindrical shape, and the igniter 22 is located on the bottom surface of the internal space. The second housing 32 has a male shape that can be fitted into the internal space of the first housing 31. A space that becomes the combustion chamber 20a is formed on the base end side (the side facing the first housing 31) of the second housing 32. By combining the two, the syringe 1 has the structure shown in FIG. 5. The structure of the syringe 1 shown in FIG. 5 is substantially the same except that the syringe body 30 is formed of two housings.

[0050] In the syringe 1 having such an assembly structure, as shown in FIG. 6, a cylindrical reinforcing member 35 is arranged on the surface of the internal space of the first housing 31, and then the second housing 32 is fitted and screwed into the first housing 31 and attached. Therefore, a gap is formed between the first housing 31 and the second housing 32 in which the reinforcing member 35 can be arranged. As a result of attaching both housings, a state is formed in which the reinforcing member 35 is sandwiched between the first housing 31 and the second housing 32, and this state is substantially the same as the arrangement state of the reinforcing member 35 shown in FIG. 1. Alternatively, the syringe 1 shown in FIG. 5 can be formed by fitting the first housing 31 into the second housing 32, screwing into the second housing 32, and attaching the first housing 31 to the second housing 32 in a state in which the cylindrical reinforcing member 35 is arranged on the outer surface of the male shape of the second housing 32.

[0051] According to this embodiment, the reinforcing member 35 can be disposed inside the syringe body 30 in the process of attaching the two housings. In the embodiment shown in FIG. 1, the reinforcing member 35 needs to be disposed at the same time as the syringe body 30 is molded from a resin material, i.e., by insert molding. However, in this embodiment, the same reinforcing member 35 can be disposed without insert molding. Therefore, the manufacture of the syringe 1 can be simplified, and the manufacturing cost can be reduced.

[0052] <Fourth embodiment> A fourth embodiment of the syringe 1 of the present disclosure will be described with reference to Fig. 7. Fig. 7 is a diagram showing a schematic configuration of the syringe 1, similar to Fig. 1, and among the configurations shown in Fig. 7, those that are substantially the same as those shown in Fig. 1 are given the same reference numerals and detailed descriptions thereof will be omitted.

[0053] The reinforcing member 35 in the syringe 1 shown in FIG. 7 is a metallic tubular member having a length extending to the first portion 30a and the second portion 30b inside the syringe body 30, similar to the reinforcing member 35 in the syringe 1 shown in FIG. 1. In the syringe 1 shown in FIG. 7, a reinforcing member 350 that forms a sliding surface with the piston 40 is further provided on the surface of the syringe body 30 that forms the internal space 36, as an additional reinforcing member. The reinforcing member 350 is made of the same metallic material as the reinforcing member 35. The reinforcing member 350 has a space that becomes the internal space 36 on the inside thereof, and is formed of a metallic material such as a tubular member made of a material other than the metallic material. Definition It is a cylindrical member having an opening 351 formed at the tip end thereof through which the piston 40 can pass. The opening 351 communicates with the internal space 37. Since the diameter of the opening 351 is smaller than the flange surface 41 of the piston 40, the opening 351 stops the advancement of the piston 40.

[0054] By providing the additional reinforcing member 350 in this manner, the strength of the second portion 30b against the pressure generated when the igniter 22 is activated can be improved, and by making the sliding surface of the piston 40 a metal surface, the frictional force acting on the piston 40 can be reduced, making it possible to more efficiently eject the ejection liquid. In addition, since the propulsion of the piston 40 is received and stopped by the metallic reinforcing member 350, the impact generated at that time is received by the metallic member, making it possible to avoid deformation and damage of the syringe body 30.

[0055] Each feature disclosed in the specification of this application may be combined with any other feature disclosed in the specification. [Explanation of symbols]

[0056] 1: Syringe (needleless syringe) 22:Igniter 30:Syringe body 30a: 1st part 30b: 2nd part 31: 1st housing 32: Second housing 35: Reinforcement member 350: Reinforcement member 351 :Aperture 40: Piston 70: Container 71: Container holder 75: Containment space 76: Flow path 77: Injection port 80: Plunger

Claims

1. A needleless syringe that injects an injection target substance into a target area without using an injection needle, A syringe body formed of a resin material; an igniter provided in the syringe body, which releases injection energy into a combustion chamber in the syringe body to inject the injection target substance by combustion of an ignition charge; a storage section provided in the syringe body, the storage section having a storage space for storing the injection objective substance and defining a flow path for ejecting the injection objective substance from an ejection port toward the target area; A piston configured to propel a predetermined passage in the syringe body communicating with the combustion chamber by the injection energy in order to pressurize the injection objective substance contained in the containing space; Equipped with a reinforcing member is provided inside the syringe body, the reinforcing member being a cylindrical member made of a metal member and surrounding at least the igniter and the combustion chamber and extending in an axial direction of the syringe body, the reinforcing member being disposed in a state of being sandwiched by the syringe body in a radial direction of the syringe body; Needleless syringe.

2. The reinforcing member extends in the axial direction of the syringe body, surrounding the igniter, the combustion chamber, and at least a portion of the predetermined passage. The needle-free syringe of claim 1.

3. In the syringe body, a thickness of the syringe body forming the combustion chamber is set to be thinner than a thickness of the syringe body forming the predetermined passage, In the reinforcing member, a thickness of a first portion surrounding the igniter and the combustion chamber is set to be thicker than a thickness of a second portion surrounding the predetermined passage. The needleless syringe according to claim 2.

4. The reinforcing member is formed by stacking a plurality of cylindrical metal sub-members having different diameters, The number of layers of the sub-members corresponding to the first portion is greater than the number of layers of the sub-members corresponding to the second portion. The needleless syringe according to claim 3.

5. The syringe body has a first housing in which the igniter is provided and a second housing in which the storage portion is provided, When the first housing and the second housing are attached to each other in a state in which the reinforcing member is disposed on a surface of the first housing or in a state in which the reinforcing member is disposed on a surface of the second housing, a state in which the reinforcing member is sandwiched between the first housing and the second housing is formed. The needleless syringe according to any one of claims 1 to 4.

6. a reinforcing member formed of a metal member and having a cylindrical shape and forming a sliding surface with the piston is provided on a surface of the syringe body forming the predetermined passage; The needleless syringe according to any one of claims 1 to 5.

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