Syringe barrel

Abstract

The present invention provides a syringe barrel equipped with a puncture needle, which can improve stability during puncture. [Solution] The syringe barrel 1 comprises a cylindrical barrel body portion 10, a cylindrical lancet attachment portion 30 provided at the tip of the barrel body portion 10, and a lancet 50 having a lancet tip 51 at its tip, with its base end inserted into and fixed to the lancet attachment portion 30. The syringe barrel 1 is provided with plate-shaped reinforcing ribs 60 that protrude outward from the outer surface of the lancet attachment portion 30 and extend in the axial direction, and the width (thickness) t1 of the reinforcing ribs 60 in the circumferential direction of the lancet attachment portion 30 is 0.5 to 1.5 mm.

Description

Technical Field

[0001] The present invention relates to a barrel for a syringe equipped with a puncture needle.

Background Art

[0002] Conventionally, in syringes with a small capacity used for insulin administration, vaccine administration, etc., a barrel for a syringe in which a puncture needle is fixed in advance may be used. For example, in FIG. 1A of Patent Document 1 (Japanese Patent Application Laid-Open No. 2023-526869), a barrel for a syringe is disclosed in which a piercing element (for example, a needle) (30) for injecting a therapeutic compound is attached to the tip of a barrel (20) as constituting a syringe (10).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The inventors of the present invention have earnestly studied to further improve the performance of such a barrel for a syringe, and as a result, they have come to think that there is room for improvement particularly in the stability during puncture. Therefore, an object of the present invention is to provide a barrel for a syringe equipped with a puncture needle, which can improve the stability during puncture.

Means for Solving the Problems

[0005] What achieves the above object is as follows. (1) A barrel for a syringe comprising a cylindrical barrel main body portion, a cylindrical puncture needle attachment portion provided at the tip of the barrel main body portion, and a puncture needle having a puncture needle tip at the tip, the base end portion of which is inserted and fixed to the puncture needle attachment portion. A syringe barrel comprising plate-shaped reinforcing ribs that protrude outward from the outer surface of the puncture needle attachment portion and extend in the axial direction, wherein the reinforcing ribs have a width of 0.5 to 1.5 mm in the circumferential direction of the puncture needle attachment portion.

[0006] (2) The puncture needle attachment portion is provided with a large-diameter tip portion at its tip, The aforementioned large-diameter tip portion comprises a tip recess that is recessed from the tip surface toward the base end, and a hollow tapered convex portion located within the tip recess and decreasing in diameter toward the tip. The syringe barrel described in (1) above, wherein the taper angle of the tapered protrusion is 15 to 50°. (3) The barrel body portion comprises a base end opening and a base end diameter reduction portion provided on the tip side of the base end opening and decreasing in diameter toward the base end, The syringe barrel according to (1) or (2) above, wherein the minimum inner diameter of the base end-side reduced diameter portion is 0.1 to 3.0 mm smaller than the maximum inner diameter of the base end-side reduced diameter portion. (4) The barrel body portion comprises a base end opening and a barrel base end tapered portion that widens toward the base end opening, A syringe barrel according to any one of (1) to (3) above, wherein the angle of inclination of the barrel base tapered portion with respect to the central axis of the barrel body portion is 3 to 45°. (5) The lancet attachment portion is provided with a cap attachment portion formed on its outer surface, and the cap attachment portion is provided with an annular recess provided a predetermined length from the tip of the lancet attachment portion toward the base end, A syringe barrel according to any one of (1) to (4) above, wherein the minimum outer diameter of the annular recess is 2.0 to 5.0 mm.

[0007] Furthermore, the following items will achieve the above objectives. (6) A syringe barrel comprising a cylindrical barrel body, a cylindrical puncture needle attachment portion provided at the tip of the barrel body, and a puncture needle having a puncture needle tip at its end, with its base end inserted into and fixed in the puncture needle attachment portion, The lancet attachment portion is provided with plate-shaped reinforcing ribs that protrude outward from the outer surface and extend in the axial direction, and the width of the reinforcing ribs in the circumferential direction of the lancet attachment portion is 0.5 to 1.5 mm. The aforementioned puncture needle attachment portion is equipped with a large-diameter tip portion at its tip, The aforementioned large-diameter tip portion comprises a tip recess that is recessed from the tip surface toward the base end, and a hollow tapered convex portion located within the tip recess and decreasing in diameter toward the tip. The taper angle of the tapered protrusion is 15 to 50°. The barrel body portion comprises a base end opening and a base end diameter reduction portion provided on the tip side of the base end opening and decreasing in diameter toward the base end. The minimum inner diameter of the base end-side reduced diameter portion is 0.1 to 3.0 mm smaller than the maximum inner diameter of the base end-side reduced diameter portion. Furthermore, the barrel body portion is provided with a barrel base end tapered portion that widens in diameter toward the base end opening, The angle of inclination of the barrel base tapered portion with respect to the central axis of the barrel body portion is 3 to 45°. The puncture needle attachment portion includes a cap attachment portion formed on its outer surface, and the cap attachment portion includes an annular recess provided a predetermined length from the tip of the puncture needle attachment portion toward the base end. A syringe barrel having a minimum outer diameter of 2.0 to 5.0 mm in the annular recess.

[0008] Furthermore, the following items will achieve the above objectives. (7) A syringe barrel comprising a cylindrical barrel body, a cylindrical puncture needle attachment portion provided at the tip of the barrel body, and a puncture needle having a puncture needle tip at its end, with its base end inserted into and fixed in the puncture needle attachment portion, The lancet attachment portion is provided with plate-shaped reinforcing ribs that protrude outward from the outer surface and extend in the axial direction, and the width of the reinforcing ribs in the circumferential direction of the lancet attachment portion is 0.5 to 1.5 mm. The aforementioned puncture needle attachment portion is equipped with a large-diameter tip portion at its tip, The tip large-diameter portion includes a tip concave portion that is recessed from the tip surface toward the proximal end direction, and a hollow tapered convex portion that is located within the tip concave portion and has a smaller diameter toward the tip direction. The taper angle of the tapered convex portion is 15 to 50°. The puncture needle attachment portion includes a cap attachment portion formed on the outer surface, and the cap attachment portion includes an annular concave portion provided on the proximal end side by a predetermined length from the tip of the puncture needle attachment portion. The syringe barrel is characterized in that the minimum outer diameter in the annular concave portion is 2.0 to 5.0 mm.

Advantages of the Invention

[0009] The syringe barrel of the present invention is a syringe barrel including a cylindrical barrel main body portion, a cylindrical puncture needle attachment portion provided at the tip portion of the barrel main body portion, a puncture needle having a puncture needle tip at the tip, and a proximal end portion of the puncture needle inserted and fixed to the puncture needle attachment portion, and includes a plate-shaped reinforcing rib that protrudes outward from the outer surface of the puncture needle attachment portion and extends in the axial direction, and the width of the reinforcing rib in the circumferential direction of the puncture needle attachment portion is 0.5 to 1.5 mm. Thereby, the stability during puncture by the syringe barrel can be improved.

Brief Description of the Drawings

[0010] [Figure 1] FIG. 1 is a perspective explanatory view showing an embodiment of the syringe barrel of the present invention. [Figure 2] FIG. 2 is a front view showing an embodiment of the syringe barrel of the present invention. [Figure 3] FIG. 3 is a cross-sectional view taken along line A-A of FIG. 2. [Figure 4] FIG. 4 is an enlarged cross-sectional view taken along line B-B of FIG. 2. [Figure 5] FIG. 5 is an enlarged front view of the tip portion of FIG. 2. [Figure 6] FIG. 6 is an enlarged cross-sectional view of the tip portion of FIG. 3. [Figure 7] FIG. 7 is an enlarged cross-sectional view taken along line C-C of FIG. 4. [Figure 8]FIG. 8 is a cross-sectional explanatory view showing an example of the process when molding the barrel for a syringe shown in FIG. 2. [Figure 9] FIG. 9 is an enlarged cross-sectional view of the tip portion corresponding to FIG. 6, showing another embodiment of the barrel for a syringe of the present invention. [Figure 10] FIG. 10 is an enlarged cross-sectional view of the tip portion corresponding to FIG. 7 of the barrel for a syringe shown in FIG. 9. [Figure 11] FIG. 11 is a cross-sectional explanatory view showing a state where a seal cap is attached to the barrel for a syringe shown in FIG. 2. [Figure 12] FIG. 12 is an enlarged cross-sectional view of the base end portion of FIG. 3. [Figure 13] FIG. 13 is a cross-sectional explanatory view showing an example of the process when molding the barrel for a syringe shown in FIG. 2. [Figure 14] FIG. 14 is an enlarged cross-sectional view of the base end portion corresponding to FIG. 12, showing another embodiment of the barrel for a syringe of the present invention. [Figure 15] FIG. 15 is a cross-sectional explanatory view showing an embodiment of a syringe including the barrel for a syringe shown in FIG. 2.

MODE FOR CARRYING OUT THE INVENTION

[0011] The barrel for a syringe of the present invention will be described using the embodiments shown in the drawings. As shown in FIGS. 1 to 7, FIGS. 11 and FIGS. 12, the barrel for a syringe 1 of the present invention includes a cylindrical barrel main body portion 10, a cylindrical puncture needle attachment portion 30 provided at the tip portion of the barrel main body portion 10, and a puncture needle 50 having a puncture needle tip 51 at the tip, and a base end portion of the puncture needle 50 is inserted and fixed to the puncture needle attachment portion 30. The barrel for a syringe 1 includes a plate-like reinforcing rib 60 that protrudes outward from the outer surface of the puncture needle attachment portion 30 and extends in the axial direction, and the reinforcing rib 60 has a width (thickness) t1 in the circumferential direction of the puncture needle attachment portion 30 of 0.5 to 1.5 mm.

[0012] Furthermore, the syringe barrel 1 of the present invention comprises a cylindrical barrel body portion 10, a cylindrical lancet attachment portion 30 provided at the tip of the barrel body portion 10, and a lancet 50 having a lancet tip 51 at its tip, with its base end inserted into and fixed in the lancet attachment portion 30. The syringe barrel 1 is provided with plate-shaped reinforcing ribs 60 that protrude outward from the outer surface of the lancet attachment portion 30 and extend in the axial direction, and the width (thickness) t1 of the reinforcing ribs 60 in the circumferential direction of the lancet attachment portion 30 is 0.5 to 1.5 mm. The lancet attachment portion 30 is also provided with a large-diameter tip portion 31 at its tip, and the large-diameter tip portion 31 comprises a tip recess 32 that is recessed from the tip surface toward the base end, and a hollow tapered convex portion 33 located within the tip recess 32 and decreasing in diameter toward the tip, and the taper angle θ2 of the tapered convex portion 33 is 15 to 50°. The barrel body portion 10 includes a base end opening 11 and a base end diameter reduction portion 12 provided on the tip side of the base end opening 11 and which decreases in diameter (internal diameter shrinks) toward the base end, with the minimum internal diameter d3min of the base end diameter reduction portion 12 being 0.1 to 3.0 mm smaller than the maximum internal diameter d3max of the base end diameter reduction portion 12. Furthermore, the barrel body portion 10 includes a barrel base end tapered portion 13 which expands in diameter (internal diameter enlarges) toward the base end opening 11, and the inclination angle θ4 of the barrel base end tapered portion 13 with respect to the central axis of the barrel body portion 10 is 3 to 45°. The lancet attachment portion 30 includes a cap attachment portion 34 formed on its outer surface, and the cap attachment portion 34 includes an annular recess 35 provided a predetermined length toward the base end from the tip of the lancet attachment portion 30, with the minimum outer diameter D5min of the annular recess 35 being 2.0 to 5.0 mm.

[0013] Furthermore, the syringe barrel 1 of the present invention comprises a cylindrical barrel body portion 10, a cylindrical lancet attachment portion 30 provided at the tip of the barrel body portion 10, and a lancet 50 having a lancet tip 51 at its tip, with its base end inserted into and fixed in the lancet attachment portion 30. The syringe barrel 1 is provided with plate-shaped reinforcing ribs 60 that protrude outward from the outer surface of the lancet attachment portion 30 and extend in the axial direction, and the width (thickness) t1 of the reinforcing ribs 60 in the circumferential direction of the lancet attachment portion 30 is 0.5 to 1.5 mm. The lancet attachment portion 30 is also provided with a large-diameter tip portion 31 at its tip, and the large-diameter tip portion 31 comprises a tip recess 32 that is recessed from the tip surface toward the base end, and a hollow tapered convex portion 33 located within the tip recess 32 and decreasing in diameter toward the tip, and the taper angle θ2 of the tapered convex portion 33 is 15 to 50°. Furthermore, the lancet attachment portion 30 is equipped with a cap attachment portion 34 formed on its outer surface, and the cap attachment portion 34 is equipped with an annular recess 35 provided a predetermined distance from the tip of the lancet attachment portion 30 toward the base end, with a minimum outer diameter D5min of 2.0 to 5.0 mm in the annular recess 35.

[0014] As shown in Figures 2 and 3, the barrel body portion 10 of the syringe barrel 1 is a substantially cylindrical portion capable of housing the gasket 70, which will be described later, in a liquid-tight and slidable manner. The barrel body portion 10 is cylindrical in shape, extending with substantially the same inner and outer diameters, and has an internal space (internal space 14).

[0015] The inner diameter da of the barrel body 10 is appropriately selected depending on the intended use of the syringe barrel 1 (type and amount of drug (medicine solution), etc.). For example, if the nominal capacity of the syringe barrel 1 is 0.5 to 100 mL, the inner diameter da of the barrel body 10 may be 4 to 33 mm. In this embodiment, the inner diameter da of the barrel body 10 is shown as being the same along the entire axial length, but there may be slight differences in the inner diameter depending on the part due to draft angles, etc. In that case, it is sufficient if at least a part of it is within the range described above. Furthermore, the axial length La of the barrel body 10 (here, as shown in Figure 2, the length from the base end of the barrel body 10 to the base end of the shoulder 15) is appropriately selected depending on the intended use of the syringe barrel 1 (type and amount of drug (medicine solution), etc.). For example, if the nominal capacity of the syringe barrel 1 is 0.5 to 100 mL, the axial length La of the barrel body 10 may be 34 to 159 mm. More specifically, if the nominal capacity of the syringe barrel 1 is 0.5 mL, the axial length La of the barrel body 10 is preferably 46 to 56 mm. Also, if the nominal capacity of the syringe barrel 1 is 1 mL, the axial length La of the barrel body 10 is preferably 34 to 56 mm (for example, 54 to 56 mm for a barrel body of normal diameter, and 34 to 37 mm for a barrel body of large diameter). Furthermore, when the nominal capacity of the syringe barrel 1 is 2.25 mL, the axial length La of the barrel body 10 is preferably 53 to 56 mm. Also, when the nominal capacity of the syringe barrel 1 is 100 mL, the axial length La of the barrel body 10 is preferably 154 to 159 mm.

[0016] The barrel body portion 10 of this embodiment is provided with a shoulder portion 15 formed at the tip and which tapers in diameter toward the tip. The barrel body portion 10 is also provided with a base end opening 11 and a flange 16 that protrudes in a flat shape from the outer circumference of the base end at the base end.

[0017] The barrel body portion 10 of the syringe barrel 1 is preferably transparent or translucent. Examples of materials for forming the barrel body portion 10 include various resins such as polypropylene, polyethylene, polystyrene, polyamide, polycarbonate, polyvinyl chloride, poly-(4-methylpentene-1), acrylic resin, polyester such as acrylonitrile-butadiene-styrene copolymer and polyethylene terephthalate, cyclic olefin polymers, and cyclic olefin copolymers. Among these, polypropylene and cyclic polyolefins (e.g., cyclic olefin polymers, cyclic olefin copolymers) are preferred because they are easy to mold and have heat resistance.

[0018] The syringe barrel 1 is equipped with a cylindrical lancet attachment portion 30. As shown in Figures 4 to 7, the lancet attachment portion 30 protrudes forward from the tip (shoulder portion 15) of the barrel body portion 10 and is a hollow cylinder with a smaller diameter than the barrel body portion 10. The base end of the lancet 50 is inserted into and fixed in the lancet attachment portion 30. As shown in Figure 5, the axial length Lb of the lancet attachment portion 30 is selected as appropriate, but is preferably 5.0 to 12.0 mm. More specifically, for example, if the nominal capacity of the syringe barrel 1 is 1 mL or 2.25 mL, the axial length Lb of the lancet attachment portion 30 is more preferably 7.0 to 11.0 mm.

[0019] The puncture needle 50 is hollow and has a puncture needle tip 51 at its end. The base end of the puncture needle 50 is inserted into and fixed within the hollow portion of the puncture needle attachment portion 30, and the inside of the puncture needle 50 is in communication with the internal space 14 of the barrel body portion 10. The material used to form the puncture needle 50 is generally metal. Stainless steel is preferred as the metal.

[0020] In this embodiment, as shown in Figures 6 and 7, the puncture needle 50 is directly fixed to the syringe barrel 1 by insert molding. In the case of insert molding, by molding the syringe barrel 1, the puncture needle mounting portion 30 becomes a cylindrical (hollow) shape into which the puncture needle 50 is inserted, and the base end of the puncture needle 50 is inserted and fixed within the hollow portion of the puncture needle mounting portion 30.

[0021] Alternatively, the puncture needle 50 may be inserted into the hollow portion of the puncture needle mounting section 30 of the pre-formed syringe barrel 1 and fixed to the puncture needle mounting section 30 by adhesive, heat welding (laser welding, etc.).

[0022] Furthermore, as shown in the syringe barrel 1a of the embodiment in Figures 9 and 10, the puncture needle 50 may be fixed to the puncture needle attachment portion 30a by fusing (for example, heat fusion, ultrasonic fusion, laser fusion, or induction heating fusion) a cylindrical member 36 made of thermoplastic resin. In this case, the puncture needle attachment portion 30a of the syringe barrel 1a is provided with a lumen 37 capable of housing the cylindrical member 36, and the cylindrical member 36 used has a communication hole 38 capable of housing the base end of the puncture needle 50. The cylindrical member 36 into which the base end of the puncture needle 50 is inserted is then inserted into the lumen 37 of the puncture needle attachment portion 30a, and the puncture needle 50 is fixed to the puncture needle attachment portion 30a via the cylindrical member 36 by directly or indirectly heating and melting the cylindrical member 36. Furthermore, when fixing the cylindrical member 36 to the puncture needle attachment portion 30a by laser fusion, it is preferable to form the puncture needle attachment portion 30a from a laser-transparent material and the cylindrical member 36 from a laser-impermeable material (a material that generates heat when irradiated with a laser).

[0023] As shown in Figures 4 to 7, more specifically regarding the puncture needle attachment portion 30 of this embodiment, the puncture needle attachment portion 30 is provided with a large-diameter tip portion 31 at its tip. The large-diameter tip portion 31 comprises a tip recess 32 that is recessed from the tip surface toward the base end, and a hollow tapered convex portion 33 located within the tip recess 32, which becomes smaller in diameter toward the tip. The taper angle θ2 of the tapered convex portion 33 is 15 to 50°. As a result, as shown in Figure 8, when insert molding the puncture needle 50, the shape of the mold 71 for forming the tapered convex portion 33 (tapered recess 72) becomes a shape that can draw in the puncture needle 50 which is temporarily fixed in another mold (not shown), thereby preventing damage to the puncture needle 50 during insert molding.

[0024] The needle attachment portion 30 of the syringe barrel 1 in this embodiment is provided with a large-diameter tip portion 31 at its tip, and the large-diameter tip portion 31 is provided with an annular tip recess 35. Specifically, the large-diameter tip portion 31 is provided with a tip recess 32 that is recessed from the tip surface toward the base end, and a hollow tapered protrusion 33 located within the tip recess 32 that becomes smaller in diameter toward the tip, thereby forming an annular tip recess 35 in the needle attachment portion 30 (large-diameter tip portion 31).

[0025] Preferably, the tapered projection 33 has an outer surface that tapers linearly toward the tip, and preferably does not have any steps or other irregularities. The outer surface of the tapered projection 33 may be slightly curved, either bulging outward or concave inward. The large-diameter tip portion may be a hollow cylindrical shape (cylindrical shape) without a tip concave portion or tapered projection.

[0026] The lancet attachment portion 30 of this embodiment has a smaller diameter than the large-diameter tip portion 31 and includes a small-diameter connecting portion 40 that connects the base end of the large-diameter tip portion 31 (the annular recess 35 of the large-diameter tip portion 31, described later) and the tip of the barrel body portion 10 (the shoulder portion 15 described above). As shown in Figures 6 and 7 (or Figures 9 and 10), the base end of the lancet 50 (and / or the base end of the cylindrical member 36) enters the small-diameter connecting portion 40 (40a). As shown in Figure 7 (Figure 10), the wall thickness t6 (t6a) of the small-diameter connecting portion 40 (40a) is preferably 0.5 to 1.5 mm (the wall thickness of the small-diameter connecting portion 40, 40a may not be constant due to the draft angle of the hollow portion, etc., but it is sufficient if at least a part of it is within the above range). In addition, the axial length L6 of the small-diameter connecting portion 40, 40a is preferably 4.0 to 8.0 mm.

[0027] The syringe barrel 1 is provided with plate-shaped reinforcing ribs 60 that protrude outward from the outer surface of the puncture needle attachment portion 30 and extend in the axial direction. In this embodiment, the syringe barrel 1 is provided with a plurality (here, four) of reinforcing ribs 60. As shown in Figures 4 and 5, in this embodiment, the reinforcing ribs 60 protrude outward from the outer surface of the small-diameter connecting portion 40 between the base end of the large-diameter tip portion 31 and the tip (shoulder portion 15) of the barrel body portion 10. In this embodiment, the protrusion height of the reinforcing ribs 60 increases toward the base end. As shown in Figure 6, the inclination (angle of inclination θ1) of the outer surface of the reinforcing rib 60 with respect to the central axis of the syringe barrel 1 is preferably 1 to 10°. As shown in Figure 4, the circumferential width (thickness) t1 of the puncture needle attachment portion of the reinforcing rib 60 is preferably 0.5 to 1.5 mm, and more preferably 0.6 to 1.2 mm. This increases the rigidity of the tip of the syringe barrel 1 (puncture needle attachment part 30), allowing the puncture needle 50 to be stably inserted into the patient or other person.

[0028] Furthermore, the reinforcing rib is not limited to the above-described configuration. For example, its tip may extend to the large-diameter tip of the puncture needle attachment portion, or its tip may be provided to terminate at the central portion of the small-diameter connecting portion. Also, the protruding height of the reinforcing rib may be constant along its entire axial length.

[0029] The reinforcing rib 60 may be a single rib, but it is preferable to have multiple ribs (for example, 3 to 6). Furthermore, it is preferable that these multiple reinforcing ribs 60 are provided at equal intervals in the circumferential direction of the puncture needle attachment portion 30 (small diameter connecting portion 40). In this embodiment, as shown in Figure 4, four reinforcing ribs 60 are provided at 90° intervals in the circumferential direction. This makes it possible to increase the rigidity of the tip portion (puncture needle attachment portion 30) of the syringe barrel 1 while ensuring the size of the non-reinforcing rib portion (recess) 41 (width in the circumferential direction of the puncture needle attachment portion 30), which will be described later.

[0030] As described above, in this embodiment, the reinforcing rib 60 protrudes outward from the outer surface of the small-diameter connecting portion 40 between the base end of the large-diameter tip portion 31 and the tip portion (shoulder portion 15) of the barrel body portion 10. As a result, multiple (in this case, four) non-reinforcing rib portions (recesses) 41 extending in the axial direction are formed on the outer surface of the puncture needle attachment portion 30. In other words, in the non-reinforcing rib portions 41, the radial wall thickness of the puncture needle attachment portion 30 is small (only the wall thickness of the small-diameter connecting portion 40). As a result, for example, in this embodiment, when the puncture needle 50 is fixed by laser welding, or when the puncture needle 50 is fixed by laser fusion using a tubular member 36 made of thermoplastic resin, as in the embodiment shown in Figures 9 and 10, by irradiating the laser from the non-reinforcement rib portion (recess) 41, the desired portion can be effectively heated and melted, and the puncture needle 50 can be fixed more securely to the syringe barrel 1,1a (puncture needle mounting portion 30,30a). Furthermore, from the viewpoint of facilitating such laser welding and laser fusion, the thickness of the reinforcement rib portion 41 (wall thickness t6 of the small diameter connecting portion 40) is preferably 0.5 to 1.5 mm.

[0031] The lancet attachment portion 30 is provided with a cap attachment portion 34 formed on its outer surface, and the cap attachment portion 34 is further provided with an annular recess 35 located a predetermined distance from the tip of the lancet attachment portion 30 towards the base end, with a minimum outer diameter D5min of 2.0 to 5.0 mm in the annular recess 35. More preferably, the minimum outer diameter D5min of such an annular recess 35 is 3.0 to 4.0 mm.

[0032] Specifically, in this embodiment, as shown in Figures 5 and 6, the annular recess 35 of the cap mounting portion 34 is provided at the base end of the large-diameter tip portion 31 and is formed between a short tapered reduced-diameter portion 42 that decreases in diameter toward the base end and the tip of the reinforcing rib 60. By engaging with the seal cap 80 (protruding portion 87), which will be described later, the cap mounting portion 34 (annular recess 35) can prevent the seal cap 80 from unintentionally falling off the syringe barrel 1.

[0033] Furthermore, the large-diameter tip portion does not necessarily have a tapered diameter reduction portion at its base end, and the annular recess may be a stepped shape provided a predetermined distance from the tip of the puncture needle attachment portion (large-diameter tip portion) towards the base end. Also, the annular recess is not limited to being provided at the base end portion (the tip of the reinforcing rib) of the large-diameter tip portion as described above, but may also be provided on the outer surface of the axial center portion of the large-diameter tip portion.

[0034] As shown in Figure 11, the syringe barrel 1 of this embodiment can be fitted with a seal cap 80 for sealing (protecting) the tip of the puncture needle 50 (puncture needle tip 51). The seal cap 80 of this embodiment comprises a closed tip portion 81, an open base portion 82, a hollow portion 85 having a puncture needle attachment portion storage portion 83 for housing the puncture needle attachment portion 30 and a puncture needle storage portion 84 continuous with the puncture needle attachment portion storage portion 83, an insertable portion 86 into which the puncture needle tip 51 of the puncture needle 50 stored in the puncture needle storage portion 84 can be inserted, and a protruding portion 87 formed on the inner surface of the puncture needle attachment portion storage portion 83.

[0035] When the seal cap 80 is attached to the puncture needle attachment portion 30 of the syringe barrel 1, as shown in Figure 11, the tip of the puncture needle 51 is inserted into the insertable portion 86 of the seal cap 80 and sealed, and the protruding portion 87 engages with the annular recess 35 of the cap attachment portion 34 of the puncture needle attachment portion 30, and the inner surface of the puncture needle attachment portion housing portion 83 and the outer surface of the puncture needle attachment portion 30 are in close contact. A coating, such as a polyparaxylylene coating, may be formed on the inner surface of the puncture needle attachment portion housing portion 83 of the seal cap 80 to prevent sticking with the puncture needle attachment portion 30.

[0036] The seal cap 80 is provided with a projection 87 on its inner surface located a predetermined distance towards the tip from the opening base end 82. The inner diameter of the lancet attachment housing portion 83 in the projection 87 is slightly smaller than the minimum outer diameter D5min of the annular recess 35 of the lancet attachment portion 30. As a result, when the seal cap 80 is attached to the syringe barrel 1 (lancet attachment portion 30), the projection 87 and the annular recess 35 of the cap attachment portion 34 engage, preventing the seal cap 80 from unintentionally detaching from the syringe barrel 1. Furthermore, it is preferable that the minimum outer diameter D5min of the annular recess 35 of the needle attachment portion 30 of the syringe barrel 1 is equal to or 2 mm or less larger than the inner diameter d7 of the protrusion 87 of the seal cap 80 (Note that in Figure 11, the inner diameter d7 of the protrusion 87 is shown in the engaged state with the annular recess 35 (slightly deformed state), but in reality, it refers to the dimension in the state before engagement (the seal cap 80 alone)).

[0037] As the material for forming the seal cap 80, it is necessary that at least the punctureable portion 86 is formed of an elastic material into which the puncture needle 50 can be inserted. Preferred materials for forming such a seal cap 80 include thermoplastic elastomers, such as styrene-based elastomers like SBS elastomer and SEBS elastomer, and olefin-based elastomers such as ethylene-α-olefin copolymer elastomer. Alternatively, the material for forming the seal cap 80 may be rubber, such as butyl rubber, isoprene rubber, latex rubber, or silicone rubber.

[0038] As shown in Figure 12, the barrel body portion 10 of the syringe barrel 1 includes a base end opening 11 and a base end diameter reduction portion 12 provided on the tip side of the base end opening 11 and which is diameter-reduced (inner diameter decreases) toward the base end. The minimum inner diameter d3min of the base end diameter reduction portion 12 is 0.1 to 3.0 mm smaller than the maximum inner diameter d3max of the base end diameter reduction portion 12. More preferably, the minimum inner diameter d3min of the base end diameter reduction portion 12 is 0.1 to 0.8 mm smaller than the maximum inner diameter d3max of the base end diameter reduction portion 12. In other words, in the base end diameter reduction portion 12 of the barrel body portion 10, the portion that defines the minimum inner diameter d3min exists on the base end side of the portion that defines the maximum inner diameter d3max. This prevents the gasket 70, which is slidably housed inside the barrel body portion 10 as described later, from unintentionally detaching from the barrel body portion 10 (base end opening 11). Furthermore, when forming the barrel body 10 (syringe barrel 1) by injection molding, as shown in Figure 13, the molded product can be left in the intended mold 71a (core pin portion 73 for forming the internal space 14 of the barrel body 10).

[0039] More specifically, as shown in Figure 12, the base-end diameter-reducing portion 12 of the syringe barrel 1 in this embodiment is a tapered diameter-reducing portion that decreases in diameter (internal diameter shrinks) toward the base end. The inner surface of the base-end diameter-reducing portion (tapered diameter-reducing portion) 12 may be slightly curved, either concave outward or bulging inward.

[0040] Furthermore, a tapered diameter-expanding portion 17 is formed on the tip side of the base-end diameter-reducing portion 12, which expands the inner diameter of the barrel body portion 10 toward the base end, and the base end of the tapered diameter-expanding portion 17 and the tip of the base-end diameter-reducing portion (tapered diameter-reducing portion) 12 are continuous. In other words, in the barrel body portion 10 of the syringe barrel 1 of this embodiment, a base-end annular recess 18 is formed on the tip side of the base-end opening 11, which has a base-end diameter-reducing portion 12 (consisting of the tapered diameter-expanding portion 17 and the base-end diameter-reducing portion 12).

[0041] In this embodiment, the maximum inner diameter d3max of the base-side reduced diameter portion 12 is defined at its tip, i.e., at the boundary with the base end of the tapered enlarged diameter portion 17. The minimum inner diameter d3min of the base-side reduced diameter portion 12 is defined at the base end of the base-side reduced diameter portion 12. Preferably, the minimum inner diameter d3min of the base-side reduced diameter portion 12 is equivalent to the inner diameter of the tip of the tapered enlarged diameter portion 17 (inner diameter da of the barrel body portion 10). This reduces the force applied to the base-side reduced diameter portion 12 from the core pin portion 73 when demolding the barrel body portion 10 from the core pin portion 73 of the mold 71a, making it easier to maintain the shape of the base-side reduced diameter portion 12 during demolding and improving the dimensional stability of the base-side reduced diameter portion 12.

[0042] Furthermore, it is preferable that the axial length L3 of the base-side reduced diameter portion (tapered reduced diameter portion) 12 is longer than the axial length L7 of the tapered enlarged diameter portion 17. In other words, it is preferable that the taper angle of the base-side reduced diameter portion (tapered reduced diameter portion) 12 is smaller than the taper angle of the tapered enlarged diameter portion 17. It is also preferable that the axial length L3 of the base-side reduced diameter portion (tapered reduced diameter portion) 12 is 1.0 to 20.0 mm longer than the axial length L7 of the tapered enlarged diameter portion 17.

[0043] Furthermore, as shown in the embodiment of the syringe barrel 1b in Figure 14, the syringe barrel 1b (barrel body portion 10b) may not have the tapered diameter-expanding portion (tapered diameter-expanding portion 17) described above. In other words, the barrel body portion 10b of the syringe barrel 1b shown in Figure 14 does not have a base-end annular recess formed on the tip side of the base-end opening 11, consisting of a tapered diameter-expanding portion and a base-end diameter-reducing portion. In the embodiment shown in Figure 14, the base-end diameter-reducing portion (tapered diameter-reducing portion) 12b is directly formed from the inner surface of the barrel body portion 10b. In this case, the maximum inner diameter d3maxb of the base-end diameter-reducing portion 12b is the inner diameter of the tip of the base-end diameter-reducing portion 12b, and is the same as the inner diameter da of the barrel body portion 10b. In this embodiment, it is preferable that the minimum inner diameter d3minb of the base-side reduced-diameter portion 12b is 0.1 to 0.8 mm smaller than the maximum inner diameter d3maxb (inner diameter da of the barrel body portion 10b) of the base-side reduced-diameter portion 12b. This reduces the force applied to the base-side reduced-diameter portion 12b from the core pin portion (73) when demolding the barrel body portion 10b from the core pin portion (73) of the mold (71a), as described above. This makes it easier to maintain the shape of the base-side reduced-diameter portion 12b during demolding and improves the dimensional stability of the base-side reduced-diameter portion 12b.

[0044] As shown in Figure 12, the barrel body portion 10 comprises a base end opening 11 and a barrel base end tapered portion 13 that expands in diameter (inner diameter increases) toward the base end opening 11, and the inclination angle θ4 of the barrel base end tapered portion 13 with respect to the central axis of the barrel body portion 10 is 3 to 45°. This makes it easy to insert the gasket 70, which will be described later, into the barrel body portion 10 from the base end opening 11. The axial length L4 of the barrel base end tapered portion 13 is preferably 1.0 to 4.0 mm, and particularly preferably 1.2 to 2.5 mm.

[0045] Furthermore, as shown in Figure 12, the inner diameter d8 of the base end opening 11 (the maximum inner diameter of the barrel base end tapered portion 13) is preferably larger than the outer diameter of the gasket 70, and is more preferably 0.5 to 10.0 mm larger, depending on the outer diameter of the gasket 70.

[0046] As shown in Figure 15, the syringe barrel 1 of this embodiment can be used as a syringe 100 by combining it with a gasket 70 slidably housed within the barrel body 10 and a plunger 74 for moving the gasket 70.

[0047] The gasket 70 is made of elastic rubber or synthetic resin. The gasket 70 comprises a roughly cylindrical main body extending with substantially the same outer diameter and an annular rib provided on the outer surface of the main body, the outer surface of which is in liquid-tight contact with the inner surface of the barrel main body 10.

[0048] It is preferable to use elastic rubber (for example, butyl rubber, latex rubber, silicone rubber, styrene-butadiene rubber, isoprene rubber, etc.), thermoplastic elastomers (for example, styrene-based elastomers such as SBS elastomer, SEBS elastomer, SEPS elastomer, etc., olefin-based elastomers such as ethylene-α-olefin copolymer elastomer, etc.) as the material for forming the gasket 70.

[0049] The gasket 70 in this embodiment is provided with a recess extending inward from its base end, and this recess serves as a plunger mounting portion. A female thread is formed on the inner surface of the plunger mounting portion, which can be screwed into a male thread formed on the outer surface of the gasket mounting portion formed on the tip of the plunger 74, which will be described later.

[0050] Within the syringe 100 (syringe barrel 1), a drug (medicinal solution) can be stored in the space (internal space 14) formed between the barrel body 10 and the gasket 70. As shown in Figure 15, the syringe 100 can also be used with the drug (medicinal solution) 75 pre-filled (a so-called pre-filled syringe).

[0051] The plunger 74 comprises a main body extending in the axial direction, a gasket mounting portion provided at its tip, and a disc-shaped pressing portion provided at the base end of the main body. The outer surface of the gasket mounting portion has a male threaded portion that screws into the plunger mounting portion (female threaded portion) of the gasket 70. The plunger 74 is attached to the gasket 70 by screwing the plunger mounting portion of the gasket 70 and the gasket mounting portion of the plunger 74 together. The plunger may not be attached to the gasket at all, but may be attached to the gasket when in use. This prevents the plunger from being accidentally pressed before use. The plunger may also contact the gasket and move the gasket. It is preferable to use a hard or semi-hard resin such as high-density polyethylene, polypropylene, polystyrene, or polyethylene terephthalate as the constituent material of the plunger 74.

[0052] Even in this syringe 100, the rigidity of the tip of the syringe barrel 1 (puncture needle attachment part 30) is enhanced by the reinforcing rib 60, allowing the puncture needle 50 to be stably inserted into the patient or other person. [Explanation of symbols]

[0053] 1,1a,1b Syringe barrel 10,10b Barrel body 11 Proximal opening 12,12b Proximal side reduced diameter section 13 Barrel base tapered section 30,30a Puncture needle attachment section 31 Large diameter tip 32. Tip recess 33 Tapered protrusion 34 Cap mounting section 35 Annular recess 50 puncture needle 51 Puncture needle tip 60 Reinforcement ribs 70 Gasket 74 Plungers 80 Seal Cap 100 syringes (pre-filled syringes)

Claims

1. A syringe barrel comprising a cylindrical barrel body, a cylindrical puncture needle attachment portion provided at the tip of the barrel body, and a puncture needle having a puncture needle tip at its end, with its base end inserted into and fixed in the puncture needle attachment portion, A syringe barrel characterized by having plate-shaped reinforcing ribs that protrude outward from the outer surface of the puncture needle attachment portion and extend in the axial direction, wherein the reinforcing ribs have a width of 0.5 to 1.5 mm in the circumferential direction of the puncture needle attachment portion.

2. The aforementioned puncture needle attachment portion is equipped with a large-diameter tip portion at its tip, The aforementioned large-diameter tip portion comprises a tip recess that is recessed from the tip surface toward the base end, and a hollow tapered convex portion located within the tip recess and decreasing in diameter toward the tip. The syringe barrel according to claim 1, wherein the taper angle of the tapered protrusion is 15 to 50°.

3. The barrel body portion comprises a base end opening and a base end diameter reduction portion provided on the tip side of the base end opening and decreasing in diameter toward the base end. The syringe barrel according to claim 1, wherein the minimum inner diameter of the base end-side reduced diameter portion is 0.1 to 3.0 mm smaller than the maximum inner diameter of the base end-side reduced diameter portion.

4. The barrel body portion comprises a base end opening and a barrel base end tapered portion that widens in diameter toward the base end opening. The syringe barrel according to claim 1, wherein the angle of inclination of the barrel base tapered portion with respect to the central axis of the barrel body portion is 3 to 45°.

5. The lancet attachment portion includes a cap attachment portion formed on its outer surface, and the cap attachment portion further includes an annular recess provided a predetermined distance from the tip of the lancet attachment portion toward the base end. A syringe barrel according to any one of claims 1 to 4, wherein the minimum outer diameter of the annular recess is 2.0 to 5.0 mm.

6. A syringe barrel comprising a cylindrical barrel body, a cylindrical puncture needle attachment portion provided at the tip of the barrel body, and a puncture needle having a puncture needle tip at its end, with its base end inserted into and fixed in the puncture needle attachment portion, The puncture needle attachment portion is provided with plate-shaped reinforcing ribs that protrude outward from the outer surface and extend in the axial direction, and the width of the reinforcing ribs in the circumferential direction of the puncture needle attachment portion is 0.5 to 1.5 mm. The aforementioned puncture needle attachment portion is equipped with a large-diameter tip portion at its tip, The aforementioned large-diameter tip portion comprises a tip recess that is recessed from the tip surface toward the base end, and a hollow tapered convex portion located within the tip recess and decreasing in diameter toward the tip. The taper angle of the tapered protrusion is 15 to 50°. The barrel body portion comprises a base end opening and a base end diameter reduction portion provided on the tip side of the base end opening and decreasing in diameter toward the base end. The minimum inner diameter of the base end-side reduced diameter portion is 0.1 to 3.0 mm smaller than the maximum inner diameter of the base end-side reduced diameter portion. Furthermore, the barrel body portion is provided with a barrel base end tapered portion that widens in diameter toward the base end opening, The angle of inclination of the barrel base tapered portion with respect to the central axis of the barrel body portion is 3 to 45°. The puncture needle attachment portion includes a cap attachment portion formed on its outer surface, and the cap attachment portion includes an annular recess provided a predetermined length from the tip of the puncture needle attachment portion toward the base end. A syringe barrel characterized in that the minimum outer diameter of the annular recess is 2.0 to 5.0 mm.

7. A syringe barrel comprising a cylindrical barrel body, a cylindrical puncture needle attachment portion provided at the tip of the barrel body, and a puncture needle having a puncture needle tip at its end, with its base end inserted into and fixed in the puncture needle attachment portion, The puncture needle attachment portion is provided with plate-shaped reinforcing ribs that protrude outward from the outer surface and extend in the axial direction, and the width of the reinforcing ribs in the circumferential direction of the puncture needle attachment portion is 0.5 to 1.5 mm. The aforementioned puncture needle attachment portion is equipped with a large-diameter tip portion at its tip, The aforementioned large-diameter tip portion comprises a tip recess that is recessed from the tip surface toward the base end, and a hollow tapered convex portion located within the tip recess and decreasing in diameter toward the tip. The taper angle of the tapered protrusion is 15 to 50°. The puncture needle attachment portion includes a cap attachment portion formed on its outer surface, and the cap attachment portion includes an annular recess provided a predetermined length from the tip of the puncture needle attachment portion toward the base end. A syringe barrel characterized in that the minimum outer diameter of the annular recess is 2.0 to 5.0 mm.

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