JP4658710B2 - Syringe for viscous liquid injection - Google Patents

Description

  The present invention relates to a viscous liquid injection syringe for injecting a liquid having a certain degree of viscosity, such as a dental photosensitive filler and a hyaluronic acid preparation, into a predetermined site.

  As shown in FIG. 9, this type of conventional dental photosensitive filler injection syringe 20 is provided with a nozzle mounting portion 22 at the tip of a cylindrical storage portion 21 for storing a dental photosensitive filler. The nozzle member 23, which is separately marketed, is attached to the nozzle mounting portion 22 so as to be attachable / detachable. The nozzle member 23 has a mounting hole 24 at the base portion, and a small hole 25 for discharging a liquid agent is formed on the top surface of the mounting hole 24, and a dental photosensitive filler is placed in small amounts through the small hole 25. Can be discharged. The nozzle mounting portion 22 has a cylindrical connection portion 26 that is inserted into the base mounting hole 24 of the nozzle member 23 and a cylindrical connection that is provided on the outer peripheral side of the insertion portion 26 and has a double threaded screw 27 formed on the inner surface. The nozzle member 23 is attached to the nozzle mounting portion 22 by engaging an engagement piece 29 formed on the base end portion of the nozzle member 23 with the screw 27. Further, an extrusion rod (not shown) is attached to the rear side of the syringe 20, and the filler in the storage portion 21 can be discharged through the nozzle member 23 by pushing the extrusion rod. Yes.

  When the conventional syringe 20 is used, the nozzle member 23 is discarded and replaced for each patient in order to prevent infection such as hepatitis C. However, since there is a large space at the back of the mounting hole 24, During use, bubbles may be mixed into the filler, and bubbles may be mixed into the material even when filling or curing the cavity, so that sufficient material properties cannot be obtained, and the discharged material Adverse effects on the wear resistance, bending strength, compressive strength, and the like. In addition, bubbles appeared on the surface due to wear, and had problems with oral hygiene such as bacterial growth. In particular, the present applicants automatically set the inside of the nozzle member after operation of the push rod to prevent the expensive dental photosensitive filler from remaining in the discarded nozzle member when the nozzle member is replaced. Has developed a syringe that sucks back the filler, but if there are minute bubbles in the corner of the inner periphery of the mounting hole 24, the filler is sucked back into the syringe together with the bubbles, and the bubbles are filled. It will be mixed in the material. Further, considering the detachability when replacing the nozzle member 23, if the screw and the engaging piece are loosely screwed together, the nozzle member 23 may fall off. However, it was difficult to detach and attach quickly.

In order to prevent air bubbles from being mixed in, Patent Document 1 proposes an improvement relating to the structure of the nozzle member.
JP 2003-260065 A

  However, the means proposed in Patent Document 1 cannot use the current nozzle member that has already been distributed in large quantities.

  Therefore, the present invention is capable of preventing air bubbles from being mixed into a viscous liquid agent while using a conventional standard nozzle member, and is capable of attaching and detaching the nozzle member with a light force. An object of the present invention is to provide a syringe that can prevent the members from being accidentally dropped.

  The viscous liquid injection syringe of the present invention is a nozzle member having a mounting hole at the base and a small hole for discharging a liquid agent at the top surface of the mounting hole at the tip of the storage section for storing the viscous liquid Has a nozzle mounting portion that is detachably mounted. The mounting portion includes a cylindrical insertion portion that is inserted into a base mounting hole of the nozzle member, a screw provided on an inner surface of the insertion portion. The nozzle member is attached to the nozzle attachment portion by an engagement piece provided at the base end portion of the nozzle member being screwed into the screw. The internal space of the insertion part communicates with the internal space of the storage part, and the liquid agent may be discharged through the internal space of the insertion part. The screw on the inner surface of the connection part can be preferably a double thread. The small hole of the nozzle member may be provided in the central portion of the shaft of the mounting hole.

  The insertion portion has an outer diameter at the midway portion in the axial direction that is substantially equal to the diameter of the mounting hole, and an inner diameter that gradually decreases from the midway portion in the axial direction to the tip side. The tip opening of the insertion portion is directly connected to the small hole by bringing the tip portion into contact with the top surface of the mounting hole of the nozzle member, so that the liquid agent discharge path from the insertion portion internal space to the small hole is directed to the tip side. It is preferable that the diameter gradually becomes smaller as it reaches. According to such a configuration, the step of the liquid agent discharge path at the opening end of the nozzle member can be made as small as possible, no bubbles are generated in the step portion, and the bubbles are contained in the filler even when the liquid agent is sucked back. Is not mixed in.

  Preferably, when the nozzle member is further screwed into the nozzle mounting portion by a predetermined amount from a position where the distal end portion of the insertion portion just contacts the top surface of the mounting hole of the nozzle member, it engages with the engagement piece. A convex portion that prevents screwing of the nozzle member can be provided on the inner surface of the connection portion. According to such a configuration, the screw fastening force can be increased by further tightening in a state where the distal end portion of the insertion portion is in contact with the top surface of the mounting hole. Therefore, even when the clearance between the thread and the engagement piece is increased so that the nozzle member can be tightened with a light force, a strong fastening force can be obtained at the screwing end, and the nozzle member can be accidentally dropped off. Can be prevented. Further, by restricting the screwing amount of the nozzle member by the convex portion, the contact force between the distal end portion of the insertion portion and the top surface of the mounting hole is made constant while preventing the front end portion of the insertion portion from being crushed. Airtightness at the site can be secured. In addition, since a predetermined clearance is formed between the screw and the engagement piece, if further tightening is performed after the distal end portion of the insertion portion comes into contact with the top surface of the mounting hole, the connection portion is The nozzle member rotates until it almost engages with the convex part without moving in the axial direction, whereby the engagement piece is strongly pressed against the lower edge of the thread of the screw, and the distal end of the insertion part is attached to the mounting hole. Strongly pressed against the top of

  Preferably, an air vent groove extending in the axial direction is formed on the outer peripheral surface of the insertion portion, and the mounting hole internal space on the distal end side of the insertion portion and the connection portion internal space on the insertion base portion side are provided via the air vent groove. Can communicate with each other. According to such a configuration, it is possible to prevent the pressure in the internal space of the storage portion at the distal end side of the insertion portion from increasing when the nozzle member is attached, and air from flowing into the insertion portion or the small hole of the nozzle member from the space. .

  According to the syringe of the present invention, it is possible to prevent bubbles from being mixed into the viscous liquid agent, and it is possible to prevent the nozzle member from being accidentally dropped while the nozzle member can be attached and detached with a light force.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.

  1 to 4 show a distal end structure of a dental filler injection syringe 1 according to an embodiment of the present invention. The syringe 1 includes a cylindrical storage portion 2 for storing a viscous liquid agent, and the storage portion. A nozzle mounting portion 3 provided at the tip of the portion 2, and a nozzle member 4 (tip tip) is detachably mounted on the mounting portion 3. An extrusion rod (not shown) is attached to the rear part of the storage unit 2, and is configured so that the liquid agent in the storage unit 2 can be discharged by pushing the rod.

  As a liquid agent accommodated in the accommodating part 2, a dental filling material, Preferably a photopolymerization type flow filler can be used, It is preferable to use the thing whose viscosity is 5-1000 Pa.s. Particularly preferably, a filler for directly filling the cavity and fissure of the tooth in the oral cavity can be used.

  As shown in FIG. 4, the nozzle member 4 includes a cylindrical base portion 6 having a circular mounting hole 5 formed in the base end side and a narrow tube 7 attached to the front end side of the base portion 6. It has. The narrow tube 7 is opened at the top surface of the mounting hole 5, and a small hole 8 for discharging the liquid agent is formed at the center of the top surface of the mounting hole 5. Engagement pieces 12 projecting in the radial direction are provided on the outer periphery of the base end portion of the base 6. In the illustrated embodiment, two engagement pieces 12 are provided at two locations in the diameter direction.

  The nozzle mounting portion 3 includes a cylindrical insertion portion 9 that is inserted into the base mounting hole 5 of the nozzle member 4 and a cylindrical shape that is provided on the outer peripheral side of the insertion portion 9 and has a double thread 10 formed on the inner surface. It consists of a connection part 11. The insertion portion 9 and the connection portion 11 are provided concentrically, and a gap for inserting the base portion 6 of the nozzle member 4 is formed between the outer peripheral surface of the insertion portion 9 and the inner peripheral surface of the connection portion 11. The engagement piece 12 provided at the base end portion of the nozzle member 4 is screwed into the screw 10 so that the nozzle member 4 is attached so as to be screwed into the nozzle attachment portion 3.

  The insertion portion 9 is formed such that the outer diameter of the midway portion in the axial direction is substantially equal to the diameter of the mounting hole 5, and the inner diameter and the outer diameter are gradually reduced from the midway portion in the axial direction to the tip side. It is formed in a tapered shape as a whole. The diameter of the distal end portion of the insertion portion 9 is preferably as small as possible, but can be set to an appropriate size from the viewpoint of moldability and yield.

  The distal end portion of the insertion portion 9 is configured to come into contact with the top surface of the mounting hole 5 of the nozzle member 4 by tightening the nozzle member 4. The tip opening of the insertion portion 9 is directly connected to the small hole 8 by being brought into contact with the top surface, whereby the liquid agent discharge path from the insertion portion 9 internal space to the small hole 8 is gradually reduced in diameter toward the distal end side. It is comprised so that it may become.

  Further, the nozzle member 4 is further screwed into the nozzle mounting portion 3 by a predetermined amount from the position where the distal end portion of the insertion portion 9 just contacts the top surface of the mounting hole 5 of the nozzle member 4 (position indicated by the phantom line in FIG. 3). At this time (a position indicated by an imaginary line in FIG. 1), a convex portion 13 that engages with the engagement piece 12 to prevent the nozzle member 3 from being screwed is provided on the inner surface of the connection portion 11. In the illustrated embodiment, the convex portion 13 is formed by a rib that protrudes higher than the thread height of the screw 10 and extends in the axial direction from a midway portion in the spiral direction of the screw 10, and corresponds to the two engagement pieces 12. Are provided at two locations in the diameter direction.

  In addition, on the outer peripheral surface of the insertion portion 9, air vent grooves 14 extending in the axial direction are formed at two locations in the diametrical direction, and the nozzle member 4 is inserted through the air vent groove 14 while being attached to the mounting portion 3. The internal space of the mounting hole 5 on the distal end side of the portion 9 communicates with the internal space of the connecting portion 11 on the base portion side of the insertion portion 9.

  According to the syringe 1 according to the above embodiment, the step in the middle part of the liquid agent discharge path can be made as small as possible while using the commercially available standard nozzle member 4, and bubbles do not stay in the step. Since the liquid agent is discharged smoothly, bubbles can be prevented from being mixed into the liquid agent such as a dental photosensitive filler having viscosity. Furthermore, since the screw fastening force is increased by performing additional tightening at the last time when the nozzle member 4 is screwed, the engagement piece 12 can be relatively loosely screwed with the screw 10, thereby Although the nozzle member 4 can be attached and detached with a light force, the nozzle member 4 can be prevented from accidentally falling off. In addition, since the final position at which the nozzle member 4 is screwed by the convex portion 13 is regulated, the contact force between the distal end surface of the insertion portion 9 and the top surface of the mounting hole 5 becomes too large and the insertion portion 9 is crushed. Can be prevented.

  In the commercially available nozzle member, there is a thin tip 4 ′ having a very small diameter of the small hole 8 as shown in FIG. 5, and in this thin tip 4 ′ around the top surface 5 ′ of the mounting hole 5. An annular groove 14 is formed. Accordingly, when the thin tip 4 ′ is attached to the syringe shown in FIGS. 1 to 3, as shown in FIG. 5, the distal end portion of the insertion portion 9 is fitted into the groove portion 14, and a relatively large step is formed in the liquid portion discharge path. And a space in which no liquid agent exists is inevitably formed in the vicinity of the distal end of the insertion portion 9 when the thin chip 4 ′ is removed. Therefore, when using the thin chip 4 ′, as shown in FIG. 6, the position where the convex portion 13 is provided is adjusted, and the thickness and the distal end of the insertion portion 9 are brought into contact with the top surface 5 ′. It is preferable to select an opening diameter. In FIG. 5, the same components as those in the above embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 7 shows still another embodiment of the present invention corresponding to the narrow chip 4 '. In the present embodiment, the insertion portion 9 ′ is composed of a tapered cylindrical holder 9a formed integrally with the distal end portion of the syringe 1 ′, and a distal tip 9b integrally fitted in the holder 9a. Become. The holder 9a has the same structure as the insertion portion 9 in the above embodiment, and the syringe 1 'of this embodiment can be configured by attaching the tip 9b to the insertion portion 9 of the syringe of the above embodiment. That is, by selecting whether or not the tip 9b is attached depending on whether or not the thin tip is used before filling the syringe with the liquid agent, the syringe having the same structure can be used for both the thin tip and the normal tip.

  The tip of the tip 9b is flush with the tip of the holder 9a, and its axial length is about half of the axial length of the holder 9a. Further, a flow passage 15 penetrating in the axial direction is formed inside the tip 9b. The flow passage 15 is provided with tapered portions 17a and 17b having a small diameter at two axial ends at the axial direction, whereby the insertion portion 9 is gradually formed to have a small inner diameter from the midway portion in the axial direction to the distal end side. Has been. The diameter of the tip opening of the tip chip 9 b is less than twice the diameter of the small hole 8 of the thin chip 4 ′, and the tip opening is directly connected to the small hole 8.

  FIG. 8 shows still another embodiment of the present invention corresponding to the thin tip 4 ′. The syringe 1 ″ of the embodiment includes a syringe body 18 and a joint 19 attached to the distal end portion of the syringe body 18. And. A plurality of joints 19 can be prepared as necessary, such as those for thin chips and those for normal chips.

  The syringe body 18 has a joint mounting portion 18a having an inner and outer double cylinder structure at the tip of the liquid agent storage portion, and a cylindrical base portion 19a of the joint 19 is fitted to the mounting portion 18a. The joint mounting portion 18a includes an outer cylinder 18b and an inner cylinder 18c, and the liquid agent is discharged through an internal flow path of the inner cylinder 18c. The inner diameter of the joint base 19a is substantially equal to the outer diameter of the inner cylinder 18c, and the joint base 19a is fitted on the outer peripheral side of the inner cylinder 18c. The inner surface of the outer cylinder 18b and the outer surface of the joint base portion 19a are respectively provided with convex portions 18d and 19b that engage with each other in the axial direction, and the engagement of the convex portions 18d and 19b prevents the joint 19 from coming off. . In addition, it is preferable to provide an air bleeding groove similar to the air bleeding groove formed on the outer circumferential surface of the insertion portion on the outer circumferential surface of the inner cylinder 18c.

  In the present embodiment, the nozzle mounting portion 3 is provided at the distal end portion of the joint 19, and the liquid agent flow passage in the insertion portion 9 has a tapered shape in which the inner diameter gradually decreases from the proximal end portion to the distal end portion. Is formed. The inner cylinder 18 c is formed in a tapered shape, and the distal end opening of the inner cylinder 18 c is directly connected to the proximal end opening of the liquid agent flow passage of the insertion portion 9. The diameters of these openings are substantially equal, and are configured such that no step is generated in the liquid agent flow passage between the inner cylinder 18 c and the insertion portion 9.

  In addition, about the structure similar to the said embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

  According to the present embodiment, at the time of use, the syringe having the same structure can be used for both the thin tip and the normal tip by selecting and attaching the joint depending on whether it is for the thin tip.

  The present invention is not limited to the above-described embodiment, and can be applied to syringes for appropriate applications such as ophthalmic liquid injection syringes. Also, in the syringe according to the embodiment shown in FIG. 7 or FIG. 8, the convex portion 13 for restricting screwing of the nozzle member can be provided.

It is the front view seen from the tip part of the syringe concerning one embodiment of the present invention. It is a longitudinal cross-sectional view of the front end portion of the syringe. It is a front view of the syringe which shows a nozzle member by a virtual line when the tip part of an insertion part just contacted the top of a mounting hole. It is a longitudinal cross-sectional view which shows the attachment state of a nozzle member. It is a longitudinal cross-sectional view which shows the attachment state of a thin chip | tip. It is a longitudinal cross-sectional view which shows other embodiment of this invention corresponding to a thin chip | tip. It is a longitudinal cross-sectional view which shows another embodiment of this invention corresponding to a thin chip | tip. It is a longitudinal cross-sectional view which shows another embodiment of this invention corresponding to a thin chip | tip. It is a longitudinal cross-sectional view of the conventional syringe.

Claims (4)

Nozzle mounting portion in which a nozzle member having a mounting hole at the base and having a small hole for discharging a liquid agent formed at the top surface of the mounting hole is detachably mounted at the tip of the storage unit that stores the viscous liquid agent The mounting portion includes a cylindrical insertion portion that is inserted into the base mounting hole of the nozzle member, and a cylindrical connection portion that is provided on the outer peripheral side of the insertion portion and has a screw formed on the inner surface. The viscous liquid injection syringe in which the nozzle member is attached to the nozzle attachment portion by screwing the engagement piece provided at the base end portion of the nozzle member into the screw,
When the nozzle member is further screwed into the nozzle mounting portion by a predetermined amount from the position where the distal end portion of the insertion portion just contacts the top surface of the mounting hole of the nozzle member, the nozzle member is screwed by engaging with the engagement piece. The syringe for viscous liquid injection | pouring characterized by the convex part which blocks | prevents being provided in the said connection part inner surface.   The insertion portion has an outer diameter at the midway portion in the axial direction that is substantially equal to the diameter of the mounting hole, and an inner diameter that gradually decreases from the midway portion in the axial direction to the tip side. The tip opening of the insertion portion is directly connected to the small hole by bringing the tip portion into contact with the top surface of the mounting hole of the nozzle member, so that the liquid agent discharge path from the insertion portion internal space to the small hole is directed to the tip side. The syringe for injecting a viscous liquid according to claim 1, wherein the syringe is configured to gradually become smaller in diameter.   An air vent groove extending in the axial direction is formed on the outer peripheral surface of the insertion portion, and the mounting hole inner space on the distal end side of the insertion portion and the connection portion inner space on the insertion portion base side through the air vent groove. The syringe for viscous liquid injection according to claim 2, wherein Nozzle mounting portion in which a nozzle member having a mounting hole at the base and having a small hole for discharging a liquid agent formed at the top surface of the mounting hole is detachably mounted at the tip of the storage unit that stores the viscous liquid agent The mounting portion includes a cylindrical insertion portion that is inserted into the base mounting hole of the nozzle member, and a cylindrical connection portion that is provided on the outer peripheral side of the insertion portion and has a screw formed on the inner surface. In the syringe for viscous liquid injection, the nozzle member is attached to the nozzle attachment portion by screwing the engagement piece provided at the base end portion of the nozzle member into the screw,
The insertion portion has an outer diameter at an axially intermediate portion that is substantially equal to the diameter of the mounting hole, and an inner diameter that gradually decreases from the intermediate portion in the axial direction toward the distal end. The tip opening of the insertion portion is directly connected to the small hole by bringing the tip portion into contact with the top surface of the mounting hole of the nozzle member. The diameter of the insertion portion is gradually decreased, and an air vent groove extending in the axial direction is formed on the outer peripheral surface of the insertion portion. A syringe for injecting a viscous liquid, characterized in that the internal space of the hole communicates with the internal space of the connecting portion on the base side of the insertion portion.

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