Liquid introduction device

Abstract

To provide a liquid introduction device with a cap which can be attached and replaced by preventing a user from directly touching a liquid introduction tip of an injection needle or the like with a hand or the like.SOLUTION: In a liquid introduction device, irregular fitting stationary parts are formed in a stationary pipe 6 and a liquid storage body to make the stationary pipe irregularly fit to the liquid storage body, a guide screw part 7a is formed on the inner wall of a cap 7, a passive screw part 6b that is screwed to the guide screw part is formed on the outer side of the stationary pipe, and the cap and the stationary pipe move relatively front and back to be attachable and detachable by relatively rotating them.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a liquid introduction device with a cap that is used to administer a medicinal liquid to a patient, and that can be attached or replaced without directly touching the liquid introduction tip of a syringe needle or the like with a hand. [Background technology]

[0002] Conventionally, as a liquid introduction device that can be attached or replaced without directly touching the liquid introduction tip of a syringe needle or the like with hands, Patent Document 1 discloses a patient connector that is fixed in the packaging with ribs and can be attached or detached by screwing it onto the container. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6666386 Summary of the Invention [Problem to be solved by the invention]

[0004] The device disclosed in Patent Document 1 has a structure in which the patient connector, which is fitted and fixed inside the packaging, is screwed onto the container, making it difficult to determine when the connection between the patient connector and the container is complete.If the connection is not sufficient, there is a risk that the introduction liquid will leak out, or that the screws will be tightened too much, leading to damage to the container or patient connector. [Means for solving the problem]

[0005] The present invention comprises at least a liquid accommodating body that accommodates an introduction liquid, a fixed tube having a liquid lead-out tip at its tip, and a bottomed cylindrical cap that can cover the liquid lead-out tip, wherein a guide screw portion is formed on the inner wall of the cap, and a passive screw portion that threadably engages with the guide screw portion is formed on the outer part of the fixed tube, and by rotating the two relative to each other, the cap and the fixed tube can move back and forth relatively to each other, making them detachable, and a rotation suppressing engagement portion is formed on the inner or outer surface of the fixed tube on the liquid accommodating body side of the passive screw portion, and a guide engagement portion is formed on the outer or inner surface of the opening of the liquid accommodating body that faces this, and the engagement between the two suppresses relative rotation of the fixed tube with respect to the liquid accommodating body while allowing relative movement in the longitudinal forward and backward directions of the two, and within the range of the screw-engagement relationship between the cap and the fixed tube, The gist of this liquid introduction device is that a concave-convex fitting fixing portion is formed between the inner surface of the fixed tube and the outer surface of the opening of the liquid storage body, or between the outer surface of the fixed tube and the inner surface of the opening of the liquid storage body, and the fixed tube and the liquid storage body can be fitted together by rotating the cap in the direction in which the fixed tube moves towards the liquid storage body, and after the fitting is complete, the cap can be removed from the fixed tube by further rotating the cap in the same direction. Also, an abutment portion is formed between the cap and the liquid storage body, and when the cap is in abutting contact with the liquid storage body, the cap can be rotated in the direction in which the cap and the fixed tube join, causing the guide screw portion and passive screw portion of the cap and the fixed tube to screw together again, moving the fixed tube in a direction away from the liquid storage body, thereby releasing the concave-convex fitting relationship between the fixed tube and the liquid storage body and allowing the fixed tube to be accommodated and fixed within the cap. [Effects of the Invention]

[0006] When a fixed tube having a liquid outlet tip at its tip, which is threadedly housed within the cap, is attached to the liquid containing body, the coupled cap and fixed tube are guided into the opening of the liquid containing body by the rotation-restricting engagement portion of the fixed tube being guided by the guiding engagement portion of the opening of the liquid containing body, preventing the fixed tube from rotating relative to the liquid containing body. When the cap is rotated in this state, the rotational force of the cap is transmitted from the guiding screw portion to the passive screw portion of the fixed tube, causing the fixed tube to move toward the liquid containing body, and the fixed tube and the liquid containing body are fixed by a concave-convex fit at a predetermined position. Further rotation of the cap causes the cap to come off the fixed tube, so the point at which the fixed tube and the liquid containing body are fixed together is clear, and damage to parts or liquid leakage due to over- or under-fixing can be minimized. Furthermore, by rotating the cap in the opposite direction to when it was attached to the fixed tube, the fixed tube is pulled through the guide screw portion and the passive screw portion, and when the fixed tube is released from the liquid containing body, the fixed tube is once again housed within the cap, making it possible to replace the liquid discharge tip with a new one without touching it with your hands. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a longitudinal cross-sectional view showing an example of a liquid introduction device of the present invention. [Figure 2] Cross-sectional view of line A-A' in Figure 1 [Figure 3] Vertical cross-sectional view of cam barrel 302 [Figure 4] Side view of slider 303 [Figure 5] A perspective view of the rotor 304 [Figure 6] Enlarged view of part B in Figure 1 [Figure 7] Vertical cross-sectional view of barrel 1 [Figure 8] A perspective view of the fixed tube 6 DETAILED DESCRIPTION OF THE INVENTION

[0008] The liquid introduction device of the present invention is basically composed of a liquid containing body that contains the introduction liquid, a fixed tube having a liquid outlet tip at its tip, and a cylindrical cap with a bottom that can cover the liquid outlet tip. In addition to the liquid containing body, fixed tube, and cap, the device may also include a connector for connecting to an apparatus, a pressure mechanism that can constantly discharge the introduction liquid, and the like.

[0009] As the introduction liquid, ink for writing instruments or cosmetics, beauty serum, medical drug, etc. can be used.

[0010] The liquid containing body, which contains the introduction liquid such as medicine, has a cylindrical shape with a bottom, and the liquid can be added or removed through the opening, but it is also possible to insert a cartridge from the rear end or to have a separate liquid tank inside. In addition, the free-state introduction liquid may be stored directly within the liquid storage body or by placing a liquid tank made of a separate material, but it may also be stored using a porous body such as a sponge or a fiber bundle impregnated with the introduction liquid. As the relay means for conducting the liquid to the liquid lead-out tip, in addition to a means having interconnected spaces, an interconnected porous body or a fiber bundle can also be used. Furthermore, if necessary, a means for pushing or squeezing out the liquid, such as a pressure mechanism, can be used. The material for the liquid containing body can be an injection-molded product of synthetic resin such as polyethylene, polypropylene, polyamide, polybutylene terephthalate, polyethylene terephthalate, polyacetal, or fluororesin, or glass, metal, or a combination of components made from any of these, but the material must be selected taking into consideration its reactivity with the liquid to be introduced and its permeability to liquids and gases, and the inside and outside of the liquid containing body can also be coated with a different material. If a transparent synthetic resin or glass is used, the amount of liquid contained can be visible from the outside, and the body can also be constructed by combining multiple parts.

[0011] The liquid containing body also has a fixing portion and an abutting portion for the cap, and an attachment portion at the opening for a fixing tube, which will be described later. The attachment portion for the fixed tube has, from the opening side toward the bottom side, a guide engagement portion that engages with the rotation-restricting engagement portion of the fixed tube to limit rotation, and a concave-convex fitting fixation portion to which the fixed tube is fixed. The guide engagement portion and the rotation-restricting engagement portion are positioned opposite each other, so that when the fixed tube is inserted into the opening of the liquid accommodating body, the guide engagement portion is formed and arranged on the inner surface of the opening of the liquid accommodating body, and the rotation-restricting engagement portion is formed and arranged on the outer surface of the fixed tube that is inserted into the opening of the liquid accommodating body, and when the fixed tube covers the opening of the liquid accommodating body (in other words, when the opening of the liquid accommodating body is inserted into the inner hole of the fixed tube), the guide engagement portion is formed and arranged on the outer surface of the opening of the liquid accommodating body, and the rotation-restricting engagement portion is formed and arranged on the inner surface of the fixed tube.

[0012] The guide engagement portion is formed as a plurality of ridges extending in the longitudinal direction and arranged circumferentially around the mounting portion, and the sides of the ridges are formed in an inclined shape to guide the rotation-inhibiting engagement portion from any position to a predetermined position between the ridges. The gap between adjacent ridges formed as the guide engagement portion is set to a level that allows the rotation-inhibiting engagement portion to move back and forth, and the rotation-inhibiting engagement portion comes into contact with the ridge sidewalls to inhibit rotation of the fixed tube while allowing forward and backward movement of the fixed tube.

[0013] The abutment portion of the liquid containing body against the cap can be a shoulder-like step when the opening is made small-diameter, or an abutment wall formed at a predetermined position, and by abutting the opening end or protrusion of the cap, the relative longitudinal position of the cap and the liquid containing body in the attached state is determined, and the attachment and detachment of the fixed tube from the liquid containing body is controlled by the back and forth movement of the fixed tube caused by the rotation of the cap. In particular, when removing the fixed tube from the liquid containing body, it serves as a support that transmits the rotational force of the cap to the fixed tube.

[0014] The concave-convex fitting and fixing portion that fits and fixes the fixed tube and the liquid containing body makes it easy to detect the completion of the connection by the fitting of the convex and concave portions. Here, "convex-convex fitting" refers not only to a case where one convex portion fits into the other concave portion, but also to a case where the convex portions overcome each other to form a fitting relationship. For fitting and fixing by concave-convex fitting, it is preferable to have one protrusion formed around the entire circumference and the other protrusion formed around a periphery, as this allows for the stress required for fitting to be distributed. In many cases, having the outer protrusion be a full-circumferential protrusion and the mating inner protrusion be a circumferentially arranged partial protrusion is preferable because it minimizes the force required for attachment and detachment in a concave-convex fitting that involves deformation of the components, achieves a reliable fixing relationship, and is easy to mold. When a liquid-tight fit and fixing portion is required, at least one full-circumferential protrusion must be in circumferential contact, but a liquid-tight contact portion can also be formed separately from the concave-convex fitting and fixing portion.

[0015] Before the fixed tube is connected to the liquid containing body, a disposable lid can be used to cover the opening of the liquid containing body so that the liquid contained in the liquid containing body alone can be contained and retained. For the same purpose, the liquid containing body can also be equipped with a valve mechanism. Naturally, from the standpoint of environmental protection, it is preferable to use a lid that is intended to be discarded, and the provision of a valve mechanism also makes handling of the liquid containing body safer and easier. The valve mechanism can be such that a valve rod is positioned as a stopper within the liquid containing body, and is biased toward the opening of the liquid containing body by a resilient member such as a coil spring, and a small inner diameter portion that serves as a valve seat is formed on the inner wall of the liquid containing body and elastically abuts against it around its circumference, so that when operated, the valve rod moves backward to create an open state where liquid can be drawn out.

[0016] In addition, the valve mechanism can be such that a support tube having a small diameter inner step at one end is fixed and positioned within the opening of the liquid-containing body, a valve rod biased toward the liquid tank by a coil spring supported on the small diameter step of the support tube is positioned as a stopper, a small inner diameter portion that serves as a valve seat is formed on the inner wall of the liquid-containing body and is elastically abutted around the circumference, and by compressing the container or arranging a pump mechanism, the liquid in the liquid tank or the air in the space can be pressurized, thereby moving the valve rod forward and opening the stopper, thereby creating a state in which the liquid can be discharged. Furthermore, the valve mechanism may be a rubber elastic body having a closable slit, which is deformed by being pressed directly or via a separate member when the fixed pipe is connected and fixed, opening the slit, and which closes the slit when the pressing force is released.

[0017] The spring-loaded member that biases the valve rod is preferably a metal coil spring for durability, while stainless steel is preferable for its corrosion resistance. The spring-loaded member can also be made of injection-molded synthetic resin and molded integrally with the stopper and liquid containing body, reducing the number of parts. The valve seat can be the inner wall of the shoulder where the opening is reduced in diameter, or a separate tubular member can be placed inside the opening. The separate member can be a metal or synthetic resin pipe with one end crimped to reduce its diameter.

[0018] The contact between the valve rod and the valve seat is preferably a line contact or other small contact area, which increases the pressure per unit area. Forming the contacting portions of either or both of the valve rod and the valve seat as a convex curved surface with a small radius of curvature allows the portions apart from the contacting portions to be separated from each other, reducing the contact area. Furthermore, making the contacting portions of the two mirror-finish allows for high liquid-tightness. Furthermore, the valve rod and / or the valve seat may be made of an elastically deformable synthetic resin or rubber to enhance their adhesion to each other.

[0019] The valve rod as a stopper can be configured to move backward when pushed by the fixed tube directly or via a separate member after the fixed tube has been connected and fixed to the liquid containing body, thereby opening the stopper. When the fixed tube is detached from the liquid containing body, the valve rod receives the biasing force of the elastic member and again makes circumferential contact with the valve seat, closing the liquid containing body, and this opening and closing can be repeated.

[0020] The fixed tube is attached to the opening of the liquid container body, allowing the introduction liquid in the liquid container body to be discharged through the inner hole and from the liquid outlet tip located at the tip. The fixed tube and the liquid outlet tip can be separate members or integrated, but in order to versatility use various types and diameters of liquid outlet tips, it is preferable to attach them as separate members. The attachment of the two can be selected appropriately depending on the application and situation, such as by fitting with a recess and a protrusion, press fitting, screwing, or bonding with an adhesive. A wide variety of applicators can be connected to the liquid-extracting tip, including, for example, applicators for writing implements and cosmetic tools such as sintered fiber compacts, sintered powder compacts, brushes, fountain pen nibs, calligraphy nibs, and ballpoint pen tips, as well as applicators for medical tools such as injection needles and pipette nozzles.

[0021] The fixed tube has a passive screw portion on its outer side that corresponds to a guide screw portion formed on the inner wall of the cap, and the relative rotation of the cap and fixed tube causes the tube to move forward and backward (approach and separate) due to the threaded relationship. The fixed tube has a rotation-inhibiting engagement portion that engages with a guide engagement portion of the liquid containing body, and when rotation with respect to the liquid containing body is prevented, the rotational force of the guide screw portion of the cap is received by the passive screw portion and converted into a back-and-forth force, causing the fixed tube to move back and forth relative to the liquid containing body, and the fixed tube and liquid containing body are attached and detached by the concave-convex fitting fixation portion formed between the fixed tube and the liquid containing body within the range of the threaded relationship between the cap and fixed tube.

[0022] The material of the fixed tube is polypropylene or polybutylene terephthalate, taking into consideration gas permeability and sliding properties between parts.

[0023] The cap covers and protects the liquid discharge tip of the liquid introduction device, and is capable of holding the fixed tube and the liquid discharge tip attached to it inside before it is attached to the liquid storage body.It is a member that can be grasped and operated when attaching or detaching the liquid discharge tip to the liquid storage body, and makes it possible to avoid having to directly touch the liquid discharge tip with one's hand when forming a combined state between the liquid discharge tip and the liquid storage body to form a liquid discharge device. The cap has an inner wall formed with a guide screw that threads into the outer wall of the fixed tube to hold the liquid outlet tip and the fixed tube, but other fixing means may also be provided. When fixed by such other fixing means, the relative rotation between the cap and the fixed tube can be free-wheeling without any forward or backward movement. Furthermore, the cap has an abutment portion for contacting the liquid containing body, and when the fixed tube is in a concave-convex fit with the liquid containing body and the cap is rotated in the direction in which the cap and fixed tube are joined, with the abutment portion of the cap in abutment with the liquid containing body, the cap is supported by the abutment portion, fixing the longitudinal positions of the cap and the liquid containing body, the rotation of the guide screw portion is received by the passive screw portion of the fixed tube, moving the fixed tube, the concave-convex fit between the fixed tube and the liquid containing body is released, and the fixed tube and the liquid discharge tip attached thereto can be accommodated in the cap and removed from the liquid containing body. Here, it is preferable to form a guide wall on the side surfaces of the rotation-inhibiting engagement portion and / or the guide engagement portion, which at least come into contact with each other when the fixed tube moves in a direction away from the liquid accommodating body due to the threaded relationship between the guide screw portion and the passive screw portion, and which is inclined in a direction in which the width of the rotation-inhibiting engagement portion and / or the guide engagement portion in the direction of rotation narrows from the midpoint in the front-rear direction toward the end. When the fixed tube is removed from the liquid accommodating body, the side surfaces of the rotation-inhibiting engagement portion and the guide engagement portion come into contact with each other as the fixed tube moves toward the cap. When the guide wall enters the area where it comes into contact with the other side surface, the force acting on the fixed tube as the cap rotates is shifted from the rotational direction to a force in the longitudinal direction (in other words, a direction moving the fixed tube away from the liquid accommodating body and closer to the cap), thereby facilitating removal of the fixed tube. The guide wall can be formed as a wall on the side surface of the rotation-inhibiting engagement portion that is inclined from the midpoint in the front-rear direction toward the end on the liquid accommodating body side and / or as a wall on the side surface of the guide engagement portion that is inclined from the midpoint in the front-rear direction toward the end on the fixed tube side.

[0024] It is also preferable to form a bottom-direction movement restriction portion in the cap to protect the liquid lead-out tip. In particular, since the present invention has a structure in which the fixed tube having the liquid lead-out tip at its tip and the cap move relatively in a threaded relationship, it is preferable to prevent the liquid lead-out tip from coming into contact with the bottom or periphery of the cap and being damaged, contaminating the inside of the cap with the lead-out liquid, or inducing liquid leakage as a result of the cap and the fixed tube moving in the direction of joining. As a method of restricting bottom-direction movement, methods of restricting relative rotation between the two parts include providing a wall on either or both of the guide screw part and the passive screw part involved in the screw engagement that will come into contact with the other, or providing a collision part on the inner wall of the cap and / or the fixed tube that restricts further rotation.In addition, rather than restricting the rotation between the fixed tube and the cap, it is also possible to provide a collision part that restricts movement of the fixed tube toward the bottom of the cap by having a circumferential step or an inwardly protruding rib formed in the cap abut against a shoulder of the fixed tube or a separate part fixed to the fixed tube. The cap is basically cylindrical with a bottom, but it is also possible to form a longitudinally communicating groove in the outer wall or a communicating hole formed by a cover covering the groove to ensure an air passage in the event of accidental ingestion. Furthermore, a cap with a communicating groove has an uneven surface, consisting of connected ridges and grooves between them, which is perpendicular to the direction of rotation, which has the advantage of making it easier to grip and apply force when rotating the cap. To make it easier to grip when rotating the cap, the transverse peripheral shape of the cap can be polygonal, such as a triangle or a rectangle, with linear portions. In this case, the corners of the polygon can be curved, and the appearance of the outer peripheral surface of the entire cap can be alternating between flat and curved surfaces. As the material for the cap, various synthetic resins such as polypropylene, polybutylene terephthalate, polyethylene terephthalate, polyacetal, polyethylene, polyvinylidene chloride, polytetrafluoroethylene, etc. can be used, taking into consideration the permeability and reactivity of liquids and gases. [Example]

[0025] An example will be described with reference to the accompanying drawings. Figure 1 shows a longitudinal cross-sectional view of a drug solution delivery device that contains a drug solution to be administered to a patient, has a mechanism for discharging the drug solution from the delivery tip by operation, and has a cap that fits over the delivery tip. The device is assumed to have a syringe with a syringe needle as the delivery tip, which can discharge a fixed amount of drug solution by operation. To make the details of the figure easier to enlarge and view, the middle of the part that contains the drug solution has been cut out and omitted by a wavy line.

[0026] As a liquid-containing body that directly contains the medicinal liquid W as the discharge liquid inside, a valve mechanism 2 is arranged at the opening on the liquid discharge destination side (lower side in the drawing) of the cylindrical barrel 1 to prevent unnecessary leakage of the medicinal liquid, and a pressure mechanism is arranged at the opening on the opposite side to the liquid discharge destination side (upper side in the drawing) so that pressure can be applied to the internal medicinal liquid W by operating it, causing it to be discharged from the opening on the liquid discharge destination side.

[0027] In the valve mechanism 2, a valve rod ball 202 disposed in a valve cylinder 201 is biased forward by a coil spring 203, allowing the valve rod ball 202 to circumferentially abut against a valve seat 201a, which is a reduced-diameter portion of an inner hole formed on the inner edge of the tip opening of the valve cylinder 201. With the valve rod ball 202 in circumferential abutment against the valve seat 201a, a portion of the valve rod ball 202 protrudes from the tip opening of the valve cylinder 201. When the protruding portion receives a rearward pressing force, the valve rod ball 202 elastically retreats against the coil spring 203, forming a liquid outlet path. When the pressing force applied to the valve rod ball 202 is released, the valve rod ball 202 is pushed by the elastic restoring force of the coil spring 203, and returns to circumferential abutment against the valve seat 201a, blocking the passage of liquid. The pressing force that moves this valve rod ball 202 backward is generated by connecting the fixed tube 6, which will be described later, to the opening of the barrel 1, and when the fixed tube 6 is completely connected to the barrel 1, the medicinal solution W can be communicated with the injection needle 5.

[0028] The pressurizing mechanism guides the built-in chemical solution or the like to the outlet tip by operation or application of power. In this example, the knock pressurizing mechanism is composed of a knock crown 301, a cam barrel 302, a slider 303, a rotor 304, a bolt rod 305, a nut barrel 306, and a piston disk 307. As shown in Figure 2, which is a cross-sectional view taken along the line A-A' in Figure 1, a cam groove 302a (Figure 3) is formed on the inner wall of cam barrel 302, which is fixed to the inner wall of barrel 1. This cam groove 302a engages with a protrusion 303a (Figure 4) formed on the outer wall of slider 303, preventing the slider 303 from rotating, while allowing the slider 303 to move back and forth within cam barrel 302 along the cam groove. A knock crown 301 that is pushed directly into barrel 1 by a finger or hand protrudes from the opening at the rear end of barrel 1, and this operation moves slider 303 forward. Cam teeth 303b formed on the tip of slider 303 come into contact with a rotational inclined wall 304a (Figure 5) formed on the side wall of rotor 304, applying a rotational force to rotor 304. 2, rotor 304 has inner bore 304b with a non-circular cross section, and bolt rod 305 is disposed in a state of being fitted into inner bore 304b with this non-circular cross section. That is, by pressing knock crown 301, slider 303 disposed in cam barrel 302 advances along cam groove 302a, and cam teeth 303b come into contact with rotating inclined wall 304a, causing rotor 304 to advance while rotating, and accordingly bolt rod 305 also advances while rotating. The bolt rod 305 has a male thread 305a extending longitudinally on its outer wall, which threads into a female thread 306b formed in an inner hole 306a of a nut tube 306. The nut tube 306 is fixed non-rotatably to the tip of the cam tube, and the bolt rod 305 moves forward relative to the nut tube 306 by rotating. A piston platen 307 is fixed to the tip of the bolt rod 305, and the piston platen 307 is in liquid-tight sliding contact with the inner wall of the shaft tube 1. The piston platen 307 moves forward as the bolt rod 305 moves forward, reducing the internal volume of the liquid containing body, and the contained medicinal solution W is pressured and discharged from the liquid discharge tip.

[0029] A coil spring 4 is disposed in a nut cylinder 306 fixed to the tip of the cam cylinder 302, and urges the rotor 303 rearward, and this rearward urging force is received by the knock crown 301 via the slider 303, and when the pressing operation of the knock crown 301 is released, the knock crown 301 elastically returns to the position before the operation. The forward movement position of this knock crown 301 is regulated by bringing its tip into contact with a movement control wall 302b formed on the inner wall of the cam cylinder 302 fixedly disposed within the barrel cylinder 1, and with a fixed forward movement, the forward distance of the piston platen 307 can be regulated with one knock operation, and the volume by which the internal volume of the liquid accommodating body is reduced is kept constant, so that the amount of liquid drawn out is constant.

[0030] A fixed tube 6, to which an injection needle 5 serving as a liquid outlet tip is fixed, is attached to the tip of the liquid accommodating body. An outlet hole 6c communicating with the inner bore of the fixed tube 6 is formed outward from the center of the end face on the injection needle side of the fixed tube 6, and the outlet hole 6c of the fixed tube 6 is connected to the inner bore of the injection needle 5. A circumferential convex portion 6a is formed on the outer surface of the rear of the fixed tube 6, and a circumferential inner convex portion 1a formed on the inner surface of the opening of the shaft 1 overcomes this to form a concave-convex fitting fixing portion, fixing the fixed tube 6 to the opening of the shaft 1. A pusher 6d protruding rearward is formed from the center of the inner wall behind the outlet hole 6c of the fixed tube 6. When the fixed tube 6 is fixed to the barrel tube 1, the pusher 6d of the fixed tube 6 presses the valve rod ball 202 and moves it rearward, allowing the outlet liquid W to communicate with the injection needle.

[0031] On the outer surface of the fixed tube 6, a driven screw portion 6b is formed on the tip side (injection needle side) of the circumferential convex portion 6a that fits in the circumferential inner convex portion 1a of the barrel 1, and is in a threaded relationship with a guide screw portion 7a formed on the inner wall of the cap 7. The cap 7 also has a circumferential inner fitting convex portion 7b that fits in a fitting recess 1b formed on the outer surface of the barrel 1, and the cap 7 is detachable from the barrel 1. The fitting position of this fitting recess 1b and the circumferential inner fitting convex portion 7b is within the range where the driven screw portion 6b of the fixed tube 6 and the guide screw portion 7a of the cap 7 are in a threaded relationship, so that the cap 7 can rotate even when the cap 7 is in a mated state with the barrel 1. When making the joint relationship between the circumferential inner fitting convex portion 7b of the cap 7 and the fitting concave portion 1b of the barrel 1 liquid-tight, it is desirable to consider the material and surface condition to prevent wear and damage to this portion, as it will slide when the cap 7 rotates. Possible options include using an elastic material, creating a mirror-like surface, or applying a lubricant such as silicone.

[0032] As shown in Figure 6, which is an enlarged view of part B in Figure 1, the fixed tube 6 and the cap 7 are in a screw-engaged relationship, so that the fixed tube 6 with the attached injection needle 5 can be held inside the cap 7. The relative rotation caused by the screw-engagement between the cap 7 and the fixed tube 6 allows the fixed tube 6 to change position back and forth within the cap 7, but to prevent the needle portion 5a of the injection needle 5 attached to the fixed tube 6 from colliding with the inner wall of the cap 7, a small-diameter step 7c is formed in the inner hole of the cap 7, so that even if the two are rotated excessively, the outer portion of the attachment portion 5b of the injection needle 5 to the fixed tube 6 abuts against the small-diameter step 7c, restricting further movement, and ensuring a gap between the tip of the needle portion 5a and the bottom of the cap 7.

[0033] With the fixed tube 6 held in a threaded relationship within the cap 7, the fixed tube 6 can be attached to the barrel 1 by placing the cap 7 over the barrel 1 and rotating it. As shown in Fig. 7 (a cross-sectional view of the barrel) and Fig. 8 (a perspective view of the fixed tube), the inner wall of the distal end opening of the barrel 1 is formed with a guide engagement portion 101, which is a combination of multiple circumferentially arranged protrusions. The guide engagement portion 101 includes guide inclined walls 101a as side walls of the protrusions and anti-rotation engagement grooves 101b as gaps between adjacent protrusions. On the other hand, a rotation-restricting engagement portion 601 is formed as a protruding rib extending longitudinally on the outer surface of the rear end of the fixed tube 6 closer to the barrel 1 than the circumferential protrusions 6a. The rotation-restricting engagement portion 601 has an inclined wall 101a at its rearmost end, which facilitates guiding the guide engagement portion 101, and an engagement wall 101c that engages with the anti-rotation engagement groove 101b and prevents substantial rotation of the fixed tube 6.

[0034] When the rear end of the fixed tube 6 is inserted into the front opening of the shaft tube 1 while the fixed tube 6 is held within the cap 7, the fixed tube 6, which is rotatable relative to the cap 7 in accordance with its threaded relationship, has its rotation-restricting engagement portion 601 move along the guide inclined wall 101a and be guided into the rotation-preventing engagement groove 101b. When the cap 7 is rotated in this state, the guide screw portion 7a of the cap 7 is transmitted to the driven screw portion 6b of the fixed tube 6, causing the fixed tube 6 to move rearward (toward the shaft tube 1), and as described above, the circumferential protrusion 6a of the fixed tube 6 engages with the circumferential inward protrusion 1a formed on the inner surface of the opening of the shaft 1, thereby fixing the fixed tube 6 to the opening of the shaft 1. When the cap 7 is further rotated in this state, the fixed tube 6 is fixed to the shaft tube 1 and cannot move rearward any further, so the cap 7 relatively detaches from the fixed tube 6. In this way, the completion of the fixation between the fixed tube 6 and the shaft tube 1 is clearly achieved by the concave-convex fit, and unnecessary operations such as forcing it in are not required, so there is no risk of liquid leakage due to insufficient fixation or damage due to excessive pressure.

[0035] With the fixed tube 6 secured to the barrel 1, the cap 7 is put back on, and the cap 1 is rotated in the opposite direction from when the fixed portion 6 was secured to the barrel 1, screwing the cap 7 and the fixed tube 6 together until the open end 7d of the cap 7 abuts against the shoulder 1c, which is the outer diameter connecting portion between the small-diameter portion with the opening and the main body. If the cap 7 is further rotated with the open end 7d of the cap 7 abutting against the shoulder 1c of the barrel 1, the cap 7 rotates while its position is fixed relative to the barrel 1, and with the rotation-restricting engagement portion 601 of the fixed tube 6 engaged with the rotation-preventing engagement groove 101b of the barrel 1, the rotational force of the cap 7 is transmitted from the guide screw portion 7a to the driven screw portion 6b, moving the fixed tube 6 in the joining direction, and the circumferential protrusion 6a of the fixed tube 6 overcomes the circumferential inward protrusion 1a formed on the inner surface of the opening of the shaft 1, thereby releasing the engagement between the fixed tube 6 and the barrel 1. At this time, as the fixed tube 6 moves in the direction of joining to the cap 7, a fixed tube-side guide wall, which is inclined from the middle in the front-to-rear direction of the side surface of the rotation restricting engagement portion 601 toward the end on the barrel 1 side, comes into contact with the inclined guide wall 101a, which also serves as the barrel-side guide wall, and the force acting on the fixed tube 6 is displaced from the rotational direction to the front-to-rear direction, making it easy to remove the fixed tube 6. The fixed tube 6 is then held by the cap 7 by being screwed together, and by removing the cap 7 from the barrel 1, the fixed tube 6 and the syringe needle 5 at its tip can be removed from the barrel 1 while remaining housed within the cap 7. At the same time that the fixed tube 6 is removed from the barrel 1, the valve mechanism 2 arranged at the opening of the barrel 1 is activated, and the valve rod ball 202 comes into circumferential contact with the valve seat portion 201a due to the repulsive action of the coil spring 203, thereby closing the barrel 1. [Explanation of symbols]

[0036] 1 shaft cylinder 1a Inner convex part 1b Mating recess 1c Shoulder 101 guide engagement portion 101a Guide inclined wall (shaft cylinder side guide wall) 101b Anti-rotation engagement groove 101c Engagement wall 2 Valve mechanism 201 Valve tube 201a Valve seat part 202 Valve plug ball 203 coil spring 3. Pressure mechanism 301 Knock Crown 302 Cam barrel 302a Cam groove 302b Movement Control Wall 303 Slider 303a Projection 303b Cam teeth 304 Rotor 304a Rotating Inclined Wall 304b inner hole 305 Bolt Rod 305a Male thread part 306 Nut tube 306a inner hole 306b Female thread part 307 Piston Disc 4 coil springs 5 Syringe needle 5a Needle part 5b Mounting part 6 Fixed tube 6a Convex part 6b Passive screw part 6c Outlet hole 6d Depressor 601 Rotation suppression engagement part 602 Fixed pipe side guide wall 7 Cap 7a Guide screw part 7b Inner fitting protrusion 7c Small diameter stepped section 7d Open end W introduction liquid

Claims

1. The device comprises at least a liquid accommodating body that accommodates an introduction liquid, a fixed tube having a liquid lead-out tip at its tip, and a bottomed cylindrical cap that can cover the liquid lead-out tip, wherein a guide screw portion is formed on the inner wall of the cap, a passive screw portion that screws into the guide screw portion is formed on the outer part of the fixed tube, a rotation suppressing engagement portion is formed on the inner surface or outer surface of the fixed tube that is closer to the liquid accommodating body than the passive screw portion, and a guide engagement portion is formed on the outer surface or inner surface of the opening of the liquid accommodating body that faces this, and the engagement between the two suppresses relative rotation of the fixed tube with respect to the liquid accommodating body while allowing relative movement of the two in the longitudinal forward and backward directions. By rotating the cap while the rotation suppressing engagement portion of the fixed tube is engaged with the guide engagement portion, the fixed tube can move back and forth relative to the liquid accommodating body due to the threaded engagement between the guide screw portion of the cap and the passive screw portion of the fixed tube, a concave-convex fitting fixing portion is formed between the inner surface of the fixed tube and the outer surface of the opening of the liquid accommodating body, or between the outer surface of the fixed tube and the inner surface of the opening of the liquid accommodating body, making the two detachable, and the cap is formed with a fixing completion abutment portion that comes into contact with the liquid accommodating body when fixing of the fixed tube to the liquid accommodating body by the concave-convex fitting fixing portion is completed.

2. 2. The liquid introduction device according to claim 1, wherein a bottom direction movement restricting portion for protecting the liquid lead-out tip portion is formed inside the cap.

3. A liquid introduction device as described in claim 1 or claim 2, wherein the side surfaces of the rotation suppression engagement portion and / or the guide engagement portion are at least the sides that come into contact with each other when the fixed tube moves in a direction away from the liquid storage body due to the threaded relationship between the guide screw portion and the passive screw portion, and a guide wall is formed that is inclined in the direction in which the width of the rotation suppression engagement portion and / or the guide engagement portion in the rotation direction narrows as it moves from the middle of the front-to-rear direction toward the end.

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