JP4919008B2 - Water flow control device and liquid injection circuit using the same - Google Patents

Description

  The present invention relates to a water flow control device, and more particularly, to a water flow control device that functions as an anti-free flow mechanism when injecting an infusion into a patient or administering a drug, and a liquid injection circuit using the same.

  Conventionally, infusion pumps have been used to regulate the flow rate of infusion to be injected into a patient. The infusion pump is attached to an infusion circuit connecting the infusion bag and the puncture needle, and sends out the infusion at a set flow rate by giving a peristaltic motion to the infusion tube constituting the infusion circuit. In general, finger-type infusion pumps and roller-type infusion pumps are known as infusion pumps.

  The finger-type infusion pump includes a plurality of fingers arranged in a line along the infusion tube, and reciprocates the plurality of fingers separately to impart a peristaltic motion to the infusion tube. Moreover, the roller-type infusion pump includes a pair of rotating rollers, and imparts a peristaltic motion to the infusion tube by moving these in a circular motion.

  However, when infusion is performed using such an infusion pump, free flow may be a problem. Free flow means that after the infusion is completed, the infusion pump is removed and the infusion fluid is injected into the patient's body more than necessary because the clamp provided near the puncture needle of the infusion tube is forgotten to be closed. Say.

  The problem of free flow may also occur in the case of drug administration using a syringe pump. For example, when a patient pulls a drug tube, etc., and a syringe comes off from a pump main body, the medicine more than a regulation amount may be inject | poured into a patient. Furthermore, in drug administration, if a drug more than necessary is administered, it may affect the life of the patient. Therefore, prevention of free flow in drug administration is more important than in the case of infusion.

In order to solve such a problem of free flow, for example, a method of incorporating a valve device (for example, see Patent Document 1) that does not allow fluid to pass unless the pressure exceeds a set pressure can be considered. In a liquid injection circuit incorporating this valve device, it is considered that free flow can be prevented because the valve does not open and infusion does not flow at a low pressure (head pressure) when free flow occurs.
Special table 2004-501686 gazette

  By the way, when the infusion liquid is sent out using the infusion pump, it is necessary to perform priming in advance and push out the air in the tube before operating the infusion pump. In the priming, at least the infusion circuit to the attachment site of the infusion pump in the infusion circuit is filled with the infusion.

  However, since the priming is performed by using a pressure drop due to a natural drop and the valve does not open at the pressure drop, it is difficult to push out the air in the tube when the valve device is incorporated in the infusion circuit. In this case, the infusion solution can flow only up to the drip tube just below the infusion bag, which causes a problem that priming cannot be performed. Furthermore, since the infusion pump does not have a suction function in structure, the infusion does not flow even if the infusion pump is operated, and priming is impossible.

  On the other hand, if the valve device is incorporated in the infusion circuit after priming, it is considered that the above problem can be solved. However, in this case, the priming operation becomes complicated, increasing the burden on the doctor and nurse. End up.

  The objective of this invention is providing the water flow control apparatus which can suppress generation | occurrence | production of a free flow, without solving the said problem, and complicating a priming operation | work, and a liquid injection circuit using the same.

In order to achieve the above object, a water flow control device according to the present invention includes a first flow path, a second flow path, a valve member disposed in the first flow path, and the second flow path. The valve member is supplied to the first flow path at a pressure equal to or higher than a set pressure, and allows only fluid flowing in one direction in the first flow path to pass therethrough, said second flow path branched from the first flow path upstream than the valve member, is formed so as to merge into the first flow path downstream than the valve member, said film member , Having hydrophobicity and air permeability, preventing liquid from passing through the second flow path, and the set pressure is higher than the drop pressure due to the natural fall of the infusion solution and lower than the supply pressure by the infusion pump It is set to a value .

  In order to achieve the above object, a liquid injection circuit according to the present invention includes at least the water flow control device according to the present invention, a first tube, and a second tube, and one end of the first flow path. Further, the first tube is connected, and the second tube is connected to the other end of the first flow path.

  In the water flow control device according to the present invention, the occurrence of free flow is suppressed by the valve member provided in the first flow path and the membrane member provided in the second flow path. In addition, the membrane member provided in the second flow path does not allow liquid to pass through but allows gas to pass through. Therefore, the water flow control device according to the present invention is attached to a liquid injection circuit such as an infusion circuit, and priming by natural fall When performing the above, the liquid can reach the membrane member. According to the water flow control device of the present invention, the occurrence of free flow can be suppressed without complicating the priming work.

The water flow control device according to the present invention includes a first flow path, a second flow path, a valve member disposed in the first flow path, and a membrane member disposed in the second flow path. The valve member is supplied to the first flow path at a pressure equal to or higher than a set pressure, and allows only fluid flowing in one direction through the first flow path, and the second flow path is branches from the valve the first flow path upstream than member, said valve member is formed so as to merge into the first flow path downstream than the membrane member, hydrophobic and breathable And preventing the liquid from passing through the second flow path, and the set pressure is set to a value higher than a drop pressure due to a natural drop of the infusion solution and lower than a supply pressure of the infusion pump. It is characterized by.

  The water flow control device according to the present invention includes a first cylinder and a second cylinder that are open at both ends, and the second cylinder has one opening of the first cylinder. The valve member is inserted into the first cylinder so as to be exposed from the opening and the other opening is located inside the first cylinder, and at a position facing the other opening. Holding the valve member such that a first gap is formed between the first cylinder and a second gap is formed between the valve member and the second cylinder; The valve member is formed of an elastic material, and when the fluid is supplied at a pressure equal to or higher than the set pressure, the valve member elastically deforms and allows the fluid to pass therethrough, and the membrane member includes the valve member and the first It arrange | positions so that the clearance gap between cylinders may be block | closed, and said 1st flow path is said 2nd cylinder from one opening of said 2nd cylinder Through the other opening and the valve member to the other opening of the first cylindrical body, and the second flow path includes the first gap and the second The aspect comprised by the clearance gap may be sufficient.

  The water flow control device according to the present invention includes a first cylinder and a second cylinder that are open at both ends, and the second cylinder has one opening of the first cylinder. A portion that is exposed from one opening and is inserted into the first cylinder so that the other opening is located inside the first cylinder, and is inserted into the first cylinder The valve member is formed of an elastic member that covers the through hole, and when the fluid is supplied at a pressure equal to or higher than the set pressure, the valve member is formed through the through hole. The membrane member is disposed so as to close the other opening of the second cylinder, and the first flow path is formed from one opening of the second cylinder. Through the through-hole and the valve member and through the flow path to the other opening of the first cylindrical body. The second flow path is configured from the place where the through hole inside the second cylinder is provided to the film member via the other opening of the second cylinder. The aspect comprised by this flow path may be sufficient.

  Furthermore, the water flow control device of the present invention includes a first cylinder and a second cylinder that are open at both ends, and the second cylinder has one opening of the first cylinder. It is inserted into the first cylinder so that it is exposed from one opening and the other opening is located inside the first cylinder, and the valve member is connected to the other of the second cylinder. An umbrella-shaped valve portion formed so as to be able to close the opening and projecting from the valve portion, and from the other opening of the second cylindrical body to the inside of the second cylindrical body And a through hole penetrating the valve member along a direction from the end of the protruding portion on the protruding direction side toward the valve portion, and the protruding portion includes the second cylinder. When inserted into the body, there is a gap that forms a part of the first flow path between the inner surface of the second cylindrical body. And is fixed to the second cylinder with the other opening of the second cylinder closed by the valve portion, and the fluid passes through the gap with a pressure equal to or higher than a set pressure. When the valve portion is pressed by this, the valve portion is elastically deformed to release the blockage by the valve portion, and the first flow path is opened from one opening of the second cylindrical body. And the passage through the valve portion and the second cylindrical body when the blocking by the valve portion is released, and is configured by a flow path to the other opening of the first cylindrical body, The second flow path may be configured by a through hole that penetrates the valve member, and the membrane member may be disposed so as to close the through hole.

  The liquid injection circuit according to the present invention includes at least the water flow control device according to the present invention, a first tube, and a second tube, and the first tube is connected to one end of the first flow path. The second tube is connected to the other end of the first flow path.

(Embodiment 1)
Hereinafter, the water flow control device according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing an appearance of a water flow control device according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view obtained by cutting the water flow control device according to Embodiment 1 of the present invention along the fluid flow direction. FIG. 3 is a cross-sectional view obtained by cutting the water flow control device according to Embodiment 1 of the present invention along a plane perpendicular to the cut plane shown in FIG. FIG. 4 is a perspective view showing the valve member shown in FIGS. 2 and 3, and a part of the valve member is shown in cross section.

  As shown in FIGS. 1 to 3, the water flow control device includes a first flow path 4, a second flow path 5, a valve member 20 disposed in the first flow path 4, and a second flow path 4. And a membrane member 8 disposed in the flow path. As shown in FIGS. 2 and 3, the valve member 20 is a one-way valve that allows only fluid flowing in one direction through the first flow path 4. Further, the valve member 20 allows only the fluid supplied to the first flow path 4 at a pressure equal to or higher than the set pressure. As shown in FIG. 3, the second flow path 5 is formed so as to branch from the first flow path 4 upstream of the valve member 20 and to merge with the first flow path 4 downstream of the valve member 20. ing. Furthermore, the membrane member 8 has hydrophobicity and air permeability, and prevents the liquid from passing through the second flow path 5.

  In this Embodiment 1, as shown in FIG.2 and FIG.3, the water flow control apparatus is provided with the 1st cylinder 1 and the 2nd cylinder 10 which both ends opened. The second cylinder 10 has one (upstream) opening 11a exposed from one (upstream) opening 2 of the first cylinder 1, and the other (downstream) opening 11a is the first cylinder. It is inserted into the first cylinder 1 so as to be located inside the body 1.

  Specifically, the second cylinder 10 includes an inner cylinder 11 provided with openings 11a and 11b, and an outer cylinder 12 provided concentrically on the outside thereof. The inner cylinder 11 and the outer cylinder 12 are connected by a ring-shaped connecting member 13. In the example shown in FIGS. 1 to 3, the inner cylinder 11, the connecting member 13, and the outer cylinder 12 are integrally formed. The outer cylinder 12 is in close contact with the inner surface of the first cylinder 1 at the outer surface thereof, and the second cylinder 10 is fixed to the first cylinder 1.

  Further, the downstream end portion of the outer cylinder 12 protrudes further downstream than the opening 11 b of the inner cylinder 11, and further includes a holding portion 14 for holding the valve member 20. The holding part 14 is formed so as to protrude toward the central axis of the outer cylinder 12, and is fitted to a protrusion 21 of a valve member 20 described later, thereby holding the valve member 20. Thus, the 2nd cylinder 10 is holding the valve member 20 in the position which opposes the downstream opening 11b.

  Furthermore, in the first embodiment, the first flow path 4 passes from the upstream opening 11 a of the second cylindrical body 10 through the downstream opening 11 b of the second cylindrical body 10 and the valve member 20. The flow path extends to the opening 3 on the downstream side of the first cylinder 1. In FIGS. 2 and 3, an arrow indicated by a solid line indicates the flow of the fluid passing through the first flow path 4.

  In the first embodiment, the valve member 20 is held by the above-described second cylinder 10 because the first gap 6 is formed between the valve member 20 and the first cylinder 1, and the valve member The second gap 7 is formed between 20 and the second cylinder 10. Further, as shown in FIG. 3, a through hole 15 is formed in a part of the holding portion 14. The second gap 7, the through hole 15, and the first gap 6 communicate with each other to form a series of flow paths. In the first embodiment, this flow path is the second flow path 5.

  As described above, the second flow path 5 branches from the first flow path 4 upstream of the valve member 20, and merges with the first flow path 4 downstream of the valve member 20. This is a bypass channel of the channel 4. In FIG. 3, an arrow indicated by a broken line indicates a flow of the fluid (gas) passing through the second flow path 5.

  In the first embodiment, the membrane member 8 is affixed to the lower surface of the protrusion 14 of the second cylinder 10, and the gap 5 between the valve member 20 and the first cylinder 1 is formed. It is arranged to close. For this reason, of the fluid that is supplied from the opening 11 a on the upstream side of the inner cylinder 11 and passes through the second gap 7 and the through hole 15, the gas passes through the second flow path 5, but the liquid is transferred by the membrane member 8. It can be stopped.

  In the first embodiment, the membrane member 8 is not particularly limited as long as it has both hydrophobicity and air permeability. Specifically, the membrane member 8 preferably has a water pressure resistance of 0.01 MPa or more, preferably 0.1 MPa or more, measured by a water pressure test specified in JIS L 1092 method B. Examples of the material for forming the film member 8 include polytetrafluoroethylene (PTFE), polyolefin (polypropylene, polyethylene, etc.), polyvinylidene fluoride, and the like. The membrane member 8 can be obtained by forming a porous layer or a nonwoven fabric with these materials.

  Moreover, in this Embodiment 1, as shown in FIGS. 2-4, the valve member 20 is formed with the elastic material. When the fluid flowing through the first flow path 4 is supplied at a pressure equal to or higher than the set pressure, the valve member 20 is elastically deformed to open the flow path and allow the fluid to pass.

  Specifically, as shown in FIG. 4, the valve member 20 forms a pair of valves 23 and 24, an annular protrusion 21 for attaching to the second cylinder 10, and the second flow path 5. And an outer wall 22 to be formed, which are integrally formed. Further, the valve 23 and the valve 24 are formed so as to have a mouth shape protruding toward a set direction (a direction from the upper side to the lower side in the figure) when both are combined.

  With this configuration, the valve 23 and the valve 24 do not open to fluid supplied from directions other than the set direction (the direction from the bottom to the top in the figure), and prevent their entry. On the other hand, when the fluid is supplied from the set direction at a pressure equal to or higher than the set pressure, the valve 23 and the valve 24 are elastically deformed as shown in FIG. It will be.

  In the first embodiment, the set pressure can be adjusted by appropriately selecting the thickness of the valves 23 and 24, the forming material, and the like. The set pressure may be set so that free flow can be prevented. For example, if the water flow control device according to the first embodiment is applied to an infusion circuit, the set pressure may be set to a pressure higher than a drop pressure due to natural drop during normal infusion.

  Moreover, as an elastic material which forms the valve member 20, various rubber materials, various thermoplastic elastomers, etc. are mentioned. Specifically, the rubber materials include natural rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, nitrile rubber, chloroprene rubber, butyl rubber, acrylic rubber, ethylene-propylene rubber, hydrin rubber, urethane rubber, silicone rubber, and fluoro rubber. Etc. Examples of the thermoplastic elastomer include thermoplastic elastomers such as styrene, polyolefin, polyvinyl chloride, polyurethane, polyester, polyamide, polybutadiene, trans polyisoprene, fluoro rubber, and chlorinated polyethylene. . Furthermore, among these materials, the most preferable material is silicon rubber. The valve member 20 can be produced by integral molding with a mold.

  As described above, the water flow control device according to the first embodiment includes the valve member 20 in the first flow path 4 and the membrane member 8 in the second flow path 5, and has a pressure lower than the set pressure. This prevents the liquid supplied in step 1 from passing through the water flow control device. Further, the liquid cannot pass through the water flow control device unless the pressure is equal to or higher than the set pressure, but the gas can always pass through the water flow control device even if the valve member 20 is not opened. For this reason, if the water flow control device according to the first embodiment is applied to the liquid injection circuit, priming in a state where it is attached to the liquid injection circuit can be performed, and the free flow described in the background section can be used. Generation can be suppressed.

  Here, the liquid injection circuit according to the first embodiment including the water flow control device shown in FIGS. 1 to 4 will be described with reference to FIG. FIG. 5 is a configuration diagram showing the overall configuration of the liquid injection circuit according to Embodiment 1 of the present invention. In the example in FIG. 5, the liquid injection circuit is an infusion circuit to which an infusion pump is attached. In the present invention, the liquid injection circuit is not limited to an infusion circuit, but may be a drug injection circuit, a blood collection circuit (A line) used in an open blood pressure measurement method, or the like.

  As shown in FIG. 5, the infusion circuit includes an infusion bag 31, a drip tube 32, a clamp 33, a water flow control device 30, and a puncture needle 34. The tube 37 connected to the inflow side of the water flow control device 1 is connected to the drip tube 32. Furthermore, the infusion pump 36 and the clamp 33 are attached to the tube 37 in order along the flow direction of the infusion. The tube 38 connected to the discharge side of the water flow control device 30 is connected to the puncture needle 34. The tube 35 connects the drip tube 32 and the infusion bag 31.

  With this configuration, even if the infusion pump 36 is removed in a state where the clamp 33 is forgotten to be closed (opened state), the infusion solution does not flow any further by the water flow control device 30, and free flow is not generated. It is suppressed. Further, as shown in FIG. 3, the water flow control device 30 is given air permeability by the second flow path 5 and the membrane member 8. Therefore, the infusion can be filled into the inside of the tube 35 and the portion from the drip tube 32 to the water flow control device 30 inside the tube 37 by the drop pressure.

  In addition, the infusion solution cannot be filled in the portion between the puncture needle 34 and the water flow control device 30 only by the drop pressure, but the infusion solution is filled up to the water flow control device 30 in this portion. This can be done by operating the infusion pump 36 later. As described above, according to the first embodiment, priming can be performed in a state where the water flow control device is attached to a liquid injection circuit such as an infusion circuit, and complication of the work of doctors and nurses is suppressed. .

(Embodiment 2)
Next, a water flow control device according to Embodiment 2 of the present invention will be described with reference to FIGS. FIG. 6 is a cross-sectional view obtained by cutting the water flow control device according to Embodiment 2 of the present invention along the fluid flow direction. 7 is a cross-sectional view obtained by cutting the water flow control device according to Embodiment 2 of the present invention along a plane perpendicular to the cut surface shown in FIG.

  As shown in FIG.6 and FIG.7, the water flow control apparatus in this Embodiment 2 differs in the structure of the valve member 25 from the water flow control apparatus in Embodiment 1. FIG. For this reason, the water flow control device according to the first embodiment is also used in the configuration of a part of the second cylinder 10 that holds the valve member 25 and the configurations of the first flow path 4 and the second flow path 5. Is different. Hereinafter, differences from the first embodiment will be described. Except for the following differences, the water flow control device in the second embodiment is configured in the same manner as the water flow control device in the first embodiment.

  Specifically, in the second embodiment, the inner cylinder 11 protrudes further downstream than the part connected to the connecting member 13. Further, a through hole 16 penetrating through the side wall of the portion protruding to the downstream side of the inner cylinder 11 is provided. The through hole 16 constitutes a part of the first flow path 4 as described later. In the second embodiment, the membrane member 8 is provided so as to close the opening 11b on the downstream side of the second cylinder 11.

  Further, the valve member 25 is constituted by a tube made of an elastic material, and covers the through-hole 16 by covering a portion protruding to the downstream side of the inner cylinder 11. Examples of the elastic material for forming the valve member 25 include those described in the first embodiment. Moreover, although the valve member 25 may be formed by metal mold | die shaping | molding and may be formed by extrusion molding, it is preferable that it is formed by metal mold | die shaping | molding from the point which is excellent in dimensional accuracy.

  Therefore, in the second embodiment, when the liquid supplied into the inner cylinder 11 is lower than the set pressure, the liquid is prevented by the valve member 25 covering the through hole 16 and the membrane member 8 covering the opening 11b. It is done. On the other hand, when the liquid is supplied at a pressure equal to or higher than the set pressure, the valve member 25 is deformed as indicated by a broken line in FIG. 7, and a gap is formed between the valve member 25 and the inner cylinder 11. As a result, the liquid flows through the through hole 16 and the formed gap to the opening 3 of the first cylinder 1. The gas supplied into the inner cylinder 11 can always pass through the water flow control device through the opening 11b and the membrane member 8.

  In the second embodiment, the first flow path 4 passes from the upstream opening 11a of the inner cylinder 11 to the downstream opening 3 of the first cylinder 1 through the through hole 16 and the valve member 25. It is comprised by the flow path to all the way (refer FIG. 7). The second flow path 5 is a flow path from the place where the through hole 16 inside the inner cylinder 11 is provided to the membrane member 8 via the opening 11 b on the downstream side of the inner cylinder 11. It is configured.

  As described above, the water flow control device according to the second embodiment also prevents the liquid supplied at a pressure smaller than the set pressure from passing through the water flow control device, as in the first embodiment. Moreover, gas can always pass the water flow control apparatus in this Embodiment 2. Therefore, even when the water flow control device according to the second embodiment is applied to the liquid injection circuit, the same effect as the water flow control device according to the first embodiment can be obtained.

(Embodiment 3)
Next, a water flow control device according to Embodiment 3 of the present invention will be described with reference to FIGS. 8 (a) and 8 (b) are cross-sectional views obtained by cutting the water flow control device according to the third embodiment of the present invention along the fluid flow direction, and FIG. 8 (a) shows the valve closed. FIG. 8B shows a state where the valve is open. FIGS. 9A to 9C are views showing the valve member shown in FIGS. 8A and 8B. FIG. 9A is a top view, and FIG. 9B is FIG. FIG. 9C is a cross-sectional view obtained by cutting along the cutting line BB ′ in FIG. 9A. FIG.

  The water flow control device according to the third embodiment is different from the water flow control device according to the first embodiment in the configuration of the second cylinder 17 and the valve member 40. Hereinafter, differences from the first embodiment will be described. Except for the following differences, the water flow control device in the third embodiment is configured in the same manner as the water flow control device in the first embodiment.

  Specifically, in the third embodiment, the second cylinder 17 includes only one cylinder. The valve member 40 includes an umbrella-shaped valve portion 41 and a protruding portion 42. The valve member 40 is also integrally formed of the elastic material shown in the first embodiment.

  The valve portion 41 is formed so as to cover the opening 17b on the downstream side of the second cylindrical body 17, that is, the diameter of the umbrella is larger than the diameter of the opening 17b. An annular contact surface 45 is formed on the upstream side of the valve portion 41 (back side of the umbrella). For this reason, the valve part 41 can closely_contact | adhere to the peripheral area | region of the opening 17b, and can obstruct | occlude the opening 17b.

  The protruding portion 42 is formed so as to protrude from the back side portion of the umbrella of the valve portion 41. As shown in FIGS. 8 and 9, the projecting portion 42 is inserted into the second cylindrical body 17 from the downstream opening 17 b, and further, the downstream opening 17 b is blocked by the valve portion 41. In the state, it is fixed to the second cylinder 17.

  The protrusion 42 is fixed to the second cylinder 17 by hooking a protrusion 44 provided on the surface of the protrusion 42 to a step 17c provided inside the second cylinder 17. . The positions of the protrusion 44 and the step 17c are adjusted so that the contact surface 45 of the valve portion 41 is in close contact with the peripheral area of the opening 17b when the protrusion 44 is hooked on the step 17c.

  Further, as shown in FIGS. 8A, 8 </ b> B, and 9 </ b> C, when the protrusion 42 is inserted into the second cylindrical body 17, the second cylindrical body is formed. It is also formed so that there is a gap constituting the first flow path 4 between the inner surface of 17. Specifically, the protrusion 42 has a recess 43 on the side surface, and the recess 43 forms a gap that forms the first flow path 4.

  Therefore, the liquid supplied to the inside of the second cylinder 17 passes through the gap between the recess 43 and the inner surface of the second cylinder 17 and then presses the valve portion 41. At this time, when the liquid is supplied at a pressure equal to or higher than the set pressure, as shown in FIG. 8B, the projecting portion 42 is elastically deformed in the extending direction, and the contact surface 45 of the valve portion 41 and the opening 17b. Release contact with the surrounding area. As a result, the liquid flows between the contact surface 45 of the valve portion 41 and the peripheral region of the opening 17 b and flows to the opening 3 of the first cylinder 1.

  In the third embodiment, the first flow path 4 is formed between the opening 11a on the upstream side of the first cylinder, the recess 43 and the inner surface of the second cylinder 17, and the contact surface 45 and the opening 17b. This is constituted by a flow path that reaches the opening 3 on the downstream side of the first cylindrical body 1 through the space between the first peripheral body 1 and the peripheral region.

  Moreover, the valve member 40 is provided with the through-hole 46 which penetrates it. The through hole 46 is provided along the direction from the end of the protruding portion 42 on the protruding direction side toward the valve portion 41. In the third embodiment, the through hole 46 constitutes the second flow path 5. The membrane member 8 is attached so as to close the opening on the downstream side of the through hole 46, that is, to cover the vicinity of the apex of the valve portion 41. Therefore, the gas supplied to the inside of the second cylinder 17 can always pass through the water flow control device through the through hole 46 and the membrane member 8. In the third embodiment, the membrane member 8 may be disposed inside the through hole 46 or may be disposed so as to close the opening on the upstream side of the through hole 46.

  As described above, the water flow control device according to the third embodiment also prevents the liquid supplied at a pressure smaller than the set pressure from passing through the water flow control device, as in the first embodiment. Moreover, gas can always pass the water flow control apparatus in this Embodiment 3. Therefore, even when the water flow control device according to the third embodiment is applied to the liquid injection circuit, the same effect as the water flow control device according to the first embodiment can be obtained.

  As described above, the water flow control device and the liquid injection circuit according to the present invention can be applied as components of an infusion circuit or a chemical injection circuit, and have industrial applicability.

FIG. 1 is a perspective view showing an appearance of a water flow control device according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view obtained by cutting the water flow control device according to Embodiment 1 of the present invention along the fluid flow direction. FIG. 3 is a cross-sectional view obtained by cutting the water flow control device according to Embodiment 1 of the present invention along a plane perpendicular to the cut plane shown in FIG. FIG. 4 is a perspective view showing the valve member shown in FIGS. 2 and 3, and a part of the valve member is shown in cross section. FIG. 5 is a configuration diagram showing the overall configuration of the liquid injection circuit according to Embodiment 1 of the present invention. FIG. 6 is a cross-sectional view obtained by cutting the water flow control device according to Embodiment 2 of the present invention along the fluid flow direction. 7 is a cross-sectional view obtained by cutting the water flow control device according to Embodiment 2 of the present invention along a plane perpendicular to the cut surface shown in FIG. 8 (a) and 8 (b) are cross-sectional views obtained by cutting the water flow control device according to the third embodiment of the present invention along the fluid flow direction, and FIG. 8 (a) shows the valve closed. FIG. 8B shows a state where the valve is open. FIGS. 9A to 9C are views showing the valve member shown in FIGS. 8A and 8B. FIG. 9A is a top view, and FIG. 9B is FIG. FIG. 9C is a cross-sectional view obtained by cutting along the cutting line BB ′ in FIG. 9A. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st cylinder 2 Opening of the upstream of a 1st cylinder 3 Opening of the downstream of a 1st cylinder 4 1st flow path 5 2nd flow path 6, 7 Crevice 8 Membrane members 10, 17 2nd cylinder 11 Inner cylinder 11a, 17a The upstream opening 11b, 17b of the 2nd cylinder 12 The downstream opening of the 2nd cylinder 12 Outer cylinder 13 Connecting member 14 Holding part 15, 16 Through-hole 17c Level | step difference 20, 25, 40 Valve member 21 Protruding portion 22 Outer wall 23, 24 Valve 41 Valve portion 42 Protruding portion 43 Recessing portion 44 Protruding 45 Contact surface 30 Water flow control device 31 Infusion bag 32 Drip tube 33 Clamp 34 Puncture needle 35, 37, 38 Tube 36 infusion pump

Claims (5)

A first flow path, a second flow path, a valve member disposed in the first flow path, and a membrane member disposed in the second flow path,
The valve member is supplied to the first flow path at a pressure equal to or higher than a set pressure, and allows only fluid flowing in one direction in the first flow path to pass through.
Said second flow path branched from the first flow path upstream than the valve member, it is formed so as to merge into the first flow path downstream than the valve member,
The membrane member has hydrophobicity and air permeability, prevents liquid from passing through the second flow path ,
The water flow control device , wherein the set pressure is set to a value higher than a drop pressure due to a natural drop of infusion and lower than a supply pressure by an infusion pump . A first cylinder and a second cylinder open at both ends;
The second cylinder has the first opening so that one opening is exposed from one opening of the first cylinder and the other opening is located inside the first cylinder. A first gap is formed between the valve member and the first cylinder at a position inserted into the cylinder and facing the other opening, and the valve member and the second cylinder. Holding the valve member such that a second gap is formed between
The valve member is formed of an elastic material, and when the fluid is supplied at a pressure equal to or higher than the set pressure, the valve member is elastically deformed to pass the fluid,
The membrane member is disposed so as to close a gap between the valve member and the first cylindrical body,
The first flow path extends from one opening of the second cylinder to the other opening of the first cylinder via the other opening of the second cylinder and the valve member. Composed of up to
The water flow control device according to claim 1, wherein the second flow path is configured by the first gap and the second gap. A first cylinder and a second cylinder open at both ends;
The second cylinder has the first opening so that one opening is exposed from one opening of the first cylinder and the other opening is located inside the first cylinder. In a portion inserted into the cylinder and inserted into the first cylinder, a through-hole penetrating the side wall is provided,
The valve member is formed of an elastic member that covers the through hole, and when the fluid is supplied at a pressure equal to or higher than the set pressure, the valve member is elastically deformed so that it can pass through the through hole.
The membrane member is disposed so as to close the other opening of the second cylindrical body,
The first flow path is configured by a flow path from one opening of the second cylindrical body to the other opening of the first cylindrical body via the through hole and the valve member. ,
The second channel is a channel from where the through-hole is provided inside the second cylinder to the membrane member via the other opening of the second cylinder. The water flow control device according to claim 1, comprising: A first cylinder and a second cylinder open at both ends;
The second cylinder has the first opening so that one opening is exposed from one opening of the first cylinder and the other opening is located inside the first cylinder. Inserted into the cylinder,
The valve member covers the other opening of the second cylindrical body and is formed so as to be able to close the umbrella-shaped valve part, and protrudes from the valve part, and the second cylindrical body A through-hole penetrating the valve member along a direction from the end of the projecting portion toward the valve portion from an end portion on the projecting direction side of the projecting portion. And
The protruding portion is formed so that a gap constituting a part of the first flow path exists between the protruding portion and the inner surface of the second cylindrical body when inserted into the second cylindrical body. And is fixed to the second cylinder with the other opening of the second cylinder closed by the valve portion, and the fluid passes through the gap with a pressure equal to or higher than a set pressure. When the valve part is pressed by this, it is elastically deformed to release the blockage by the valve part,
The first flow path passes from one opening of the second cylinder through the gap and between the valve part and the second cylinder when the blockage by the valve part is released. And constituted by a flow path leading to the other opening of the first cylindrical body,
The second flow path is constituted by a through-hole penetrating the valve member,
The water flow control device according to claim 1, wherein the membrane member is disposed so as to close the through hole. At least the water flow control device according to any one of claims 1 to 4, a first tube, and a second tube,
The liquid injection circuit, wherein the first tube is connected to one end of the first flow path, and the second tube is connected to the other end of the first flow path.

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