JPH0221075Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a check valve used in a medical low-pressure evacuation device.

[Background of the idea]

Generally, check valves are used to prevent backflow of fluid, but check valves have a structure that uses a moving valve body made of balls or small metal pieces, or for medical use, a flat thin film tube made of rubber or plastic. There are also types that exhibit a backflow prevention effect by opening and closing. A check valve of this rubber or plastic membrane tube construction is used, for example, in a device such as that shown in FIG. In FIG. 4, reference numeral 11 indicates a plastic tube, which was inserted into the body and leaked into the body cavity after surgery. This tube is used to discharge unnecessary body fluids and gases such as pus, and since these body fluids and gases accumulate in the body after a certain period of time, they are discharged through this tube periodically or irregularly. 12 is an inlet, into which the plastic tube 11 is inserted and connected.

Reference numeral 13 denotes a check valve having a normally closed slit 14, and when unnecessary liquid or gas deposited in a body cavity with positive pressure flows through the tube 11, the slit 14 opens due to the pressure and enters a container 15 outside the check valve. It is discharged and deposited in the pump 16 and discharged by the pump 16. The check valve slit has an extremely low water column of 20~
It functions as a valve that opens and closes with a pressure of about 100 mm.

By the way, conventional check valves used for such purposes typically have the shapes shown in FIGS. 5 to 9, for example, and are usually made of latex. For example, as shown in Figure 5, a long opening is easier to close over the entire surface during suction, so the tip is cut into a fishtail shape, or the tip of a flat or cylindrical tube is flattened. Many of them are closed and have a slit-like opening in the closed part. However, although these check valves are effective when the pressure is high, many of them are not effective in preventing backflow when the pressure is low because they close the slit in the flat part in response to external pressure. Furthermore, even if the flat, thin-walled tube type check valve shown in Figure 7 is used, there is a slight gap between the bends on both sides (see Figure 7D).
This is effective when the tube is upright, but if the tube is tilted or laid down, it may be Since the valve opened and did not operate sufficiently against the suction pressure, a sufficient effect could not be obtained. In addition, a check valve of the type shown in Figure 6, which is made by forming two rubber or plastic sheets into a band shape and bonding both sides together, can operate even at low pressure if the sheet thickness is made thin. However, if the adhesive is made too thin, the applied area will become wavy, making it difficult to bond and making it impossible to obtain a stable valve.

[Purpose of invention]

In view of the above drawbacks, the present invention aims to provide a check valve that is easy to manufacture, has stable dimensional accuracy, and repeats stable operation even at low pressures.

[Summary of the idea]

Therefore, the feature of the check valve of the present invention made for this purpose is that one end side has a sleeve shape with a liquid inflow opening having a generally circular cross section, and the other end side has a flat strip shape with a liquid outflow slit. With eggplant,
The flexible check valve is made of silicone rubber and includes a connecting part having an internal flow path that connects these two ends, and the connecting part extends outward from both sides and both sides of the strip-shaped strip at the other end, respectively. It is connected to the sleeve-shaped portion on the one end side by an arcuate surface that is concave with respect to the other end.

The reason for adopting this configuration in the present invention is as follows.

Conventional check valves have generally been made from natural rubber latex products or from a combination of natural extruded rubber tubes and natural rubber latex, but these have low dimensional accuracy, are time-consuming to manufacture, and latex products tend to be sticky and prone to aging. In order to quickly prevent this, surface treatment with a sodium hypochlorite solution or the like is required. If this treatment is not carried out, the slit will not open and close properly, especially at low pressures, due to the sticky nature of the rubber.

Therefore, we have developed a silicone elastomer as a material that has aging resistance that can withstand repeated high temperature sterilization at around 100℃, flexibility and elasticity even at high or low temperatures, and has no stickiness and is excellent in hygiene as a medical product. was used.

In particular, silicone elastomer is a material with excellent non-adhesion and non-staining properties compared to other rubber materials, and is also excellent in preventing the check valve slit from becoming sticky and not being properly closed during suction. When using a device that suctions extremely sticky human body fluids, etc., the adhesiveness of the body fluid may prevent the opening and closing of the slit, and the slit may become blocked, making suction impossible. Therefore, a check valve made of silicone elastomer is used was found to be extremely effective in terms of non-adhesion.

In addition, since the check valve of the present invention has a concave (negative) curved surface on all four sides between the outflow opening and the inflow opening, which are normally open slits, when negative internal pressure is generated during suction, This has the effect of reducing the internal volume extremely smoothly and closing the slit uniformly over the entire surface. Especially when used at low pressure, a negative curved surface has a larger area to which pressure is applied, and the stress applied to the surface of the outlet with the slit is more likely to concentrate, so that the opening surface of the slit is uniformly and well tightened over the entire surface. Moreover, since all four sides are negative curved surfaces, a synergistic effect is further added.

[Example of idea]

The configuration of the present invention will be explained in detail below with reference to the drawings.

In Figures 1 to 3, a check valve 1 is made of molded silicone rubber, and a sleeve-shaped part 2 on one end thereof has a circular cross section and is housed within a relatively thick cylindrical shell. The flow path 2a is connected to the inflow opening 2b. Reference numeral 3 denotes a flat strip-shaped portion on the other end side of the check valve, and a slit 4 is formed so as to cover almost the entire area of the strip-shaped portion 3 in the flat direction. The slit 4 is substantially normally closed in its natural state. Reference numeral 5 denotes a connecting portion that connects the sleeve-shaped portion 2 and the strip-shaped portion 3, and in this example, arcuate surfaces 6, 6 are concave (negative) toward the outside with approximately the same width from both sides of the strip-shaped portion 3. and is connected to the sleeve-shaped part 2 by a pair of symmetrical surfaces connected to the sleeve-shaped part 2 and arc-shaped surfaces 7, 7 that are concave (negative) toward the outside while gradually increasing the width from both side edges of the strip-shaped part 3. It consists of a pair of symmetrical surfaces.

According to the check valve having such a structure, since it is formed with a relatively thick wall, the whole has sufficient shape retention properties, and the strip-shaped portion 3 can close the slit 4 easily and reliably. Therefore, it has been experimentally confirmed that backflow prevention can be suitably achieved even when used in a low pressure state, and that there is no problem with liquid outflow even at low pressure when internal pressure is applied.

[Effect of idea]

When the check valve according to the present invention is used in a medical low-pressure suction and discharge device, it is highly safe because it uses silicone rubber that is hygienic and non-adhesive.
Since the normally closed slit is non-adhesive, it does not become sticky due to body fluids and maintains high safety at all times.
Since the space between the inflow opening and the outflow opening is configured with negative curved surfaces on all four sides, it has the effect that liquid or gas flows out extremely smoothly.

In addition, in the case of latex products, the mold is repeatedly immersed in a compounded latex solution several times to produce it, so there is a problem with dimensional accuracy, but in this invention, silicone rubber is filled in a two-part mold and heated. Since it can be manufactured by molding, it also has the feature of producing products with extremely improved dimensional accuracy.

[Brief explanation of drawings]

1 to 3 are diagrams showing a check valve according to an embodiment of the present invention, in which FIG. 1 is a front view thereof, FIG. 2 is a side view including a partial cross section, and FIG. 3 is a plan view. It is a diagram.
Fig. 4 is a diagram showing an example of a medical device to which the present invention is applied;
Figures A and B are diagrams illustrating conventional check valves, respectively. DESCRIPTION OF SYMBOLS 1... Check valve, 2... Sleeve-shaped part, 3... Strip-shaped part, 4... Slit, 5... Connecting part, 6, 7
...Arc-shaped surface.

Claims (1)

[Scope of utility model registration request] A silicone material consisting of a sleeve-like shape with one end having a liquid inflow opening with a generally circular cross section, and a flat strip-like shape with a liquid outflow slit at the other end, and a connecting part with an internal flow path that connects both ends. The flexible check valve is made of rubber, and the connecting portion is connected to the sleeve-shaped portion on the one end side by an arcuate surface that is concave outward from both sides and both side edges of the strip on the other end side. A medical low pressure check valve characterized by: