JP2005218668A - Check valve for internal pressure adjustment of endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a check valve for adjusting the internal pressure of an endoscope which blocks the inside of an endoscope from outside credibly in a closed valve state and prevents the movement in a valve opening direction from getting heavy. <P>SOLUTION: An O ring 20 is arranged between a valve body 18 and a valve seat 16 and a spring 21 is provided for energizing the valve body 18 to a valve closing direction, that is, to an O ring crushing direction. The equipped capacity of the spring and the rubber hardness of the O ring are set so that the collapse ratio of the O ring 20 is 10-30% when there is no pressure difference between the inside and outside of the endoscope and so that the valve body 18 moves to the valve opening direction to prevent the O ring 20 from sealing the opposing faces of the valve body 18 and the valve seat 16 before the external pressure of the endoscope is reduced by 1 atmosphere (more preferably, when the external pressure is reduced by about 0.3 atmosphere) than the internal pressure. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a check valve for adjusting an internal pressure of an endoscope that may be sterilized by an autoclave or ethylene oxide gas (EOG).

  To perform ethylene oxide gas sterilization or autoclave to sterilize the endoscope, it is necessary to depressurize the sterilization chamber that houses the endoscope, and the endoscope can withstand such a low-pressure environment. It is necessary to.

  At that time, the problem is that the most flexible part of the exterior of the endoscope in which all the partitions partitioning from the outside are hermetically configured, such as a covering tube of a curved part generally formed of rubber, etc. However, it may swell and burst during decompression.

  Therefore, by providing a check valve for internal pressure adjustment that allows gas to pass from the inside of the endoscope to the outside and does not allow gas to pass from the outside to the inside of the endoscope, the air inside the endoscope can be The internal pressure is lowered and the internal pressure is lowered and at the time of sterilization and cleaning, steam, gas, cleaning water or the like is prevented from entering the endoscope.

As the configuration of the check valve for adjusting the internal pressure of such an endoscope, an internal / external communication hole for communicating the inside and the outside of the endoscope, a valve seat formed near the outer side of the internal / external communication hole, and an internal / external communication An O-ring composed of a valve body disposed at a position facing the valve seat from the outside so as to be movable in the axial direction of the hole, and an elastic material disposed on a facing surface portion between the valve body and the valve seat And a spring that urges the valve body in a valve closing direction in which the O-ring is sandwiched between the valve body and the valve seat and crushed (for example, Patent Document 1).
JP 10-328132 A

  In the check valve for adjusting the internal pressure of the endoscope having the above-described configuration, the O-ring disposed on the facing surface portion between the valve seat and the valve body is pushed by the biasing force of the spring when the valve is closed. By being crushed, the space between the inside and the outside of the endoscope is reliably blocked, and the larger the collapse rate of the O-ring, the more reliable the closed state.

  Therefore, in order to ensure the valve closing state, it is only necessary to increase the force of the spring so that the O-ring is crushed well. However, if this is done, the operation in the valve opening direction becomes heavy and the endoscope is There is a risk that the internal / external pressure difference becomes too large.

  Therefore, the present invention provides a check valve for adjusting the internal pressure of an endoscope that reliably closes the inside and outside of the endoscope when the valve is closed and does not increase the operation in the valve opening direction. For the purpose.

  In order to achieve the above object, the internal pressure adjusting check valve of the endoscope according to the present invention has an internal / external communication hole for communicating between the inside and the outside of the endoscope in which all partition walls partitioning the outside are hermetically configured. A valve seat formed near the outside mouth of the inner and outer communication holes, a valve body disposed so as to face the valve seat from the outside so as to be movable in the axial direction of the inner and outer communication holes, and a valve body, An O-ring made of an elastic material disposed on the surface facing the valve seat, and a spring that urges the valve body in the valve closing direction to clamp the O-ring between the valve body and the valve seat. In the check valve for adjusting the internal pressure of the endoscope, the O-ring collapse rate is 10-30% when there is no pressure difference between the inside and outside of the endoscope. Before the pressure outside the endoscope is 1 atmosphere lower than the internal pressure. Body is one that was set as O-ring started to move in the valve opening direction is opened without sealing the facing surfaces of the valve body and the valve seat.

  It should be noted that when the pressure outside the endoscope is reduced by about 0.3 atm compared to the internal pressure, the valve body begins to move in the valve opening direction and the O-ring moves between the valve body and the valve seat. It is most preferable to set so that the surface opposite to is not sealed. In that case, the rubber hardness of the O-ring is preferably set to about durometer A40 °.

  According to the present invention, the amount of force of the spring that urges the valve body in the valve closing direction to crush the O-ring disposed between the valve body and the valve seat and the rubber hardness of the O-ring are determined by the endoscope. When there is no pressure difference between the inside and outside, the collapse rate of the O-ring is in the range of 10 to 30%, and the valve body opens before the pressure outside the endoscope is 1 atmosphere lower than the internal pressure. By setting the O-ring so that it begins to move in the valve direction and the O-ring does not seal the opposing surface of the valve body and valve seat, the gap between the inside and outside of the endoscope is maintained when the valve is closed. The valve is reliably closed, and the operation in the valve opening direction does not become heavy and can operate smoothly.

  There is no difference in pressure between the inside and outside of the endoscope between the installed force of the spring that urges the valve body in the closing direction to crush the O-ring disposed between the valve body and the valve seat, and the rubber hardness of the O-ring. When the O-ring collapse rate is in the range of 10 to 30% in the state, and the pressure outside the endoscope is about 0.3 atm lower than the internal pressure, the valve body opens The O-ring is set so as not to seal the opposed surface between the valve body and the valve seat. The rubber hardness of the O-ring at that time is about durometer A 40 °.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 2 shows the overall configuration of the endoscope. A bending portion that can be bent by a remote operation by an operation lever 3 provided on the operation unit 1 is provided at the distal end portion of the insertion unit 2 connected to the operation unit 1. 4 is provided. The curved portion 4 is covered with a flexible rubber tube.

  A connector portion 7 detachably connected to a light source device (not shown) is attached to the distal end of the flexible connecting tube 6 extending from the operation portion 1. Reference numeral 5 denotes an eyepiece, which is unnecessary in the case of an electronic endoscope.

  In this endoscope, the partition walls that are partitioned from the outside are all hermetically configured by packing, O-rings, and the like, and the insides are in communication with each other. The connector portion 7 is provided with a check valve 10 for adjusting the pressure inside the endoscope at the time of sterilization with ethylene oxide gas or autoclave.

  The check valve 10 is opened when the pressure outside the endoscope is lower than the internal pressure to some extent, and allows the gas to pass from the inside of the endoscope to the outside. The valve is set to a closed state that does not allow gas to pass from the outside to the inside.

  FIG. 1 shows a check valve 10 in which a stepped cylindrical pedestal cylinder 11 is screwed and connected to the outer surface portion of the outer wall of the connector portion 7. An O-ring 12 is attached. Reference numeral 13 denotes a guide pin serving as a guide when connecting a valve opening adapter (not shown).

  The cylindrical member 14 inserted into the pedestal cylinder 11 from the outer surface opening side and fixed with screws is formed as a separate part from the pedestal cylinder 11 for the convenience of parts processing and assembly, but functionally the pedestal cylinder 11. And a sealing O-ring 17 is mounted on the fitting surface with the base tube 11.

  Through holes 15A and 15B are formed at the axial position of the base cylinder 11 and the axial position of the cylindrical member 14, respectively, so that they are connected straight, and an internal / external communication hole 15 that connects the inside and the outside of the endoscope is formed. The two through holes 15A and 15B are formed. A valve seat 16 having a tapered surface is formed on the inner peripheral portion of the cylindrical member 14 corresponding to the outer side mouth of the inner and outer communication holes 15.

  A valve body 18 formed in a substantially mushroom shape is disposed at the axial position of the cylindrical member 14 so as to be movable in the axial direction, and a portion corresponding to the neck portion is formed in a tapered surface facing the valve seat 16. Has been.

  A portion corresponding to the shaft portion of the valve body 18 passes through the inside of the valve seat 16 and is inserted into the inner and outer communication holes 15. However, a gap for ventilation is secured in the inner and outer communication holes 15 over the entire length so that the inner and outer communication holes 15 are not blocked by the valve body 18.

  An O-ring 20 made of an elastic rubber material or the like is disposed on the facing surface portion between the valve seat 16 and the valve body 18. In this embodiment, the O-ring 20 is mounted on the annular groove formed on the valve body 18 side, but a groove for mounting the O-ring 20 may be formed on the valve seat 16 side.

  With such a configuration, when the O-ring 20 is sandwiched between the valve body 18 and the valve seat 16 and is crushed, the check valve 10 is closed, and the space between the inside and the outside of the endoscope is reduced. The valve is closed. FIG. 1 shows a cross-sectional shape of a perfect circle before the O-ring 20 is crushed.

  As indicated by the arrow Y, when the valve body 18 moves outward and the O-ring 20 moves away from the valve seat 16, the inside of the endoscope is connected via the gap portion and the inner and outer communication holes 15. The valve is in open communication with the outside.

  A spring receiving cylinder 22 that receives one end of a compression coil spring 21 disposed inside the cylindrical member 14 is connected and fixed to the inner end portion of the shaft portion of the valve body 18 by a drive pin 23. The spring receiving cylinder 22 is loosely fitted in the cylindrical member 14, but can be moved forward and backward in the axial direction integrally with the valve body 18, and a plurality of spring receiving cylinders 22 are arranged in the direction parallel to the axis in the outer peripheral portion. A ventilation groove 24 is formed.

  The compression coil spring 21 urges the valve body 18 in a valve closing direction in which the O-ring 20 is sandwiched between the valve body 18 and the valve seat 16 and is crushed. The urging force in the state) is such that when the pressure outside the endoscope becomes lower by about 0.3 atm (0.03 MPa) than the internal pressure, the valve body 18 starts moving in the valve opening direction and the O-ring 20 It is set to a value that does not seal the opposing surface of the valve body 18 and the valve seat 16. When manufacturing error is taken into consideration, about 0.3 atm means about 0.2 to 0.4 atm.

  The O-ring 20 sandwiched between the valve body 18 and the valve seat 16 receives a force in a direction in which it is crushed by the compression coil spring 21, but there is no pressure difference between the inside and outside of the endoscope, and the compression coil spring 21 When receiving only the equipment strength, the crushing rate of the O-ring 20 (the crushing rate in the radial direction, (e / D) × 100 shown in FIG. 1) is set to 10 to 30%. In order to do so, the rubber hardness of the O-ring 20 may be set to about durometer A40 °.

  The drive pin 23 is for pushing up the valve body 18 against the urging force of the compression coil spring 21 to forcibly open the check valve 10 from the outside. 18 and is screwed in from the side.

  And the cam groove 26 for driving the drive pin 23 is formed in the side wall part of the cylindrical member 14, and when a valve opening adapter (not shown) is attached to the check valve 10, the drive pin 23 is pushed up by the cam groove 26 to forcibly open the valve.

  In the check valve 10 configured as described above, the O-ring 20 is pushed about 10 to 30% in the radial direction between the valve body 18 and the valve seat 16 by the urging force based on the amount of force of the compression coil spring 21. It is in a reliable valve closing state sandwiched between the crushed states.

  When the pressure outside the endoscope decreases by about 0.3 atm or more from the internal pressure, the differential pressure causes the valve body 18 to be pushed outward, creating a gap between the valve seat 16 and the O-ring 20. Since the valve is in an open state, the air in the endoscope flows out to the outside, the endoscope internal pressure is lowered, and the rupture of the curved portion rubber or the like is prevented.

  At this time, if the installation force of the compression coil spring 21 is set so that the pressure outside the endoscope is opened at about 0.1 atm (0.01 MPa) from the internal pressure, A stable water-tight state cannot be obtained, for example, there is a possibility that a chemical solution may enter the endoscope due to an increase in internal pressure to the extent that the endoscope is immersed in a warm chemical solution.

  In addition, this invention is not limited to the said Example, For example, the installation force quantity of the compression coil spring 21 is a valve-opening state when the pressure outside an endoscope falls about 0.3 atmosphere or more from the internal pressure. It is most preferable to set the pressure so that the valve becomes open at least before the pressure outside the endoscope becomes 1 atm lower than the pressure inside (that is, the pressure difference between the inside and outside is less than 1 atm). It should be set as follows.

It is a longitudinal cross-sectional view of the check valve for internal pressure adjustment of the endoscope of the Example of this invention. It is an external view which shows the whole structure of the endoscope of the Example of this invention.

Explanation of symbols

10 Check valve 15 Inner / outer communication hole 16 Valve seat 18 Valve element 20 O-ring 21 Compression coil spring

Claims (3)

Internal and external communication holes for communicating between the inside and outside of the endoscope in which all the partitions partitioning the outside are hermetically configured, the valve seat formed in the vicinity of the external side mouth of the internal and external communication holes, and the internal and external communication holes The valve body is disposed so as to face the valve seat from the outside so as to be movable in the axial direction of the valve body, and is made of a resilient material disposed on the facing surface portion between the valve body and the valve seat. In an internal pressure adjusting check valve for an endoscope having an O-ring and a spring that urges the valve body in a valve closing direction to sandwich and crush the O-ring between the valve body and the valve seat,
The amount of force of the spring and the rubber hardness of the O-ring are determined so that the collapse rate of the O-ring is in the range of 10 to 30% when there is no pressure difference between the inside and outside of the endoscope. The valve body starts moving in the valve opening direction before the pressure outside the endoscope becomes 1 atm lower than the internal pressure, and the O-ring does not seal the opposing surface between the valve body and the valve seat. A check valve for adjusting the internal pressure of an endoscope, characterized by being set to be. When the pressure outside the endoscope is reduced by about 0.3 atm compared to the internal pressure, the valve body starts to move in the valve opening direction, and the O-ring A check valve for adjusting an internal pressure of an endoscope according to claim 1, wherein the opposite surface between the valve seat and the valve seat is not sealed. The check valve for internal pressure adjustment of an endoscope according to claim 2, wherein the rubber hardness of the O-ring is set to about durometer A 40 °.

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