JP3655687B2 - Endoscope pipe switching device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an endoscope conduit switching device.
[0002]
[Prior art]
In general, a pipe switching device for an endoscope is fitted in a cylinder body in which a plurality of pipes for allowing fluid to pass are opened and connected, and a piston body for switching the connection state between the pipes is slidable in an axial direction. It is inserted.
[0003]
In order to seal the fitting surface portion between the cylinder body and the piston body, a seal ring made of a resilient O-ring using rubber or the like is provided in a circumferential groove formed on the outer circumferential surface of the piston body. Is inserted.
[0004]
FIG. 6 illustrates such a conventional circumferential groove and O-ring. A cross-sectional shape of the first circumferential groove 91 formed in the piston body 90 is substantially rectangular, and a seal ring 92 made of an O-ring having a circular cross-sectional shape is fitted therein.
[0005]
[Problems to be solved by the invention]
However, if the circumferential groove and the seal ring are formed in such a shape, dirt or the like is easily accumulated in the gap formed on the back surface side of the seal ring 92 and becomes filthy.
[0006]
Therefore, it is conceivable to rubber-line the circumferential groove 93 as in a second seal ring 94 shown next. However, with such a configuration, since the seal ring 94 alone cannot be replaced when the rubber seal ring 94 deteriorates, the entire piston body 90 must be replaced, which is very uneconomical.
[0007]
Therefore, it is conceivable to form the back surface side into a deformed shape that closely adheres to the bottom of the circumferential groove 95 as in the third seal ring 96 at the bottom. In doing so, as shown in FIG. 7, the seal ring 96 may be erroneously mounted in an inverted state and the sealing function may be impaired.
[0008]
Therefore, an object of the present invention is to provide an endoscope pipe switching device capable of easily replacing only a seal ring when dirt does not accumulate on the back side of the seal ring and the seal ring deteriorates. .
[0009]
[Means for Solving the Problems]
In order to achieve the above-described object, the endoscope channel switching device of the present invention is configured to switch a connection state between a cylinder body in which a plurality of channels for passing fluid are open-connected and the above-described channels. A piston body fitted in the cylinder body so as to be movable back and forth in the axial direction, and a circumferential groove formed on the outer circumferential surface of the piston body for sealing a fitting surface portion between the cylinder body and the piston body In an endoscope channel switching device having a seal ring made of a resilient member that is detachably fitted inside, a cross-sectional shape of the circumferential groove is formed in a U-shape with a curved bottom. In addition, the cross-sectional shape of the seal ring is formed in a shape in which the inner diameter side is substantially in close contact with the circumferential groove having the U-shaped cross-section, and the outer diameter side is symmetrical with the inner diameter side.
[0010]
It should be noted that a plurality of the circumferential grooves are provided at different positions in the axial direction of the piston, and the cross-sectional shape of at least one of the circumferential grooves is formed in a U shape with a curved bottom. Good.
[0011]
Also, a liquid passage pipe whose opening is connected to the cylinder by the seal ring fitted in the circumferential groove having a U-shaped cross-sectional shape with a curved bottom portion moving the piston in the axial direction. It may move across the opening of the road.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
FIG. 2 shows an air / water supply operation valve 10 provided in the operation unit 1 of the endoscope, and a stainless steel cylinder body 11 disposed in the operation unit 1 has an opening opening outward. In this manner, the operation nut 1 is fixed by a fixing nut 12. Reference numeral 13 denotes an O-ring for sealing.
[0013]
The cylinder body 11 includes an air supply pipe 14 to which pressurized air is supplied, a water supply pipe 15 to which pressurized water is supplied, and an air supply pipe 16 and a water supply pipe 17 that reach the distal end of an insertion portion (not shown). It is connected.
[0014]
Among them, the air supply pipe 14 and the water supply pipe 15 are openly connected to the side wall surface of the cylinder body 11 so as to be open. Further, the air supply pipe 16 is opened and connected to the central axis position of the bottom lid 11 a that closes the back of the cylinder body 11. Is connected to the opening at an angle.
[0015]
A piston body 21 is fitted into the cylinder body 11 so as to be slidable in the axial direction. Circumferential grooves 26 to 29 are formed in portions of the piston body 21 located between the openings of the water supply pipe 17, the water supply pipe 15, the air supply pipe 14, and the air supply pipe 16. 29 is fitted with O-rings 22 to 25 (seal rings) made of a resilient member for sealing a fitting surface portion between the cylinder body 11 and the piston body 21.
[0016]
The piston body 21 is formed with circumferential communication grooves 32 and 33 at two locations. The axial portion of the piston body 21 has a vent hole 34 penetrating therethrough. The first communication groove 32 communicates directly with the vent hole 34.
[0017]
A check valve 30 is attached to the end of the piston body 21 on the back side. The check valve 30 is composed of a cup-shaped component made of a resilient rubber material, and is detachably placed on the cylindrical portion at the tip of the piston body 21. An edge portion of the check valve 30 is formed thin, and a through hole 35 is formed in a wall surface of the piston body 21 inside thereof.
[0018]
Therefore, when the pressure inside the vent hole 34 increases, the pressure leaks outward from the through hole 35 and the check valve 30 is pushed outward. When the ambient pressure is higher, the check valve 30 is in close contact with the periphery of the through hole 35 and is closed, and acts as a check valve.
[0019]
An operation button 37 is attached to the head of the piston body 21 via a connecting ring 36, and they are urged integrally outward by a compression coil spring 38.
[0020]
The operation button 37 is provided with a leak hole 39 that communicates straight with the vent hole 34 of the piston body 21 and is opened to the atmosphere, and a portion around the leak hole 39 is formed of a plastic cylinder 40. Yes.
[0021]
The receiving ring 41 that receives the proximal end side of the compression coil spring 38 serves as a stopper that prevents the piston body 21 from jumping outward, and an elastic rubber stationary ring 42 is provided on the outer periphery thereof. It is lined integrally.
[0022]
The inner peripheral portion of the lower end of the fixed ring 42 is hooked and engaged with the protruding end portion of the fixed nut 12 to fix the unit of the piston body 21 and the operation button 37 to the cylinder body 11, and the fixed ring 42 is elastically deformed. If the engagement is released, the piston body 21 can be pulled out from the cylinder body 11.
[0023]
In the air / water supply operation valve 10 configured as described above, in the standby state, as shown in FIG. 2, the pressurized air sent from the air supply pipe 14 passes through the vent hole 34 from the communication groove 32. It is discharged from the leak hole 39 to the atmosphere. The outlet of the water supply pipe 15 is closed by the piston body 21.
[0024]
Since the air in the vent hole 34 escapes to the leak hole 39, a force sufficient to push open the check valve 30 is not generated. Further, the reverse flow of the fluid from the distal end side of the air supply pipe 16 is blocked by the check valve 30.
[0025]
As shown in FIG. 3, when the leak hole 39 is closed with a fingertip, there is no place for the pressurized air sent from the air supply pipe 14 into the vent hole 34, and the air passes through the through hole 35. The check valve 30 is pushed outward and sent to the air supply pipe 16. As a result, air is supplied toward the surface of the observation window provided at the distal end of the insertion portion (not shown).
[0026]
As shown in FIG. 4, when the operation button 37 is pushed in with the leak hole 39 closed, the piston body 21 is pushed into the cylinder body 11, and the water supply pipe 15 and the water supply pipe are connected via the communication groove 33. 17 communicates.
[0027]
As a result, the pressurized water sent through the water supply pipe 15 is sent to the water supply pipe 17 through the communication groove 33, and the water supply is directed toward the surface of the observation window provided at the distal end of the insertion portion (not shown). Done.
[0028]
Returning to FIG. 2, after using the endoscope, the fixed ring 42 is elastically deformed, the piston body 21 is removed from the cylinder body 11, and a brush for cleaning is inserted into the water supply pipe 17 and the air supply pipe 16 for brushing. Can be cleaned. Also, the piston body 21 removed from the cylinder body 11 can be cleaned and disinfected well outside.
[0029]
The four O-rings 22 to 25 attached to the piston body 21 are all formed in a circular cross-sectional shape. Among them, the second O-ring 23 that is the second closest to the mouth of the cylinder body 11 moves across the opening of the water supply pipe 15 when the piston body 21 is pushed in.
[0030]
Of the four circumferential grooves 26 to 29 in which the O-rings 22 to 25 are fitted, the circumferential grooves 26, 28, and 29 other than the second circumferential groove 27 are cut along a plane including the axis of the piston body 21. The cross-sectional shape at the time is formed into a very general rectangle.
[0031]
However, the second circumferential groove 27 into which the second O-ring 23 is fitted has a bottom portion formed in a semicircular U shape as shown in an enlarged view in FIG. The portion on the inner diameter side of the second O-ring 23 is closely adhered. Therefore, no dirt or the like accumulates on the back side of the second O-ring 23.
[0032]
Further, even if the second O-ring 23 having a circular cross-sectional shape of the strand is attached to the second circumferential groove 27 in a state where the inner diameter side and the outer diameter side are mistakenly reversed, Since the circumferential groove 27 is formed in a U-shaped cross-sectional shape with a semicircular bottom, it is possible to obtain a close contact state similar to the case where it is normally attached, and on the back side of the second O-ring 23. Dirt does not collect.
[0033]
FIG. 5 shows a second embodiment of the present invention, in which the cross-sectional shape of the second circumferential groove 27 when cut along a plane including the axis line of the piston body 21 is shown, with the bottom part being a part of a circular arc (half The second O-ring 23 is formed in a U-shape that is narrower than the circle), and the inner diameter side and the outer diameter side are symmetrical with respect to each other. It is formed in a shape that is in close contact with the bottom of the groove 27. Also when formed in this way, the same effects as those of the first embodiment described above can be obtained.
[0034]
In addition, this invention is not limited to said embodiment, For example, in said each embodiment, when pushing-in operation of the piston body 21, it moves across the opening part of the water supply pipe | tube 15 is 2nd. Although the present invention is applied only to the O-ring 23 and the second circumferential groove 27 portion, the present invention is not limited thereto, and may be applied to the O-ring and the circumferential groove in other portions. Further, the present invention may be applied to a suction switching valve.
[0035]
【The invention's effect】
According to the present invention, the cross-sectional shape of the circumferential groove is formed in a U-shape with a curved bottom, and the cross-sectional shape of the seal ring is substantially in close contact with the circumferential groove having a U-shaped cross-section on the inner diameter side. As the seal ring is detachable from the piston body, the seal ring can be easily replaced when the seal ring deteriorates. Since the shape is formed in a curved surface in which the outer diameter side and the inner diameter side are symmetrical, the sealing performance is not deteriorated even when the seal ring is turned over and mounted when the seal ring is exchanged. Moreover, there is no possibility that filth will accumulate.
[Brief description of the drawings]
FIG. 1 is a partially enlarged sectional view of a first embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of the air / water supply operation valve in a standby state according to the first embodiment of the present invention.
FIG. 3 is a longitudinal sectional view of an air / water supply operation valve in an air supply state according to the first embodiment of the present invention.
FIG. 4 is a longitudinal sectional view of the air / water supply operation valve in the water supply state according to the first embodiment of the present invention.
FIG. 5 is a partial enlarged cross-sectional view of a second embodiment of the present invention.
FIG. 6 is a partially enlarged sectional view of a conventional example.
FIG. 7 is a partially enlarged cross-sectional view of a conventional example in an erroneous mounting state.
[Explanation of symbols]
11 Cylinder body 15 Water supply pipe 17 Water supply pipe 21 Piston body 23 Second O-ring 27 Second circumferential groove

Claims (3)

A cylinder body in which a plurality of pipes for allowing fluid to pass are opened and connected, a piston body that is fitted in the cylinder body so as to be able to advance and retreat in the axial direction in order to switch the connection state between the pipes, and the cylinder body And a sealing ring made of a resilient member detachably fitted in a circumferential groove formed on the outer peripheral surface of the piston body in order to seal the fitting surface portion between the piston body and the piston body. In the endoscope channel switching device,
The cross-sectional shape of the circumferential groove is formed in a U-shape consisting of a semicircular portion near the bottom and a parallel portion near the opening, and the cross-sectional shape of the seal ring has an inner diameter side closer to the bottom of the circumferential groove. An endoscope conduit switching device characterized by being formed in a shape that is substantially in close contact with a semicircular portion and whose outer diameter side is symmetrical to the inner diameter side. 2. A plurality of the circumferential grooves are provided at different positions in the axial direction of the piston, and the cross-sectional shape of at least one of the circumferential grooves is formed in a U shape with a curved bottom. The endoscope channel switching device according to claim. The seal ring fitted in the circumferential groove having a U-shaped cross-sectional shape with a curved bottom portion moves the piston forward and backward in the axial direction, thereby opening the liquid passage conduit connected to the cylinder. The endoscope channel switching device according to claim 1 or 2, which moves across the opening.

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