JP2009045126A - Piping switching valve of endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the piping switching valve of an endoscope with excellent durability, in which an abutting plug directly pressed to the opening of a cylinder inner peripheral surface to close the opening is not easily worn out even when repeatedly used. <P>SOLUTION: The abutting plug 34 is formed of a metal body for which a part facing the opening 8b of the inner peripheral surface of a cylinder 11 is formed into the spherical shape of a curvature radius smaller than the radius of the inner peripheral surface of the cylinder 11, and a spring part 37 for elastically energizing the abutting plug 34 so as to press it to the opening 8b of the inner peripheral surface of the cylinder 11 is formed integrally with the abutting plug 34. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pipe switching valve for an endoscope for switching a connection state of pipes provided in the endoscope.

  In general, the pipe switching valve provided in the operation section of the endoscope for switching the connection status of air / water supply pipes and suction pipes is generally free to advance and retract in the axial direction of a cylinder connected to multiple pipes. The pipes are sealed by an O-ring or the like attached to a circumferential groove formed in the piston.

  However, in an endoscope (for example, an ultrasonic endoscope) in which a balloon that can be expanded and contracted is attached to the distal end of the insertion portion, a switching function for piping communicating with the balloon is added. If the O-ring is used, the length of the pipe switching valve becomes too long.

Therefore, in such a pipe switching valve of an endoscope, a contact plug that is pressed directly against the opening of the cylinder inner peripheral surface of the pipe communicating with the balloon to close the opening is formed on the outer peripheral surface of the piston. It arrange | positions in a bottom hole (for example, patent document 1).
JP2007-14439

  In the conventional endoscope pipe switching valve as described above, the abutting plug is formed of a resilient rubber material, and the piston is advanced and retracted while being pressed against the inner peripheral surface of the cylinder and elastically deformed. As it moves, it moves along the inner peripheral surface of the cylinder. As a result, the contact plug wears out during repeated use.

  Similar wear occurs even in the case of ordinary O-rings, but in the case of a contact plug, it is pressed directly against the opening and the opening is closed by a single contact plug, so even a slight amount of wear may cause fluid leakage. For example, there may be a problem that the balloon is deflated by natural suction from within the balloon.

  The present invention provides an endoscope pipe switching valve having excellent durability, in which a contact plug that is directly pressed against an opening of a cylinder inner peripheral surface and closes the opening is not easily worn by repeated use. With the goal.

  In order to achieve the above object, an endoscope pipe switching valve according to the present invention is such that at least one of a plurality of pipes is opened in an inner peripheral surface portion of a cylinder to which a plurality of pipes are connected, and an axis line in the cylinder. An endoscope in which an abutment plug is disposed in a bottomed hole formed on an outer peripheral surface of a piston that is disposed so as to be freely movable in a direction, and is pressed against an opening on the inner peripheral surface of the cylinder to close the opening. In the piping switching valve, the contact plug is formed of a metal body in which a portion facing the opening of the inner peripheral surface of the cylinder is formed in a spherical shape having a curvature radius smaller than the radius of the inner peripheral surface of the cylinder. Is formed integrally with the contact plug so as to be elastically biased so as to press against the opening on the inner peripheral surface of the cylinder.

  The spring portion may be formed in the shape of a leaf spring on the outer edge of the contact plug, and a stopper is formed in the bottomed hole to prevent the contact plug from being detached from the bottomed hole. May be. And the leaf | plate spring-shaped spring part may be in the state stored in the back side area | region of the stopper.

  According to the present invention, the contact plug that is pressed directly against the opening on the inner peripheral surface of the cylinder to close the opening is formed of a spherical metal body. It is difficult to wear even if it comes into sliding contact, and has excellent durability.

  In the bottomed hole formed on the outer peripheral surface of the piston, in which at least one of the plurality of pipes opens in the inner peripheral surface portion of the cylinder to which the plurality of pipes are connected, and is movable in the axial direction in the cylinder. Furthermore, in an endoscope pipe switching valve in which a contact plug for directly closing the opening of the cylinder to close the opening is arranged, the contact plug faces the opening of the inner peripheral surface of the cylinder. A spring portion that is formed of a metal body having a spherical shape with a radius of curvature smaller than the radius of the inner peripheral surface of the cylinder, and that elastically biases the contact plug against the opening on the inner peripheral surface of the cylinder Are formed integrally with the contact plug.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 2 shows an ultrasonic endoscope to which the present invention is applied. An operation unit 2 is connected to a proximal end of a flexible insertion unit 1, and an ultrasonic wave is formed around the axis at the distal end of the insertion unit 1. For example, an ultrasonic probe 3 for radial scanning for transmitting and receiving signals is disposed, and an optical observation window 4 for optically observing the front is disposed on the distal end surface.

  In addition, the distal end portion of the insertion portion 1 is inflated and contracted by deaerated water or the like so that there is no air layer with poor ultrasonic signal transmission between the ultrasonic probe 3 and the test portion. 5 is attached to surround the ultrasonic probe 3.

  A forceps channel 6 for inserting and removing forceps, an injection tool, and the like is inserted through the entire length in the insertion portion 1, and a channel suction port 6 a that is a distal end opening of the forceps channel 6 is located outside the balloon 5. 1 is disposed on the front end surface.

  The forceps insertion port 6b is disposed in the vicinity of the connection portion between the insertion portion 1 and the operation portion 2, and a channel suction pipe 7 connected to the forceps channel 6 in the vicinity of the proximal end thereof is connected to the operation portion 2. Is connected to a suction operation valve 10 (pipe switching valve) disposed in the upper half of the valve.

  A balloon suction pipe 8 or the like for sucking deaerated water filled in the balloon 5 is also inserted from the insertion section 1 into the operation section 2, and a balloon suction that is a front end opening of the balloon suction pipe 8. The mouth 8a opens to the inside of the balloon 5 at the distal end of the insertion portion 1, and the proximal end of the balloon suction pipe 8 is connected to the suction operation valve 10 in the operation portion 2. A suction source pipe 9 connects the suction operation valve 10 and a suction source (not shown) in communication.

  1 and 3 are longitudinal sectional views showing a standby state of the suction operation valve 10. FIG. 1 is a cross-sectional view taken along the line II in FIG. 4, showing a pipe switching state in the standby state. 4 is a cross-sectional view taken along the line III-III in FIG. 4, and is associated with a rotation stop protrusion 25 for restricting the suction pipe switching piston 14 (piston of claim 1) from rotating about the axis with respect to the cylinder 11. The groove 26 is included.

  The cylinder 11 arranged in the operation unit 2 is fixed to the operation unit 2 by a fixing nut 12 so as to open outward. Reference numeral 13 denotes an O-ring for sealing. In addition, the state before being crushed is shown in the drawings for the types of seal members that are elastic and are crushed.

  The cylinder 11 formed in a cylindrical shape with a bottom is formed such that the inner diameter of the inner half near the back is narrower than the inner diameter of the half near the mouth, and the proximal end of the channel suction pipe 7 is An opening is connected to the bottom surface.

  Further, the balloon suction pipe 8 and the suction source pipe 9 are shifted in the direction around the axis as shown in FIG. 4 showing the IV-IV cross section in FIG. 8 is connected to the side surface of the portion near the mouth of the cylinder 11 in a positional relationship on the back side (downward in FIG. 3), and the base end opening 8b (opening of claim 1) of the balloon suction pipe 8 and the suction source pipe Nine connection openings 9 a open to the inner peripheral surface of the cylinder 11.

  As shown in FIGS. 1 and 3, the piston inserted into the cylinder 11 so as to advance and retract in the axial direction is a cylindrical suction pipe switching piston 14 that is inscribed in the cylinder 11 so as to advance and retract in the axial direction. And an outside air suction switching piston 15 that is slidably inscribed in the axial direction with respect to the suction pipe switching piston 14 are arranged coaxially. The outside air suction switching piston 15 is sucked over its entire length. The outer diameter of the pipe switching piston 14 is smaller than the inner diameter.

  The outer diameter of each of the suction pipe switching piston 14 and the outside air suction switching piston 15 is such that only the outside air suction switching piston 15 is inscribed on the inner peripheral surface of the half (small diameter portion) near the back of the cylinder 11. Only the suction pipe switching piston 14 is inscribed on the inner peripheral surface of the half portion (large diameter portion) near the mouth of the cylinder 11.

  The heads of the suction pipe switching piston 14 and the outside air suction switching piston 15 protrude from the mouth of the cylinder 11 that opens to the outer surface of the operation unit 2. The operation button 16 is attached via the spring receiving member 18 and the connecting shaft 150 also shown in the exploded perspective view of FIG.

  As shown in FIG. 6, a second spring receiving member 19 formed in a flange shape is screwed to the head portion of the suction pipe switching piston 14, and the first spring receiving member 18. The first compression coil spring 21 mounted between the second spring receiving member 19 and the second spring receiving member 19 causes the outside air suction switching piston 15 to jump out of the suction pipe switching piston 14 (in FIGS. 1 and 3). (Upward).

  However, the step formed in the middle of the inner surface of the suction pipe switching piston 14 and the step formed in the middle of the outer surface of the outside air suction switching piston 15 come into contact with each other, so that the outside air suction switching piston 15 is shown in FIG. From the state shown in FIG. 1 and FIG. 3, the suction pipe switching piston 14 is restricted so as not to protrude relatively outward.

  Further, the first cover cylinder 17 that covers the first compression coil spring 21 so as not to be seen from the outside is attached in a state of being pressed against the second spring receiving member 19 by the first compression coil spring 21. ing.

  Reference numeral 22 denotes a second compression coil spring which is set to a spring constant several times larger than that of the first compression coil spring 21, and is arranged in a series relationship with the first compression coil spring 21, and the second The spring receiving member 19 is urged outward.

  The piston retaining ring 20A that receives the proximal end side of the second compression coil spring 22 also serves as a stopper that prevents the suction pipe switching piston 14 from slipping out of the cylinder 11 beyond a predetermined state. It also has a cover function for making the coil spring 22 invisible from the outside.

  Further, the inner claw portion of the lower end portion of the locking ring 20B made of a resilient plastic material lined integrally with the piston locking ring 20A is hooked and engaged with the outer peripheral flange portion of the fixing nut 12, thereby sucking it. A unit including a pipe switching piston 14, an outside air suction switching piston 15, and an operation button 16 is fixed to the cylinder 11.

  Therefore, if the engagement ring 20B is elastically deformed to release the engagement with the fixing nut 12, the suction pipe switching piston 14 and the outside air suction switching piston 15 can be pulled out from the cylinder 11 together with the operation button 16 and the like. it can.

  Further, the suction pipe switching piston 14 and the outside air suction switching piston 15 are arranged at 180 ° symmetrical positions on the outer surface of the outside air suction switching piston 15 as shown in FIG. 7 illustrating a section VII-VII in FIG. And the flat portion 15a formed on the inner surface of the suction pipe switching piston 14 in a state where the flat portion 15a is loosely sandwiched between the flat portion 15a and the flat portion 15a. The pipe switching piston 14 and the outside air suction switching piston 15 are also relatively movable in the axial direction, but cannot rotate around the axis.

  As shown in FIG. 6, the suction pipe switching piston 14 has an intermediate portion on the outer peripheral surface of the suction pipe switching piston 14 so as to be in sliding contact with the inner peripheral surface of the portion near the mouth of the cylinder 11. An outer position side hole 28 and an inner position side hole 29 are formed on both sides of the mounted sealing O-ring 27 so as to penetrate the side walls.

  Further, the inner surface of the cylinder 11 is closed so that only the proximal end opening 8b of the balloon suction pipe 8 is closed on the outer peripheral surface near the rear end of the suction pipe switching piston 14 fitted to the inner peripheral surface of the cylinder 11. The contact plug 34 slidably contacting the peripheral surface is fitted in a circular bottomed hole 33 formed at a position facing the proximal end opening 8b of the balloon suction pipe 8 so that the vicinity of the center protrudes slightly. It is attached.

  The contact plug 34 is made of metal, and as shown in an enlarged view in FIG. 8, the portion facing the proximal end opening 8 b of the balloon suction pipe 8 formed on the inner peripheral surface of the cylinder 11 is the inner portion of the cylinder 11. It is formed in a spherical shape with a radius of curvature smaller than the radius of the peripheral surface.

  Further, a leaf spring-like spring portion 37 that elastically urges the contact plug 34 against the proximal end opening 8b of the balloon suction pipe 8 is formed integrally with the contact plug 34. The spring portion 37 is formed in a bowl shape protruding obliquely rearwardly outward from the entire outer periphery of the base portion of the contact plug 34, and is in contact with the bottom surface of the bottomed hole 33.

  With such a configuration, the hemispherical surface portion of the contact plug 34 urged by the spring portion 37 slightly protrudes from the outer surface of the suction pipe switching piston 14 and is pressed against the proximal end opening 8 b of the balloon suction pipe 8. The base end opening 8b is sealed.

  When the suction pipe switching piston 14 moves back and forth in the cylinder 11 and moves to a position where the contact plug 34 does not face the base end opening 8b, the contact plug 34 contacts the inner peripheral surface of the cylinder 11, and the spring The part 37 is elastically deformed in the compression direction.

  Also, as shown in FIG. 8, the bottomed hole 33 of this embodiment is a circular hole having a larger diameter in the space in which the spring portion 37 is housed than in the space in which the contact plug 34 is housed. It is formed in the shape, and the spring part 37 cannot jump out ahead of the step part 38 of the boundary part.

  Accordingly, the stepped portion 38 serves as a stopper for preventing the contact plug 34 from being detached from the bottomed hole 33, and the spring portion 37 is stored in the back side region of the stopper (stepped portion 38). It has become. As a result, even when the suction pipe switching piston 14 is removed from the cylinder 11, the contact plug 34 is not detached from the bottomed hole 33, and there is no risk of loss.

  For example, if the contact plug 34 is formed of a shape memory alloy or the like, the spring portion 37 can pass through the stepped portion 38 when the bottomed hole 33 is mounted or replaced. It can be easily deformed.

  As shown in FIG. 1 and FIG. 4 and the like, the suction passage 30 serving as a fluid passage partially cuts off the outer surface near the back end of the suction pipe switching piston 14 along with the contact plug 34. Such a suction path 30 is formed at a position facing the connection opening 9a of the suction source pipe 9 and a position 180 [deg.] Symmetrical to it.

  However, as shown in FIG. 4, the outer peripheral surface of the suction pipe switching piston 14 is sucked at the back side position A symmetrical 180 ° with respect to the position where the contact plug 34 of the suction pipe switching piston 14 is attached. It is in perfect contact with the inner peripheral surface of the cylinder 11 without being cut out by the path 30 or the like.

  Therefore, although the suction pipe switching piston 14 is strongly urged in the direction of the rear side A by the repulsive force generated from the contact plug 34 crushed between the suction pipe switching piston 14 and the cylinder 11, As a result, the axial line position of the suction pipe switching piston 14 does not shift, and the suction pipe switching piston 14 smoothly moves back and forth in the axial direction.

  As shown in FIG. 1, the outside air suction switching piston 15 is formed with an L-shaped channel suction communication hole 31 that opens to the side surface and the back end surface. 31a is a back side opening, and 31b is a side opening.

  As shown in FIG. 5, the outer air suction switching piston 15 has cylinders in the vicinity of the rear end and on both sides of the side opening 31 b of the channel suction communication hole 31. A sealing O-ring 35 slidably in contact with the inner peripheral surface of 11 is mounted. An O-ring 36 is also mounted near the base of the connecting shaft 150.

  Further, as shown in FIG. 3, the rotation stop protrusion 25 for restricting the suction pipe switching piston 14 from rotating about the axis relative to the cylinder 11 is provided at the foremost position of the suction pipe switching piston 14. It protrudes from the outer peripheral surface in the vicinity of (i.e., the position most dive in the back side of the cylinder 11).

  An engagement groove 26 that engages with the rotation-stop projection 25 is formed on the inner peripheral surface of the cylinder 11 so as to be straight in the direction parallel to the axis corresponding to the movement range of the rotation-stop projection 25. As a result, the suction pipe switching piston 14 is movable in the axial direction with respect to the cylinder 11, but cannot rotate around the axial line.

  The rotation stop projection 25 is fixedly embedded in the suction pipe switching piston 14, and a portion protruding laterally from the outer peripheral surface of the suction pipe switching piston 14 is formed in a spherical shape. The cross-sectional shape of the engagement groove 26 is formed in an arc shape that allows a certain slight gap to the rotation stop projection 25. Therefore, when the suction pipe switching piston 14 moves back and forth in the axial direction, the sliding resistance with the engagement groove 26 is small and smoothly moves back and forth even if a rotational force or the like is applied in the direction around the axis.

  As shown in FIGS. 3 and 4, the rotation stopper protrusion 25 and the engagement groove 26 are disposed slightly with respect to the suction pipe switching piston 14 and the cylinder 11. The engagement groove 26 is disposed in a positional relationship that does not interfere with the base end opening 8b of the balloon suction pipe 8, the connection opening 9a of the suction source pipe 9, and the like. Yes.

  The pipe switching valve of the endoscope according to the embodiment configured as described above is configured such that the suction pipe switching piston 14 and the outside air suction switching piston 15 are the second compression coil in the standby state shown in FIGS. The springs 22 and the first compression coil springs 21 are pushed up to the maximum extent to project outward.

  After the outside air passes through the outer position side hole 28 and enters the suction pipe switching piston 14, the outside air exits from the inner position side hole 29 to the gap between the suction pipe switching piston 14 and the cylinder 11, and from there the suction path It passes through the inside 30 and is sucked into the suction source pipe 9. Suction from the channel suction pipe 7 and the balloon suction pipe 8 is blocked by the O-ring 35 and the contact plug 34.

  From this state, the operation button 16 is pushed in with the fingertip, and the operation button is moved to a position where the first compression coil spring 21 is compressed and the second compression coil spring 22 begins to be compressed as shown in FIG. When 16 reaches, a large resistance acts on the finger that operates the operation button 16, and at that time, the side opening 31 b of the channel suction communication hole 31 formed in the outside air suction switching piston 15 is connected to the connection opening of the suction source pipe 9. It comes to the position facing 9a.

  As a result, the channel suction pipe 7 and the suction source pipe 9 communicate with each other via the inside of the cylinder 11 and the channel suction communication hole 31, and sewage and the like in the body from the channel suction port 6 a at the tip of the insertion portion 1 serve as a suction source. Sucked.

  In this state, the suction pipe switching piston 14 is not yet moved, and if the finger is released from the operation button 16 in this state, the original standby state is restored. Therefore, only the suction operation from the channel suction pipe 7 can be performed while the proximal end opening 8 b of the balloon suction pipe 8 is completely closed by the contact plug 34.

  Further, as described above, the rotation between the cylinder 11 and the suction pipe switching piston 14 is stopped around the axis by the engagement of the rotation prevention projection 25 and the engagement groove 26, and the suction pipe switching piston 14 Since the rotation of the periphery of the axis line is stopped by engaging the flat portions 14a and 15a with the outside air suction switching piston 15, the side surface opening 31b of the channel suction communication hole 31 is always accurately connected to the suction source pipe 9. Since it opposes the connection opening 9a, even if there is a solid sucking substance or the like, it is surely sucked and discharged to the suction source pipe 9 without being clogged in the suction operation valve 10.

  When the operation button 16 is pushed in with further force applied to the fingertip from the state shown in FIG. 9, the rotation stop projection 25 slides to the back side position (downward in the figure) of the engagement groove 26 as shown in FIG. Then, as shown in FIG. 11, the second compression coil spring 22 is also compressed following the first compression coil spring 21, and the suction pipe switching piston 14 together with the outside air suction switching piston 15 is placed in the cylinder 11. It will be pushed in.

  Then, the contact plug 34 moves from the position facing the proximal end opening 8b of the balloon suction pipe 8 to the back side, and at the same time, the side opening 31b of the channel suction communication hole 31 faces the back of the cylinder 11 from the position facing the connection opening 9a. It will be in a state where it is retracted and closed in the side half.

  As a result, only the base end opening 8b of the balloon suction pipe 8 and the connection opening 9a of the suction source pipe 9 are formed between the inner peripheral surface of the cylinder 11 and the outer peripheral surface of the suction pipe switching piston 14. Since the communication is established via the space B and the suction path 30, degassed water or the like in the balloon 5 may be sucked from the balloon suction port 8 a at the distal end of the insertion portion 1 to the suction source to contract the balloon 5. it can.

  When the finger is released from the operation button 16, the suction state from the channel suction pipe 7 shown in FIG. 9 is returned to the standby state shown in FIGS. 1 and 3, and the contact plug 34 is connected to the balloon suction pipe 8. The base end opening 8b is closed.

  In this way, the contact plug 34 moves together with the suction pipe switching piston 14 and is slidably pressed against the inner peripheral surface of the cylinder 11, but the contact plug 34 is made of metal, so that The degree of wear is significantly smaller than that of rubber, and the balloon 5 is not naturally deflated due to seal leakage at the proximal end opening 8b of the balloon suction pipe 8 and deflated.

  In addition, this invention is not limited to the said Example, For example, as FIG. 12 shows, while forming the notch 39 in the outer peripheral part of the spring part 37, the shape which passes the inside of the notch 39 The projection 38 ′ is formed so as to protrude inward from the outer peripheral portion of the bottomed hole 33, and the projection 38 ′ is not formed in a region near the bottom of the bottomed hole 33.

  With this configuration, the protrusion 38 ′ prevents the contact plug 34 from being detached by rotating the spring portion 37 after aligning the positions of the notch 39 and the protrusion 38 ′ and fitting the spring portion 37 into the bottomed hole 33. Therefore, the contact plug 34 and the spring portion 37 can be formed of stainless steel or the like that is not a shape memory alloy.

  Further, the present invention may be applied to a general endoscope other than an ultrasonic endoscope, and can also be applied to an air / water supply operation valve and other various operation valves.

It is a longitudinal cross-sectional view (II sectional drawing in FIG. 4) of the standby state in the piping switching valve of the endoscope of the Example of this invention. 1 is a side view showing an overall configuration of an ultrasonic endoscope according to an embodiment of the present invention. It is a longitudinal cross-sectional view (III-III sectional drawing in FIG. 4) including the protrusion for rotation prevention in the standby state in the piping switching valve of the endoscope of the Example of this invention. It is IV-IV sectional drawing in FIG. 3 of the piping switching valve of the endoscope of the Example of this invention. It is a disassembled perspective view of the outside air suction switching piston of the pipe switching valve of the endoscope of the embodiment of the present invention. It is a disassembled perspective view of the suction pipe switching piston of the pipe switching valve of the endoscope of the embodiment of the present invention. It is VII-VII sectional drawing in FIG. 1 of the piping switching valve of the endoscope of the Example of this invention. It is an expanded longitudinal cross-sectional view of the contact plug part of the piping switching valve of the endoscope of the Example of this invention. It is a longitudinal cross-sectional view of the state attracted | sucked from channel suction piping in the piping switching valve of the endoscope of the Example of this invention. It is a longitudinal cross-sectional view containing the protrusion for rotation prevention of the state attracted | sucked from balloon suction piping in the piping switching valve of the endoscope of the Example of this invention. It is a longitudinal cross-sectional view of the state attracted | sucked from balloon suction piping in the piping switching valve of the endoscope of the Example of this invention. It is a perspective view of the contact stopper of the Example of this invention, and the other structural example of a bottomed hole.

Explanation of symbols

7 Channel suction piping (piping)
8 Balloon suction piping (piping)
8b Base end opening (opening)
9 Suction source piping (piping)
10 Suction operation valve (pipe switching valve)
11 Cylinder 14 Suction piping switching piston (piston)
33 Bottomed hole 34 Contact plug 37 Spring part 38 Step part (stopper)
38 'Protrusion (stopper)

Claims (4)

A bottomed surface formed on an outer peripheral surface of a piston, in which at least one of the plurality of pipes opens in an inner peripheral surface portion of a cylinder to which a plurality of pipes are connected, and is movable in the axial direction in the cylinder In the endoscope pipe switching valve in which a contact plug for closing the opening by being pressed directly against the opening of the inner peripheral surface of the cylinder is disposed in the hole,
The contact plug is formed of a metal body having a spherical surface with a radius of curvature smaller than the radius of the inner peripheral surface of the cylinder, and a portion facing the opening of the inner peripheral surface of the cylinder. A pipe switching valve for an endoscope, wherein a spring portion that is elastically biased so as to be pressed against an opening on an inner peripheral surface of the cylinder is formed integrally with the contact plug.   The pipe switching valve for an endoscope according to claim 1, wherein the spring portion is formed in a leaf spring shape at an outer edge portion of the contact plug.   The pipe switching valve for an endoscope according to claim 2, wherein a stopper for preventing the contact plug from being detached from the bottomed hole is formed in the bottomed hole.   The pipe switching valve for an endoscope according to claim 3, wherein the leaf spring-like spring portion is stored in a back side region of the stopper.

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