JP5276771B2 - Endoscope suction valve - Google Patents

Description

  The present invention relates to a suction valve for performing suction from the inside of an endoscope used for medical purposes.

  Some endoscopes include a suction mechanism for sucking body fluid, blood, and the like from the body. The suction mechanism has a suction path that opens at the distal end of the insertion portion of the endoscope and passes through the main body operation portion, and is configured such that a suction source device is detachably connected to the other end of the suction passage. . Here, the suction path provided in the endoscope may be configured as a unique path, but from the viewpoint of reducing the diameter of the insertion portion, a treatment instrument insertion channel provided for inserting a treatment instrument such as forceps and the like It is common to supply a flow path. Therefore, a forceps port for introducing a treatment tool into the treatment tool insertion channel is formed in the main body operation unit, and the treatment tool insertion channel has a branch portion formed at a position in front of the forceps port. The channel is branched into a channel side conduit leading to the forceps opening and a suction conduit leading to the suction source device. The end of the suction conduit passes through the inside of the universal cord connected to the main body operation unit, and a connector that is detachably connected to the pipe from the suction source device is provided at the end of the universal cord. Here, the suction source device is usually installed in a hospital, a clinic, or the like, and a connection port to the suction source device is provided in the endoscopic examination room.

  In order to perform the suction operation, a suction valve is attached to the main body operation portion of the endoscope. An operation button, that is, a suction button is connected to the suction valve, and the suction button can be operated by a finger of a hand holding the main body operation unit. The suction valve always shuts off the flow path on the treatment instrument insertion channel side, opens the flow path on the connection side to the suction source device to the atmosphere, and operates to push in the suction button. The flow path on the channel side is connected to the flow path on the suction source device side, and communication with the atmosphere is blocked. As a result, a negative pressure suction force acts in the treatment instrument insertion channel, and body fluid, blood, and other body fluids are sucked from the body.

  Here, in order to efficiently perform suction from the body, it is conceivable to increase the negative pressure suction force in the suction source device, but the suction source device equipped in hospitals etc. is only the suction mechanism of the endoscope In addition, it is also used for various devices, and the pressure of the suction source device is generally set to be in a constant state in consideration of the efficiency and safety of the suction operation. Accordingly, the negative pressure suction force is applied to the treatment instrument insertion channel side by operating the suction button, and the fluid in the body is suctioned and removed. Therefore, in order to effectively use the negative pressure suction force from the suction source device, when the flow path on the treatment instrument insertion channel side is connected to the flow path on the suction source device side, this flow path is completely connected to the atmosphere. Shut off so that there is no inhalation from the atmosphere. For this purpose, a seal member is attached to the sliding portion between the outer peripheral surface of the valve body and the inner peripheral surface of the valve casing, and the port formed in the valve casing and connected to the flow path on the suction source side is connected to the atmosphere. Generally, it is configured so that it can be completely blocked from the open path. This seal member is usually configured to form an annular concave groove on the outer peripheral surface of the valve body and to fit an elastic ring into the concave groove.

  By the way, when the suction operation from the body is performed by the endoscope, the whole suction path is soiled by the fluid in the body. This fouling extends not only to the treatment instrument insertion channel and the suction passage, but also to the flow path formed inside the suction valve. For this reason, the endoscope cannot be reused unless the contaminants are removed by washing. The contamination in the treatment instrument insertion channel and the suction passage can be removed by flowing a cleaning and disinfecting solution inside. It is also necessary to thoroughly clean the inside of the suction valve. For this reason, the valve body can be separated from the valve casing, so that the valve body is taken out from the valve casing and the inside of the valve casing and the valve body are cleaned.

  When cleaning the valve body, the most difficult part is a part of a concave groove in which an elastic ring as a seal member is mounted. Conventionally, not only cleaning but also thorough heat sterilization or the like, but if used over a long period of time, there is a risk that the contaminated material will enter the lower part of the portion covered with the elastic ring in the groove.

In view of the above points, Patent Document 1 discloses a structure in which a seal member is not attached to the outer peripheral surface of the valve body, and the inner surface of the valve casing and the outer surface of the valve body that are contaminated during a suction operation are easily cleaned. It is shown. In this Patent Document 1, instead of a seal member attached to a valve body, an inner peripheral step portion is formed in a housing member that is connected to an upper end portion of a valve casing and protrudes from a casing of a main body operation portion. An annular airtight elastic sheet made of an elastic member is attached to the stepped portion, and a surrounding wall portion is provided on the lower surface of the operation button so that the surrounding wall portion can be brought into contact with and separated from the elastic sheet. With this configuration, the suction source side is in communication with the atmosphere when the operation button is separated from the elastic sheet. When the operation button is pushed in, the inside of the valve body valve casing slides and the treatment instrument insertion channel side constituting the suction passage communicates with the suction source side. At this time, the elastic sheet is pressed by the surrounding wall portion. By this, the communication between the suction source side and the atmosphere is blocked.
Japanese Patent Laid-Open No. 2004-223121

  However, the configuration of the suction valve according to Patent Document 1 described above still has problems. That is, the valve casing and the valve body constituting the suction valve are made of a metal material, particularly a stainless steel material, in view of strength, workability and price, and in consideration of chemical resistance at the time of cleaning or the like. It is common. As already described, the elastic seal member is attached to the valve body from the viewpoint of airtightness maintenance, but by configuring in this way, the valve casing and the valve body are held so as not to be in direct contact with each other, This also has the advantage of preventing galling or the like from occurring. However, as disclosed in Patent Document 1, a valve body made of a metal material directly contacts a valve casing formed of the metal material. In other words, since it becomes sliding between metals, depending on the processing accuracy of the sliding surface, and depending on how to clean and disinfect after each use, the smooth slidability of the valve element is impaired, When operating the suction button, the resistance may increase. In particular, since the operation button is pressed with a finger, the operation force acts on the valve body connected to the operation button in an oblique direction rather than an axial direction, resulting in poor movement of the valve body relative to the valve casing. Nevertheless, if the valve body is forced to be pushed in, there is a possibility that galling or biting may occur at the contact portion between the metals.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a seal member that exhibits a function of blocking communication between a valve body and a valve casing constituting a suction valve. An object is to smoothly operate the valve body without interposing it and to perform an efficient suction action.

In order to achieve the above-described object, the present invention provides a suction port provided in a main body operation portion of an endoscope and communicating with a suction passage that opens at a distal end of an insertion portion that is connected to the main body operation portion. A suction stop position in which the negative pressure generation passage is communicated with the atmosphere, and the negative pressure generation passage is in communication with the suction passage in a valve casing formed with a port communicating with the negative pressure generation passage connected to the power source device. In a suction valve equipped with a valve body that switches to a suction operation position to be made, a solid lubricant coating is formed on at least one of the sliding surfaces between the inner peripheral surface of the valve casing and the outer peripheral surface of the valve body Thus, a throttle passage that communicates with the atmosphere is formed in the sliding surface, and the inner peripheral surface of the valve casing and the outer peripheral surface of the valve body that constitute the throttle passage. the clearance between the Or by a 18 [mu] m, when the switching said valve body to said suction actuating position, and characterized by being configured to air leakage amount of the throttle passage to be equal to or less than 20 cc / 30 sec.

  First, it is configured to slide directly without interposing a seal member between the inner surface of the valve casing and the outer surface of the valve body. However, a solid lubricant film is formed on at least one of the valve casing and the valve body so that the metals are not in direct contact with each other, and the space between the valve body and the valve casing is not airtight. Some gaps are provided between them. As a result, the movement of the valve body becomes smooth, and the valve body can be smoothly slid with a light load, thereby improving the durability. The switching operation of the valve body can be performed by, for example, an electric type, but is generally configured to be operated by a finger of an operator's hand holding the main body operation unit. In order to enable finger operation, an operation button, that is, a suction button is connected to the valve body.

  The valve body and the valve casing are used to switch between the closed state and the connected state, rather than blocking or communicating the passage. That is, even if the suction valve is in the suction stop position or in the suction operation position, the communication between the atmosphere and the negative pressure generation passage or the suction passage is not completely blocked, but airtight leakage due to the throttle is prevented. Allow generation. However, when the amount of air leakage from the atmosphere is large when the suction valve is set to the suction operation position, the suction efficiency from the body is lowered, and suction from the body may not be performed. Therefore, the gap between the valve body and the valve casing forming the throttle passage is set so that a negative pressure suction force that enables suction from the body acts when the suction valve is in the suction operation position. It will be. Further, at the suction stop position of the suction valve, it is necessary to prevent suction from the body.

  Here, if the clearance between the valve casing and the valve casing is widened, the smoothness of the sliding motion of the valve body can be improved. However, if this is done, the amount of airtight leakage increases and the suction efficiency decreases (during suction operation). Will be sucked in (when sucking is stopped). On the contrary, when the gap is reduced, the smoothness of the movement of the valve body is lowered. Specifically, if this gap is set to 18 μm or less and the airtight leakage amount between them is set to 20 cc / 30 seconds or less, the suction operation in the suction passage becomes possible and the valve element moves smoothly. And if considering the points of slidability and suction efficiency of the valve body, if the gap is managed to be 1 to 5 μm and the leakage amount is suppressed to 5 cc / 30 seconds or less, it will be removed from the body when the suction is stopped. This is most desirable because no suction occurs and suction is possible during the suction operation.

  The throttle passage described above does not always have to be formed, and a state in which communication with the atmosphere is almost completely blocked can be provided. However, a mechanism for completely blocking communication with the atmosphere is not provided between the valve body and the valve casing. For this purpose, for example, the front end of the valve casing is opened to the atmosphere, and an airtight elastic sheet made of an elastic material is fixedly provided on the periphery of the opening. Then, the valve body is extended from the opening by a predetermined length from the inside of the valve casing, and an operation button is attached to the extended portion. The operation button is provided with a surrounding wall portion so as to surround the periphery of the valve body. It is set as the structure to provide. A return spring is applied to the operation button, and the return spring holds the negative pressure generating passage at the suction stop position communicating with the atmosphere, and the operation button is pushed in a direction against the return spring to switch to the suction operation position. Try to change. And the operation button should just be able to stroke to the position which the surrounding wall part presses an elastic sheet, and interrupts | blocks a negative pressure generation channel | path from air | atmosphere.

  The coating film of the solid lubricant is formed on one or both of the valve body and the valve casing. Preferably, the coating film is formed on the outer peripheral surface of the valve body, and may be formed on the entire surface of the valve body. It can also be formed limited to the sliding surface with the valve casing. As a material for the solid lubricant film, a material mainly composed of one or a plurality of materials of fluororesin, molybdenum disulfide, and graphite is preferably used. In order to increase the film strength of the coating film of this solid lubricant, it is desirable to use a material in which minute irregularities are formed on the outer peripheral surface of the valve body, which is coated on the minute irregular surface and dried by heating. And the film thickness of a solid lubricant film should just be about 1-2 micrometers considering not only the durability but the clearance management mentioned above. Further, the valve casing on which the valve body slides has an inner surface higher in hardness than the outer peripheral surface of the valve body, and preferably has a surface hardness of Hv400 or more, and the surface roughness Ra of the inner surface by burnishing. Is smoothed so as to be 0.1 or less.

  A sealing member for blocking communication between the passage and the valve casing constituting the suction valve is not interposed between the valve body and the valve casing so that the metal does not slide between each other. It can be operated and an efficient suction action can be performed.

  Embodiments of the present invention will be described below with reference to the drawings. First, FIG. 1 shows a schematic configuration of an endoscope suction mechanism. In the drawing, the endoscope 1 is roughly composed of an insertion part 2, a main body operation part 3, and a universal cord 4.

  The insertion section 2 is provided with a treatment instrument insertion channel 5 for inserting a treatment instrument such as forceps. The treatment instrument insertion channel 5 is provided at the distal end of the insertion section 2 together with illumination means and observation means (not shown). The treatment tool outlet 5a is opened. The proximal end portion of the treatment instrument insertion channel 5 extends to the main body operation portion 3 and is connected to a branch portion 6 provided in the main body operation portion 3. A treatment instrument introduction conduit 7 and a suction conduit 8 are connected to the branch portion 6. The treatment instrument introduction conduit 7 is connected to a forceps port 9 formed in the main body operation unit 3, and a forceps plug is attached to the forceps port 9 so as to be sealed except when the treatment instrument is inserted. Yes.

  The suction line 8 is led into the universal cord 4 from the main body operation unit 3, and the pipe 11 from the suction source device 10 is detachably connected. Here, the suction source device 10 includes a negative pressure generating means 12 including a suction pump and a suction tank 13, and the suction tank 13 stores a suction substance made of a fluid in the body.

  As shown in FIGS. 2 and 3, the suction valve 20 is attached to the housing 3 a of the main body operation unit 3. The suction valve 20 is for performing a suction operation from inside the body. By this suction valve 20, the suction pipe 8 is connected to the suction passage 8a leading to the treatment instrument insertion channel 5 and the suction source device 10. It is divided into a pressure generation passage 8b. The suction valve 20 has a valve casing 21, and a suction side port 22 to which the suction passage 8a is connected and a negative pressure side port 23 to which the negative pressure generation passage 8b is connected are formed in the valve casing 21. ing.

  A valve body 24 is mounted in the valve casing 21 so as to be movable in the axial direction thereof. The valve body 24 allows the negative pressure side port 23 to communicate with the atmosphere and a state where it communicates with the suction side port 22. Switch. The state in which the valve body 24 communicates the negative pressure side port 23 to the atmosphere, that is, the state of FIG. 2 is the suction stop position, and the suction side port 22 does not communicate with the negative pressure side port 23 and the atmosphere. There is no. As shown in FIG. 3, when the valve body 24 is switched in a state where the negative pressure side port 23 communicates with the suction side port 22, a negative pressure suction force acts on the suction side port 22 to be in the suction operation position.

  Thus, in order to switch the flow path, the valve body 24 is formed with the first land portion 24a at the lower end portion in the drawing, and the upper position of the first land portion 24a is an annular concave portion. A groove 24b is formed, and a second land portion 24c is formed at an upper position of the annular groove 24b. Further, the upper position of the second land portion 24c is a thin shaft portion 24d. The valve body 24 is provided with a communication path 25. One end of the communication path 25 opens as a bottom opening 25a on the lower end surface of the valve body 24, and the other end serves as a side opening 25b. Open to the side surface of the land portion 24c.

  A recess 26 is formed at a position that is 180 ° out of phase with the opening of the side opening 25b of the second land portion 24c, and a rotation-preventing projection 27 is implanted in the recess 26. The protrusion 27 protrudes laterally from the outer peripheral surface of the second land portion 24 c and is inserted into a guide groove 28 provided in the axial direction on the inner surface of the valve casing 21. Accordingly, the valve body 24 does not rotate in the valve casing 21, and the relative positional relationship in the rotational direction between the side opening 25 b of the communication passage 25 and the negative pressure side port 23 in the valve casing 21 is maintained. It is like that. In addition, by applying a sealing material or an adhesive around the mounting portion of the protrusion 27 to the concave portion 26, a gap can be prevented from being generated therebetween.

  An air communication path 29 is provided in the second land portion 24c. As shown in FIGS. 4 and 5, the atmosphere communication passage 29 is formed on the outer peripheral surface of the second land portion 24 c at positions on both sides avoiding the opening position of the side opening 25 b and the mounting portion of the protrusion 27. It is formed by the notch. The atmospheric communication passage 29 extends over the entire length of the second land portion 24c in the axial direction, and therefore, the lower end portion of the atmospheric communication passage 29 communicates with the annular groove 24b.

  The valve casing 21 is fixedly held in the housing 3 a of the main body operation unit 3. For this purpose, an annular projecting portion 21a is formed at the upper position of the valve casing 21, and an enlarged diameter portion 21b having a thread groove on the inner peripheral surface and the outer peripheral surface is formed at the upper end portion. The end of the portion 21b is open. In the valve casing 21, the annular projecting portion 21a is brought into contact with the inner surface of the mounting opening formed in the housing 3a of the main body operating portion 2, and the fixing nut 30 is screwed into the outer peripheral portion of the enlarged diameter portion 21a. As a result, the housing 3a is sandwiched between the annular projecting portion 21a and the fixing nut 30, whereby the valve casing 21 is fixed to the housing 3a.

  A retaining ring 31 is screwed into the inner circumferential groove of the enlarged diameter portion 21b. The upper end of the retaining ring 31 protrudes from the housing 3a, and an outward flange portion 31a is continuously provided. ing. A spring receiving member 32 is placed on the flange portion 31a. An elastic member 33 is attached to the spring receiving member 32, and the lower end folded portion 33a of the elastic member 33 is configured to hold the flange portion 31a, so that the holding ring 31 provided integrally with the elastic member 33 is a valve. The casing 21 is detachably fixed.

  A suction button 34 is connected to the valve body 24, and the suction button 34 protrudes from the housing 3 a of the main body operation unit 3 by a predetermined height. By doing so, the suction valve 20 is switched between the suction stop position and the suction operation position. The suction button 34 is connected to the tip of the shaft portion 24 d of the valve body 24, and a return spring 35 is mounted between the suction button 34 and the spring receiving member 32. The return spring 35 urges the valve body 24 connected to the suction button 34 in a direction protruding from the valve casing 21, and the urging force causes the second land portion 24 c and the shaft portion 24 d to be urged. 2 is held at the suction stop position of FIG. At this time, the negative pressure side port 23 communicates with the atmosphere via the atmosphere communication passage 29, but communicates with the atmosphere through a gap formed in the outer peripheral portion of the suction button 34, and the communication with the atmosphere is reliably performed. In order to achieve this, a plurality of vent holes 36 are formed in the peripheral body portion of the spring receiving member 32.

  When the suction valve 20 is in the suction stop position of FIG. 2, the side passage 25b of the communication passage 25 communicating with the suction side port 22 faces the inner wall of the valve casing 21, and therefore the negative pressure generation passage 8b. Both are blocked from the atmosphere. When the suction button 34 is pushed against the return spring 35 in a state where the insertion portion 2 is inserted into the body cavity, the valve body 24 slides in the valve casing 21 and communicates with the atmosphere communication passage 29. The communication between the recessed groove 24 b and the negative pressure side port 23 is blocked, and the side surface opening 25 b of the communication path 25 communicates with the negative pressure side port 23. As a result, the suction passage 8a communicates with the negative pressure generation passage 8b, and a negative pressure suction force acts on the inside of the treatment instrument insertion channel 5 from the suction passage 8a. As a result, suction of a sucked material such as body fluid is performed from the treatment instrument outlet 5a at the distal end of the treatment instrument insertion channel 5.

  The suction button 34 is provided with a skirt portion 34a. The skirt portion 34a is a surrounding wall portion. The suction button 34 to which the valve body 24 is connected has an annular shape at the lower end surface of the skirt portion 34a. It is possible to move to the position shown in FIG. In this stroke end state, when the skirt portion 34a of the suction button 34 presses and deforms the elastic sheet portion 33b, the opening at the upper end of the valve casing 21 is closed. As a result, both the suction side and negative pressure side ports 22 and 23 are completely blocked from the atmosphere. However, in order to push the suction button 34 to the stroke end position and completely shut off the atmosphere, the suction button 34 resists the spring force of the return spring 35, and the skirt portion 34a presses and deforms the elastic sheet portion 33b. It must be pushed down until it is released, which requires a large operating force. Therefore, even if the suction button 34 is not pushed down to the stroke end shown in FIG. 3, suction from the body is possible.

  Thus, in the suction valve 20, sliding of the valve body 24 with respect to the valve casing 21 by operation of the suction button 34 is smoothly performed with a light load. For this reason, with a slight dimensional difference between the outer diameter of the valve body 24 and the inner diameter of the valve casing 21, the clearance C is interposed between the valve body 24 and the valve casing 21. It is trying to occur. As shown in FIG. 6, a clearance C is generated between the valve body 24 and the valve casing 21 even at the suction stop position or at the suction operation position as shown in FIG. ing. Thereby, when the valve body 24 moves along the valve casing 21, the frictional resistance is remarkably reduced. As a result, the negative pressure side port 23 does not communicate with the suction side port 22 or the atmosphere communication path 29 or is blocked, but communicates through the throttle path or in a fully opened state.

  By accurately managing the clearance C of the throttle passage formed between the valve body 24 and the valve casing 21 and controlling the amount of leakage due to this clearance C, suction can be performed without any trouble.

  Therefore, as shown in FIGS. 6 and 7, if the clearance C constituting the throttle passage formed between the valve body 24 and the valve casing 21 is 1 to 18 μm, the airtight leakage amount is 20 cc / 30 seconds or less. Become. Even when pressure loss due to such an airtight leak occurs, a sufficient negative pressure suction force can be applied to the treatment instrument outlet 5a when the suction valve 20 is set to the suction operation position. Further, in FIG. 6, even if there is a clearance C between the first land portion 24a of the valve body 24 and the valve casing 21, this clearance C is very small. Since the inside of the annular groove 24b is also sucked from the atmosphere, it does not become as low as the negative pressure generation passage 8b, and prevents body fluids and the like from entering the treatment instrument insertion channel 5 from the body when the suction is stopped. can do.

  Further, when the suction valve 20 is set to the suction operation position, the negative pressure side port 23 is not completely cut off from the atmosphere, and a throttle passage is formed between them. I can't deny that. For example, in the case where a large amount of body fluid such as blood is accumulated, it may be necessary to suck it quickly. In this case, by pushing the suction button 34 to the stroke end position, the negative pressure side port 23 can be completely cut off from the atmosphere, and quick and efficient suction is possible.

  Thus, by providing the clearance C between the valve body 24 and the valve casing 21, the frictional resistance when the valve body 24 is moved by operating the suction button 34 is remarkably reduced. 6 and FIG. 7, by forming the solid lubricant film 37 on the outer peripheral surface of the valve body 24, the valve body 24 can be moved more smoothly and the operability of the suction valve 20 is improved. This reduces the wear of the valve body 24 and the valve casing 21 and prevents the occurrence of galling.

  Here, the valve casing 21 and the valve body 24 are both formed of a metal material such as stainless steel because they have advantages such as strength and chemical resistance, are easy to process, and are inexpensive. However, the valve casing 21 is smoothed so that the inner surface has a surface hardness of Hv400 or more (for example, SUS303) and the inner surface has a surface roughness Ra of 0.1 or less. In the smoothing process, it is convenient to perform burnishing, particularly burnishing (Superoll processing) using Superoll from the viewpoint of productivity and the like. The valve body 24 can be formed of a material different from that of the valve casing 21, but is formed of the same metal material as the valve casing 21 in consideration of the above-described characteristics. Further, by forming the solid lubricant film 37 on the outer peripheral surface of the valve body 24, it is possible to avoid a situation in which the same kind of metal is in direct contact, there is no possibility of galling or the like in the sliding portion, and solid lubrication. The slidability is improved by the material coating 37, and a smoother movement is possible. Further, since the solid lubricant film 37 is a softer member than the valve casing 21, the valve body 24 moves very smoothly without resistance. As a result, the durability of the suction valve 20 is improved, and a stable operation can be performed even if it is repeatedly used for a long time.

  As already described, since the clearance between the valve body 24 and the valve casing 21 is strictly controlled, specifically, about 1 to 2 μm so as not to increase the thickness of the solid lubricant film 37 more than necessary. And The solid lubricant film 37 is preferably made of any one of fluororesin, molybdenum disulfide, and graphite, or a composite material of two or more thereof.

  And as an example of the film formation method, the valve body 24 is degreased and minute irregularities are formed on the surface by means such as sandblasting. Further, a chemical conversion treatment including etching or the like is performed so as to be sufficiently dried. Then, a lubricant film is formed by dipping, spraying, or the like, and dried by heating. The film thickness of the solid lubricant film is set to 1 to 2 μm in consideration of its durability, management of clearance C, and the like. By forming a film by such a technique, an anchor effect for the film can be obtained by performing a pre-treatment especially for forming minute irregularities, and thus the adhesion strength of the film can be extremely increased, and the valve body Even if 24 is operated frequently, the solid lubricant film 37 is not peeled off or damaged.

It is explanatory drawing which shows the structure of the suction mechanism of an endoscope. It is a longitudinal cross-sectional view of the suction valve which shows one Embodiment of this invention. It is a longitudinal cross-sectional view of the suction valve which shows the operation state different from FIG. It is XX sectional drawing of FIG. It is a general-view figure of a valve element. It is a principal part expanded sectional view of FIG. It is a principal part expanded sectional view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Endoscope 2 Insertion part 3 Main body operation part 3a Housing 5 Treatment tool insertion channel 5a Treatment tool lead-out port 8 Suction conduit 8a Suction passage 8b Negative pressure generation passage 10 Suction source device 20 Suction valve 21 Valve casing 22 Suction side port 23 Negative pressure side port 24 Valve body 25 Communication passage 29 Atmospheric communication passage 33 Elastic member 33b Elastic sheet 34 Suction button 34a Skirt portion 36 Vent hole 37 Solid lubricant coating C Clearance

Claims (4)

A port that is provided in the main body operation unit of the endoscope and communicates with a suction passage that opens at the distal end of the insertion portion that is connected to the main body operation unit and a negative pressure generation passage that is connected to the suction source device communicate with each other. A suction valve equipped with a valve body for switching between a suction stop position in which the negative pressure generation passage communicates with the atmosphere and a suction operation position in which the negative pressure generation passage communicates with the suction passage in a valve casing formed with a port. In the valve
By forming a solid lubricant film on at least one of the sliding surfaces between the inner peripheral surface of the valve casing and the outer peripheral surface of the valve body, a sliding surface is formed,
In the portion of the sliding surface, a throttle passage communicating with the atmosphere is formed,
When the clearance between the inner peripheral surface of the valve casing constituting the throttle passage and the outer peripheral surface of the valve body is set to 1 to 18 μm, the throttle is changed when the valve body is switched to the suction operation position. An endoscope suction valve, characterized in that an airtight leak amount in a passage is 20 cc / 30 seconds or less.   A front end of the valve casing is opened to the atmosphere, and an elastic material sheet is fixedly provided on a peripheral edge of the opening. The valve body extends from the opening to the predetermined length from the inside of the valve casing. An operation button with a return spring acting on the part is mounted, and an enclosure wall part is provided on the operation button so as to be in contact with and away from the elastic material sheet. The return spring serves as a suction stop position where the negative pressure generation passage communicates with the atmosphere. By holding the valve body and pushing the operation button in a direction against the return spring, the operation button is switched to the suction operation position, and the surrounding wall portion of the operation button presses the elastic material sheet. The endoscope suction valve according to claim 1, wherein the negative pressure generation passage is configured to be cut off from the atmosphere.   The coating of the solid lubricant is formed at least on the outer peripheral surface of the valve body, and the solid lubricant is mainly composed of one or more materials of fluororesin, molybdenum disulfide, and graphite. 3. The inner surface according to claim 1, wherein minute irregularities are formed on an outer peripheral surface of the valve body, and the solid lubricant is applied to the minute irregularities and dried by heating. 4. Endoscopic suction valve.   The endoscope suction valve according to any one of claims 1 to 3, wherein the valve casing has a hardness of Hv400 or more.

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