JP2012254136A - Conduit switching device and endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent stagging by smoothly sliding a piston of a conduit switching device such as a suction button.SOLUTION: A piston 51 is movably inserted into a cylinder 50. An operation cap 41 is attached to a cap attaching end 51B of the piston 51. A coil spring 48 is disposed between the operation cap 41 and the cylinder cap 52. O-rings 65A-65D are accommodated in O-ring accommodating grooves 61-64 of the piston 51. Rolling regions for moving the O-rings 65A-65D by rolling are provided in the O-ring accommodating grooves 61-64. The rolling length of the rolling regions are made to be different for each of the O-ring accommodating grooves 61-64. This configuration can shift the time when sliding resistance is generated in the O-rings 65A-65D after finishing of rolling, and the frictional resistance can be reduced as much. Since the sliding resistance acts on piston 51 simultaneously, stagging can be prevented in restoration of the piston 51.

Description

  The present invention relates to a pipeline switching device and an endoscope that switch connection states of a plurality of pipelines.

  An endoscope has an observation window for capturing image light of a subject at the distal end of an insertion portion that is inserted into the subject, and air / water feeding that injects fluid (water or air) toward the observation window. A nozzle is provided. The observation window and the air / water supply nozzle are arranged on the distal end surface of the insertion portion. The observation window is formed at the distal end surface of the insertion portion, and the liquid and dirt in the subject are likely to adhere to the surface of the observation window. For this reason, water is jetted from the jet port of the air / water feed nozzle to wash away the dirt on the observation window, and air is jetted from the jet port to blow away water droplets remaining on the surface of the observation window.

  An air / water supply button as a pipeline switching device is connected to the air / water supply nozzle. The air / water supply button adopts a two-stage push structure in which the button is half-pressed and fully pressed from an OFF state where no button operation is performed (see Patent Documents 1 and 2). In the two-stage push structure, two coil springs are used, half-pressed state is realized by pressing against the bias of one coil spring, and fully pressed by pressing against the bias of two coil springs Is realized. Thus, by changing the number of coil springs to be pressed, a different resistance can be given to the operator, and the half-pressed state can be clearly known.

  For example, in the air / water supply buttons described in Patent Documents 1 and 2, when an air supply operation of the air supply pump is performed in a state where no operation is performed, from the exhaust opening opened in the operation cap of the air / water supply button Do a leak. When the exhaust port is closed in this state, the exhaust port is closed in the air supply state, so that the check valve in the air / water supply button is opened and air is supplied from the air / water supply nozzle. When the operation cap is half-pressed, the air supply state is switched to the water supply state, and water is supplied from the air supply / water supply nozzle. Further, when the operation cap is fully pressed, the water supply pipe is switched, and balloon water is supplied through the balloon pipe leading to the inside of the balloon to inflate the balloon.

  In the suction buttons described in Patent Documents 1 and 2, when a suction operation is performed by a suction pump in a state where no operation is performed, the suction pump sucks external air through a predetermined air passage. When the operation cap of the suction button is half-pressed, the suction pump communicates with the treatment instrument channel and performs suction from the treatment instrument channel. When the operation cap is fully pressed, the suction pump communicates with the balloon conduit, the water filled in the balloon is sucked through the balloon conduit, drainage is performed, and the balloon is deflated.

  By the way, in an endoscope, carbon dioxide gas is also used in addition to pressurized air by an air supply pump. Carbon dioxide gas is easily absorbed by the body, and has an advantage that it does not burden the subject as compared to pressurized air. When pressurized air is used, in a state where no button operation is performed, for example, air is leaked from the discharge port of the operation cap, and no load is applied to the pressure pump. On the other hand, when carbon dioxide is used, since a carbon dioxide cylinder serves as a supply source, it is necessary to avoid unnecessary leakage. For this reason, the gas feed / water feed button also adopts a two-stage push structure with two coil springs, and realizes an OFF state in which no button operation is performed, a gas feed state by a half-push operation, for example, a water feed state by a full push operation.

Japanese Patent No. 3017957 JP 2007-111266 A

  As described above, in the pipeline switching device, a plurality of ring-shaped packings are usually attached. The packing has various cross-sections such as an O shape, an X shape, and a Y shape. Among them, O-shaped ring packing (hereinafter simply referred to as O-ring) is most widely used because it is easy to manufacture and inexpensive. This O-ring is a squeeze-type packing, and airtightness is ensured by crushing the packing. Therefore, in order to improve airtightness, it is necessary to make a larger crushing allowance.

  On the other hand, for example, the air / water button is required to be smoothly slid in order to turn on / off the flow of gas or liquid when the user (surgeon) presses it with a finger. This slidability and airtightness are in a so-called trade-off relationship, and if one is satisfied, the other is sacrificed and it is difficult to satisfy both characteristics. For this reason, this trade-off is avoided by applying a lubricant such as silicon oil around the packing.

  In addition, the lubricant may flow in the air / water supply pipeline of the endoscope, for example, and may cause clogging of the pipeline. Moreover, if it remains in the observation window at the distal end of the endoscope, it leads to deterioration of water drainage, and good observation becomes impossible due to adhesion of water droplets.

  The present invention has been made in view of the above problems, avoids the tradeoff between airtightness and slidability, and ensures airtightness and slidability without using a lubricant or the like in the O-ring. An object of the present invention is to provide a conduit switching device capable of smooth operation and an endoscope using the same.

  In order to achieve the above object, the present invention comprises an operation member, an operation member attachment end portion to which the operation member is attached, and a main body portion, a piston having a communication path on a peripheral surface of the main body portion, and the piston. A cylinder having a fluid inlet and a fluid outlet that are held movably between a first position that is a movement start end and a second position that is a movement end, and face the communication path in the first position state or the second position state. A cylinder cap that has a through-hole through which the operating member mounting end passes, is attached to the opening of the cylinder, and prevents the piston body from falling off the cylinder, and between the piston and the cylinder A plurality of O-rings for holding the communication passage in an airtight manner and a plurality of O-rings that are formed on one of the sliding surfaces of the piston or the cylinder and store the O-rings When, and a said O-ring respectively provided receiving groove, the rolling region O-ring rolling length for rolling the O-ring with the movement of the piston are different.

  The O-ring rolling length is preferably different for each O-ring storage groove. In this case, the frictional resistance due to the static friction area of the O-ring is not generated simultaneously in each O-ring, and the generation time of the frictional resistance due to the static frictional area of each O-ring is dispersed, so the frictional resistance increases at once. Smooth operation is possible without doing. Also in the return operation, smooth return is possible, frictional resistance is generated at once, and stag is avoided without hindering the return operation due to the repulsive force of the coil spring, for example. In addition, by dividing the plurality of O-ring storage grooves into groups and setting the O-ring rolling lengths different for each group, the generation time of the frictional resistance due to the respective O-rings is similarly distributed. Operation and avoiding stag. Therefore, it is not necessary to apply the lubricant, and the lubricant is transported from the pipeline, causing clogging, and in the case of an endoscope, the visual field is obstructed by the lubricant remaining in the observation window. There is nothing to do.

  All or a part of the O-rings are provided during the movement of the piston by having a rolling region provided in the O-ring storage groove and rolling the O-ring as the piston moves from the first position to the second position. Will roll during the stroke, the sliding resistance of the O-ring will be reduced by the amount of this rolling, and the piston can be moved smoothly.

  The operation member includes an operation cap, and a biasing member that is disposed between the operation cap and the cylinder cap and biases the piston toward the first position against a pressing operation of the operation cap. Preferably, it is configured.

  The rolling region of the O-ring receiving groove at a position where the O-ring passes through the fluid inlet or the fluid outlet is an O-ring rolling in which the O-ring rolls over the opening of the fluid inlet or the fluid outlet. Preferably it has a length. In this case, when the O-ring passes through the fluid inlet or the fluid outlet, the O-ring can be rolled. Therefore, when the O-ring slides when passing through the fluid inlet or the like, the O-ring may be scraped at the opening edge of the inlet or outlet, but this is eliminated and the durability is improved. In addition, there is no need to apply a lubricant so that it will not be scraped off, and there will be no cause of tube clogging or visual field obstruction due to the circulating agent.

  The piston can be positioned at a third position which is an intermediate position between the first position and the second position, and a pipe connection port formed in the cylinder at the third position and a connection formed in the piston. By switching the communication and blocking of a plurality of pipelines by changing the combination communicating with the passage, two-stage switching is possible in addition to one-stage switching.

  Since the biasing member is a coil spring, the configuration is simplified, and a stag is avoided when restoring the pipeline by the repulsive force of the coil spring.

  It is preferable to provide the pipe switching device in the endoscope, and it is more preferable that the endoscope has a hand operation unit to which the pipe switching device is attached. In this case, it is possible to obtain an endoscope that has a light operation feeling without applying a lubricant or the like to the packing, and that does not cause clogging of the pipe line or deterioration of drainage of the observation window due to the lubricant.

  According to the present invention, the rolling region that allows the O-ring to roll is formed in the O-ring housing groove that holds the space between the cylinder and the piston in an airtight manner. For this reason, when the O-ring rolls, its pressing resistance is small. When the rolling of the O-ring is completed and the O-ring and the cylinder start to slide, the pressing resistance increases due to the frictional resistance (sliding resistance). Then, by varying the length of the rolling region in each O-ring storage groove, the time point at which the rolling of the O-ring ends is different for each O-ring. Accordingly, the sliding resistance due to the respective O-rings is not increased all at once and is dispersed, so that a smooth operational feeling can be obtained. Further, the restoring force does not stagnate due to the sliding resistance in the restoring operation.

  By causing all or some of the O-rings to roll over the entire stroke, the piston can be smoothly moved by the action of the rolling O-rings. Since the pressing resistance is reduced, it is not necessary to apply a lubricant such as silicone oil to the O-ring. This eliminates the outflow of the lubricant to the pipeline, and eliminates the clogging of the pipeline caused by the lubricant and the decrease in water drainage due to the lubricant remaining in the observation window.

  By positioning the opening formed on the contact surface of the O-ring in the rolling area of the O-ring, the O-ring rolls and moves when passing through the opening. In comparison, the O-ring is not scraped at the edge of the opening, and durability is improved. Further, it is not necessary to apply a lubricant so as not to be scraped off, and the adverse effects associated with the outflow of the circulating agent to the pipeline are eliminated.

It is a schematic diagram of an endoscope. It is sectional drawing of a suction button when the operation cap is not pressed. It is sectional drawing of a suction button when an operation cap is fully pressed. It is sectional drawing which shows a general O-ring accommodation groove | channel and an O-ring. It is sectional drawing which shows O-ring before pressing operation. It is sectional drawing which shows the O-ring in rolling immediately after pressing operation start. It is sectional drawing which shows the state which O-ring located in the terminal end of the rolling area and finished rolling. It is sectional drawing which shows the state which O-ring is sliding. It is a graph which shows the relationship between the stroke of a piston, and the pressing force at that time. It is sectional drawing which shows the gas / water feed button of 2nd Embodiment of OFF position. It is sectional drawing which shows a two-stage press mechanism. It is sectional drawing which shows the gas / water feeding button of 2nd Embodiment of a half-pressed position. It is sectional drawing which shows the gas / water supply button of 2nd Embodiment of a fully pressed position. It is sectional drawing which shows the state of the 1st-3rd O-ring of the gas supply water supply button before a press start. It is sectional drawing which shows the state of the 1st-3rd O-ring of the gas supply water supply button during pressing operation. It is sectional drawing which shows the O-ring and O-ring accommodation groove | channel of 3rd Embodiment. Similarly it is sectional drawing which shows the principal part of 3rd Embodiment in which an O-ring rolls a connection port.

  As shown in FIG. 1, an endoscope 10 has an insertion portion 11 inserted into a subject, an operation portion 12 connected to a proximal end portion of the insertion portion 11, and one end connected to the operation portion 12. Universal code 13. A connector 14 is attached to the other end of the universal cord 13. The light source device 15 is connected via the connector 14. Further, the connection cord 16 branches from the connector 14, and the processor device 17 is connected via the connection cord 16.

  The insertion portion 11 is formed in a tubular shape with a circular cross section and has flexibility. The distal end portion 11A of the insertion portion 11 is provided with an observation window 20, an illumination window (not shown), a gas / water supply nozzle 21, a forceps / suction port (suction port) 22, and the like. An imaging unit 23 is disposed inside the tip at a position facing the observation window 20. The imaging unit 23 is connected to the processor device 17 via the insertion unit 11, the operation unit 12, the universal cord 13, and the connection cord 16 by a signal cable (not shown). The gas supply / water supply nozzle 21 cleans the observation window 20 and the illumination window together with the observation window 20 by supplying water or supplying air. The suction port 22 serves as an outlet of a treatment tool such as a forceps or a snare and is used as a suction port for sucking suctioned matter such as blood and filth in the body.

  In the insertion section 11 and the operation section 12, a treatment instrument channel 24 whose one end communicates with the suction port 22 and a gas supply / water supply conduit 25 whose one end communicates with the gas supply / water supply nozzle 21 are provided. In addition, in order to distinguish each pipe line easily, parts other than a pipe line (a hollow part is included) are displayed with the oblique line.

  The other end of the treatment instrument channel 24 is connected to a treatment instrument inlet 27 provided in the insertion portion 11. The treatment instrument inlet 27 is closed by a stopper (not shown) except when the treatment instrument is inserted. Further, a suction line 28 is branched from the treatment instrument channel 24, and this suction line 28 is connected to a suction button 29 provided in the operation unit 12.

  The other end of the gas supply / water supply line 25 branches into a gas supply line 31 and a water supply line 32. The gas supply line 31 and the water supply line 32 are connected to a gas supply / water supply button 33 provided in the operation unit 12.

  In addition to the gas supply line 31 and the water supply line 32, the gas supply / water supply button 33 includes one end of the gas supply source line 35 that leads to the gas supply unit 34 and one end of the water supply source line 37 that leads to the water supply tank 36. And are connected. The gas supply unit 34 depressurizes the carbon dioxide gas from the carbon dioxide cylinder to a constant pressure and supplies it to the gas supply source line 35.

  The other end of the gas supply source line 35 is branched by a branch line 38 in the connector 14. The branch pipe line 38 is connected to the inlet of the water supply tank 36. The other end of the water supply source line 37 is inserted into the water supply tank 36 through the branch line 38. When the internal pressure of the water supply tank 36 is increased by the carbon dioxide gas from the gas supply unit 34 via the branch pipe 38, the water in the water supply tank 36 is supplied to the water supply source pipe 37.

  The gas supply / water supply button 33 blocks the gas supply source line 35 and the water supply source line 37 in the OFF state in which the operation cap 40 is not operated. In addition, when the operation cap 40 is half-pressed, the gas supply / water supply button 33 blocks the water supply source conduit 37 and allows the gas supply source conduit 35 to communicate only with the gas supply conduit 31. As a result, the carbon dioxide gas is ejected from the gas supply / water supply nozzle 21 through the gas supply conduit 31 from the gas supply source line 35. When the operation cap 40 is fully pressed, the gas supply / water supply button 33 blocks the gas supply source line 35 and connects the water supply source line 37 to the water supply line 32. Thereby, the water sent from the water supply source line 37 is ejected from the gas supply nozzle.

  In addition to the suction line 28, the other end of the suction source line 43 whose one end communicates with the suction pump 42 is connected to the suction button 29. The suction pump 42 is always operated during the operation of the endoscope. As shown in FIG. 2, the suction button 29 causes the suction source pipe line 43 to communicate with the outside (atmosphere) via the atmosphere communication pipe line 30 when the operation cap 41 is not operated. This is because, since the suction pump 42 is always operating, the load applied to the suction pump 42 increases if the suction source line 43 does not communicate with the atmosphere. For this reason, the increase in the load of the suction pump 42 can be suppressed by making the suction source line 43 communicate with the atmosphere.

  The suction button 29 allows the suction source line 43 to communicate only with the suction line 28 when the operation cap 41 is pressed. As a result, the negative pressure suction force of the suction pipe line 28 and the treatment instrument channel 24 is increased, and various suction objects are sucked from the suction port 22.

  As shown in FIG. 2, the suction button 29 includes a cylinder 50, a piston 51, and a cylinder cap 52. The piston 51 is slidably accommodated in the cylinder 50. The cylinder cap 52 includes an operation member 45.

  The operation member 45 includes an operation cap 41 and a coil spring 48. The coil spring 48 is disposed between the operation cap 41 and the cylinder cap 52. The coil spring 48 urges the piston 51 toward the OFF position (first position) against the pressing operation of the operation cap 41. The operation member 45 is switched between an OFF position where nothing is operated on the operation cap 41 and an ON position where the piston 51 is pressed as shown in FIG.

  The cylinder 50 is formed in a bottomed cylindrical shape. A suction source pipe connection port 55A, an atmosphere communication pipe connection port 55B, and a suction pipe connection port 55C are formed on the outer peripheral surface of the cylinder 50, and the pipes 28, 30,. 43 are connected to each other. The cylinder 50 may be formed of two parts, a cylinder main plate made of an inner cylinder and a cylinder case made of an outer cylinder. Further, the atmosphere communication pipeline connection port 55B may be connected to the atmosphere by being connected to the free state without connecting the pipeline 30.

  The piston 51 includes a piston main body 51A and a cap attachment end 51B. The piston main body 51A is movably inserted into the cylinder 50. The cap attachment end portion 51B is continuous to the piston main body 51A via the stepped portion 51C, and is formed with a smaller diameter than the piston main body 51A.

  A communication passage 58 including a circumferential groove is formed on the outer peripheral surface of the piston main body 51A. Instead of the circumferential groove, the communication path 58 may be formed from a communication hole formed in the piston main body 51A.

  First to fourth O-ring housing grooves 61 to 64 are formed on the outer peripheral surface of the piston main body 51 </ b> A on both sides in the piston axial direction with respect to the communication passage 58. The first O-ring storage groove 61 and the second O-ring storage groove 62 are formed on the operation cap 41 side with respect to the communication path 58. The third O-ring storage groove 63 and the fourth O-ring storage groove 64 are formed on the side opposite to the operation cap 41 side with respect to the communication path 58. O-rings 65 </ b> A to 65 </ b> D are housed in the first to fourth O-ring housing grooves 61 to 64.

  As shown in FIG. 4, the groove width W1 of the general O-ring storage groove 66 is such that the O-ring 65 is crushed and deformed in the storage groove 66 to deform the sliding surface to be sealed (the inner peripheral surface 50A of the cylinder 50). ). For this reason, the groove width W <b> 1 is formed to be substantially the same as or slightly smaller than the line D <b> 1, and the O-ring 65 does not roll in the storage groove 66.

  On the other hand, as shown in FIGS. 5-8, the 1st O-ring accommodation groove | channel 61 is formed longer than the general groove width W1 compared with the line diameter D1. A difference (W1−D1) obtained by subtracting the line D1 from the groove width W1 is the rolling length WR1. The extra space for the rolling length WR1 is the rolling area RA1, and the O-ring 65A can roll for the rolling length WR1 in the rolling area RA1. The second to fourth O-ring storage grooves 62 to 64 also have rolling regions RA2, RA3, and RA4, respectively. The relationship between the rolling lengths WR1, WR2, WR3, and WR4 in each of the rolling regions RA1 to RA4 is that the rolling length WR1 of the first O-ring housing groove 61 is the shortest, and the rolling of the second O-ring housing groove 62 is next. The length WR2, the rolling length WR3 of the third O-ring housing groove 63, and the rolling length WR4 of the fourth O-ring housing groove 64 increase in this order (WR1 <WR2 <WR3 <WR4).

  As shown in FIG. 2, the cylinder cap 52 is formed in a double cylinder shape of an inner cylinder part 52A and an outer cylinder part 52B, and the inner cylinder part 52A and the outer cylinder part 52B are integrated by a partition part 52C. ing. A female screw portion (not shown) is formed on the piston mounting side of the outer cylinder portion 52 </ b> B, and is screwed with the male screw portion of the cylinder 50, so that the cylinder cap 52 is attached to the cylinder 50. If necessary, packing such as an O-ring is appropriately disposed on each of the mounting surfaces although not shown. Although not shown, a bracket is extended to the outer cylinder portion 52B, and is attached to the hand operating portion 12 (see FIG. 1) of the endoscope 10 by screwing or the like through the bracket.

  An operation cap 41 is attached to the cap attachment end portion 51 </ b> B of the piston 51. Between the operation cap 41 and the cylinder cap 52, one coil spring 48 is mounted on the cap attachment end 51B. The coil spring 48 is disposed between the operation cap 41 and the cylinder cap 52 in a state where the coil spring 48 is compressed in the axial direction of the piston 51 rather than the natural length, and the cap attachment end 51B is inserted through the center thereof.

  Due to the compression of the coil spring 48, the operation cap 41 is always lifted from the cylinder cap 52. This state is an OFF position where nothing is operated on the suction button 29. As shown in FIG. 2, in the OFF position, the suction source pipe connection port 55 </ b> A of the cylinder 50 and the atmospheric communication pipe connection port 55 </ b> B face the communication path 58 of the piston 51. Thereby, in the OFF position, the atmosphere is sucked from the atmosphere communication pipe line 30 by the suction pump 42 (see FIG. 1). In the OFF position, the suction line connection port 55C to which the suction line 28 is connected is shielded by the shielding part 60 between the third O ring 65C and the fourth O ring 65D.

  As shown in FIG. 3, when the operation cap 41 is pressed and the piston 51 is turned on, the suction source pipe connection port 55 </ b> A and the suction pipe connection port 55 </ b> C of the cylinder 50 face each other in the communication path 58 of the piston 51. To do. Further, the atmosphere communication pipe connection port 55B is shielded by the shielding part 59 between the first O-ring 65A and the second O-ring 65B. Thereby, suction is started from the suction line 28.

  FIG. 9 is a graph showing changes in the pressing force due to the movement of the piston 51. When the piston 51 starts to move, static friction acts between the O-ring 65A and the cylinder 50, and the pressing force gradually increases due to this static friction. When the pressing force becomes F1, the O-ring 65A starts rolling in the O-ring housing groove 61 (see FIG. 6). During the O-ring rolling, the rolling resistance is smaller than the sliding resistance, so the increase in pressing force is very small. The pressing resistance (rolling resistance) during O-ring rolling and the sliding between the O-ring 65A and the cylinder 50 after reaching the end of the rolling area and restricting rolling of the O-ring 65A (see FIG. 7). It is different from pressing resistance (sliding resistance) due to movement. Moreover, since the sliding resistance is larger than the rolling resistance, the pressing resistance increases rapidly when the O-ring 65 reaches the end of the rolling region due to the difference in resistance. Immediately after the O-ring 65 reaches the end of the rolling region, as shown in FIG. 8, static friction is generated in the sliding friction generation region A1, the pressing resistance due to the static friction peaks, and the pressing force is F2. Become the maximum. Eventually, when the piston moves beyond the pressing resistance due to static friction, it receives dynamic frictional resistance due to sliding. Since the dynamic frictional resistance due to sliding is lower than that at the peak of static friction, the pressing force is F3 smaller than F2.

  In this embodiment, since four O-rings 65A to 65D are used, in the case of an O-ring housing groove 66 that does not use rolling as in the prior art, sliding by these four O-rings 65A to 65D. Resistance acts all at once. Since the sliding resistance of each O-ring is integrated and acts, the pressing resistance is increased.

  On the other hand, in this embodiment, the rolling lengths WR1 to WR4 of the rolling regions RA1 to RA4 of the O-ring storage grooves 61 to 64 are changed, and the sliding resistance of the O-rings 65A to 65D is changed. It occurs with a time difference corresponding to the difference between the rolling lengths WR1 to WR4 of the moving regions RA1 to RA4. Accordingly, the sliding resistance due to the O-rings 65A to 65D is dispersed without being concentrated at the start of pressing of each stroke, so that the pressing force can be small and the sliding resistance does not increase rapidly, so that smooth A pressing operation is possible. Similarly, during the return operation, each of the O-rings 65A to 65D similarly starts rolling sequentially, and the generation timing of the sliding resistance can be shifted by each of the O-rings 65A to 65D. Although the sliding resistance does not act all at once, the repulsive force of the coil spring 48 loses the sliding resistance, and a button may not be restored, but this is avoided. Thereby, a pressing resistance does not rise at a stretch, and a smooth operation feeling is obtained.

  Next, a second embodiment will be described with reference to FIGS. In the second embodiment, the present invention is applied to the gas / water supply button 33. The gas / water feed button 33 includes a pipe switching device main body 70 and a two-stage pressing mechanism 71. As shown in FIG. 11, the pipe switching device main body 70 includes a piston 76 and a cylinder 77. The two-stage pressing mechanism 71 includes an operation cap 40, a cylinder cap 72, two coil springs 73 and 74, and an intermediate guide cylinder 75. By this two-stage pressing mechanism 71, the piston 76 is moved in the cylinder 77 from the OFF position (see FIG. 10) where no operation is performed, to the half-pressed position (see FIG. 12) and the fully-pressed position (see FIG. 13). Move.

  As shown in FIG. 11, when the operation cap 40 is pressed, the first coil spring 73 whose urging force is weaker than that of the second coil spring 74 starts to deform, and the bottom of the operation cap 40 and the upper end of the intermediate guide cylinder 75 come into contact with each other. If the pressing is further continued from this state, the repulsive force of the second coil spring 74 is added to the repulsive force of the first coil spring 73, so that the pressing resistance increases. Accordingly, as shown in FIG. 12, the position immediately before the repulsive force of the second coil spring 74 is applied is set to the half-pressed position. When the operation cap 40 is further pressed beyond the half-pressed position, the piston 76 reaches the end of the stroke, and further pressing becomes impossible. As shown in FIG. 13, this position becomes the fully pressed position.

  As shown in FIG. 10, the cylinder 77 is composed of a cylinder body 78 made of an inner cylinder and a cylinder case 79 made of an outer cylinder. The cylinder case 79 is formed with a gas supply pipe connection port 79A, a water supply pipe connection port 79B, a gas supply source pipe connection port 79C, and a water supply source pipe connection port 79D. These connection ports 79A to 79D correspond to these connection ports 79A to 79D. Pipe lines 31, 32, 35 and 37 to be connected are respectively connected. In the cylinder body 78, communication grooves 80A, 80B, 80C and communication holes 81A, 81B, 81C are formed at positions corresponding to the connection ports 79A to 79D.

  The piston 76 includes a piston body 76A and a cap attachment end portion 76B. The piston body 76A is movably inserted into the cylinder body 78. The cap attachment end portion 76B is continuous with the piston main body 76A via the stepped portion 76C, and is formed with a smaller diameter than the piston main body 76A.

  A first communication path 85 and a second communication path 86 are formed on the outer peripheral surface of the piston main body 76A so as to be separated from each other in the axial direction. These communication passages 85 and 86 are constituted by circumferential grooves.

  First and second O-ring housing grooves 87 and 88 are formed on both sides in the piston axial direction with respect to the second communication path 86. In addition, third and fourth O-ring housing grooves 89 and 90 are formed on both sides of the first communication passage 85 in the piston axial direction. O-rings 91 </ b> A to 91 </ b> D are stored in the first to fourth O-ring storage grooves 87 to 90.

  As shown in FIGS. 14 and 15, the first to third O-ring housing grooves 87 to 89 have rolling regions RA1 to RA3. In these rolling regions RA1 to RA3, for example, the rolling lengths WR1, WR2, and WR3 (WR1 <WR2 <WR3) are gradually increased in order.

  As shown in FIG. 10, the fourth O-ring storage groove 90 is formed in the same manner as the general O-ring storage groove 66 shown in FIG. 4 because it is not necessary to roll the O-ring 91D. The fourth O-ring 91D housed in the fourth O-ring housing groove 90 acts as an abutment packing. The fourth O-ring storage groove 90 is formed at the end opposite to the cap attachment end 76B with respect to the piston main body 76A. The fourth O-ring 91 </ b> D is abutted against the inclined surface 78 </ b> B at the other end of the cylinder body 78 by the bias of the coil springs 73 and 74. By this abutment, the space between the cylinder inner peripheral surface and the piston outer peripheral surface is kept airtight. A stepped surface may be used instead of the inclined surface 78B against which the O-ring 91D is abutted.

  A first communication path 85 is formed adjacent to the fourth O-ring 91D. The lower end of the first communication passage 85 communicates with the fourth O-ring storage groove 90. Therefore, when the operation cap 40 is pushed against the bias of the coil springs 73 and 74, a gap 92 is generated between the inclined surface 78B and the O-ring 91D as shown in FIG. By this gap 92, the gas supply source line 35 and the gas supply line 31 communicate with each other via the first communication path 85, and carbon dioxide gas is sent to the gas supply / water supply nozzle 21 (see FIG. 1). The pressing stroke ST1 when half-pressed by the operation cap 40 may be as small as about 0.1 mm to 0.5 mm, for example. Even with such a slight stroke, air is reliably supplied because the fourth O-ring 91 </ b> D is shut off by abutment.

  As shown in FIG. 10, in the OFF position where no operation cap 40 is operated, the communication groove 80A communicating with the water supply source pipe connection port 79D of the cylinder 77 is located in the second communication path 86 of the piston 76. The water pipe connection port 79B is shielded by a shielding part 93 sandwiched between the second O-ring 91B and the third O-ring 91C, and water is not supplied. Similarly, in this OFF state, although the communication hole 81C communicating with the gas supply source line connection port 79C of the cylinder 77 is located in the first communication path 85 of the piston 76, the gas supply line connection port is provided by the fourth O-ring 91D. Since 79A and the first communication passage 85 of the piston 76 are blocked, air is not supplied.

  When the piston 76 is pushed down by the pressing operation of the operation cap 40, as shown in FIG. 12, a gap 92 is generated between the inclined surface 78B and the O-ring 91D. By this gap 92, the gas supply source line 35 and the gas supply line 31 communicate with each other via the first communication path 85, and carbon dioxide gas is sent to the gas supply / water supply nozzle 21 (see FIG. 1).

  As shown in FIG. 13, when the piston 76 is further pushed down by the pressing operation of the operation cap 40, the gas supply line connection is made by the shielding portion 93 between the second O-ring 91B and the third O-ring 91C of the piston main body 76A. Since the opening 79C is blocked, the carbon dioxide gas is blocked. Further, the tip of the piston body 76A hits the bottom of the cylinder case 79 and reaches the moving end. At this movement end position, the water supply source pipe connection port 79D and the water supply pipe connection port 79B communicate with each other through the second communication path 86, and water is supplied from the water supply source pipe connection port 79D to the gas supply / water supply nozzle 21.

  In the present embodiment, as shown in FIG. 14, the rolling lengths WR1 to WR3 of the rolling regions RA1 to RA3 of the O-ring storage grooves 87 to 89 are respectively changed, so that the timing when the sliding resistance is generated. The O-rings 91 </ b> A to 91 </ b> C are displaced from each other, and the pressing resistance can be reduced as compared with the conventional case where sliding resistance acts simultaneously. Therefore, smooth pressing can be performed. Further, when returning from the fully-pressed position to the OFF position, the O-rings 91A to 91C are sequentially switched to slide while rolling in the respective rolling regions RA1 to RA3. The sliding resistance does not act all at once and is dispersed, so that a smooth return is possible. Further, since the sliding resistance does not act at the same time, the repulsive force of the coil springs 73 and 74 (see FIG. 11) loses the frictional resistance, so that the piston 76 may not be restored. Can be avoided.

  Next, a third embodiment of the present invention will be described with reference to FIGS. In the third embodiment, the rolling lengths of the second O-ring storage groove 62 and the third O-ring storage groove 63 of the first embodiment shown in FIGS. 2 and 3 are formed longer than the full stroke length of the piston 51. The others are formed in the same manner as in the first embodiment. The second O-ring 65B and the third O-ring 65C in the O-ring housing grooves 62 and 63 move over the connection ports 55A and 55B, respectively. A rolling region RA5 having a rolling length WR5 longer than the stroke of the suction button 29 is provided in each of the O-ring housing grooves 62 and 63 so as to perform this overcoming movement by rolling. 16 and 17, the second O-ring storage groove 62 is described, but the third O-ring storage groove 63 is configured in the same manner as the second O-ring storage groove 62. Accordingly, for example, the second O-ring 65B moves while rolling through the opening 95 of the atmosphere communication pipe connection port 55B, so that the O-ring 65B is cut at the edge of the opening 95, unlike the case where the second O-ring 65B slides and moves as in the prior art. It will not be done. Therefore, the durability of the O-ring 65B can be improved. In addition, during the movement of the piston 51, the O-rings 65B and 65C roll in the entire region during the stroke, and the sliding resistance of the O-rings 65B and 65C decreases by the amount of this rolling, and the piston 51 Can be moved smoothly. In addition, since rolling occurs, it is not necessary to apply the lubricant to the O-rings 65B and 65C, and there is no occurrence of clogging of the pipe line or obstruction of the viewing window due to the lubricant flowing out of the pipe line.

  In the third embodiment, during the stroke of the piston 51, only the O-ring storage grooves 62 and 63 in which the O-rings 65B and 65C that go over the opening 95 of the connection port 55B are stored are longer than the stroke. Although the rolling region RA5 having the length WR5 is provided, the present invention is not limited to this, and the rolling region RA5 having the rolling length WR5 longer than the stroke may be provided in all the O-ring housing grooves 61 to 64. In this case, since all of the O-rings 65A to 65D roll and move, sliding resistance does not occur, the pressing resistance can be reduced, and smooth pressing is possible. In addition, since the pressing is smooth, it is not necessary to apply the lubricant, and there is no problem caused by the lubricant.

  In addition, O-ring storage grooves 61 and 63 having odd-numbered first O-rings 65A and third O-rings 65C of the first embodiment, and O-ring storage grooves 62 having even-numbered second O-rings 65B and fourth O-rings 65D, 64, the O-rings 65A to 65D and the O-ring storage grooves 61 to 64 may be divided into groups, and the O-ring rolling lengths may be different for each group. In this case, since the generation time of the frictional resistance by each O-ring is distributed for each group, smooth operation and avoidance of stag becomes possible. Therefore, it is not necessary to apply the lubricant, and the lubricant is transported from the pipeline, causing clogging, and in the case of an endoscope, the visual field is obstructed by the lubricant remaining in the observation window. There is nothing to do.

  In the above embodiment, gas is supplied by pressing from the OFF position to the half-pressed position, and water is supplied by pressing from the half-pressed position to the fully-pressed position. However, the connection ports for gas supply and water supply may be switched. In this case, it switches to water supply at the half-pressed position, and switches to air supply at the fully-pressed position.

  In each of the above embodiments, the first and second communication passages 85 and 86 are formed from circumferential grooves, but instead of this, they may be formed by communication holes communicating with the inside of the piston. Further, for example, the O-ring housing grooves 87 to 89 having the rolling regions RA1 to RA3 are formed in the piston 76, but this may be formed in the cylinder 77. Moreover, although the two-stage press was demonstrated using the rolling of O-rings 91A-91C, you may implement this invention to a three-stage press and the press beyond it in addition to this. Although the coil springs 73 and 74 are used as the urging members, the urging members may be urged by using an elastic body such as other rubber.

  In the above embodiment, the example in which the present invention is applied to the suction button 29 and the gas / water supply button 33 has been described. However, for the balloon operation in other endoscope channel switching devices, for example, an ultrasonic endoscope. The present invention may be implemented in the air / water button. For example, in a suction button for balloon operation, a total of three pipe lines, a suction pipe line, a balloon drain pipe line, and a suction source pipe line, are connected. Furthermore, in addition to these pipelines, other pipelines may be connected to connect, for example, four or more types of pipelines. In addition, switching of the various pipelines in the first embodiment and the second embodiment is an example, and any switching is possible as long as the pipelines can be switched.

  In addition, the pressing resistance can be reduced with a simple configuration by applying the present invention not only to an endoscope but also to a pipeline switching device using other O-rings. In addition, the switching of pipelines can be performed for switching pipelines other than gas and water. Although an example of manual operation using an operation cap has been described for the operation member, the present invention can also be applied to a pipeline switching device including an operation member using various actuators such as a solenoid and a motor.

DESCRIPTION OF SYMBOLS 10 Endoscope 11 Insertion part 12 Operation part 28 Suction pipe 29 Suction button 31 Gas feed pipe 32 Water feed pipe 33 Gas feed water feed button 35 Gas feed source pipe 37 Water feed source pipe 40, 41 Operation cap 48 Coil spring 50 Cylinder 51 Piston 52 Cylinder cap 55A Suction source line connection port 55B Atmospheric communication line connection port 55C Suction line connection port 58 Communication path 61-64 O-ring storage groove 65A-65D O-ring 72 Cylinder cap 79A Gas supply line connection Port 79B Water supply pipe connection port 79C Gas supply source pipe connection port 79D Water supply source pipe connection port 85 First communication path 86 Second communication path 87-90 O-ring storage groove 91A-91D O-ring

Claims (10)

An operation member;
A piston having an operation member attachment end and a main body to which the operation member is attached, and having a communication path on a peripheral surface of the main body;
A fluid inlet and a fluid outlet that hold the piston movably between a first position that is a movement start end and a second position that is a movement end, and face the communication path in the first position state or the second position state. A cylinder having
A cylinder cap that has a through-hole through which the operation member mounting end passes, is attached to an opening of the cylinder, and prevents the piston main body from dropping off from the cylinder;
A plurality of O-rings for hermetically holding the communication path between the piston and the cylinder;
A plurality of O-ring storage grooves formed on one of the sliding surfaces of the piston or the cylinder and storing the O-ring;
A pipe switching device comprising: a rolling region provided in each of the O-ring housing grooves and having a different O-ring rolling length for rolling the O-ring as the piston moves.   The pipeline switching device according to claim 1, wherein the O-ring rolling length is different for each O-ring storage groove.   The pipe switching device according to claim 1, wherein the plurality of O-ring storage grooves are divided into groups, and the O-ring rolling lengths are different for each group. An operation member;
A piston having an operation member attachment end and a main body to which the operation member is attached;
A fluid inlet and a fluid outlet that hold the piston movably between a first position that is a movement start end and a second position that is a movement end, and face the communication path in the first position state or the second position state. A cylinder having
A cylinder cap that has a through-hole through which the operation member mounting end passes, is attached to an opening of the cylinder, and prevents the piston main body from dropping off from the cylinder;
A plurality of O-rings for hermetically holding the communication path between the piston and the cylinder;
A plurality of O-ring storage grooves formed on one of the sliding surfaces of the piston or the cylinder and storing the O-ring;
A conduit switching device, comprising: a rolling region provided in the O-ring housing groove and rolling the O-ring as the piston moves from a first position to a second position. The operating member is
An operation cap;
An urging member disposed between the operation cap and the cylinder cap and configured to urge the piston toward the first position against a pressing operation of the operation cap. Item 5. The conduit switching device according to any one of Items 1 to 4.   The rolling region of the O-ring receiving groove at a position where the O-ring passes through the fluid inlet or the fluid outlet is an O-ring rolling in which the O-ring rolls over the opening of the fluid inlet or the fluid outlet. 6. The pipeline switching device according to claim 1, wherein the pipeline switching device has a length.   The piston can be positioned at a third position which is an intermediate position between the first position and the second position, and a pipe connection port formed in the cylinder at the third position and a connection formed in the piston. The pipe switching device according to any one of claims 1 to 6, wherein a combination of communication with a passage is changed to switch communication and blocking of a plurality of pipes.   The pipe switching device according to any one of claims 1 to 7, wherein the biasing member is a coil spring.   The pipeline switching device according to any one of claims 1 to 8, wherein the pipeline switching device is provided in an endoscope.   An endoscope having a hand operation unit to which the conduit switching device according to any one of claims 1 to 9 is attached.

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