JPH0235566B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a switching operation device for an endoscope.

Generally, some endoscopes are equipped with the above-mentioned switching device for switching between air supply and liquid supply into a body cavity. In this switching operation device, a piston having a valve body is fitted into a cylinder provided in an operation section of an endoscope, and the piston is elastically urged outward from the cylinder. When switching from the air supply state to the liquid supply state, push the piston and
By bringing the above-mentioned valve body into contact with a valve seat provided in the cylinder, the air supply passage is shut off and the liquid supply passage is opened.

By the way, the above-mentioned valve body is usually formed of an elastic body such as rubber. Therefore, when this valve body is brought into contact with the valve seat, a fairly large repulsive force is generated on the valve body, and if the operator loosens the force pressing the piston even slightly due to this repulsive force, the piston will return. Since the air supply path may not be properly blocked and air may be supplied, the operator must constantly push the piston with strong force, which causes fatigue and has the disadvantage of poor operability. Ta. Also, if you apply further force to the piston from the state where the valve body is in contact with the valve seat, the valve body is an elastic body, so it will elastically deform according to the force applied to the piston. There was also a problem with the operational feel of the system, as it was difficult to tell whether the road had been reliably blocked.

This invention was made based on the above circumstances, and its purpose is to prevent large repulsive force from being applied to the piston so that the air passage can be easily blocked, and to prevent the piston from being pushed in sufficiently. Therefore, it is an object of the present invention to provide a switching operation device for an endoscope that allows an operator to feel the operation feeling.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. In the figure, reference numeral 1 denotes an endoscope consisting of an operating section 2 and an insertion section 3. As shown in FIG. The distal end surface 3a of the insertion section 3 is provided with an observation window 4 and an ejection nozzle 5 arranged toward the observation window 4. An image guide 7 is disposed inside the observation window 4 with its front end faces facing each other via a plurality of objective lenses 6. The image can be observed through an eyepiece section 8 provided on the operation section 2.

Furthermore, a supply path 9 is formed within the endoscope 1 . This supply path 9 is composed of an air supply tube 10 and a liquid supply tube 11, the distal ends of which merge inside the insertion section 3 and communicate with the jet nozzle 5. Further, the air supply tube 10 and the liquid supply tube 11 are inserted through a universal cord 12 connected to the operation section 2 via the operation section 2 described above. A connector 13 is provided at the end of this universal cord 12, and by connecting this connector 13 to an air/liquid feeding unit 14, the air feeding tube 10 becomes an air feeding pump 15, and the liquid feeding tube 11 becomes a liquid feeding tank. 16
They are now connected to each other. In addition,
A pressure tube 18 branched from the air supply tube 10 is connected to the upper space of the liquid supply tank 16 in which the cleaning liquid 17 is stored.

On the other hand, the operation section 2 is provided with a switching operation section 19 for switching between air supply and liquid supply. This switching operation section 19 is composed of a cylinder 20 and a piston 21, as shown in FIGS. 2 and 3.
That is, the cylinder 20 has a cylindrical shape with a bottom whose lower end opening is closed by a bottom cover 22, and the upper outer circumferential surface is formed into a mounting portion 24 having a threaded portion 23. The mounting portion 24 is fitted into a mounting hole 26 formed in the wall 25 of the operating portion 2, and the threaded portion 23 protruding from the mounting hole 26 to the outside of the operating portion 2 has an annular mounting member. 27 is screwed on. This mounting member 27 has a lower flange 27a and an upper flange 27b.
7a and a protrusion 2 protruding from the outer peripheral surface of the cylinder 20.
The cylinder 20 is held and fixed to the wall 25 by sandwiching the wall 25 between the cylinders 0a and 0a via an O-ring 20b. The inside of the cylinder 20 is formed with a large-diameter cylindrical portion 28 on the open end side and a small-diameter cylindrical portion 29 on the bottom cover 22 side, and a first cylindrical portion is formed at the boundary between these parts.
A tapered portion 30a and a second tapered portion 30b are formed. Further, an escape groove 31 is formed around the entire circumference of the small diameter cylindrical portion 29 near the bottom cover 22 . And, the upstream side 1 of the air supply tube 10
0a is connected between the large diameter cylindrical portion 28 and the small diameter cylindrical portion 29, and the downstream side 10b is connected to the large diameter cylindrical portion 28. Further, the upstream side 11a of the liquid feeding tube 11 is connected to a position corresponding to the relief groove 31 of the small diameter cylindrical portion 29, and the downstream side 11b is connected to the small diameter cylindrical portion 29.
It is connected to a position above the upstream side 11a of.

The piston 21 is fitted into the cylinder 20 configured in this way. This piston 21
The first shaft part 32 and the second shaft part 33 formed of an electrically insulating material such as synthetic resin are connected, and the outer peripheral surface of these connected parts is made of Teflon, polypropylene, or nylon. A lubricating member 34 made of resin is provided, and the lubricating member 34 guides the piston 21 and seals the cylinder 20. Further, a leak hole 35 is formed in the piston 21 over the entire length of the first shaft portion 32 and a part of the second shaft portion 33, and this leak hole 35 is formed from the cylinder 20 of the first shaft portion 32. Starting at the protruding end. Further, a finger rest member 36 having a mounting groove 36a is provided at the end of the first shaft portion 32. This piston 21 is a biasing member 3 made of an elastic body such as rubber.
7 to project outwardly from the cylinder 20. The biasing member 37 has a substantially skirt-like shape with a constricted part 38 projecting inward in the middle of the peripheral wall, and its lower end is engaged with the mounting member 27, and its upper end is attached to the mounting groove of the finger rest member 36. 36
It is attached to a. Further, a tongue piece 39 protruding into the cylinder 20 is provided on the inner circumferential surface of the lower end of the biasing member 37.
is provided, and the lubricating member 34 comes into contact with this tongue piece 39 to restrict the upward position of the piston 21.
Therefore, when the piston 21 is pushed in from the holding state shown in FIG. 2 as shown in FIG. 3 by placing a finger on the finger rest member 36, the constricted portion 38 is bent inward and elastically deformed. The piston 21 can be pushed into the cylinder 20 against the urging force of the urging member 37.

Further, a first annular groove 40 is formed on the outer circumferential surface of the midway portion of the second shaft portion 33 of the piston 21, and a valve body 41 made of an elastic body is attached to the first annular groove 40. This valve body 41 has a base 4 fitted in the first annular groove 40.
2, and a flexible portion 4 extending obliquely upward from the base portion 42 and having a tip thereof in contact with the inner circumferential surface of the large diameter cylindrical portion 28.
3 and a stepped step 44 as a deformable portion formed at the connecting portion between the flexible portion 43 and the base 42, and when the piston 21 is pushed in as shown in FIG. 44 is in pressure contact with the first tapered portion 30a formed on the inner circumferential surface of the cylinder 20 to fluid-tightly isolate the large diameter cylindrical portion 28 and the small diameter cylindrical portion 29 of the cylinder 20. Also, the second
A tapered wall 45 as an abutting portion is formed protruding from the shaft portion 33 at a lower end side than the first annular groove 40 . After the piston 21 is pushed in and the stepped portion 44 of the valve body 41 comes into pressure contact with the first tapered portion 30a, the tapered wall 45 is rigidly attached to the second tapered portion 30b formed on the inner peripheral surface of the cylinder 20. It is starting to come into contact with the target.

Further, a second annular groove 46 is formed in the downstream portion of the second shaft portion 33, and a sealing member 47 made of an elastic body is attached thereto. This second annular groove 46 includes a pair of side grooves 48, 48 spaced apart in the vertical direction of the second shaft portion 33, and an intermediate groove 49 formed between these side grooves 48, 48, which is shallower than the side grooves 48, 48. It consists of. The sealing member 47 also has a pair of protrusions 50, 5 that fit into the pair of side grooves 48, 48 and come into close contact with the inner peripheral surface of the small diameter cylindrical portion 29 of the cylinder 20.
0 and a thin wall portion 51 corresponding to the intermediate groove 49, and a communication path 52 is formed between the thin wall portion 51 and the inner peripheral surface of the small diameter cylindrical portion 29. This communication path 52 is designed to allow passage of the upstream side 11a and downstream side 11b of the liquid feeding tube 11 when the piston 21 is pushed in as shown in FIG. Further, in the second shaft portion 33 of the piston 21, a communication hole 53 is bored in the radial direction between the first annular groove 40 and the second annular groove 46 and communicates with the leak hole 35. This communication hole 53 is connected to the piston 21
is formed in a size that communicates with the upstream side 10a of the air supply tube 10 both in the outwardly biased state as shown in FIG. 2 and in the pushed state as shown in FIG. There is.

Next, the operation of the above configuration will be explained. First, when the air supply pump 15 is operated without operating the switching operation part 19, the gas sent to the upstream side 10a of the air supply tube 10 enters the leak hole 35 through the communication hole 53. released into the atmosphere. At this time, the above gas is in cylinder 2
However, since this passage is closed by the flexible part 43 of the valve body 41, the flow from the leak hole 35 to the atmosphere is Since the gas is large compared to the road resistance, the gas flows to the downstream side 10b of the air supply tube 10.
It is dissipated into the atmosphere without flowing into the atmosphere. and,
When supplying air into the body cavity, the leak hole 35 is closed by placing a finger on the finger rest member 36 . Then, the gas released from the leak hole 35 flows from the upstream side 10a of the air supply tube 10 to the large diameter cylindrical portion 28 of the cylinder 20 as shown by the arrow in FIG.
1 by elastically deforming the flexible portion 43 of the air supply tube 1.
0 flows into the downstream side 10b. Therefore, the gas from the air pump 15 flows out from the jet nozzle 5 provided on the distal end surface 3a of the insertion section 3.

On the other hand, when feeding liquid, as shown in FIG.
1 against the urging force of the urging member 37. Then, the stepped portion 44 of the valve body 41 comes into contact with the first tapered portion 30a of the cylinder 20 and is elastically deformed, and the upstream side 10a and downstream side 10b of the air supply tube 10 are cut off. When the piston 21 is further pushed in from this blocked state, its tapered wall 45
comes into rigid contact with the second tapered portion 30b, making it impossible to push the piston 21 any further. By blocking the upstream side 10a and the downstream side 10b of the air supply tube 10, the gas discharged from the air supply pump 15 flows into the pressurization tube 18 and pressurizes the liquid supply tank 16. Therefore, cleaning water flows from the liquid feeding tank 16 to the upstream side 11a of the liquid feeding tube 11. Further, by pushing the piston 21 into the state shown in FIG. 3, the upstream side 11a and downstream side 11b of the liquid feeding tube 11 communicate with each other via the communication path 52 formed by the sealing member 47. Therefore, the cleaning water pressurized by the gas pressure of the air pump 15 and flowing to the upstream side 11a of the liquid feeding tube 11 flows to the downstream side 11b through the communication passage 52, and is discharged from the jet nozzle 5. Squirts into body cavity.

By the way, during such a liquid feeding operation, the stepped portion 44 of the valve body 41 that comes into contact with the first tapered portion 30a of the cylinder 20 to shut off the upstream side 10a and the downstream side 10b of the air feeding tube 10 has a step-like shape. Since it is formed on an uneven surface, it is elastically deformed with a relatively light force and comes into close contact with the first tapered portion 30a. Therefore,
Since a very large repulsive force is not generated on the valve body 41, there is no need to keep pressing the piston 21 with strong force to maintain the close contact between the valve body 41 and the first tapered portion 30a, resulting in good operability. . Further, the upstream side 10a and the downstream side 1 of the air supply tube 10 are controlled by the valve body 41.
When the piston 21 is further pushed in after the 0b is cut off, the tapered wall 45 provided on the piston 21 comes into rigid contact with the second tapered portion 30b provided on the cylinder 20, so that this hard contact occurs. This is conveyed to the operator, and the operator can feel that the upstream side 10a and downstream side b of the air supply tube 10 are reliably blocked.

Further, since the piston 21 is made of an electrically insulating material, it is possible to prevent an accidental electric shock to the operator during high frequency treatment.

Note that this invention is not limited to the above embodiment,
The deformed portion formed in the valve body 41 may have a shape shown in FIGS. 4 to 8 in addition to the step-like step 44.
That is, in FIG. 4, a protrusion 61 as the deformed part is formed by a V-shaped notch 60 at the connecting portion between the flexible part 43 and the base part 42, and in FIG. A tongue piece 63 serving as a deformable portion is formed along the axial direction of the piston 21 by the letter-shaped notch 62. Further, in FIG. 6, a tongue piece 65 as a deformable portion is formed in a direction perpendicular to the axial direction of the piston 21 by means of a notch 64 along the radial direction of the base portion 42. As shown in FIG. Furthermore, in FIG. 7, the flexible portion 43 is directly used as a deformable portion, and in this case, the flexible portion 43 is deformed elastically with a light force at the joint portion between the flexible portion 43 and the base portion 42. A notch 65 is formed on the upper surface side of the flexible portion 43, and in FIG. 8, the base portion 42 is brought into contact with the first tapered portion 30 and elastically deformed. A cavity 66 is provided in the base 42 so that the base 42 can easily be elastically deformed.

Although not shown, a projection is provided on the inner circumferential surface of the large-diameter cylindrical portion 28 of the cylinder 20 as a contact portion for rigidly abutting the piston 21.
The lubricating member 34 may be brought into rigid contact with the piston 21 when the piston 21 is pushed in.
The lower end surface of the cylinder 20 may be brought into rigid contact with the bottom cover 22 of the cylinder 20.

As described above, the present invention provides the valve body with a deformable portion that deforms with a relatively light force while maintaining the closed state of the air supply passage, and after the valve body discloses the closed state of the air supply passage. Since the abutting portion against which the piston comes into rigid contact is provided, the operator can easily maintain the closed state of the air supply path, and even if the piston returns slightly, air supply will not be started inadvertently. In addition, the operator can feel that the piston has made rigid contact with the abutment part, that is, that the air supply path is reliably blocked, which not only provides a good operating feel, but also allows the operator to force the piston harder than necessary. There is no need to force it in.

[Brief explanation of drawings]

1 to 3 show an embodiment of the present invention, FIG. 1 is a schematic diagram of the entire endoscope, FIG. 2 is a sectional view of the switching operation section, and FIG. 3 is a diagram showing the switching operation section. Cross-sectional views when operated in liquid state, Figures 4 to 8
The figures are sectional views showing other embodiments of the valve body of the present invention. 2... Operating unit, 20... Cylinder, 21... Piston, 30b... Second tapered part (contact part),
41...Valve body, 44...Step part (deformed part), 45...
...Tapered wall (contact part), 61...Protrusion (deformed part),
63, 65... Tongue piece (deformed part).

Claims (1)

[Claims] 1. An endoscope switching operation device in which a cylinder and a piston having a valve body fitted into the cylinder are provided in the operation part of the endoscope, and the air supply and liquid supply are switched by pushing the piston. A deformable portion is provided on the body that deforms while maintaining the air supply passage closed state with a relatively light force, and the piston is rigidly abutted after the air supply passage starts to be closed by the valve body. A switching operation device for an endoscope, characterized in that a switching operation device for an endoscope is provided with a section.