JPS6243526Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement in an air/water supply switching valve for an endoscope that selectively supplies cleaning water and gas to a nozzle provided toward an observation window.

Generally, when observing the inside of a body cavity with an endoscope, gas is sent through a nozzle provided at the tip of the insertion section in order to inflate the body cavity to some extent. In addition, since the observation window of an endoscope is easily contaminated by mucus and dirt in the body cavity, it has become possible to clean the observation window by successively spraying cleaning water and gas through the nozzle provided toward the observation window. There is. By the way, in the past, for example,
As known in Japanese Patent No. 34638, there is a system in which air and water are supplied to the nozzle through one tube from an air and water supply switching valve provided in the operation section, and a system in which air and water are supplied to the nozzle through one tube as shown in Fig. 1. There is a method in which air and water are individually delivered using However, 1
In a system in which a book tube is used for both air and water supply, even if air is supplied after water is supplied, the system does not switch to the air supply state until the water in the long tube is released. In other words, there is a fairly long time lag between when the air supply operation is performed and when the air supply state is achieved, which makes it difficult for the operator to perform the test because the operator's performance deteriorates, and the test is often interrupted, causing unnecessary pain to the patient during this time. There are drawbacks to giving. On the other hand, in the system shown in FIG. 1, air and water are fed through separate tubes 1 and 2, so the above-mentioned problems do not occur.

However, since all of the above air/water switching valves have a structure in which a piston with a leak hole is inserted into a cylinder, two tubes 1 and 2 are used compared to a system that uses one tube. This method requires one extra packing 3, 4, 5 such as an O-ring. Therefore, the sliding resistance increases accordingly, and an operating force is required. By the way, in the method of Publication No. 48-34638, packing is 2.
Since the pushing force of the piston is 2
Individual sliding resistance and piston return spring resistance α,
In other words, it would have been sufficient to use the force equivalent to four packings, but since there are three packings in the method shown in Figure 1, the pushing force of the piston is due to the sliding resistance of three packings and the piston return spring. A drag force α', that is, equivalent to six packings is required. In this way, even if the number of packings increases by one, the amount of operating force increases significantly, resulting in the operator's fatigue and the inability to perform smooth operations.

The present invention was developed in view of the above circumstances, and its purpose is to reduce the amount of operating skill required.
To provide an air/water supply switching valve for an endoscope with good operability for switching air/water supply.

Hereinafter, one embodiment of the present invention will be described based on FIG. 2.

11 in FIG. 2 is an endoscope, and this endoscope 11
is composed of an operating section 12 and an insertion section 13.
An observation window 14 is provided on the distal end surface 13a of the insertion section 13, and the distal end of an image guide 16 is placed facing inside the observation window 14 via an objective lens 15. The image guide 16 is guided through the insertion section 13 and the operating section 12 to a contact section 17 in the operating section 12 . A water supply nozzle 18 and an air supply nozzle 19 are independently provided on the distal end surface 13a of the insertion portion 13, and each nozzle 18, 19
are both provided facing the observation window 14. Further, a water supply tube 20 and an air supply tube 21 are inserted into the endoscope 11, and the water supply tube 20 is connected to the water supply nozzle 18, and the air supply tube 21 is connected to the air supply nozzle 19. There is.
On the other hand, the operation unit 12 includes an air/water supply switching valve 2 inserted between the water supply tube 20 and the air supply tube 21.
2 is provided.

That is, this air/water supply switching valve 22 is connected to a cylinder 23 provided in the operating section 12 and this cylinder 2.
The outer end of the piston 24 projects outside the cylinder 23, and an operating outer end 25 is formed at the outer end. Further, a communication passage 26 consisting of an annular groove is formed on the circumferential surface of the sliding portion of the piston 24. A pair of packings 27 made of O-rings are provided on the circumferential surface of the sliding part located at both ends of this communication path 25.
28 is fitted, and this packing 27,
28 is in sliding contact with the inner surface of the cylinder 23 to airtightly isolate the communication path 26. Furthermore, the outer end 29 of the piston 24 is formed to have a smaller diameter than other parts, and a biasing member 30 made of a coil spring is wound around this. This biasing member 30 is interposed between a locking edge 31 formed at the outer open end of the cylinder 23 and the operating outer end 25, and is configured to bias the piston 24 outward. Therefore, the piston 24 is normally kept in a standby state with its operating outer end 25 projecting outward, as shown in FIG. In addition, the piston 24
is positioned against the locking edge 31 of the cylinder 23.

In addition, the outer end 29 of the piston 24 and the cylinder 2
A ventilation path 32 is formed between the gaps 3 and 3. This ventilation passage 32 has an air supply tube 21
The inflow side tip of is connected. A valve body 33 made of annular packing is provided on the inner end surface of the outer operating end portion 25, and faces a valve seat 34 made of the outer end surface of the cylinder 23. and,
When the piston 24 is pushed in, the valve body 33 touches the valve seat 3.
4 and closes the air passage 32. On the other hand, as shown in FIG. 2, the base end of the air supply tube 21 on the outflow side is located outside the valve body 33 and the valve seat 34, and is opened and connected to the outer end surface of the cylinder 23. Therefore, when the valve body 33 comes into contact with the valve seat 34 by pushing the piston 24,
Thereby, the inflow side and the outflow side of the air supply tube 21 can be shut off. Note that the outer end surface of the cylinder 23 and the vicinity of the outer end of the piston 24 are covered with a thin film 35. This thin film 35 is the piston 2
It is airtightly attached to the operating outer end 25 of the cylinder 23 by adhesive or the like, and is also airtightly attached to the outer end circumferential wall of the cylinder 23 via a seal ring 36.

Furthermore, a leak hole 37 that can be closed with a finger is provided at the outer operating end 25 of the piston 24. This leak hole 37 is always communicated with the inflow side of the air supply tube 21 via the ventilation path 32.

On the other hand, the inflow side of the water supply tube 20 is a cylinder 23
The outflow side of the water supply tube 20 is connected to the side wall of the cylinder 23 facing the circumferential surface of the sliding portion of the piston 24 in the standby state. When the piston 24 is pushed in, the communication passage 26 is located between the inflow side and the outflow side of the water supply tube 20 so that they communicate with each other.
Furthermore, when the piston 24 is in the standby state, the inlet and outlet sides of the water supply tube 20 are packed with packing 27.
blocked by.

Note that the base end side of the water supply tube 20 is connected to a water supply tank 38 , and the base end side of the air supply tube 21 is connected to an air supply pump 39 . Further, the water supply tank 38 is connected to the air supply pump 39, and receives the discharge pressure from the water supply tank 38 to pressurize the cleaning water to the air supply tube 2.
It is set to be sent to 1.

Next, the operation of the above embodiment will be explained. First, the second
In the standby state shown in the figure, air and water are not supplied.
Air is supplied from the air supply pump 39 side through the air supply tube 21
However, since it is discharged to the outside through the ventilation path 32 and the leak hole 37,
It does not flow to the outflow side where the flow path resistance is higher than this. Since the water supply tube 20 is blocked by the piston 24, no water is supplied.

Therefore, when air is to be supplied, the leak hole 37 is closed by placing a finger on the operating outer end 25 of the piston 24. As a result, the air cannot be discharged to the outside, so it flows to the outflow side of the air supply tube 21, and the air flows through the air supply nozzle 19.
and ejects into the body cavity.

Furthermore, when water is to be fed, the piston 24 is pushed in by placing a finger on the operating outer end 25 of the piston 24 and keeping the leak hole 37 closed. The valve body 33 then descends and presses against the valve seat 34 to close the air passage 32. As a result, the inflow side and the outflow side of the air supply tube 21 are cut off, and the water supply tube 20 is opened through the communication path 26. Therefore, the wash water in the water supply tank 38 pressurized by the discharge pressure of the air supply pump 39 can be supplied to the water supply nozzle 18 through the water supply tube 20 . Note that when the pressure on the piston 24 is released, the piston 24 automatically returns to its original standby position due to the urging force of the urging member 30. In this way, air and water can be selectively fed. Therefore, normal air supply and water supply and air supply for cleaning the observation window 14 can be selected and carried out as desired.

FIG. 3 shows an air/water supply switching valve 40 as another embodiment of the present invention. In the air/water supply switching valve 40 of this embodiment, the piston 41 itself is formed of an elastic material, and the valve body 42 and biasing member 43 are also formed integrally. That is, packing portions 44 and 45 are integrally formed on the circumferential surface of the sliding portion of the piston 41, and a communication path 46 is formed between the pair of packing portions 44 and 45. Further, a valve body 42 having a tapered circumferential surface is formed on the outer end side of the piston 41, and a tapered valve seat 48 is formed in the cylinder 47 correspondingly.
The air supply tube 2 is formed at the inner end of this valve seat 48.
1 and the outflow side of the air supply tube 21 is connected to the outer end of the valve seat 48. Furthermore, a cylindrical biasing member 43 is formed at the outer end of the piston 41, thereby biasing the piston 41 outward. The outer end of the biasing member 43 is airtightly fitted into a fitting ring 49 on the cylinder 47 side. Therefore, in this embodiment as well, the switching operation can be performed in the same manner as in the above embodiment. In addition, in this embodiment, necessary parts are formed integrally with the piston, so it can be manufactured at low cost, and the cleaning operation is easy and sanitary.

In each of the embodiments described above, the air supply tube and the water supply tube are constructed to be completely independent, but the present invention is not limited to this, and may be constructed so that they join near the nozzle at the tip.

As explained above, the present invention is configured to switch the air and water supply operation without sliding the valve body on the air tube side into the cylinder, so the number of packings that slide on the cylinder is reduced, and the piston can be moved easily.
Therefore, the biasing force of the biasing member for return may be small, and the force for pushing the piston can be reduced. In other words, the piston is easy to operate, and operability can be improved.

[Brief explanation of the drawing]

Figure 1 is a side sectional view of an air/water supply switching valve as an example of the conventional one, Figure 2 is a side sectional view showing the main parts of an embodiment of the present invention, and Figure 3 is a side sectional view showing another embodiment of the present invention. FIG. 3 is a side sectional view of the air/water supply switching valve shown in FIG. 11... Endoscope, 12... Operation unit, 14... Observation window,
18... Water supply nozzle, 19... Air supply nozzle, 22
...Air/water supply switching valve, 23...Cylinder, 24...Piston, 25...Operation outer end, 26...Communication path, 27
... packing, 28... packing, 30... biasing member, 33... valve body, 34... valve seat, 37... leak hole,
40...Air/water supply switching valve, 41...Piston, 42
...valve body, 43...biasing member, 44...packing part,
45...Packing part, 46...Communication path, 47...Cylinder, 48...Valve seat.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A cylinder provided in the operating section of the endoscope, and a cylinder fitted into the cylinder to form a communication path on the sliding surface, and the above-mentioned slide for partitioning the communication path. A piston provided with packing on its moving circumferential surface, an urging member that urges the piston outward and holds the operating outer end of the piston in a protruding state, and is connected to the cylinder and pushes the piston. a water supply tube that opens through the communication passage, a leak hole that opens at the outer operating end of the piston and can be closed with a finger, and a leak hole that is provided on the piston and is connected to the cylinder side when the piston is in a standby state. The piston is separated from the formed valve seat to communicate the inflow side of the air supply tube with its outflow side and the leak hole, and when the piston is pushed in, it contacts the valve seat and blocks the inflow side and the outflow side of the air supply tube. An air/water supply switching valve for an endoscope, characterized by comprising a valve body. (2) The air supply/water supply switching valve for an endoscope according to claim 1 of the utility model registration claim, characterized in that the piston and the biasing member are integrally formed of an elastic material. Water supply switching valve.