JPS6349502B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an endoscope with improved means for cleaning the outer surface of the observation window.

Generally, an observation window provided at the tip of an insertion section of an endoscope is often contaminated with dirt and the like when the endoscope is introduced into a body cavity, thereby impeding normal observation. Therefore, a conventional practice has been to provide a spray nozzle near the observation window and to spray cleaning water from the spray nozzle toward the observation window for cleaning.

However, even if the cleaning water is sprayed from the jet nozzle, it cannot be sufficiently sprayed over the entire outer surface, and often ends up in only a partial cleaning. In particular, as there is a trend toward larger observation windows in recent endoscopes in order to widen the field of view, there is a strong desire for a device that can thoroughly clean the outer surface of the observation window over a wide area. This is where it is being held.

One possible method is to increase the amount of cleaning water ejected by enlarging the ejection nozzle.
However, increasing the size of the ejection nozzle is subject to significant restrictions due to the relationship with other members, and is therefore practically impossible.

Therefore, recently, a method has been devised in which air is mixed into the cleaning water and the mixed fluid is sprayed in the form of a spray from a jet nozzle, thereby effectively cleaning a wide area. However, in this method, a mixed fluid is sprayed from a jet nozzle by simultaneously supplying air and water, so a large amount of air is supplied even during cleaning. Therefore, during irrigation, a large amount of air is sent into the body cavity, causing the body cavity to distend excessively, which may lead to an accidental rupture. In particular, cleaning time tends to be long in order to remove stubborn stains, which poses a great risk.

The present invention has been made focusing on the above circumstances,
The purpose of this is to mix gas with the cleaning fluid and spray this mixed fluid onto the observation window for cleaning, but the amount of air supplied during cleaning is relatively small to prevent excessive distension of the body cavity. The purpose of the present invention is to provide an endoscope with improved safety.

Hereinafter, each embodiment of the present invention will be described based on the drawings.

A first embodiment of the invention is shown in FIGS. 1 and 2. In the figure, 1 is an endoscope main body, and this endoscope main body 1 is composed of an operating section 2 and an insertion section 3. An observation window 5 and an ejection nozzle 6 are provided at the distal end of the insertion portion 3, for example, the distal end surface 4. The jet nozzle 6 is installed toward the outer surface of the observation window 5. Note that a hood (not shown) is fitted onto the distal end of the insertion portion 3. Further, an imaging optical system 7 is installed inside the observation window 5 , and the imaging optical system 7 forms an image of the observation field on the distal end surface of the image guide 8 . Then, the observation light image is guided to the eyepiece section 9 of the operation section 2 by the image guide 8,
The inside of the body cavity can be observed through the eyepiece 9.

On the other hand, a supply path 11 is inserted into the endoscope main body 1 to supply cleaning liquid and gas to the jet nozzle 6. This supply path 11 is composed of an air feed path 12 and a liquid feed path 13 each made of a pipe, and the tip portions of the air feed path 12 and liquid feed path 13 merge into one and communicate with the jet nozzle 6. . Furthermore, the proximal ends of the air supply path 12 and the liquid supply path 13 are connected to an air supply pump 14 as a supply source installed in an external air supply unit. That is, the base end of the air supply path 12 is connected to the air supply pump 14 as a supply source, and
A base end of the liquid feeding path 13 is connected to a liquid feeding tank 15 . The liquid supply tank 15 is also connected to the discharge side of the air supply pump 14, and the cleaning liquid is sent to the liquid supply path 13 by the discharge pressure of the air supply pump 14.

In addition, the operation section 2 of the endoscope main body 1 is provided with a supply path 11 consisting of the air supply path 12 and liquid supply path 13, which is switched between supplying only air and supplying a mixed fluid of cleaning liquid and gas to the jet nozzle 6 side. A switching valve 16 is provided to selectively perform the following. In other words, this switching valve 16 constitutes an operating means for switching the supply state. The switching valve 16 is formed by fitting a piston 18 into a bottomed cylindrical cylinder 17, and the upper end of the piston 18 has a small outer diameter.
8a is adapted to protrude to the outside. A first communication groove 2 is formed in an annular shape from the upper end side on the outer periphery of the large diameter portion 19 that slides inside the cylinder 17.
0, the closing circumferential surface 21 and the second communication groove 22 are sequentially formed. In addition, between them and at the ends, there are O-rings 23 for airtightly partitioning them.
...is fitted. Small diameter portion 1 of piston 18
A collar 24 is formed at the outer end of the cylinder 8a, and a return coil spring 25 is inserted between the collar 24 and the upper end of the cylinder 17. The piston 18 is urged by the coil spring 25 in the direction of protruding outward, and the step 26 between the small diameter portion 18a and the large diameter portion 19 is formed on the upper edge 17 of the cylinder 17.
It is designed to wait at a position where it stops when it hits point a. Further, a leak hole 27 communicating with the outside is formed in the piston 18, and this leak hole 27 communicates with the second communication groove 22 through a sufficiently large communication hole 28. Also,
A throttle 29 consisting of a fine hole is formed in the bottom wall of the piston 18, and the leak hole 27 communicates with the bottom space of the cylinder 17 through the throttle 29. However, the inner diameter of this throttle 29 is set smaller than the flow path diameters of the air supply path 12, the second communication groove 22, the leak hole 27, and the communication hole 28. In addition,
As will be described later, this throttle 29 constitutes a suppressing means for suppressing the amount of air sent when the mixed fluid is supplied. Furthermore, in the standby state shown in FIG. 1, the inflow side tip end opening of the liquid feeding path 13 is connected to the side wall of the cylinder 17 so as to face the closing peripheral surface 21, and the outflow side proximal opening of the liquid feeding path 13 is connected to the side wall of the cylinder 17. The third communication groove 30 is connected so as to face the lower end of the first communication groove 20 , and the inlet end opening of the air supply path 12 is connected to communicate with a third communication groove 30 formed in an annular shape on the inner wall surface of the cylinder 17 . The third communication groove 30 is provided so that its lower end faces and communicates with the second communication groove 22. Further, the outflow side base end opening of the air supply path 12 is connected to a position facing the bottom space of the cylinder 17. Then, when the piston 18 is pushed down as shown in FIG.
Further, the second communication groove 22 is still in communication with the lower end of the third communication groove 30. Also,
The base end opening on the outflow side of the air supply path 12 is not closed by the circumferential surface of the piston 18 and is in communication with the bottom of the cylinder 17.

Next, the operation of the endoscope of this embodiment will be explained.

First, in the standby state shown in FIG. 1, the piston 18 of the switching valve 16 is raised by the biasing force of the coil spring 25. In addition, air supply pump 1
4 is to be operated at all times. Therefore, liquid sending tank 1
5 is pressurized by the air supply pump 14, so that the cleaning liquid can be sent out through the liquid supply path 13. However, as described above, the liquid feeding path 13 is blocked by the piston 18, so the liquid is not fed. Moreover, since the air supply path 12 communicates with the leak hole 27 through the third communication groove 30, the second communication groove 22, and the communication hole 28, gas is constantly released to the outside through these. Therefore, the pressure inside the liquid feeding tank 15 does not become very high. At this time, the leak hole 27 also communicates with the bottom space of the cylinder 17 and the air supply path 12 on the outflow side through the throttle 29, but since the fluid resistance on this side is significantly larger than that on the atmosphere side, air is not supplied. Note that since the throttle 29 is provided, its fluid resistance is greater, and its effect is greater. In other words, neither air nor liquid is fed in this standby state.

Further, when only air is to be supplied to inflate the inside of the body cavity, the outer end opening of the leak hole 27 is closed with a finger without pushing in the piston 18. As a result, gas is sent into the air supply path 12 on the tip side through the throttle 29 or directly from the third communication groove 30 through the bottom space of the cylinder 17 . Note that liquid feeding is not performed as in the case described above. Air can thus be supplied to the jet nozzle 6.

In addition, when cleaning the observation window 5, the leak hole 2
Push in the piston 18 while blocking 7 with your finger,
The state shown in FIG. 2 is established. However, the liquid feeding path 13
are communicated through the first communication groove 20, and liquid is transferred. At the same time, the air supply path 12 communicates with the third communication groove 30, the second communication groove 22, the communication hole 28, the leak hole 27, the throttle 29, and the bottom space of the cylinder 17, so air is also supplied. It will be done. Thus, liquid and air are simultaneously fed through the air supply path 12 and the liquid supply path 13, and the ejection nozzle 6
Immediately before the cleaning, the cleaning liquid and the gas are mixed. This mixed fluid is then sprayed from the jet nozzle 6 in the form of a spray to clean the outer surface of the observation window 5. Since the gas is mixed with the cleaning liquid and sprayed in this manner, even the observation window 5, which has a wide blowout, can be sufficiently cleaned in its entirety. Also, since the gas is mixed, water drains easily after washing. Therefore, the subsequent air supply only needs to be carried out in a short time. Furthermore, even if dirt is stuck inside the hood, the dirt can be removed from a wide range inside the hood.

Furthermore, since there is a throttle 29 in the middle of the air supply path 12 during this cleaning, the amount of air supplied at that time is suppressed. In other words, the amount of air supplied is significantly reduced compared to when only normal air is supplied. Therefore, the proportion of gas mixed into the cleaning liquid is also greatly reduced. However, as will be described later, the cleaning power itself does not decrease much. Therefore, the reason for this will be explained in comparison with a case in which it is assumed that the amount of air supplied during cleaning is the same as when only air is supplied in this embodiment. first,
In this hypothetical case, due to the relationship between the discharge pressure or flow rate characteristics of the air supply pump 14 and the flow resistance of the supply path 11, the discharge pressure of the air supply pump 14 during cleaning is 0.25 kg/
Suppose it is ^cm2 . At this time, the feeding pressure and liquid feeding pressure are both 0.25 Kg/cm ² . Further, at this time, for example, the air supply rate is set to 2.1/min and the liquid supply rate is set to 42 ml/min. In other words, spraying is performed with 2.1 ml of air mixed with 42 ml of cleaning liquid. On the other hand, in this embodiment, since the air passage 12 is restricted in the middle by the throttle 29, the fluid resistance of the air passage 12 becomes large, and the discharge pressure of the air supply pump 14 is, for example, 0.4.
Kg/ ^cm2 . Therefore, the air flow rate decreases to 0.6/min, and the liquid flow rate increases to 61 ml/min. In other words, during cleaning, by narrowing the air supply path 12, the amount of air supplied decreases, but on the contrary, the amount of liquid supplied increases, so the cleaning power does not decrease much.

In this embodiment, excessive air supply is suppressed during cleaning and the necessary minimum amount of air is supplied.
The risk of excessive distension of the body cavity can be prevented.

Further, in the above embodiment, air is supplied through the air supply path 12 even during cleaning, so that the cleaning liquid does not flow back into the air supply path 12.

A second embodiment of the invention is shown in FIGS. 3 and 4. This embodiment differs from the first embodiment in the structure of the diaphragm 31. That is, the leak hole 27 of the piston 18 is vertically penetrated, and an end portion 32 slightly smaller than the large diameter of the large diameter portion 19 is formed extending from the inner end of the piston 18. When pushed in, it is positioned opposite to the inflow opening end of the air supply path 12.
That is, a gap 33 is formed facing the inflow opening end. This gap 33 functions as a suppressing means for suppressing the amount of air supplied during cleaning, similar to the function of the throttle 29 in the above embodiment.

In the standby state shown in FIG. 3, the liquid supply path 13 is blocked as in the embodiment described above, and the leak hole 27 communicating with the air supply path 12 is open, so that the air supply pump 14 side Even if air is supplied from the inside, it is discharged to the outside from the leak hole 27. Therefore, air is not supplied to the distal end, and
No liquid is sent. Further, air can only be supplied by closing the opening of the leak hole 27 with a finger without pushing the piston 18. When cleaning, the piston 18 is pushed in while blocking the opening of the leak hole 27 with a finger. As a result, as shown in FIG. 4, the liquid feeding path 13 is opened through the first communication groove 20, and liquid is fed. In addition, the air supply path 12
The inflow opening end of the cylinder 17 communicates with the bottom space of the cylinder 17 via a throttle 31 formed by a gap 33, so that air is supplied through this. However, since air supply is significantly suppressed in the gap 33, the amount of air supplied to the distal end side can be significantly reduced. Therefore, the same effects as those of the above embodiment are achieved.

A third embodiment of the invention is shown in FIGS. 5 and 6. In this embodiment, the air supply switching section and the liquid supply switching section are interchanged vertically, and a conical seat valve 41 is used in the liquid supply switching section. That is, the liquid feeding valve seat 4 is attached to the lower side wall of the cylinder 17.
2, and a liquid feeding valve body 43 that engages with the liquid feeding valve seat 42 is provided at the lower part of the piston 18, and as shown in FIG. The liquid feeding valve body 43 is brought into close contact with 42 to block the liquid feeding path 13. Also, piston 1
8 is pushed in during cleaning, the liquid feeding valve element 43 separates from the liquid feeding valve seat 42, opening the liquid feeding path 13, as shown in FIG. The air supply path 12 is always connected to a communication groove 44 formed in an annular shape on the outer periphery of the piston 18, and a conical seat valve 45 is provided between the inflow side opening end and the outflow side opening end. It is configured. That is, an air supply valve seat 46 is formed on the cylinder 17 side, and an air supply valve body 47 is formed on the piston 18 side, which are opened in the standby state shown in FIG. 5, and are opened in the standby state shown in FIG. When pushed in (during cleaning), the lower end of the piston 18 hits the bottom surface of the cylinder 17, so that they face each other with a slight gap (throttle) left. During cleaning, air is also fed at the same time as liquid feeding as shown in FIG. 6, but since the amount of air fed is suppressed by the conical seat valve 45, it functions in the same manner as in the previous embodiment.

A fourth embodiment of the invention is shown in FIG.
This is the conical seat valve 4 for air supply in the third embodiment.
The air supply valve seat 46 of No. 5 and the air supply valve body 47 are made to interfere with each other, and a ventilation groove 48 is provided on the surface of the air supply valve body 47 to perform a throttling action. This is what I did. Note that this ventilation groove 48 may be provided on the side of the air supply valve seat 46, or may be configured to have a rough surface to provide ventilation.

A fifth embodiment of the invention is shown in FIGS. 8 and 9. In this embodiment, a communication groove 49 and a closing circumferential surface 50 are formed on the circumferential surface of the large diameter portion 19 of the piston 18 fitted into the cylinder 17, and the inflow opening of the liquid feeding path 13 is opened in the standby state shown in FIG. The ends of the air passage 12 are connected to each other so as to face the closing surface 50, and the inflow opening end and the outflow opening end of the air supply passage 12 are connected to the cylinder 1.
It is connected so as to face the bottom space of 7. Furthermore, a bypass passage 51 is provided on the outflow side of the air supply passage 12 and connected to a position facing the bottommost space of the cylinder 17 . A variable throttle valve 52 that can be adjusted from the outside is inserted in the middle of this bypass path 51. In the standby state shown in FIG. 8, the liquid supply path 13 is blocked by the closing peripheral surface 50 of the piston 18, and the air supply path 12 communicates through the bottom space of the cylinder 17, but at the same time there is no leakage hole. 2
7, the air is discharged to the outside through this leak hole 27 and no air is supplied. During cleaning when the leak hole 27 is closed and the piston 18 is pushed in, the liquid feeding path 13 is connected to the communication groove 4 as shown in FIG.
9 for liquid delivery. In addition, the air supply path 12
communicates with the bottom space of the cylinder 17 only through the bypass passage 51. Therefore, air is supplied through the variable throttle valve 52, and the amount of air supplied is significantly reduced compared to the case where only normal air is supplied. In other words, the amount of air supplied during cleaning can be suppressed. Furthermore, since the variable throttle 52 is used in this embodiment, the amount of air supplied can be freely adjusted. In addition, in the above embodiment, it is necessary to replace the piston etc. to change the air supply amount.
It was inconvenient to adjust the amount by which the piston was pushed in with one's fingers, but in this embodiment, the desired amount of air to be blown can be easily and accurately obtained.

Further, in this fifth embodiment, an air pump 54 for a water supply source is provided independently in addition to an air supply pump 53 for an air supply source. Therefore, the amount of liquid fed is constant regardless of the amount of air fed during cleaning. In general, the larger the amount of air supplied, the stronger the cleaning power. Therefore, normally, the variable throttle 52 is closed and the air supply amount is reduced. Especially when there is stubborn dirt, such as highly viscous fibrous dirt stubbornly adhering to the inside of the hood, the variable throttle 52 is closed. It can be used to increase the cleaning power by opening it slightly, and cleaning while being careful not to blow too much air. At this time, if an air pump is used for both air supply and liquid supply, even if an attempt is made to increase the amount of air supplied by opening the variable throttle valve 52, the amount of liquid supplied will decrease, and the cleaning power will not become stronger after all. Therefore, in this embodiment, each air pump 53,
54 is made independent.

A sixth embodiment of the present invention is shown in FIGS. 10 and 11.
Shown in the figure. In this embodiment, a tapered valve seat 62 is formed at the bottom of the cylinder 61, and a piston 63 is formed.
A valve body 64 made of an elastic member that presses against the valve seat 62 is provided at the lower end of the valve body 62, and the amount of air supplied to the air supply path 12 is suppressed by this valve body 64.
That is, in the standby state shown in FIG.
Since the valve body 64 does not strongly hit the leak hole, if the leak hole is closed, sufficient air can be supplied without being inhibited by the valve body 64. Further, during cleaning, the piston 63 is pushed down while closing the leak hole 27 with a finger, as shown in FIG. 11, so the valve body 64 strongly hits the valve seat 62, and the amount of air supplied is greatly suppressed.

A seventh embodiment of the invention is shown in FIG. This embodiment includes an air supply path 12 and a liquid supply path 1 on the tip side.
3 is provided within the operation section 2 or in the middle of the insertion section 3 on the relatively proximal side. If you do this,
During cleaning, after the cleaning liquid and gas join together, the fluid resistance when the mixed fluid flows is greater than when it is only gas, and the amount of air supplied can be suppressed accordingly. Therefore, the longer the pipe through which the mixed fluid flows after merging, the greater the effect will be. Moreover, in this embodiment, the configuration of the air supply amount suppressing means is simplified.

An eighth embodiment of the invention is shown in FIG. In this embodiment, an air supply passage 12 and a liquid supply passage 13 are inserted into the endoscope body 1 in the same manner as in the first embodiment. The base end side of the air supply path 12 is connected to the second port of a switching valve 71 consisting of a spring return type three-port two-position solenoid valve. An air supply pump 70 is connected to a first port of the switching valve 71. Furthermore, the base end of a conduit 72 that branches into two is connected to the third port of the switching valve 71, and one of the branched conduits 72 is connected to the above-mentioned one through a throttle valve 73 and a check valve 74 in series. It is connected to the air supply path 12. Further, the other branched end of the pipe line 72 is connected to a liquid supply tank 75. Note that the check valve 74 is designed to allow only flow from the throttle valve 73 side to pass therethrough. On the other hand, the base end of the liquid feeding path 13 is connected to the water in the liquid feeding tank 75. Further, the operating section 2 is provided with an air supply switch 76 and a cleaning switch 77, which are of a pressure-sensitive conductive rubber type, for example. The air supply switch 76 is connected to the air supply pump 70, and the air supply switch 76 is connected to the air supply pump 70.
When 6 is pressed, the air pump 70 is operated. Further, the cleaning switch 77 is connected to the switching valve 71 and the air supply pump 70, and when the cleaning switch 77 is pressed, the air supply pump 70 is operated and the switching valve 71 is switched. In other words, during normal times, the switching valve 71 only communicates between the first port and the second port, but when the cleaning switch 77 is pressed, the signal causes communication between the first port and the second port.
Only the third port is communicated with the third port. Then, when the signal from the cleaning switch 77 stops,
It's starting to get back to normal.

When the air supply switch 76 is pressed, the air supply pump 70 is operated and air is supplied to the air supply path 12 from the first port of the switching valve 71 to the second port. At this time, a relatively large amount of air is blown. Further, the liquid does not flow into the pipe line 72 side, and therefore no liquid is sent. Next, when cleaning is to be performed, the cleaning switch 77 is pressed and the air supply pump 70 is operated. At the same time, the first port and the third port of the switching valve 71 communicate with each other, and air is supplied to the pipe line 72 side. That is, the liquid supply tank 75
While pressurizing the inside and sending liquid to the liquid sending path 13, air is also sent to the air feeding path 12 through the throttle valve 73 and the check valve 74. However, the amount of air supplied is suppressed by passing through the throttle valve 73, and is significantly reduced compared to when the air is supplied. Therefore, less gas can be mixed into the cleaning liquid. Furthermore, when the cleaning switch 77 is released, the operation of the air pump 70 is stopped and the switching valve 71 is returned to its original state by the spring.

A ninth embodiment of the present invention is shown in FIG. In this embodiment, an air supply pump 81 dedicated to air supply is provided in an air supply unit 80, and an air supply pump 83 dedicated to liquid supply is separately provided to supply pressurized air to a liquid supply tank 82. The outputs of the air pumps 81 and 83 are individually controlled by an output control device 84. Furthermore, the operation section 2 of the endoscope body 1 is provided with an air supply switch 85 and a cleaning switch 86.
The air supply unit 80 is provided with a switch 87 for powerful cleaning. Each of these switches 85, 86, and 87 is connected to an output control device 84 and controlled and operated as described later.

That is, when performing normal air supply, the air supply switch 85 is pressed. While this is pressed, the control device 8
During this time, the control device 84 operates the air pump 81 exclusively for air feeding at a relatively high output. Therefore, a large amount of air can be supplied through the air supply path 12. Further, when performing normal cleaning, the cleaning switch 86 is pressed. While this button is pressed, the control device 84 controls the air supply pump 81 exclusively for air supply.
is driven at a relatively low output, and at the same time, an air pump 83 dedicated to liquid feeding is driven. Therefore, a relatively weak air supply is performed simultaneously with the liquid supply, so that cleaning can be performed while mixing the gas with the cleaning liquid.
It is clear that the amount of air supplied at this time is smaller than that in the case of normal air supply. If the dirt on the observation window 5 does not come off even after this cleaning, after confirming that there is no risk of excessive air supply, press the powerful cleaning switch 87 and use the air supply pump 83 exclusively for liquid supply. The air pump 81 dedicated to air is operated at high output for a short period of time. This short time (for example 1
The cleaning power is extremely strong because it blows out a large amount of air (seconds). Since this powerful cleaning switch 87 is provided on the air supply unit 80 side, there is no risk of excessive air supply due to accidentally operating it during an endoscopy.

Note that the output of the air pumps 81 and 83 can be adjusted by changing the voltage or frequency. Further, the strong cleaning switch 87 may be provided in a remote controller connected to the air supply unit 80, or may be a foot switch.
Furthermore, it may be provided in the operation section.

A tenth embodiment of the present invention is shown in FIG. In this embodiment, an air pump 91 exclusively used for air supply and an air pump 93 exclusively used for liquid supply for supplying pressurized air to a liquid supply tank 92 are provided in an air supply unit 80. An exhaust pipe 9 is branched in the middle of the
4 are connected. Furthermore, the exhaust pipe 9
4 is connected to a relief valve 95, and a relief port of this relief valve 95 is connected to an on-off valve 96 consisting of a normally closed spring return type 2-port 2-position solenoid valve. On the other hand, the operating section 2 of the endoscope body 1 is provided with an air supply switch 97 and a cleaning switch 98, and the air supply switch 97 is connected to an air supply pump 91 dedicated to air supply. Further, the cleaning switch 98 is connected to each of the air pumps 91 and 93 and the on-off valve 96.

Then, by operating the air supply switch 97, normal air supply can be performed. In other words, the air pump 91 dedicated to air supply is driven to supply air to the air passage 12 . Note that at this time, since the on-off valve 96 is closed, the water will not be discharged through the discharge pipe 94.

Further, by operating the cleaning switch 98, a cleaning operation can be performed. That is, each air pump 91, 93 starts operating, and at the same time, the on-off valve 96 opens. In addition, the relief valve 9
The relief pressure No. 5 is set to, for example, 0.1 Kg/cm ² when the discharge pressure on the air supply pump 91 side (this changes depending on the combination with the air supply path 12) is 0.25 Kg/cm ^{2 .} . As a result, the relief valve 95 works and some of the gas is released from the on-off valve 96 to the outside, and the pressure inside the air passage 12 becomes only 0.1 kg/cm ² , which is the set pressure of the relief valve 95. Decrease the amount. Therefore, the proportion of gas mixed into the cleaning liquid can be reduced. Note that since a dedicated air pump 93 is used for liquid feeding, the liquid feeding pressure can be kept constant to ensure cleaning power.

As explained above, the present invention mixes gas into the cleaning fluid and cleanses with this mixed fluid, and since the amount of air sent is suppressed when the mixed fluid is supplied, the body cavity is not excessively cleaned during the cleaning. The danger of expansion can be prevented as much as possible and safety can be improved.

[Brief explanation of the drawing]

1 and 2 are schematic side sectional views of an endoscope in different states according to a first embodiment of the present invention, and FIGS. 3 and 4 are respectively schematic side sectional views of an endoscope according to a second embodiment of the present invention. FIGS. 5 and 6 are side sectional views of the switching valve showing different states in the third embodiment of the present invention, and FIG. 7 is a side sectional view of the switching valve showing different states in the third embodiment of the present invention. FIGS. 8 and 9 are schematic side sectional views of a fifth embodiment of the present invention, and FIGS. 10 and 11 are schematic side sectional views of a fifth embodiment of the present invention, respectively. 12 is a schematic side sectional view showing an endoscope according to the seventh embodiment of the present invention, and FIG. 13 is a schematic side sectional view showing the endoscope according to the seventh embodiment of the present invention.
Schematic configuration diagram showing the endoscope according to the embodiment, No. 14
FIG. 15 is a schematic diagram of an endoscope according to a ninth embodiment of the present invention, and FIG. 15 is a schematic diagram of an endoscope according to a tenth embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Endoscope main body, 5... Observation window, 6... Ejection nozzle, 11... Supply path, 12... Air supply path, 13
...Liquid feed path, 16...Switching valve, 29...Aperture,
31... Throttle, 45... Conical seat valve, 48... Ventilation groove, 52... Variable throttle valve, 53.54... Air supply pump, 62... Valve seat, 64... Valve body, 73...
Throttle valve, 84...Control device, 95...Relief valve, 96...Opening/closing valve.

Claims (1)

[Scope of Claims] 1. A jet nozzle is provided at the tip of the insertion section toward the observation window, and the jet nozzle is provided with a supply path to select between supplying only gas or supplying a mixed fluid of cleaning liquid and gas from the supply source. What is claimed is: 1. An endoscope equipped with an operating means for controlling the air flow, characterized in that an endoscope is provided with a suppressing means for suppressing the amount of air supplied when the mixed fluid is supplied, compared to when only gas is supplied. 2. An endoscope according to claim 1, characterized in that the suppressing means is a valve that adjusts the flow rate provided in the air supply path of the supply path composed of the air supply path and the liquid feed path. . 3. The endoscope according to claim 1, wherein the suppressing means controls the output of the gas supply source to suppress the amount of air supplied. 4. An endoscope according to claim 1, characterized in that the suppressing means is a valve that adjusts the pressure provided in the air supply path of the supply path composed of the air feed path and the liquid feed path. . 5. The endoscope according to claim 1, characterized in that the supply source is separated into a gas supply source and a cleaning liquid supply source.