JPS6241012B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an endoscope equipped with an air supply passage.

Generally, an endoscope is provided with an air supply passageway for supplying air into a body cavity. Further, a liquid feeding passage is provided separately from the air feeding passage, and the liquid feeding passage joins at the distal end of the insertion portion and communicates with the nozzle and the like. A pressure relief hole is provided that branches off from the middle of the air supply passage and opens on the outer surface of the operating section.When air is not supplied, the air sent from the air supply device is passed through this pressure relief hole to the atmosphere. It is configured so that the air escapes into the body cavity and is not sent into the body cavity, and when the above-mentioned pressure relief hole is closed with a finger, all the air from the air supply device is sent to the air supply passage and is not sent into the body cavity. It is composed of By the way, a check valve is provided in the middle of the above-mentioned air supply passageway in order to prevent the backflow of the air delivered into the body cavity and the backflow of liquid into the air supply passageway when the liquid is sent. However, with such check valves, the valve body may become stuck during use, and if the valve body becomes stuck, increasing the air supply pressure a little will not release the sticking, making it impossible to supply air. The situation was ripe. Conventionally, in order to eliminate such problems, a pressing protrusion was provided on the end face of the switching valve body that switches between air supply and liquid supply, and if the check valve becomes stuck, the switching valve body can be removed. The check valve was configured to be able to be pushed all the way down to press the valve body of the check valve with the pressing protrusion to forcibly open the check valve. However, with these types of check valves, the valve body of the check valve is easily damaged, causing problems such as leakage, and the switching valve body must be operated unnecessarily to release the check valve from sticking. First, there were problems such as undesired liquid feeding.

The present invention has been made based on the above circumstances, and its purpose is to provide an endoscope that can reliably prevent backflow in the air supply passage, prevent valves from sticking, and ensure reliable operation. It's about getting.

The present invention will be described below with reference to embodiments shown in the drawings. 1 to 5 show a first embodiment of the present invention, in which 1 is an operating section and 2 is an insertion section.
An air supply passage 3 and a liquid supply passage 4 are formed in the insertion section 2, and the air supply passage 3 and the liquid supply passage 4 meet at the distal end of the insertion section 2, and are opened at the distal end of the insertion section 2. It communicates with the nozzle 5. The air supply passage 2 and the liquid supply passage 3 are connected to an air supply pipe 7 and a liquid supply pipe 8 via a switching valve mechanism 6 provided in the operating section 1, and this air supply pipe 7 is connected to an air supply device (Fig. (not shown) are connected thereto, and liquid feeding devices (not shown) are connected to the liquid feeding pipes 8, respectively. The switching valve mechanism 6 is constructed as follows. That is, 9 is a cylinder and is attached to the operating section 1. A liquid feeding passage 4 and a liquid feeding pipe 8 are opened on the inner circumferential surface of the central portion of the cylinder 9 so as to face each other. Also,
An air supply pipe 7 opens at the inner peripheral surface of the lower end of the cylinder 9, and an air supply passage 3 communicates with the lower end of the cylinder 9. A switching valve body 10 is slidably and airtightly fitted into the cylinder 9, and its upper end protrudes from the upper end of the cylinder 9.
An annular communication groove 11 is formed on the outer periphery of the central portion of the switching valve body 10.
0 is always biased upward by the biasing force of the spring 12. Normally, the communication groove 11 of the switching valve body 10 is located above the openings of the liquid feeding passage 4 and the liquid feeding pipe 8, and the communication between the liquid feeding passage 4 and the liquid feeding pipe 8 is cut off. The lower end portion of the valve body 10 is located above the opening of the air supply pipe 7, and is configured so that the air supply pipe 7 and the air supply passage 3 are communicated with each other. In addition, 13... is an O-ring for maintaining airtightness. Further, a sliding hole 14 is formed in the center of the switching valve body 10 along the axial direction, and a piston 15 is slidably inserted into the sliding hole 14 in an airtight manner. The piston 15 is always biased upward by a spring 16, and the upper end of the piston 15 is configured to protrude from the upper end of the switching valve body 10. In addition, a pressure relief hole 17 is formed in the center of the piston 15 along the axial direction. is configured so that it is released into the atmosphere through this pressure relief hole 17. Note that the spring constant of the spring 16 that biases the piston 15 is set smaller than the spring constant of the spring 12 that biases the switching valve body 10. A backflow prevention valve 18 is provided in the middle of a portion of the air supply passage 3 that communicates with the cylinder 9. 19
The valve box is formed to have a large diameter, and valve ports 20 and 21 are formed on both end faces of the valve box so as to face each other. A valve body 22 is housed within this valve box 19. This valve body 22 is the valve body 19
The diameter is smaller than the inner diameter, and when this valve body 22 is separated from both valve ports 20 and 21, the air supply passage 3
is configured to communicate with the inside of the cylinder 9. As shown in FIG. 5, this valve body 22 is connected to the piston 1 through rod-shaped connecting members 23, 23.
It is mechanically connected to the lower end of 5. and,
In the normal state, the switching valve body 1 as shown in FIG.
0 and the piston 15 are biased upward by the biasing forces of the springs 12 and 16, the valve body 22 moves upward and seats on the upper valve port 20 to close it. It is configured to block communication between the inside of the cylinder 9 and the air supply passage 3. Also,
As shown in FIG.
When the piston 15 is pressed down to close the pressure relief hole 17 and only the piston 15 is pressed down, the valve body 22 is located approximately in the center of the valve box 19 and both valve ports 20, 2 are pressed down.
1, and the inside of the cylinder 9 and the air supply passage 3 are configured to communicate with each other. Further, as shown in FIG. 4, when the piston 15 is further pressed and the switching valve element 10 is also pushed down together with the piston 15, the valve element 22 moves downward and seats on the lower valve opening 21, closing it. , is configured to block communication between the inside of the cylinder 9 and the air supply passage 3.

The first embodiment of the present invention configured as described above is as follows:
Normally, as shown in FIG. 2, the switching valve body 10 and the piston 15 are biased upward, so communication between the liquid feeding pipe 8 and the liquid feeding passage 4 is cut off, and liquid is not fed. Further, the liquid feeding pipe 7 communicates with the inside of the cylinder 9, but since the pressure relief hole 17 is open, the air to be sent escapes from the pressure relief hole 17, and air is not fed into the body cavity. And in this case, the check valve 1
Since the valve body 22 of No. 8 is seated on the upper valve port 20, the communication between the air supply passage 3 and the cylinder 9 is cut off, and of course air is not supplied into the body cavity, and this air supply Backflow in the passage 3 is also prevented.
When air is to be supplied, a finger 24 is placed on the upper end of the piston 15 to push down only the piston 15, as shown in FIG. Therefore, this pressure relief hole 17 is closed and the check valve 18 is closed.
The valve body 22 moves to the center of the valve box 19, and both valve ports 20 and 21 open, so that the air supply passage 3 and the cylinder 9 are
All the air sent from the air supply pipe 7 is sent to the air supply passage 3, and air is sent into the body cavity. In addition, when sending liquid, the piston 15 is further pushed down as shown in FIG.
0 together with this piston 15. Therefore, the opening of the air supply pipe 7 is closed by the switching valve body 10, air is not supplied, and the liquid supply pipe 8 and the liquid supply passage 4 are closed.
communicates with via the communication groove 11 of the switching valve body 10,
Fluid is delivered into the body cavity. In this case, the valve body 22 of the check valve 18 seats on the lower valve port 21 and closes it, thereby preventing the sent liquid etc. from flowing back into the air supply passage 3. and,
Since the valve body 22 of the check valve 18 moves in conjunction with the vertical movement of the piston 15, the valve body 22 of the check valve 18 does not become stuck, and reliable operation can be achieved.

Note that the present invention is not limited to the first embodiment described above.

For example, FIGS. 6 to 8 show the second embodiment of the present invention.
An example is shown. In this second embodiment, the air supply passage 3 is opened at the lower inner circumferential surface of the cylinder 9, and the check valve 1
8 is installed horizontally. The piston 15 is provided with a flexible connecting member 23' having a flexible rod shape.
The flexible connecting member 23' is bent at a substantially right angle along a guide surface 25 formed on the inner bottom surface of the cylinder 15, and connected to the valve body 22 of the check valve 18. The second embodiment operates in the same manner as the first embodiment, as shown in FIGS. 6 to 8. In this second embodiment, the air supply passage 3 and the check valve 18 are connected laterally to the cylinder 9, so that the size is reduced. This second embodiment has the same structure as the first embodiment except for the above points, and in FIGS. 6 to 8, the same reference numerals are given to the parts corresponding to the first embodiment. The explanation will be omitted.

Furthermore, the present invention is not limited to the second embodiment described above.

For example, the piston is not necessarily provided together with the switching valve body, and the piston for switching the air supply may be provided separately from the switching valve body for switching the liquid supply.
In this case, the check valve only needs to have one valve port, and the valve body only needs to be separated from the valve port when the piston is pushed down.

As described above, the present invention provides a piston that can be freely protruded and retracted into the operating section, a pressure relief hole is formed in the piston, a check valve is provided in the air supply passage, and the valve body of the check valve is mechanically attached to the piston. The check valve is configured to open only when the piston is connected and retracted by pushing the piston. Therefore, when you release your finger from this piston, the air that is being sent escapes into the atmosphere through the pressure relief hole and is not sent into the body cavity, and in this case, the valve body of the check valve is The valve closes by sitting on the valve opening, thus preventing backflow in the air supply passage. When air is to be supplied, the pressure release hole is closed with a finger, the piston is sunk, and the valve body of the check valve is separated from its seat, allowing air to be supplied into the body cavity. Therefore, the same backflow prevention effect as in the past can be achieved, and since the valve body of this check valve is operated by being mechanically connected to the piston, there is no possibility of the valve body sticking, and the valve body is reliable. The effects are great, such as the ability to operate.

[Brief explanation of the drawing]

1 to 5 show a first embodiment of the present invention, in which FIG. 1 is an overall schematic diagram, FIGS. 2 to 4 are longitudinal sectional views of main parts showing different operating states, and FIG. The figure is a perspective view showing a part of the main part. Moreover, FIGS. 6 to 8 are longitudinal cross-sectional views of essential parts of the second embodiment, respectively showing different operating states. DESCRIPTION OF SYMBOLS 1... Operation part, 2... Insertion part, 3... Air supply passage, 4... Liquid supply passage, 6... Switching valve mechanism, 9...
Cylinder, 10...Switching valve, 11...Communication groove, 1
5...Piston, 17...Pressure hole, 18...Return prevention valve, 19...Valve box, 20, 21...Valve port, 2
2... Valve body, 23... Connection member, 23'... Flexible connection member, 25... Guide surface.

Claims (1)

[Claims] 1: an air supply passage; a piston that is provided in the operating section so as to be protrusive and retractable; a spring that biases the piston in the protruding direction; a pressure relief hole that opens at the end surface; and a check valve that is provided in the middle of the air supply passage and mechanically interlocks with the piston to close when the piston is in the protruding state and open when the piston is in the retracted state. An endoscope characterized by comprising: