JP2002172086A - Air/water supply valve structure for endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air/water supply valve structure for endoscope, which is improved in operating feeling of the air/water supply valve equipped on the at-hand operating part of an endoscope and is prevented from early abrasion of the seal part of a check valve equipped on the air/water supply valve to extend life thereof. SOLUTION: A check valve 70 is equipped on a recess part 52 formed on a piston 50 of this air/water supply valve. The seal part 73 of the check valve 70 is made in contact with the inner periphery face 74 of the recess part 52 to prevent the back flow of liquid from an air sending pipe to an air supply pipe 24. That is, since the seal part of the check valve is not in contact with the inner periphery face different from a conventional way but in contact with the inner periphery face 74 of the recess part 52 formed on the piston 50, feeling of operating the piston 50 is improved and early abrasion of the seal part 72 of the check valve 70 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air / water supply valve structure for an endoscope, and more particularly to an endoscope used for medical use, for switching and supplying air and water into a body cavity. Related to the structure of a valve.

[0002]

2. Description of the Related Art A medical endoscope has an air supply / water supply valve attached to a hand operation unit, and operates the air supply / water supply valve with an operator's finger to switch between air and water to enter a body cavity. It is configured to supply.

[0003] A conventional air / water supply valve comprises a cylinder, a piston, and the like. The cylinder is fixed to a predetermined position of the hand operation unit, and a piston is slidably fitted in the cylinder in the axial direction. A button having an air leak hole is attached to the upper part of the piston. According to the air supply / water supply valve having such a structure, when the air leak hole of the button is closed by the operator's finger, the air supplied to the cylinder is supplied into the body cavity through the air supply tube.
Further, when the piston is pressed down with the button, the air supply is stopped, and the water supplied to the cylinder is supplied into the body cavity via the water supply pipe.

Incidentally, a check valve is provided in the air supply pipe, and the check valve prevents liquid in the body cavity from flowing back from the air supply pipe to the air supply pipe. However, if a check valve is provided in the air supply pipe, there is a disadvantage that it is difficult to clean the entire air supply pipe because the check valve hinders the cleaning of the air supply pipe with a brush.

Japanese Patent Laid-Open Publication No. 57-110228 discloses an air / water supply valve in which a check valve is attached to a piston. According to this air / water supply valve, the check valve slides in the cylinder integrally with the piston, and the seal portion of the check valve contacts the inner surface of the cylinder, thereby preventing the backflow of the fluid.

[0006]

However, the air / water supply valve disclosed in Japanese Patent Laid-Open Publication No. Sho 57-110228 has a structure in which the seal portion of the check valve is brought into contact with the inner surface of the cylinder. Accordingly, the operating feeling of the piston is increased, and the seal portion is worn out early.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and an endoscope which can improve the operational feeling of the piston and prevent the wear of the seal portion of the check valve at an early stage to extend the service life. An object of the present invention is to provide an air / water supply valve structure.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a cylinder of an air / water supply valve provided in a hand-held operation unit of an endoscope, and supplies air into the cylinder. An air supply pipe and a water supply pipe for supplying water, and the water supplied to the air supply pipe and the cylinder that guide the air supplied to the cylinder to an air supply / water supply port formed at the distal end of the insertion portion of the endoscope. A cylinder connected to a water supply pipe leading to the air supply / water supply port, and slidably fitted in the cylinder, and changing the axial position with respect to the cylinder, thereby changing the air supply pipe and the air supply pipe. A piston that communicates or connects the water supply pipe and the water supply pipe is provided, and the piston has a flow path that connects the air supply pipe and the air supply pipe, and is formed at an end of the flow path. A check valve is attached to the recess, The valve is characterized in that to prevent backflow of fluid into the air charge from the inner peripheral surface thereof the seal portion is contacted flue of the recess.

According to the first aspect of the present invention, the check valve is attached to the concave portion formed in the piston, and the seal portion of the check valve is brought into contact with the inner peripheral surface of the concave portion, so that the air supply pipe is connected to the air supply pipe. Prevent backflow of fluid to the In the present invention, the seal portion of the check valve is configured not to contact the inner surface of the cylinder but to the inner peripheral surface of the recess formed in the piston. Premature wear of the stop valve can also be prevented.

Further, according to the present invention, a flow path communicating the air supply pipe and the air supply pipe is formed in the piston, and a check valve formed in an umbrella shape is formed in a concave portion formed at an end of the flow path. Was attached. When the recess is formed at the end of the flow path as described above, the processing is easier than when a recess is formed at an intermediate portion of the flow path, and the check valve is easily mounted. Further, by installing a check valve at the end of the flow path, it is possible to prevent the fluid from flowing back into the flow path.

According to the second aspect of the present invention, the flow path of the piston is formed so as to be inclined so that air is substantially perpendicular to the inclined surface of the check valve formed in an umbrella shape. This allows
The air pressure of the air flowing through the flow path is efficiently transmitted to the check valve, and the check valve elastically deforms in the opening direction with the minimum air pressure, minimizing pressure loss due to the check valve. Air can be supplied to the air line.

According to the third aspect of the present invention, when the axial position of the piston is changed and the water supply pipe and the water supply pipe are communicated with each other, the step portion with which the entire circumference of the seal portion of the check valve abuts is provided. Since it is formed on the inner peripheral surface of the cylinder, the sealing performance of the check valve can be improved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an air / water supply valve structure for an endoscope according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view showing the appearance of an endoscope hand operation unit 10 to which the air / water supply valve structure according to the embodiment is applied, and FIG. 2 is a sectional view of the hand operation unit 10.

A button 14 constituting the air / water supply valve of the embodiment is provided on the upper part of the main body case 12 of the hand operation unit 10 shown in FIGS. And a shutter button 18 are juxtaposed. An eyepiece 20 is provided at the rear end of the main body case 12, as shown in FIG. Furthermore, body case 1
A connector 22 is connected to a lower portion of the connector 2, and a connection tube 30 is connected to the connector 22. An air supply pipe 24, a water supply pipe 26, a suction pipe 28, a light guide cable (not shown) and the like shown in FIG. Reference numeral 32 in FIG. 1 denotes a forceps hole into which a treatment tool such as forceps is inserted, and reference numeral 34 denotes an angle knob for performing a bending operation on a bending portion (not shown) of the insertion portion 40.

The suction tube 28 shown in FIG.
The suction tube 38 is connected to the cylinder 36. The suction tube 38 is inserted through the insertion portion 40 shown in FIG. 1 and is connected to a suction port of a not-shown hard tip portion provided at the tip of the insertion portion 40. A piston (not shown) for connecting / disconnecting the suction tube 28 and the suction tube 38 is fitted into the cylinder 36 shown in FIG. 2, and the suction button 16 is attached to the upper end of the piston. The suction button 16 or the piston is urged by an unillustrated urging member in a direction to shut off the suction tube 28 and the suction tube 38. When the suction button 16 is pressed against the urging force of the urging member, the suction tube 28 and the suction tube 38 are communicated. As a result, dirt and the like in the body cavity are sucked from the suction port of the hard distal end portion and discharged to the outside of the hand operation unit 10 through the suction tube 38 and the suction tube 28.

The distal end of each of the air supply pipe 24 and the water supply pipe 26 is connected to a predetermined position of a cylinder 42 constituting an air supply / water supply valve. The cylinder 42 has an air supply pipe 4
The base end of each of 4 and the water pipe 46 is connected to a predetermined position. The base end of the air supply pipe 24 is connected to an air supply device (not shown), and when the air supply device is driven, air is supplied into the cylinder 42 via the air supply pipe 24. The proximal end of the water supply pipe 26 is connected to a water supply tank (not shown). When the piston 50 is pressed down with the button 14, the air supply pipe 24 is closed, and the air flowing through the air supply pipe 24 is supplied to the water supply tank. by this,
The internal pressure in the water supply tank increases, and the water in the water supply tank is supplied into the cylinder 42 via the water supply pipe 26.

The distal end of each of the air supply pipe 44 and the water supply pipe 46 is connected to one air supply / water supply pipe (not shown) inside the hand operation unit 10. This air supply / water supply pipe is inserted through the insertion section 40 of FIG. 1 and connected to an air supply / water supply port (not shown) formed in the distal end hard portion.

The air / water supply valve is connected to the cylinder 4 as shown in FIG.
2, the piston 50, the button 14, and the like.

The cylinder 42 is fixed at a predetermined position of the main body case 12 shown in FIG. Further, four ports 5 are provided on the outer peripheral portion and the bottom portion of the cylinder 42 as shown in FIG.
4, 56, 58, 60 are formed, the air supply pipe 24 is connected to the port 54, the water supply pipe 26 is connected to the port 56, the air supply pipe 44 is connected to the port 58, and the port 60 is connected to the port 60. A water pipe 46 is connected.

The piston 50 is formed in a substantially cylindrical shape, and is slidably and removably inserted in a cylinder 42 through a plurality of O-rings 62 in the vertical direction (axial direction).
In addition, a communication port 64 as shown in FIG.
Is formed, and the flow path 48 in the piston 50 and the port 54 are communicated through the communication port 64. Thereby, the air supplied from the air supply pipe 24 is blown out to the flow path 48.

A communication groove 66 is formed around the entire periphery of the piston 50 at the substantially central outer periphery as shown in FIG. When the port 56 and the port 60 communicate with each other through the communication groove 66, the water supplied from the water supply pipe 26 flows into the communication groove 66.
Is supplied to the water pipe 46 via the

The button 14 is fitted into the upper end of the piston 50 and is urged upward by the urging force of a compression spring 68 arranged on the outer periphery of the piston 50. The compression spring 68 is disposed between the stopper ring 51 screwed to the upper end of the piston 50 and the stopper ring 53 fitted to the upper end of the cylinder 42. An air leak hole 15 is formed in the center of the button 14, and the air leak hole 15 is formed through the air leak hole 15 in FIG.
The air blown out is released to the outside.

As shown in FIGS. 4 and 6, a check valve 70 is attached to a concave portion 52 formed at a lower portion of the piston 50 of the air / water supply valve according to the embodiment. The check valve 70 is formed in an approximately umbrella-like shape with an elastic material such as silicon-based resin or ethylene propylene diene monomer (EPDM), and an engagement portion 72 protruding from an upper portion thereof is engaged with the piston 50. The concave portion 5
2. In addition, a peripheral portion serving as a seal portion 73 of the check valve 72 is in close contact with the inner peripheral surface 75 of the concave portion 52 by its own elastic force.

On the other hand, a plurality of channels 76, 76... Communicating with the channel 48 are formed in the piston 50, and the outlets of these channels 76, 76. Are formed at an angle of about 90 degrees with respect to the inclined surface 71 so as to inject air in the vertical direction onto the inclined surface 71 of the check valve 70.

Next, the operation of the air / water supply valve configured as described above will be described.

First, the state of the air / water supply valve when the air / water supply valve is not operated is the state shown in FIG. 3 in which the piston 50 is raised by the urging force of the compression spring 68. In this state, the port 56 is blocked from the communication groove 66, but since the port 54 is connected to the flow path 48, the air sent from the air supply pipe 24 is blown out to the flow path 48,
Then, the air is discharged outside through the air leak hole 15 of the button 14.

Next, when the air sent from the air supply pipe 24 is supplied to the air supply pipe 44, the air leak hole 15 is closed with the operator's finger 80 as shown by a two-dot chain line in FIG. As a result, the air exhausted from the air leak hole 15 loses its escape space, flows from the flow path 48 to the flow path 76, and is injected substantially perpendicularly from the opening of the flow path 76 toward the inclined surface 71 of the check valve 70. Is done. Due to the air pressure of the air, the check valve 70 is elastically deformed in the opening direction, and the inner peripheral surface 7 of the seal portion 73 and the concave portion 52 is formed.
5, air is blown out from the gap, and the air flows to the air supply pipe 44. Thereby, the air sent from the air supply pipe 24 is supplied to the air supply pipe 24.

As described above, in the present embodiment, the flow path 76 is formed so as to be inclined so that air is substantially perpendicular to the inclined surface 71 of the check valve 70 formed in an umbrella shape. The air pressure of the air flowing through is transmitted to the check valve 70 efficiently, and the check valve 70 is elastically deformed in the opening direction with a minimum air pressure. Therefore, the air can be supplied to the air supply pipe 44 while minimizing the pressure loss due to the check valve 70.

Next, when supplying water to the water supply pipe 46, the piston 50 is pushed against the urging force of the compression spring 68 as shown in FIG. As a result, the port 54 is blocked from the flow path 48, and the port 56 communicates with the communication path 66, so that the water sent from the water supply pipe 26 is supplied from the port 56 to the water supply pipe 46 via the communication groove 66. Is done.

The backflow phenomenon of the fluid from the air supply pipe 44 to the air supply pipe 24 occurs at this time. At this time, the seal portion 73 of the check valve 70 has a lower peripheral portion as shown in FIG.
Steps 4 formed on the lower inner peripheral surface of the cylinder 42
3 is pressed. Therefore, even if the fluid flows back to the air supply pipe 44, the seal portion 73 of the check valve 70 is pressed against the inner peripheral surface 75 of the concave portion 52 and also pressed against the step portion 43, so that the sealability of the check valve 70 is improved. Since the air pressure is improved, the air in the air supply pipe 44 does not leak to the cylinder 42, and the internal pressure of the air supply pipe 44 increases, so that the occurrence of the backflow phenomenon can be prevented.

As described above, in the air / water supply valve of the embodiment, the check valve 70 is attached to the concave portion 52 formed in the piston 50, and the seal portion 73 of the check valve 70 is attached to the inner peripheral surface 75 of the concave portion 52. The contact was made to prevent the backflow of the fluid from the air supply pipe 44 to the air supply pipe 24. That is, in the air / water supply valve,
The seal portion of the check valve is not brought into contact with the inner surface of the cylinder as in the prior art.
5, the feeling of operation of the piston 50 is improved,
Premature wear of the seal portion 73 of the check valve 70 can also be prevented.

The flow path 76 formed in the piston 50
Since the concave portion 52 is formed at the end of the flow path, the processing is easier than forming the concave portion at an intermediate portion of the flow path.
The attachment of 0 is also easy. Further, by attaching the check valve 70 to the end of the flow passage 76, the backflow of the fluid to the flow passage 48 can be prevented.

[0034]

As described above, according to the air supply / water supply valve structure of the endoscope according to the present invention, the check valve is attached to the concave portion formed in the piston, and the seal portion of the check valve is formed inside the concave portion. By contacting the peripheral surface, backflow of fluid from the air supply pipe to the air supply pipe was prevented, so the feeling of operation of the piston was improved,
Premature wear of the check valve can also be prevented.

Further, according to the present invention, the flow path of the piston is formed so as to be inclined substantially perpendicularly to the inclined portion of the umbrella-shaped check valve. Air can be supplied to the air line with minimal loss.

[Brief description of the drawings]

FIG. 1 is a perspective view of an endoscope hand operation unit to which an air / water supply valve structure according to an embodiment is applied;

FIG. 2 is a sectional view of the endoscope hand operation unit shown in FIG. 1;

FIG. 3 is a sectional view showing an air / water supply valve according to the embodiment;

FIG. 4 is an enlarged sectional view showing a position of a check valve of the air / water supply valve in an air supply state.

FIG. 5 is a sectional view showing an air / water supply valve in a water supply state.

FIG. 6 is an enlarged sectional view showing a position of a check valve of the air / water supply valve in a water supply state.

[Description of Signs] 10: Hand operation unit, 14: Button, 24: Air supply pipe, 26
... water supply pipe, 42 ... cylinder, 44 ... air supply pipe, 46 ... water supply pipe, 50 ... piston, 52 ... concave part, 70 ... check valve, 71
... Slope, 73 ... Seal

Claims (3)

[Claims] 1. A cylinder of an air supply / water supply valve provided in a hand operation unit of an endoscope, comprising: an air supply pipe for supplying air into the cylinder, a water supply pipe for supplying water, and a supply pipe to the cylinder. A cylinder connected to an air supply pipe for guiding the air to an air supply / water supply port formed at the end of the insertion portion of the endoscope and a water supply pipe for introducing the water supplied to the cylinder to the air supply / water supply port; A piston that is slidably fitted into the cylinder and changes the axial position with respect to the cylinder to allow the air supply pipe to communicate with the air supply pipe or to allow the water supply pipe to communicate with the water supply pipe A flow path communicating the air supply pipe and the air supply pipe is formed in the piston, and a check valve is attached to a concave portion formed at an end of the flow path; The seal portion is in contact with the inner peripheral surface of the concave portion. An air / water supply valve structure for an endoscope, wherein a backflow of a fluid from the air supply pipe to the air supply pipe is prevented. 2. The piston according to claim 1, wherein the flow path of the piston is formed so as to be inclined substantially perpendicularly to the inclined surface of the check valve formed in an umbrella shape so that air is applied thereto. 1
2. The air / water supply valve structure of the endoscope according to item 1. 3. When the axial position of the piston is changed to communicate the water supply pipe with the water supply pipe, the entire circumference of the seal portion of the check valve is applied to the inner peripheral surface of the cylinder. The air / water supply valve structure for an endoscope according to claim 1 or 2, wherein a step portion that is in contact with the endoscope is formed.