JP3737848B2 - Endoscope exposed part fixing part - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an exposed component fixing portion of an endoscope arranged so that a surface is exposed to an outer surface of the endoscope.
[0002]
[Prior art]
The cover lens of the endoscope is fixed to the endoscope so as to be exposed on the outer surface. Therefore, conventionally, the fixing member is water-tightly fixed to the attachment member with an epoxy adhesive or the like so that water or the like does not enter the endoscope.
[0003]
In addition, mechanical parts and electrical parts provided on the endoscope so as to be exposed on the outer surface are also bonded to the mounting member with an epoxy-based adhesive, or fixed by screws, soldering or brazing. Yes.
[0004]
[Problems to be solved by the invention]
However, since epoxy adhesives do not have good adhesion to glass, the joints will peel off over time, causing water leaks that cause water to enter the endoscope, lens dropping, etc. May occur.
[0005]
Then, after being used in an endoscope and placed in a high-pressure steam sterilizer or the like and heated, peeling or cracking occurs in the adhesive due to the difference in thermal expansion coefficient between the adhesive-bonded member and the adhesive There is a case.
[0006]
In addition, when fixed by screws, etc., or by soldering or brazing, the metal part is exposed on the outer surface of the endoscope. Or corrosion may occur and the joint may be destroyed.
[0007]
Accordingly, an object of the present invention is to provide an exposed component fixing portion of an endoscope that is less likely to deteriorate the fixed state of the exposed component to the endoscope and has high durability.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the exposed component fixing portion of the endoscope of the present invention is arranged such that the surface is exposed to the outer surface of the endoscope and is fixed to the attachment member of the endoscope. In the exposed component fixing portion, a silicon-based adhesive is applied to the periphery of the boundary portion between the exposed component and the attachment member from the outer surface side.
[0009]
The silicon-based adhesive may be applied so as not to expose the mounting member on the surface. Further, the exposed component may be fixed to the mounting member by caulking, soldering, brazing, or adhesion, and the silicon adhesive may be applied from the outer surface so as to touch the exposed component.
[0010]
The exposed component may be an optical cover lens, or may be a mechanical component or an electrical component used in an endoscope.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows the distal end of an insertion portion of an endoscope. The distal end portion body 1 is surrounded by an electrically insulating plastic block portion 1b so that a metal block portion 1a made of, for example, stainless steel is not exposed to the outer surface. Is formed.
[0012]
The observation objective optical system 10 is fixed in a cylindrical lens frame 15 made of metal such as brass, for example, and the lens frame 15 is inserted and supported near the image incident end of the image guide fiber bundle 20. It is bonded and fixed to the tip portion of the tubular support frame 21. The support frame 21 is fitted and fixed in a hole drilled in the distal end main body 1.
[0013]
An aperture stop 16 is disposed between the first lens 11 (cover lens) forming the front group of the objective optical system 10 and the next second lens 12, and the third lens forming the rear group. The lens 13 and the fourth lens 14 at the end are a cemented lens.
[0014]
The first lens 11 having the surface exposed to the outer surface is mechanically crimped and fixed so that the inclined surface formed at the intermediate portion of the outer peripheral surface is pressed by the tip portion of the lens frame 15. Reference numeral 17 denotes a caulking portion.
[0015]
The other lenses 12 to 14 are fitted into the lens frame 15 in order from the rear side, and are fixedly bonded to the lens frame 15. Reference numeral 18 denotes a spacer for properly regulating the distance between the second lens 12 and the third lens 13.
[0016]
The caulking part 17 is located at a position slightly behind the surface of the tip part main body 1 (for example, 0.5 to 2 mm), and a silicon-based adhesive (for example, one-component ultraviolet curable silicone) is formed in an annular recess formed in the part. System adhesive) 30 is applied and filled.
[0017]
Accordingly, the silicon-based adhesive 30 is filled between the outer peripheral surface of the first lens 11, the distal end portion main body 1 (the metal block portion 1 a and the plastic block portion 1 b), and the distal end portion of the lens frame 15. The metal part is shielded, thereby preventing corrosion of the metal part.
[0018]
Silicon is a polymer having Si—O (cyclohexane bond) as a main skeleton and an organic group in a side chain. On the other hand, glass usually forms a network structure based on Si—O bonds, and metal ions such as alkalis and alkaline earths are contained in the network and are stabilized.
[0019]
The glass surface immediately after production has a composition in which bonds such as Si—O and Si—O—Na are spread in the space, but when exposed to air, it immediately hydrates to form Si—OH groups (silanol groups) on the surface. ) Is formed and further absorbs water.
[0020]
Accordingly, the silicon-based adhesive forms a bond by the condensation reaction of Si—OH groups on the glass surface or adsorbed water, adheres very well to the glass, and does not require primer treatment on the first lens 11. The system adhesive 30 adheres very well.
[0021]
In addition, since the silicon-based adhesive 30 is rich in elasticity, even if it is placed in a high-temperature environment during sterilization after use of the endoscope, it follows the thermal expansion of the adherend, causing peeling and cracking. do not do.
[0022]
However, since the silicon-based adhesive 30 is rich in elasticity and the joint may move slightly, the first lens 11 is first mechanically firmly fixed to the lens frame 15 as described above. In this case, the first lens 11 is not misaligned.
[0023]
Therefore, as in this embodiment, by caulking and fixing the first lens 11 to the lens frame 15, and applying and filling the silicon-based adhesive 30 around the boundary portion between the first lens 11 and the lens frame 15, Excellent fixing strength and water tightness can be obtained.
[0024]
Note that the silicon-based adhesive 30 may be applied also to the direct contact surface between the lens frame 15 of the crimping portion 17 and the first lens 11, but when the silicon-based adhesive 30 is too viscous to be applied, An epoxy adhesive or the like may be used only for that portion.
[0025]
FIG. 2 shows an exit end portion of the light guide fiber bundle 23 at the distal end of the insertion portion of the endoscope, and a cover lens 51 made of a concave lens having a flat outer peripheral surface is disposed in close contact with the exit end surface. ing. The ridge line portion on the outer surface side of the cover lens 51 is chamfered to about 45 °.
[0026]
Since the cover lens 51 having a flat outer peripheral surface cannot be fixed by caulking, a metal film 31 such as copper, nickel, or chromium is formed on a part or the entire outer peripheral surface by plating or vapor deposition. The metal film 31 is mechanically firmly fixed to the metal block 1a of the tip body 1 by soldering or silver soldering.
[0027]
Then, the silicon adhesive 30 is applied and filled in the groove portion formed in the chamfered portion on the front side, so that the metal film 31 does not touch the outer surface. Therefore, the fixed metal portion is shielded from the outside by the silicon-based adhesive 30, and corrosion or the like is prevented.
[0028]
The metal film 31 portion and the tip body 1 may be bonded and fixed with an epoxy-based adhesive or the like, and the cover lens 51 may be slightly misaligned as in the illumination light emitting portion. In the portion, a silicon-based adhesive may be used for the joint portion. In addition, the “cover lens” of the present invention is a broad concept including a plane parallel plate having no curvature surface.
[0029]
FIG. 3 shows a second embodiment of the present invention, and shows a fixing structure of a metal ground terminal 61 that is an electrical component protruding from the connector part 60 or the operation part of the endoscope. Yes.
[0030]
Here, the ground terminal 61 is screwed and fixed to the screw hole formed in the outer wall of the connector portion 60, and the flange portion 61 a that comes into contact with the outer wall of the connector portion 60 from the outside is attached to the connector portion 60 by the epoxy adhesive 62. A silicon adhesive 63 is applied from the outside so that the epoxy adhesive 62 is not exposed on the surface.
[0031]
As a result, loosening of the screwed portion between the ground terminal 61 and the connector portion 60 is prevented by the bonding force of the epoxy adhesive 62, and the epoxy adhesive 62 over time is applied by the silicon adhesive 63 applied from the outside. Is prevented from peeling off.
[0032]
FIG. 4 shows a third embodiment of the present invention, in which a treatment instrument insertion channel 71 (mechanical part) made of a plastic tube is fixed to a distal end portion body 70 provided at the distal end of an insertion portion of an endoscope. The structure is shown. The distal end of the treatment instrument insertion channel 71 is open to the outside.
[0033]
In this embodiment, the distal end portion of the treatment instrument insertion channel 71 is passed through a hole 70a drilled through the distal end main body 70, and the treatment instrument insertion channel 71 is inserted into the hole 70a by the epoxy adhesive 72. A silicon-based adhesive 73 is applied to both end portions of the hole 70a so that the epoxy-based adhesive 72 is not exposed on the surface.
[0034]
As a result, the treatment instrument insertion channel 71 is firmly fixed to the distal end main body 70 by the bonding force of the epoxy adhesive 72, and the epoxy adhesive 72 is peeled off over time by the silicon adhesive 73 applied from the outside. Etc. are prevented.
[0035]
[Example 1]
In order to test the difference in durability between the silicone-based adhesive and other adhesives, samples cured with various adhesives were immersed in ethanol for 4 weeks. As shown in FIG. It was confirmed that the adhesive was superior to ethanol in comparison with other adhesives.
[0036]
[Example 2]
When the sample in which the adhesive was cured was immersed in boiling water, volume expansion of the adhesive portion of the sample other than the silicon-based adhesive was visually observed.
[0037]
Then, when the weight increase with time was measured, as shown in FIG. 6, it was confirmed that the silicon-based adhesive had an extremely small weight increase compared to other adhesives. Adhesive A is silicon-based, E is phonol-based, and F is epoxy-based.
[0038]
【The invention's effect】
According to the present invention, by applying a silicon-based adhesive that is well bonded to glass or the like around the boundary between the exposed part and the mounting member, the silicon-based adhesive is well bonded to the exposed part and peeled off. Since cracks do not occur, the fixed state of the exposed part with respect to the endoscope is unlikely to deteriorate, and excellent durability can be obtained.
[0039]
If the silicone adhesive is applied so that the mounting member is not exposed on the surface, corrosion of the fixing portion can be prevented, and the exposed part is caulked, soldered, brazed or bonded to the mounting member. If it is fixed by, the exposed part is fixed firmly in place, and no deviation occurs.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an observation objective optical system portion at a distal end of an insertion portion of an endoscope according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view of an illumination light emission portion at the distal end of the insertion portion of the endoscope according to the first embodiment of the present invention.
FIG. 3 is a partial cross-sectional view of a second embodiment of the present invention.
FIG. 4 is a partial cross-sectional view of a third embodiment of the present invention.
FIG. 5 is a chart showing experimental results of the first example of the present invention.
FIG. 6 is a diagram showing experimental results of the second example of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Tip part main body 1a Metal block part 11 1st lens (cover lens)
15 Mirror frame (attachment member)
17 Caulking part 30 Silicone adhesive 31 Metal film 51 Cover lens 60 Connector part 61 Ground terminal 62 Epoxy adhesive 63 Silicone adhesive 70 Tip body 71 Treatment instrument insertion channel 72 Epoxy adhesive 73 Silicone adhesive

Claims (4)

In the exposed part fixing part of the endoscope, which is arranged so that the surface is exposed to the outer surface of the endoscope and fixed to the attachment member of the endoscope,
The exposed parts are joined by an epoxy adhesive to the mounting member, so that its epoxy adhesive is not exposed to the outer surface of the endoscope, near the boundary portion between the exposed part and the mounting member exposed parts fixing section of the endoscope silicone adhesive from the outer table surface of the endoscope is characterized in that it is applied to. The exposed part fixing portion for an endoscope according to claim 1, wherein the silicon-based adhesive is applied so as not to expose the attachment member on the surface. The exposed part fixing part for an endoscope according to claim 1 or 2 , wherein the exposed part is a cover lens of an optical system. The exposed part fixing part for an endoscope according to claim 1 or 2 , wherein the exposed part is a mechanical part or an electric part used in the endoscope.

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