JP2010240245A - Endoscope tip and method for manufacturing the endoscope tip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an endoscope tip in which an optical element and a holding member are certainly joined by an alternative method for soldering and which is excellent in strength, durability, tightness, and productivity. <P>SOLUTION: The endoscope tip is provided, which is provided with: the optical element 12; and a holding member 10 formed of amorphous alloy having a glass transition region at 20°C or higher to hold the optical element at a state that it is stored in a storage part 18, wherein the optical element is joined to the storage part by being pressurized at a state that the storage part around the optical element is heated to temperature in the glass transition region after the optical element is stored in the storage part. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an endoscope distal end portion and a manufacturing method thereof.

  In general, the distal end portion of an endoscope is mainly configured by an optical system including a lens that is an optical element and a front frame that is a holding member that holds the lens. Usually, the lens and the front frame are joined. As a bonding method, first, metallization for improving the wettability of solder is performed on the inner peripheral surface of the front frame and the outer peripheral surface of the lens, and then the lens is installed on the front frame. The lens is joined to the front frame by soldering. Thus, the method of joining by soldering is generally employ | adopted. This is an indispensable work to achieve the “sealing property between the front frame and the lens” required for the distal end portion of the endoscope.

JP 2004-94043 A

  However, the conventional method requires a metallizing process and a soldering process when the lens and the front frame are joined, so that the manufacturing process is inevitably complicated and productivity is reduced. There was an inconvenience.

  An object of the present invention is to provide an endoscope distal end portion in which an optical element and a holding member are securely bonded by a method instead of soldering, and excellent in strength, durability, sealing performance and productivity, and a manufacturing method for manufacturing the endoscope distal end portion. Is to provide.

In order to achieve the above object, the present invention provides the following means.
An endoscope tip part manufacturing method according to the present invention includes an optical element and a holding member that is formed of an amorphous alloy having a glass transition region of 20 ° C. or higher and holds the optical element in a state of being accommodated in the accommodating part. A step of inserting the optical element into the accommodating portion and accommodating the optical element, and the accommodating portion around the optical element accommodated in the glass transition. A heating step of heating to a temperature in the region, and a bonding step of pressing the holding member against the optical element using a pressing tool to bond the housing portion and the optical element. It is characterized by.

  An endoscope distal end portion according to the present invention includes an optical element and a holding member that is formed of an amorphous alloy having a glass transition region of 20 ° C. or higher and holds the optical element in a state of being accommodated in the accommodating portion. And after the optical element is accommodated in the accommodating portion, the accommodating portion around the optical element is pressed in a state heated to the temperature in the glass transition region, thereby being joined to the accommodating portion. It is characterized by being.

  In the endoscope tip portion and the endoscope tip portion manufacturing method according to the present invention, the holding member holding the optical element has a glass transition region (a value obtained by subtracting the glass transition temperature from the crystallization temperature) of 20 ° C. or more. It is formed from the amorphous alloy. Such an amorphous alloy is called a so-called metallic glass, and does not cause solidification shrinkage like a crystalline metal, so it has a high precision transfer property and is hot like a glass in a glass transition region. Press working is also possible. Therefore, after performing the insertion step and the heating step, when the optical element is pressed against the holding portion of the holding member using a pressurizing tool in the joining step, the holding portion is deformed following the shape of the optical element. Are joined in close contact. Thereby, both join in the state which contact | adhered. As a result, an endoscope distal end portion in which the optical element and the holding member are securely bonded can be obtained.

  In particular, unlike conventional soldering, it can be manufactured by a simple method that only involves heating and pressurization, so that it is excellent in productivity. In addition, since the optical element and the holding member are bonded in close contact with each other, it is possible to obtain an endoscope distal end portion having excellent sealing performance. In addition, the metallic glass has characteristics such as low Young's modulus and high strength, and low expansion against heat. Therefore, it can be set as the endoscope front-end | tip part excellent in mechanical strength. In addition, the metallic glass does not have a grain boundary as found in ordinary crystalline metals, and does not cause grain boundary corrosion (a phenomenon in which corrosion proceeds along the grain boundary) due to the grain boundary. Therefore, it also has the property of being excellent in corrosion resistance. Therefore, it can be set as the endoscope front-end | tip part excellent in durability.

  Further, in the method for manufacturing an endoscope tip portion according to the present invention, in the method for manufacturing an endoscope tip portion according to the present invention, a protrusion is formed on the holding member along the opening of the housing portion. During the heating step, the protrusion is heated until it reaches a temperature in the glass transition region, and during the bonding step, the protrusion is pressed and deformed by the pressing tool, and the protrusion is pressed. The optical element is pressurized against the housing portion by utilizing deformation.

  In the endoscope distal end portion according to the present invention, in the endoscope distal end portion according to the present invention, a protrusion is formed on the holding member along the opening of the accommodating portion, and the optical element is It is characterized by being pressurized by pressure deformation of the protrusion.

  In the endoscope front end portion and the endoscope front end portion manufacturing method according to the present invention, the optical element can be pressurized by applying pressure deformation using a pressurizing tool after heating the protrusion. In particular, since the protruding portion is formed along the opening of the housing portion, the protruding portion is deformed so as to evenly press the entire optical element during pressure deformation. Therefore, the optical element and the holding member can be more reliably joined, and the sealing performance can be further improved.

  Further, the method for manufacturing an endoscope tip portion according to the present invention is the method for manufacturing an endoscope tip portion according to the present invention, wherein an inner diameter is the outer diameter of the optical element as the pressurizing tool in the joining step. The protrusion is pressure-deformed using a cylindrical tool that is larger and smaller than the outer diameter of the protrusion.

  In the method for manufacturing the endoscope distal end according to the present invention, a cylindrical pressure tool having an inner diameter larger than the outer diameter of the optical element and smaller than the outer diameter of the protrusion is used. Only the side) can be deformed under pressure. Then, the remaining part (inner surface side) of the protrusion is pushed to the optical element side by this pressure-deformed part, so that the optical element can be pressed with a stronger force. Therefore, the bonding between the optical element and the holding member can be further ensured.

  In addition, the method for manufacturing an endoscope distal end according to the present invention is the method for manufacturing an endoscope distal end according to the present invention described above, wherein the projecting portion that is deformed by pressure is separated from the optical element before the joining step. A restricting member for restricting spreading in a direction to be installed is provided so as to surround the periphery of the protrusion.

  In the method for manufacturing the endoscope distal end according to the present invention, the restricting member is installed so as to surround the periphery of the protrusion before performing the joining step. Thereby, when a part (outer surface side) of the protruding portion is deformed under pressure, it can be prevented that the protruding portion spreads in a direction away from the optical element. Therefore, a part of the protrusion can be deformed so that the remaining part (the inner surface side) of the protrusion is pushed toward the optical element. Therefore, the bonding between the optical element and the holding member can be further ensured.

  In addition, the method for manufacturing an endoscope distal end portion according to the present invention is the above-described method for manufacturing an endoscope distal end portion according to the present invention, wherein the concave portion is recessed inwardly on the outer peripheral surface of the optical element before the inserting step. It is characterized by forming.

  Moreover, the endoscope front-end | tip part which concerns on this invention is the endoscope front-end | tip part of the said invention, The recessed part dented inwardly is formed in the outer peripheral surface of the said optical element, It is characterized by the above-mentioned.

  In the endoscope tip portion and the endoscope tip portion manufacturing method according to the present invention, since the concave portion formed inward is formed on the outer peripheral surface of the optical element, the contact between the optical element and the holding member is brought into contact. The area can be increased. Therefore, both adhesiveness can be improved more.

  In addition, the method for manufacturing an endoscope distal end portion according to the present invention is the method for manufacturing an endoscope distal end portion according to the present invention, wherein the optical element is accommodated by using the pressing tool during the insertion step. In the pressurizing step, the entire optical element is heated via the pressurizing tool, and the housing portion in a portion in contact with the optical element is locally heated, and the joining step In this case, the optical element and the accommodating portion are joined by pressing the optical element directly against the accommodating portion with the pressing tool.

  In the method for manufacturing an endoscope distal end according to the present invention, each step can be performed in a series of flows using a pressurizing tool, so that productivity can be further increased. In particular, since the entire optical element is heated via the pressurizing tool, and the accommodating portion of the portion in contact with the optical element is locally heated, the points requiring heating can be efficiently heated without waste. Also in this respect, productivity can be improved. In addition, since the optical element is directly pressed against the housing portion by the pressing tool, the force is more easily transmitted, and the bonding can be reliably performed even with a low applied pressure.

  In addition, the method for manufacturing an endoscope tip according to the present invention is the method for manufacturing an endoscope tip according to the present invention described above, wherein the tip of the optical element is chamfered to form a cut surface before the insertion step. It is formed over the entire circumference, and an inclined surface with which the cut surface comes into surface contact is formed on the inner surface of the housing portion.

  In the method for manufacturing the endoscope distal end according to the present invention, the cut surface on the optical element side and the inclined surface on the holding member side are in surface contact during the joining process, so that the adhesion can be improved and more reliable. Bonding can be performed.

  Moreover, the manufacturing method of the endoscope front-end | tip part which concerns on this invention WHEREIN: In the manufacturing method of the endoscope front-end | tip part of the said invention, the said optical element is pressurized with the applied pressure of 1 Mpa or more in the said joining process. Features.

  In the method for manufacturing the endoscope distal end according to the present invention, the optical element is pressurized with a pressure of 1 MPa or more, so that the optical element and the holding member can be reliably bonded in a close contact state, and the sealing performance is ensured. can do. If the pressure is applied with a pressure of less than 1 MPa, the optical element and the holding member are not in close contact with each other, which may impair the sealing performance.

According to the endoscope front-end | tip part which concerns on this invention, an optical element and a holding member are joined reliably, and it is excellent in intensity | strength, durability, and sealing performance.
Further, according to the method for manufacturing an endoscope distal end according to the present invention, the endoscope distal end can be efficiently produced by a method replacing soldering, and productivity can be increased.

1 is an overall view of a medical endoscope to which an endoscope distal end portion according to a first embodiment of the present invention is attached. It is the figure which looked at the endoscope front-end | tip part shown in FIG. 1 from the front. It is a figure which shows the front frame which comprises the endoscope front-end | tip part shown in FIG. 2, Comprising: (a) is the figure seen from the front, (b) is the cross-section BB figure of (a). FIG. 3 is a process diagram when manufacturing the distal end portion of the endoscope shown in FIG. 2, and is a view showing a state in which a protrusion is formed along the opening of the illumination hole of the front frame. FIG. 5 is a process diagram for manufacturing the distal end portion of the endoscope illustrated in FIG. 2, and is a diagram illustrating a state in which an illumination lens is inserted into the illumination hole from the state illustrated in FIG. 4. FIG. 6 is a process diagram when manufacturing the distal end portion of the endoscope illustrated in FIG. 2, and is a diagram illustrating a state in which a jig is set from the state illustrated in FIG. 5. It is a block diagram of the jig | tool shown in FIG. FIG. 7 is a process diagram for manufacturing the endoscope distal end portion shown in FIG. 2, in which the protrusion is heated and pressure-deformed using the jig from the state shown in FIG. It is a figure which shows the state which joined the lens. FIG. 3 is a graph showing the result of measuring the change in the amorphous state of the front frame before and after manufacture by the X-ray diffraction method in manufacturing the endoscope distal end portion shown in FIG. 2. FIG. 10 is a graph for comparison with the graph of FIG. 9, in which a peak indicating crystallization appears. It is a process figure of the manufacturing method of the endoscope front-end | tip part which concerns on 2nd Embodiment of this invention, Comprising: The figure which shows the state which set the jig | tool after inserting the illumination lens in the illumination hole of a front frame. It is. It is a figure which shows the state which heated the opening of the hole for illumination using the jig | tool from the state shown in FIG. 11, and made it press-deform, and joined the front frame and the lens for illumination. It is a process figure of the manufacturing method of the endoscope front-end | tip part which concerns on 3rd Embodiment of this invention, Comprising: While forming a recessed part in the outer peripheral surface of the lens for illumination, it protrudes along opening of the hole for illumination of a front frame It is a figure which shows the state which formed the part. It is a figure which shows the state which inserted the lens for illumination in the hole for illumination from the state shown in FIG. It is a figure which shows the state which set the ring and the jig | tool from the state shown in FIG. It is a block diagram of the jig | tool shown in FIG. It is a figure which shows the state which heated the projection part using the jig | tool from the state shown in FIG. 14, and made it press-deform, and joined the front frame and the lens for illumination. It is a figure which shows the state which removed the jig | tool from the state shown in FIG. It is sectional drawing of the endoscope front-end | tip part which concerns on 4th Embodiment of this invention. FIG. 20 is a process diagram of a method for manufacturing the endoscope distal end portion shown in FIG. 19, in which the front end of the lens is chamfered to form a cut surface, and an inclined surface is formed in the lens hole of the front frame to be a cut surface. It is a figure which shows the state which carried out. It is a figure which shows the state which held the front frame with the holding jig from the state shown in FIG. 20, and fixed the lens to the front-end | tip of a heating jig. It is a figure which shows the state which inserted the lens in the lens hole of the front frame using the heating jig from the state shown in FIG. It is a figure which shows the state which pressed the lens further from the state shown in FIG. 22, and joined the front frame and the lens. It is a figure which shows the modification of the endoscope front-end | tip part shown in FIG.

(First embodiment)
Hereinafter, a first embodiment according to the present invention will be described with reference to FIGS. 1 to 10.
As shown in FIG. 1, the endoscope distal end portion 1 of the present embodiment is one of the components constituting the medical endoscope A, and is a flexible insertion portion 2 that is inserted into a body cavity. It can be attached to the tip. Note that the insertion portion 2 is freely bent by the operation portion 3 to change its orientation.

  As shown in FIGS. 1 and 2, the endoscope distal end 1 includes a front frame (holding member) 10, an objective lens 11 and an illumination lens (optical element) 12 held by the front frame 10, and a tip. The unit cover 13 is mainly composed of a unit cover 13 fixed to the front surface of the frame 10, and is formed in a circular shape when viewed from the front. The objective lens 11 and the illumination lens 12 are not limited to a circular shape when viewed from the front, and may be atypical. The front frame 10 is formed in a substantially fan shape when viewed from the front as shown in FIG. 3 by, for example, a known pressure casting method which is a kind of near net shape molding method. The tip frame 10 may be formed by other processing methods such as a cutting method and a forming method, without being limited to the pressure casting method.

Further, at a predetermined position of the front frame 10, a fixing screw hole 15 for fixing the front frame 10, a groove portion 16 for fixing the unit cover 13, and an imaging hole for holding the objective lens 11. 17, an illumination hole (accommodating portion) 18 for holding the illumination lens 12, and a treatment instrument channel 19 for inserting various endoscope treatment instruments are formed.
The objective lens 11 is held as described above by being joined to the front frame 10 while being accommodated in the imaging hole 17. An imaging element (not shown) such as a CCD or CMOS is fixed in the imaging hole 17 so that a captured image is transmitted to a monitor, a recording device, etc. via a transmission cable (not shown).

  Similarly to the objective lens 11, the illumination lens 12 is held by being joined to the front frame 10 while being accommodated in the illumination hole 18. An optical fiber (not shown) is fixed in the illumination hole 18 so that illumination light emitted from the light source is guided to the illumination lens 12.

By the way, the front frame 10 is a zirconium (Zr) -based alloy (composition: Zr ₅₅ Cu ₃₀ Al ₁₀ Ni ₅ , crystallization temperature (Tx) = 494 ° C., glass transition, which is classified as a metal glass among amorphous alloys. (Tg) = 410 ° C., glass transition region (ΔTx) = 84 ° C.).
Here, the amorphous alloy is an alloy obtained by solidifying (amorphizing) a plurality of metal elements without forming a crystal structure. This type of amorphous alloy is formed by rapidly cooling a molten metal raw material composed of a plurality of metal elements until the temperature falls below the glass transition temperature. Amorphous alloys do not have the grain boundaries found in ordinary crystalline metals, and cause grain boundary corrosion (a phenomenon in which corrosion proceeds along the grain boundaries) due to the grain boundaries. Since it does not exist, it has the feature that it is excellent in corrosion resistance.

Metallic glass is an amorphous alloy having a glass transition region (a value obtained by subtracting the glass transition temperature from the crystallization temperature) of 20 ° C. or higher. Metallic glass does not cause solidification shrinkage like crystalline metal, so it has high-precision transferability to molding dies, and injection molding is also possible. Excellent productivity. In addition, metallic glass has the characteristics of low Young's modulus and high strength as its physical properties and low expansion against heat.
Examples of this type of metallic glass include Zr-based alloys, Fe-based alloys, Ti-based alloys, and Mg-based alloys. Among them, Zr-based alloys have particularly excellent low expansion and dimensional accuracy.

Of the two types of lenses at the endoscope distal end 1, the illumination lens 12 is accommodated in the illumination hole 18, and then the illumination hole 18 around the illumination lens 12 is heated to a temperature in the glass transition region. By being pressurized in a state, it is joined to the illumination hole 18. This will be described in detail later.
The illumination hole 18 of the present embodiment has an inner diameter of 1.505 mm and a depth of 1.55 mm. The illumination lens 12 is a sapphire lens having an outer diameter of 1.495 mm and a thickness of 0.995 mm.

Next, a method for manufacturing the endoscope distal end portion 1 configured as described above will be described.
First, the leading frame 10 having a predetermined shape is manufactured using a Zr-based alloy. At this time, as shown in FIG. 4, an annular claw portion (projection portion) 20 is formed along the opening of the illumination hole 18. The dimensions of the claw portion 20 are, for example, a height of 0.50 mm and a width of 0.50 mm.
Next, as shown in FIG. 5, an insertion process is performed in which the illumination lens 12 is inserted and accommodated in the illumination hole 18. At this time, the outer diameter of the illumination lens 12 is the value described above, but it is preferable that the clearance from the inner diameter of the illumination hole 18 is as small as possible. Since the clearance is small, the adhesion between the front frame 10 and the illumination lens 12 can be improved.

After the insertion step, as shown in FIG. 6, a jig (pressing tool) 25 capable of performing heating and pressing simultaneously is set. Here, the jig 25 will be briefly described.
As shown in FIG. 7, the jig 25 is mainly composed of a sleeve 28 formed in a cylindrical shape, a heater 29 movable within the sleeve 28, and a temperature sensor 30 for measuring the temperature of the heater 29. Has been.
The sleeve 28 is made of zirconia having a thermal conductivity of 3.0 W / m · K and has an inner diameter of 2.05 mm. As shown in FIG. 6, the nail is formed along the opening of the illumination hole 18. The part 20 can be surrounded. At this time, it is preferable that the sleeve 28 has as small a clearance as possible from the outer diameter of the claw portion 20. This small clearance facilitates hot water flow control when the leading frame 10 is later heated to a temperature in the glass transition region. The material of the sleeve 28 is not limited to zirconia, and may be formed of alumina, magnesia, or the like.

  The heater 29 is a ceramic heater that can easily adjust the temperature by controlling the current and voltage of the power supply unit 31. The temperature sensor 30 is attached to the heater 29 and measures the temperature of the heater 29 using a thermocouple.

After the jig 25 configured in this manner is set as shown in FIG. 6, the heater 29 is set to 420 ° C., which is the temperature within the glass transition region ΔTx of the front frame 10 (crystallization temperature Tx−glass transition temperature Tg). And the heater 29 is brought into contact with the claw portion 20. Thereby, the nail | claw part 20 can be heated to the temperature in a glass transition area | region (heating process). That is, only the nail | claw part 20 can be heated locally, keeping the front frame 10 whole in an amorphous state.
In particular, the amount of heat of the heated claw portion 20 is extremely small with respect to the heat capacity of the heater 29, and the amount of heat transferred from the heater 29 to the claw portion 20 is negligible. Therefore, it can be said that the heater 29 temperature measured by the temperature sensor 30 and the temperature of the claw portion 20 are substantially equal. Thereby, the temperature measurement of the nail | claw part 20 can be performed efficiently. The temperature sensor 30 is preferably located directly above the claw portion 20.

After the heating step, the heater 29 is pushed in with a pressure of 20 MPa, the claw portion 20 is pressurized and deformed, and the illumination lens 12 is pressed against the illumination hole 18 using the pressure deformation of the claw portion 20. A joining process is performed. That is, the nail | claw part 20 which is a part of the front frame 10 is already heated by the heating process, Therefore The Newtonian viscosity is shown in a glass transition area | region. Therefore, the claw portion 20 is deformed so as to flow by the pressurization by the jig 25, and is deformed so as to partially cover the end surface of the illumination lens 12, as shown in FIG. Thereby, the illumination lens 12 can be pressurized against the illumination hole 18 using the jig 25, and the illumination hole 18 and the illumination lens 12 can be bonded together. In addition, the front frame 10 is naturally cooled to 200 degreeC after a heating and pressurization. Thereby, the front frame 10 is solidified while maintaining an amorphous state.
Note that the heating, pressurizing, and cooling steps described above are preferably performed in an inert atmosphere such as Ar gas or a vacuum atmosphere.

As a result, it is possible to obtain the endoscope distal end portion 1 in which the illumination lens 12 and the front frame 10 are reliably joined.
In particular, unlike conventional soldering, it can be manufactured by a simple method of heating and pressurization. Therefore, the production lead time can be shortened and the productivity is excellent. In addition, since the illumination lens 12 and the front frame 10 are joined in close contact with each other, the endoscope distal end portion 1 having excellent airtightness can be obtained. In addition, the metallic glass has characteristics such as low Young's modulus and high strength, and low expansion against heat. Therefore, it can be set as the endoscope front-end | tip part 1 excellent in mechanical strength. In addition, the metallic glass does not have a grain boundary as found in ordinary crystalline metals, and does not cause grain boundary corrosion (a phenomenon in which corrosion proceeds along the grain boundary) due to the grain boundary. Therefore, it also has the property of being excellent in corrosion resistance. Therefore, it can be set as the endoscope front-end | tip part 1 excellent in durability.

Moreover, in the present embodiment, when the claw portion 20 formed in an annular shape along the opening of the illumination hole 18 is deformed under pressure, the claw portion 20 presses the entire illumination lens 12 evenly. Transforms into Therefore, the illumination lens 12 and the front frame 10 can be more reliably joined, and the sealing performance can be further improved. Further, in the present embodiment, by using the jig 25, only the claw portion 20 can be heated and pressurized locally and efficiently, and the sleeve 28 is made of a low heat conductive material, so The thermal effect can be reduced as much as possible.
In this embodiment, the case where heating and pressurization are performed using the ceramic heater 29 has been described as an example. However, the present invention is not limited to this, and heating and pressurization using a spin welding method, an ultrasonic welding method, and other methods are possible. Pressurization may be performed.

[Example 1]
Next, after actually manufacturing the endoscope tip 1 by joining the illumination lens 12 and the front frame 10 by the manufacturing method of the first embodiment described above, When the sterilization, sterilization, and sterilization processes that were performed were performed, liquid intrusion from the interface between the front frame 10 and the illumination lens 12 and material corrosion were not confirmed. As a result, it was possible to actually confirm the adhesion (sealing) property and durability exceeding the level that can be used as an endoscope part.

  Moreover, the amorphous property by the X-ray diffraction method was evaluated using the X-ray diffraction apparatus (XRD) with respect to the junction part of the front frame 10 and the illumination lens 12 actually joined. The result is shown in FIG. In FIG. 9, the vertical axis represents the diffraction intensity (CPS), and the horizontal axis represents the diffraction angle (2θ (deg)). As is clear from FIG. 9, a peak peculiar to the crystallized metal could not be confirmed. If crystallization occurs, a peak appears in the analysis result as shown in FIG. However, since such a peak was not confirmed, it was confirmed that the front frame 10 after bonding was still amorphous.

[Comparative Example 1]
Next, in manufacturing the endoscope distal end portion 1 by actually joining the illumination lens 12 and the front frame 10 by the manufacturing method of the first embodiment described above, the applied pressure during the joining process is less than 1 MPa. A case of manufacturing at 0.5 MPa will be described as a comparative example. The other conditions are the same.
When the endoscope tip 1 manufactured under these conditions was similarly sterilized, sterilized, and sterilized, liquid intrusion was confirmed from the interface between the front frame 10 and the illumination lens 12. That is, it was confirmed that it was not a usable level as an endoscope part.

[Comparative Example 2]
Subsequently, in manufacturing the endoscope distal end portion 1 by actually joining the illumination lens 12 and the front frame 10 by the manufacturing method of the first embodiment described above, the temperature of the heater 29 during the joining process is determined by the temperature of the front frame. The case where it is produced at 510 ° C., which is 10 or higher, is described as a comparative example. The other conditions are the same.
The endoscope distal end portion 1 manufactured under these conditions was evaluated for amorphousness by an X-ray diffraction method using an X-ray diffractometer (XRD). Then, as shown in FIG. 10, a peak showing crystallinity appeared in the analysis result, and it was confirmed that the front frame 10 after bonding was crystallized.
Further, when the endoscope tip 1 manufactured under these conditions was similarly sterilized, sterilized, and sterilized, liquid intrusion was confirmed from the interface between the front frame 10 and the illumination lens 12. That is, it was confirmed that it was not a usable level as an endoscope part.
From these facts, it was confirmed that when the front frame 10 was crystallized, the sealing property between the illumination lens 12 and the front frame 10 required for the endoscope component could not be satisfied.

(Second Embodiment)
Next, a second embodiment according to the present invention will be described. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
The difference between the second embodiment and the first embodiment is that in the first embodiment, the illumination lens 12 is added by pressurizing and deforming the claw portion 20 formed in an annular shape along the opening of the illumination hole 18. However, in the second embodiment, the illumination lens 12 is pressurized by applying pressure deformation to a part of the illumination hole 18.

That is, in the manufacturing method of the present embodiment, after the insertion step, the jig 25 is set so as to surround the opening of the illumination hole 18 as shown in FIG. Then, the heater 29 is heated to 420 ° C. which is the temperature in the glass transition region ΔTx of the front frame 10, and the heater 29 is brought into contact with the illumination hole 18. Thereby, a part of the illumination hole 18 around the accommodated illumination lens 12 can be locally heated to the temperature in the glass transition region (heating process). After this heating step, the heater 29 is pushed in with a pressure of 20 MPa, and a part of the illumination hole 18 is pressurized and deformed.
Then, as shown in FIG. 12, the pressed portion is deformed so as to partially cover the end surface of the illumination lens 12. Thereby, the illumination lens 12 can be pressurized with respect to the illumination hole 18, and the illumination hole 18 and the illumination lens 12 can be bonded together (bonding step).

  Thus, even in the case of the present embodiment, the endoscope distal end portion 1 in which the illumination lens 12 and the front frame 10 are reliably joined can be obtained as in the first embodiment.

[Example 2]
In addition, after the illumination lens 12 and the front frame 10 are actually joined by the manufacturing method of the second embodiment, the disinfection / sterilization generally performed on the endoscope parts is performed as before. -Sterilized. As a result, liquid intrusion and material corrosion from the interface between the front frame 10 and the illumination lens 12 are not confirmed, and the adhesion (sealing) performance and durability more than the level that can be used as an endoscope part are similarly obtained. We were able to confirm it actually.
In addition, the amorphous property by the X-ray diffraction method was evaluated for the joint portion between the front frame 10 and the illumination lens 12 that were actually joined. As a result, a peak peculiar to the crystallized metal was not confirmed, and similarly, it was confirmed that the front frame 10 after joining was still amorphous.

(Third embodiment)
Next, a third embodiment according to the present invention will be described. In the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
The main difference between the third embodiment and the first embodiment is that in the first embodiment, the entire claw portion 20 formed in an annular shape along the opening of the illumination hole 18 is pressure-deformed. In the third embodiment, only a part (outer surface side) of the claw portion 20 is subjected to pressure deformation. Note that the endoscope distal end portion 40 of the present embodiment is used as a part of an industrial endoscope.

As shown in FIG. 13, the front frame (holding member) 41 of this embodiment is a zirconium (Zr) -based alloy (composition: Zr ₆₀ Cu ₂₀ Al ₁₀ Ni ₁₀ , crystallization temperature (Tx) = 481 ° C., glass transition. (Tg) = 389 ° C., glass transition region (ΔTx) = 92 ° C.). The illumination hole 18 has an inner diameter of 3.02 mm and a depth of 3.01 mm, and the claw portion 20 has a height of 50 mm and a width of 1.00 mm.
The illumination lens (optical element) 42 of the present embodiment is a glass lens having an outer diameter of 2.99 mm, a thickness of 2.49 mm, and a glass transition temperature of 430 ° C.

Next, a method for manufacturing the endoscope distal end portion 40 of this embodiment will be described.
First, as shown in FIG. 13, a recess 42a that is recessed inward with respect to the outer peripheral surface of the illumination lens 42 is formed before the insertion step. In the present embodiment, the recess 42 a is formed so as to be recessed in a semicircular shape over the entire circumference of the illumination lens 42. In addition, it is not limited to this case, You may form an infinite number of recessed parts recessed inward in the outer peripheral surface.
Next, a tip frame 41 having a predetermined shape is manufactured using a Zr-based alloy. At this time, the claw portion 20 having the dimensions described above is formed along the opening of the illumination hole 18.

  Next, as shown in FIG. 14, an insertion process is performed in which the illumination lens 42 is inserted and accommodated in the illumination hole 18. At this time, the outer diameter of the illumination lens 42 is the value described above, but it is preferable that the clearance from the inner diameter of the illumination hole 18 is as small as possible. Since the clearance is small, it is possible to improve the adhesion between the front frame 41 and the illumination lens 42.

After the insertion step, as shown in FIG. 15, an annular ring (regulating member) 43 that restricts the claw part 20 that is deformed by pressure later from spreading in the direction away from the illumination lens 42 is formed around the claw part 20. Install so that it surrounds. The ring 43 may be made of alumina, ceramics or metal.
After the ring 43 is installed, a jig (pressurizing tool) 45 capable of simultaneously performing heating and pressurization is set. Here, the jig 45 will be briefly described.
As shown in FIG. 16, the jig 45 includes a sleeve 28 formed in a cylindrical shape, a heater 29 that is movable in the sleeve 28 and has a concave tip, and a temperature sensor that measures the temperature of the heater 29. 30 mainly. The temperature sensor 30 is installed on the illumination lens 42 near the claw portion 20 as shown in FIG.

  The sleeve 28 is made of zirconia having a thermal conductivity of 3.0 W / m · K, and has a size that can surround the periphery of the ring 43. On the other hand, the inner diameter of the heater 29 having a concave tip is larger than the outer diameter of the illumination lens 42 and smaller than the outer diameter of the claw portion 20, for example, 4.0 mm. That is, the heater 29 according to the present embodiment has a cylindrical tip, so that only a part (outer surface side) of the claw portion 20 can be pressurized and deformed.

  And after setting the jig | tool 45 comprised in this way, while heating the heater 29 to 410 degreeC which is the temperature (crystallization temperature Tx-glass transition temperature Tg) in the glass transition area | region (DELTA) Tx of the front frame 41, The heater 29 is brought into contact with the claw portion 20. Thereby, the nail | claw part 20 can be heated to the temperature in a glass transition area | region (heating process). That is, only the nail | claw part 20 can be heated locally, keeping the front frame 41 whole in an amorphous state.

After the heating step, the heater 29 is pushed in with a pressure of 10 MPa, and as shown in FIG. 17, a part (outer surface side) of the claw portion 20 is pressurized and deformed. That is, a part of the claw portion 20 has already been heated by the heating process, and thus exhibits Newtonian viscosity in the glass transition region. Therefore, the claw portion 20 is deformed by pressure so as to flow by pressurization. Then, the remaining part (inner surface side) of the claw portion 20 is pushed toward the illumination lens 42 by the part subjected to the pressure deformation, so that the illumination lens 42 can be pressed with a stronger force.
In addition, since a part of the claw 20 that has been deformed under pressure flows into the inside of the ring 43, it can be prevented from spreading in a direction away from the illumination lens 42, and the hot water flow can be controlled. Thereby, the inner surface side of the nail | claw part 20 can be reliably pushed to the lens 42 for illumination. Therefore, the joining of the illumination lens 42 and the front frame 41 can be ensured.

  In addition, since the recess 42a is formed on the outer peripheral surface of the illumination lens 42, when a part of the claw 20 is deformed by pressure, it flows into the recess 42a. Therefore, the contact area where the illumination lens 42 and the front frame 41 are in contact can be increased, and the adhesion between them can be further increased. And after heating and pressurization, it is naturally cooled until the temperature of the illumination lens 42 reaches 250 ° C. The front frame 41 is solidified as it is when the temperature is equal to or lower than the glass transition temperature. As a result, as shown in FIG. 18, it is possible to obtain the endoscope distal end portion 40 in which the illumination lens 42 and the front frame 41 are securely joined.

  Even in the case of this embodiment, unlike the first embodiment, unlike the conventional soldering, it can be manufactured by a simple method of heating and pressurization, so the production lead time can be shortened. Can be achieved, and is excellent in productivity.

  In particular, by installing the ring 43, the hot water flow control and shape accuracy can be ensured, and the high-quality endoscope distal end portion 40 can be obtained. In addition, since the recess 42a is formed on the outer peripheral surface of the illumination lens 42, the bonding area between the front frame 41 and the illumination lens 42 can be increased, and the adhesion and the sealing performance can be improved.

Example 3
After actually manufacturing the endoscope front end portion 40 by joining the illumination lens 42 and the front frame 41 by the manufacturing method of the third embodiment, as in the previous case, it is common for the endoscope parts. The disinfection, sterilization, and sterilization processes that were carried out were performed. As a result, liquid intrusion from the interface between the front frame 41 and the illumination lens 42, material corrosion, etc. are not confirmed, and the adhesion (sealing) and durability more than a level that can be used as an endoscope part are similarly obtained. We were able to confirm it actually.
In addition, the amorphous property by the X-ray diffraction method was evaluated for the joint portion between the front frame 41 and the illumination lens 42 that were actually joined. As a result, a peak peculiar to the crystallized metal was not confirmed, and it was confirmed that the front frame 41 after joining was still amorphous.

[Comparative Example 3]
Subsequently, in manufacturing the endoscope distal end portion 40 by actually joining the illumination lens 42 and the front frame 41 by the manufacturing method of the third embodiment described above, the temperature of the heater 29 at the time of the joining step is set. The case where it is manufactured at 450 ° C. which is 41 glass transition temperature (Tg) or higher and lower than the crystallization temperature (Tx) will be described as a comparative example. At this time, the temperature of the illumination lens 42 at the time of bonding was 445 ° C., which was equal to or higher than the glass transition temperature (Tg), but the bonding process was performed. Other conditions are the same. In addition, it cooled until the temperature of the lens 42 for illumination became 250 degreeC after a joining process.

Since the temperature of the illumination lens 42 at the time of the joining process is equal to or higher than the glass transition temperature (Tg) of the front frame 41, the illumination lens 42 is softened and deformed. The illumination lens 42 inserted into the frame 41 has been inclined more than expected in the initial design. Therefore, the optical characteristics required for the lens cannot be obtained.
Subsequently, disinfection, sterilization, and sterilization were similarly performed on the endoscope distal end portion 40 manufactured under these conditions, and liquid intrusion was confirmed from the interface between the front frame 41 and the illumination lens 42. That is, it was confirmed that it was not a usable level as an endoscope part.

(Fourth embodiment)
Next, a fourth embodiment according to the present invention will be described. In the fourth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
The main difference between the fourth embodiment and the first embodiment is that in the first embodiment, the illumination lens 12 is pressurized via the claw portion 20, but in the fourth embodiment, the lens (optical element). It is a point which pressurizes 53 directly.

As shown in FIG. 19, the endoscope distal end portion 50 of the present embodiment is accommodated in a cylindrical front frame (holding member) 51 having a lens hole (accommodating portion) 52 formed therein and a lens hole 52. And the lens 53 held by the front frame 51 in a state where the head frame 51 is held.
The front frame 51 is composed of a zirconium (Zr) -based alloy (composition: Zr ₅₅ Cu ₃₀ Al ₁₀ Ni _2.5 Ti _2.5, crystallization temperature (Tx) = 480 ° C., glass transition temperature (Tg) = 398 ° C., glass Transition region (ΔTx) = 82 ° C.). The front frame 51 of the present embodiment has a structure in which the lens 53 can be inserted from the inside but cannot be inserted from the outside.

  Further, the lens 53 of the present embodiment is a sapphire lens. This is because the softening point of sapphire is higher than the crystallization temperature (Tx) of the front frame 51. Therefore, as long as it is for a material having a softening point higher than the crystallization temperature (Tx) of the front frame 51, a high melting point glass, YAG (yttrium aluminum garnet), quartz glass, or the like may be used instead of the sapphire lens. Absent.

Next, a method for manufacturing the endoscope distal end portion 50 of the present embodiment will be described.
First, before the insertion step, as shown in FIG. 20, the front end of the lens 53 is chamfered to form a cut surface 53a over the entire circumference, and the cut surface 53a is formed on the inner surface of the lens hole 52 of the front frame 51. An inclined surface 52a having a tapered cross section in surface contact is formed. In addition, it is preferable that the cut surface 53a and the inclined surface 52a have high parallelism.

Next, as shown in FIG. 21, the lens 53 is inserted into the lens hole 52 from the inside of the front frame 51 using a jig (pressure tool) 55 including a holding jig 56 and a heating jig 57. The insertion process is performed.
Here, the holding jig 56 and the heating jig 57 will be briefly described. The holding jig 56 is formed in a concave shape with a metal material such as copper, and can be held by fitting the tip of the front frame 51. The concave inner diameter is formed to be larger than the outer diameter of the front frame 51. The clearance with the front frame 51 is preferably as small as possible.

The heating jig 57 is designed so that the lens 53 can be inserted into the front frame 51 while the lens 53 is fixed at the tip, and a ceramic heater 58 that can heat the lens 53 is incorporated therein. Yes. Note that the present invention is not limited to the ceramic heater 58, and other heating means may be incorporated.
The temperature sensor 30 is attached to the heating jig 57 so as to be positioned in the vicinity of the fixed lens 53. The heating jig 57 can easily control the temperature to a desired temperature by controlling the current / voltage of the ceramic heater 58 based on the temperature measured by the temperature sensor 30. Here, since the heat capacity of the lens 53 is extremely small with respect to the heat capacity of the heating jig 57, it can be said that the temperature of the heating jig 57 measured by the temperature sensor 30 is substantially equal to the temperature of the lens 53.

  Then, after holding the front frame 51 by the holding jig 56 configured as described above, the lens 53 is fixed to the tip of the heating jig 57. Then, the heating jig 57 is heated to 420 ° C., which is the temperature in the glass transition region ΔTx of the front frame 51 (crystallization temperature Tx−glass transition temperature Tg). Thereby, the entire lens 53 can be heated via the heating jig 57. Subsequently, the heating jig 57 is moved so that the heated lens 53 is inserted into the lens hole 52 from the inside of the front frame 51 as shown in FIG. Push it into the frame 51. That is, in this embodiment, the insertion process, the heating process, and the bonding process are performed simultaneously.

  First, when the lens 53 is inserted into the lens hole 52 by the insertion process, the cut surface 53a comes into surface contact with the inclined surface 52a. Then, since the lens 53 is already heated, the part of the front frame 51 in contact with the lens 53 is locally heated. Specifically, since the cut surface 53a of the lens 53 comes into surface contact with the inclined surface 52a of the lens hole 52, the front frame 51 is locally heated and softened around the inclined surface 52a, and exhibits Newtonian viscosity. Further, since the lens 53 is directly pressurized through the heating jig 57, the softened portion flows and deforms due to the applied pressure. Accordingly, as shown in FIG. 23, the front frame 51 is deformed following the shape of the lens 53, so that the lens 53 and the front frame 51 can be joined. Then, after this joining, the heating jig 57 is naturally cooled until the temperature of the heating jig 57 reaches 250 ° C., and the holding jig 56 and the heating jig 57 are removed from the front frame 51.

  As a result, as shown in FIG. 19, it is possible to obtain the endoscope distal end portion 50 in which the lens 53 and the front frame 51 are securely joined. Even in the case of this embodiment, unlike the first embodiment, unlike the conventional soldering, it can be manufactured by a simple method of heating and pressurization, so the production lead time can be shortened. Can be achieved, and is excellent in productivity.

In particular, the insertion process, the heating process, and the joining process can be performed in a series of flows using the jig 55 including the holding jig 56 and the heating jig 57, so that productivity can be further improved. In addition, since the entire lens 53 is heated and the lens hole 52 in a portion in contact with the lens 53 is locally heated, it is possible to efficiently heat the points that require heating without waste. Also in this respect, productivity can be improved. Further, since the lens 53 is directly pressed against the lens hole 52, the force is more easily transmitted, and the bonding can be reliably performed even with a low applied pressure.
In addition, since the cut surface 53a of the lens 53 and the inclined surface 52a of the lens hole 52 are in surface contact with each other, adhesion can be improved and more reliable bonding can be performed. In addition, since the endoscope front-end | tip part 50 of this embodiment is especially excellent in the adhesiveness of the lens 53 and the front frame 51, the lens 53 does not drop out.

Furthermore, in the endoscope distal end portion 50 of the present embodiment, the end surface of the front frame 51 and the lens surface are flush with each other, and the distal end is a smooth surface. Therefore, even if dirt is attached to the tip, it is easy to remove dirt during cleaning and disinfection. Even if body fluid (mucus, blood, etc.) is placed on the lens surface during the treatment, these body fluids are easily removed. For this reason, if it is used as an illumination lens, it is difficult to reduce the amount of light, and if it is used as an objective lens, it is easy to secure a field of view. In the scope for digestive organs, there is usually a dedicated nozzle for cleaning the lens surface. However, if the tip is smooth, it is easy to clean and the water drainage is improved.
In addition, in the case of a structure in which a lens frame is protruded around the tip, flare is generated by the light reflected on the lens frame, and the image may be deteriorated. If is smooth, flare hardly occurs.

Example 4
In addition, after actually manufacturing the endoscope distal end portion 50 by joining the lens 53 and the front frame 51 by the manufacturing method of the fourth embodiment, as in the previous case, it is common for the endoscope components. The disinfection, sterilization, and sterilization processes that were carried out were performed. As a result, liquid intrusion from the interface between the front frame 51 and the lens 53, material corrosion, etc. are not confirmed, and the adhesion (sealing) performance and durability that are more than a level that can be used as an endoscope part are actually realized. I was able to confirm.
In addition, the amorphous property by the X-ray diffraction method was evaluated for the joint portion between the front frame 51 and the lens 53 that were actually joined. As a result, a peak peculiar to the crystallized metal was not confirmed, and it was confirmed that the front frame 51 after joining was still amorphous.

  In the fourth embodiment, the tip of the front frame 51 may be cut obliquely over the entire circumference as shown in FIG. Even in this case, the lens 53 and the front frame 51 can be joined through the same process, and the endoscope distal end portion 50 in which both are reliably joined can be obtained. In this case, the shape of the holding jig 56 may be matched with the shape of the front frame 51.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

For example, in each of the above-described embodiments, the case where a metal glass of a Zr-based alloy is used as the material of the front frame 51 is taken as an example, but the material is not limited to this. Any amorphous alloy having a glass transition region of at least 20 ° C. or more may be freely selected.
Further, the applied pressure may be at least 1 MPa or more. If the applied pressure is less than 1 MPa, as shown in the comparative example of the first embodiment, sufficient adhesion cannot be obtained, and the sealing performance may be impaired.

1, 40, 50 ... End of endoscope 10, 41, 51 ... Front frame (holding member)
12, 42 ... Illumination lens (optical element)
18 ... Lighting hole (accommodating part)
20 ... nail part (protrusion part)
25, 45, 55 ... Jig (pressurizing tool)
42a ... concave 43 ... ring (regulating member)
52 ... Lens hole (accommodating part)
52a ... inclined surface 53 ... lens (optical element)
53a ... Cut surface

Claims (11)

A method for manufacturing an endoscope distal end portion including an optical element and a holding member that is formed of an amorphous alloy having a glass transition region of 20 ° C. or higher and holds the optical element in a storage portion. There,
An insertion step of inserting and accommodating the optical element in the accommodating portion;
A heating step of heating the accommodating portion around the accommodated optical element to a temperature in the glass transition region;
A step of pressing the holding member against the optical element by using a pressurizing tool, and bonding the housing portion and the optical element. Method. In the manufacturing method of the endoscope front-end | tip part of Claim 1,
The holding member is formed with a protrusion along the opening of the housing portion,
During the heating step, heat until the protrusion reaches a temperature in the glass transition region,
In the joining step, the protrusion is pressed and deformed by the pressing tool, and the optical element is pressed against the housing portion using the pressure deformation of the protrusion. A method for manufacturing a distal end portion of an endoscope. In the manufacturing method of the endoscope front-end | tip part of Claim 2,
In the joining step, the protrusion is pressed and deformed by using a cylindrical tool having an inner diameter larger than the outer diameter of the optical element and smaller than the outer diameter of the protrusion as the pressure tool. The manufacturing method of the endoscope front-end | tip part. In the manufacturing method of the endoscope front-end | tip part of Claim 3,
An endoscope, characterized in that, before the joining step, a restricting member that restricts the pressure-deformed protrusion from spreading in a direction away from the optical element is provided so as to surround the periphery of the protrusion. A method for manufacturing the tip. In the manufacturing method of the endoscope front-end | tip part of any one of Claim 1 to 4,
Prior to the inserting step, a concave portion that is recessed inward is formed on the outer peripheral surface of the optical element. In the manufacturing method of the endoscope front-end | tip part of Claim 1,
During the insertion step, the optical element is inserted into the housing using the pressure tool,
During the pressurizing step, the entire optical element is heated through the pressurizing tool, and the accommodating portion of the portion in contact with the optical element is locally heated.
In the joining step, the optical element and the housing portion are joined by directly pressing the optical element against the housing portion with the pressing tool. Method. In the manufacturing method of the endoscope front-end | tip part of Claim 6,
Before the inserting step, the tip of the optical element is chamfered to form a cut surface over the entire circumference, and an inclined surface is formed on the inner surface of the housing portion so that the cut surface is in surface contact. The manufacturing method of the endoscope front-end | tip part. In the manufacturing method of the endoscope front-end | tip part of any one of Claim 1 to 7,
In the joining step, the optical element is pressurized with a pressurizing force of 1 MPa or more. An optical element;
A holding member that is formed of an amorphous alloy having a glass transition region of 20 ° C. or higher, and holds the optical element in a state of being housed in a housing portion;
After the optical element is accommodated in the accommodating portion, the accommodating portion around the optical element is bonded to the accommodating portion by being pressurized while being heated to the temperature in the glass transition region. Endoscope tip characterized by. In the endoscope front-end | tip part of Claim 9,
The holding member is formed with a protrusion along the opening of the housing portion,
The endoscope tip portion, wherein the optical element is pressurized by pressure deformation of the protrusion. In the endoscope front-end | tip part of Claim 9 or 10,
A distal end portion of an endoscope, wherein a concave portion recessed inward is formed on an outer peripheral surface of the optical element.

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