Endoscope eyepiece assembly and endoscope thereof

Abstract

The invention discloses an endoscope eyepiece assembly and an endoscope thereof. The endoscope eyepiece assembly comprises an eyepiece main body; the eyepiece window is arranged at the free end of the eyepiece main body to form airtight packaging, and a buffer assembly is arranged on the contact surface between the eyepiece window and the eyepiece main body to absorb stress causing deformation of the eyepiece window. The buffer assembly is arranged on the contact surface between the eyepiece window and the eyepiece main body and is used for absorbing the stress causing deformation of the eyepiece window, so that the risks of layering of a welding area of the eyepiece window and cracking of a base body caused by overlarge stress due to direct welding of the eyepiece window and the eyepiece main body are avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of medical endoscopes, and in particular to an endoscope eyepiece assembly and an endoscope thereof. Background Art

[0002] The traditional medical endoscope eyepiece assembly includes an eyepiece body and an eyepiece window, and the eyepiece window is directly brazed on the eyepiece body. Figure 1 The connection diagram of the eyepiece end of the endoscope is shown.

[0003] Among them, the eyepiece body is made of medical-grade SUS316L stainless steel, and the eyepiece window is made of sapphire window.

[0004] Although brazing the eyepiece window directly on the eyepiece body is a mature technology with simple process and low cost, there are still some shortcomings in the airtight brazing between the sapphire window and stainless steel using gold-tin solder: On the one hand, since the thermal expansion coefficients of the sapphire window and stainless steel are quite different, and the metallized welding layer on the sapphire window is prepared by thin-film sputtering, the eyepiece window will undergo local deformation after the two are directly welded, causing welding stress concentration and becoming a potential destructive factor.

[0005] On the other hand, due to the stress concentration and the residual stress inside the product, in the extreme environment of -65℃ to +150℃, the traditional eyepiece end components often cannot withstand more than 100 hot and cold alternating cycle tests without failure. The residual welding stress may cause the metallized welding layer on the sapphire window to delaminate, resulting in the failure of the airtightness of the medical endoscope, and then the failure of optical imaging. Summary of the invention

[0006] The technical problem to be solved by the present invention is how to solve the stress concentration problem existing when the eyepiece window is brazed on the eyepiece body.

[0007] In a first aspect of the present invention, in order to solve the above technical problems, an endoscope eyepiece assembly is provided, comprising: Eyepiece body; An eyepiece window is arranged at the free end of the eyepiece body to form an airtight package, and a buffer component is arranged on the contact surface between the eyepiece window and the eyepiece body to absorb the stress causing the deformation of the eyepiece window.

[0008] Furthermore, the buffer assembly includes a stress absorber, which is arranged on the annular step surface inside the free end of the eyepiece body; the eyepiece window is coaxially inlaid and fixed with the stress absorber.

[0009] Furthermore, the thermal expansion coefficient of the stress absorber is between that of sapphire and stainless steel.

[0010] Furthermore, the stress absorber is made of titanium alloy.

[0011] Furthermore, the buffer assembly also includes a stress release groove, which is arranged between the side wall of the eyepiece window and the inner wall of the eyepiece body to eliminate part of the residual stress after the eyepiece window is welded and fixed.

[0012] Furthermore, the buffer component can absorb a stress of 170-235 Mpa acting on the side wall of the eyepiece window; the buffer component can absorb a stress of 90-100 Mpa acting on the welding surface of the eyepiece window.

[0013] A second aspect of the present invention provides an endoscope, comprising an eyepiece end, a bending portion, an insertion portion, an operating portion, and a light guide portion, wherein the eyepiece end comprises the endoscope eyepiece assembly.

[0014] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: The present invention provides a buffer component on the contact surface between the eyepiece window and the eyepiece body to absorb the stress causing deformation of the eyepiece window, thereby avoiding the risk of delamination and matrix cracking in the welding area of ​​the eyepiece window due to excessive stress caused by direct welding of the eyepiece window and the eyepiece body. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 It is a connection diagram of the eyepiece assembly of a conventional endoscope; Figure 2 A schematic diagram of the connection of an endoscope eyepiece assembly disclosed in an embodiment of the present invention; Figure 3 A three-dimensional cross-sectional view of an endoscope eyepiece assembly disclosed in an embodiment of the present invention; Figure 4 This is a simulation diagram of the stress distribution of the eyepiece component of a traditional endoscope; Figure 5 A stress distribution simulation diagram when the endoscope eyepiece assembly disclosed in an embodiment of the present invention is provided with a stress absorbing member without a stress release groove; Figure 6This is a stress distribution simulation diagram when the endoscope eyepiece assembly disclosed in an embodiment of the present invention is provided with a stress absorbing member and a stress releasing groove at the same time.

[0017] In the figure: 100. Eyepiece body; 200, eyepiece window; 201, annular step surface 300, buffer assembly; 310, stress absorber; 320, stress release groove. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] See also Figure 2-3 The present invention aims to provide an endoscope eyepiece assembly, which can solve the stress concentration problem existing in the current eyepiece window being directly brazed on the eyepiece body.

[0020] A person skilled in the art further explained that the eyepiece body 100 is made of medical grade SUS316L stainless steel; the eyepiece window 200 is made of a sapphire window. Currently, the eyepiece window 200 is directly brazed and fixed to the eyepiece body 100, that is, the sapphire material and the stainless steel material are directly brazed in an airtight manner using gold-tin solder. Since the thermal expansion coefficients of the two materials are quite different, the sapphire window will be locally deformed after welding, resulting in welding stress concentration. These residual welding stresses will cause the metallized welding layer on the sapphire window to delaminate and fall off, thereby causing the airtightness failure of the medical endoscope.

[0021] Embodiment 1 The endoscope eyepiece assembly mainly includes an eyepiece body 100 and an eyepiece window 200, wherein the eyepiece window 200 is arranged at the free end of the eyepiece body 100 to form an airtight package to prevent external water vapor from corroding the internal chip, and its sealing performance satisfies: the airtightness level of the eyepiece assembly is R≤1.0*E-9Pa.m3 / s.

[0022] In particular, a buffer assembly 300 is provided on the contact surface between the eyepiece window 200 and the eyepiece body 100 to absorb the stress causing the deformation of the eyepiece window 200 .

[0023] A person skilled in the art further explains that the stress causing the deformation of the eyepiece window 200 is the stress that cannot be released after the eyepiece window 200 and the eyepiece body 100 are fixed by brazing.

[0024] In a further solution of this embodiment, the buffer assembly 300 includes a stress absorber 310, and the stress absorber 310 is disposed on the annular step surface 201 inside the free end of the eyepiece body 100. The eyepiece window 200 and the stress absorber 310 are coaxially inlaid and fixed.

[0025] Due to the large difference in thermal expansion coefficients between sapphire and stainless steel materials, and the fact that the metallized welding layer on the sapphire window is prepared by thin film sputtering, that is, the structural strength of the metallized welding layer on the sapphire window is insufficient, the thermal expansion coefficient of the stress absorber 310 should be between sapphire and stainless steel, and used as a transition welding structure to buffer the welding stress of the metallized welding layer on the sapphire window.

[0026] Preferably, the stress absorber 310 is made of titanium alloy.

[0027] Those skilled in the art further explained that titanium alloy is embedded between stainless steel and sapphire as a transition welding structure, forming a gradient structure from stainless steel to titanium alloy and then to sapphire, so that the thermal expansion coefficient changes gradually, which buffers the stress of direct welding of sapphire and stainless steel, and forms a stress reduction structure of stainless steel to titanium alloy, and titanium alloy to sapphire, thereby alleviating the stress concentration problem of the sapphire welding layer during direct welding and avoiding the risk of stratification of the welding area of ​​the sapphire window and cracking of the substrate.

[0028] See also Figure 4-5 , a stress distribution simulation experiment is performed through simulation software, and by comparing the stress distribution simulation results of the traditional endoscope eyepiece assembly and the endoscope eyepiece assembly provided in Example 1, it can be concluded that: Figure 4 The stress distribution simulation results of the traditional endoscope eyepiece assembly are shown as follows: The stress acting on the side of the sapphire window is about 260 MPa.

[0029] The stress acting on the welding surface of the sapphire window is about 150Mpa.

[0030] Figure 5 The stress distribution simulation results of the endoscope eyepiece assembly provided in the first embodiment are shown as follows: The stress acting on the side of the sapphire window is about 90 MPa.

[0031] The stress acting on the welding surface of the sapphire window is about 60Mpa.

[0032] It can be seen that in the case where the buffer assembly 300 is provided in the first embodiment and only the stress absorber 310 is provided, the stress acting on the side surface and the welding surface of the sapphire window is reduced accordingly.

[0033] Embodiment 2 On the basis of the first embodiment, the second embodiment further introduces the design of the stress release groove 320 .

[0034] In a further solution of the second embodiment, the buffer assembly 300 further includes a stress release groove 320, which is arranged between the side wall of the eyepiece window 200 and the inner wall of the eyepiece body 100, and is used to further eliminate part of the residual stress after the eyepiece window 200 is welded and fixed.

[0035] See also Figure 5-6 , a stress distribution simulation experiment is performed by simulation software, and by comparing the stress distribution simulation results of the endoscope eyepiece assembly provided in Example 1 with that provided in Example 2, it can be concluded that: Figure 5 The stress distribution simulation results of the endoscope eyepiece assembly provided in the first embodiment are shown as follows: The stress acting on the side of the sapphire window is about 90 MPa.

[0036] The stress acting on the welding surface of the sapphire window is about 60Mpa.

[0037] Figure 6 The stress distribution simulation results of the endoscope eyepiece assembly provided in the second embodiment are shown as follows: The stress acting on the side of the sapphire window is about 25 MPa.

[0038] The stress acting on the welding surface of the sapphire window is about 50Mpa.

[0039] visible: The buffer assembly 300 provided in the second embodiment can absorb the stress of 170-235 MPa acting on the side wall of the eyepiece window 200.

[0040] The buffer assembly 300 provided in the second embodiment can absorb the stress of 90-100 MPa acting on the welding surface of the eyepiece window 200.

[0041] The air tightness test of the endoscope eyepiece assembly provided in Example 2 yielded the following results: Experimental conditions: Temperature range: -60℃ to +150℃ for steady-state use.

[0042] Temperature cycle: from -65℃ to +150℃, the conversion time does not exceed 60 seconds; from +150℃ to +65℃, the conversion time does not exceed 60 seconds.

[0043] Continuous cycle times: Able to withstand 500 continuous cycles.

[0044] Experimental results: Air-tightness level: Under all the above conditions, the air-tightness level of the endoscope eyepiece assembly does not change.

[0045] The present invention also protects an endoscope, comprising an eyepiece end, a bending portion, an insertion portion, an operating portion, and a light guide portion, wherein the eyepiece end comprises the above-mentioned endoscope eyepiece assembly.

[0046] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An endoscope eyepiece assembly, characterized in that: include: Eyepiece body (100); An eyepiece window (200) is arranged at the free end of the eyepiece body (100) to form an airtight package, and a buffer component (300) is provided on the contact surface between the eyepiece window (200) and the eyepiece body (100) to absorb stress that causes deformation of the eyepiece window (200).

2. The endoscope eyepiece assembly according to claim 1, characterized in that: The buffer assembly (300) comprises a stress absorbing member (310), wherein the stress absorbing member (310) is arranged on an annular step surface (201) inside the free end of the eyepiece body (100); the eyepiece window (200) and the stress absorbing member (310) are coaxially inlaid and fixed.

3. The endoscope eyepiece assembly according to claim 2, characterized in that: The thermal expansion coefficient of the stress absorbing member (310) is between that of sapphire and stainless steel.

4. The endoscope eyepiece assembly according to claim 2, characterized in that: The stress absorbing component (310) is made of titanium alloy.

5. The endoscope eyepiece assembly according to claim 2, characterized in that: The buffer assembly (300) further comprises a stress release groove (320), wherein the stress release groove (320) is arranged between the side wall of the eyepiece window (200) and the inner wall of the eyepiece body (100) to eliminate part of the residual stress after the eyepiece window (200) is welded and fixed.

6. The endoscope eyepiece assembly according to claim 1, characterized in that: The buffer component (300) can absorb a stress of 170-235 Mpa acting on the side wall of the eyepiece window (200); and the buffer component (300) can absorb a stress of 90-100 Mpa acting on the welding surface of the eyepiece window (200).

7. An endoscope, comprising an eyepiece end, a bending portion, an insertion portion, an operation portion, and a light guide portion, characterized in that: The eyepiece end includes an endoscope eyepiece assembly as described in any one of claims 1-6.

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