JPH08286127A - Top end part of endoscope - Google Patents

Abstract

PURPOSE: To provide a top end part of an endoscope capable of mechanically and surely connecting the metallic part of the top end part main body and a plastic part by easy processing and work. CONSTITUTION: As for the top end part of the endoscope, the inner part of the top end part main body 1 with built-in objective optical system etc., and connected to the top end of an insertion part is formed of metal, and also, a part exposed to the surface is formed of plastic, through-holes 41 and 42 opening at a boundary part between the metallic part 1a and the plastic part 1b are drilled in the metallic part 1a, and also, bar-shaped projections 43 and 44 projecting into the other end sides of the through-holes 41 and 42 while fitting into the through-holes 41 and 42 are projectingiy installed on the plastic part 1b, then, the projecting end parts of the projections 43 and 44 projecting from the through-holes 41 and 42 are melted so that they may become larger than the diameters of the holes 41 and 42, and then, the projecting end parts are brought into close contact with the metallic part 1a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distal end portion of an endoscope in which a portion on the inner side of a tip portion main body is made of metal and a portion on the surface exposed side is made of plastic.

[0002]

2. Description of the Related Art The body of the distal end portion of an endoscope is made of metal for the purpose of ensuring mechanical strength, and plastic for the portion exposed to the surface for the sake of electrical safety. It is often done. In such a tip body, it is necessary to surely connect and fix both the metal portion and the plastic portion so as not to separate from each other.

Therefore, conventionally, a protrusion formed on a plastic portion is fitted into a concave portion on the metal portion side (actually, the 62-
No. 6716), Tegsu is passed through a groove formed in the plastic portion (Actual No. 4-111301), and a joining state reinforcing means for joining the metal portion and the plastic portion to further reinforce them is provided ( Actual fair 6-49281
issue).

[0004]

However, the structure in which the protrusion formed on the plastic portion is fitted into the concave portion on the metal portion side is extremely difficult to process in order to form the fitting portion so that the fitting portion does not easily come off. difficult.

[0007] Further, the one in which the gut is passed through the groove is not sufficient as a measure for preventing separation because the gut may be cut.
Since the one provided with the joining state reinforcing means is only for reinforcing the adhesion, the mechanical strength is not always sufficient.
There is also a problem that the number of parts increases.

Therefore, an object of the present invention is to provide a distal end portion of an endoscope capable of mechanically and reliably connecting the metal portion and the plastic portion of the distal end portion main body with simple processing and work.

[0007]

In order to achieve the above-mentioned object, the distal end portion of the endoscope of the present invention has an internal side of the distal end portion main body, which has a built-in objective optical system and is connected to the distal end of the insertion portion. At the tip of the endoscope in which the part of the metal part is formed of metal and the part on the side exposed on the surface is formed of plastic, a through hole is opened in the boundary part between the metal part and the plastic part. A rod-shaped protrusion that is fitted in the through hole and protrudes to the other end side of the through hole from the plastic portion, and the protruding end portion of the protrusion protruding from the through hole is the through hole. It is characterized in that it is melted so as to be thicker than the diameter of and is brought into close contact with the metal portion.

The projections and the through holes may be provided at positions displaced from the central axis of the tip end body, and a plurality of the projections and the through holes may be provided. Further, the projection may be provided with an insertion hole for inserting an internal component of the endoscope, and the rear end side outer peripheral part of the plastic part is formed in the front end side of the metal part. The protrusion may be formed so as to fit inside the portion, and the protrusion may be formed so as to project outward from the outer peripheral surface of the rear end of the plastic portion.

[0009]

Embodiments will be described with reference to the drawings. 1 to 4 show a first embodiment of the present invention.
[Fig. 3] is a perspective view of a distal end portion of an insertion portion of an endoscope, Fig. 3 is a front view thereof, and Fig. 1 is a side sectional view.

Insertion part 1 formed by an elongated flexible tube
A bending portion 2 which is bendable by a remote operation from an operation portion (not shown) is provided at the tip of 00, and the tip portion main body 1 is connected to the tip portion.

The bending portion 2 has a large number of node rings 3 rotatably connected by rivets, the outer periphery of which is covered with a mesh tube 5, which is further covered with a rubber tube 6 or the like, and the end portion thereof is the tip portion main body. It is configured by binding and bonding to the outer peripheral surface of 1.

The tip portion main body 1 is provided on the inner side so as not to be exposed to the outer surface, and is connected to the tip of the curved portion 2 by a metal block portion 1a made of stainless steel, and a metal block portion 1a.
And an electrically insulating plastic block portion 1b that is connected and fixed to the front side of the and exposed on the outer surface.

The endoscope of this embodiment is a so-called front-viewing type endoscope for observing the front of the tube axis, and an observation window 7, an illumination window 8 and a forceps channel are provided on the tip surface of the tip body 1. An outlet hole 9 is arranged.

Reference numeral 50 denotes a tip cap formed of a material having no elasticity such as polyurethane rubber, which is not conductive, and covers the outer peripheral surface of the tip body 1 from the tip side of the tip body 1. Installed.

An air / water supply nozzle 11 that opens toward the surface of the observation window 7 and a jet injection nozzle 12 that opens forward toward the subject are formed in the tip cap 50.

Reference numerals 13 and 14 denote an air supply conduit and a water supply conduit formed in the tip end main body 1 so as to communicate with the air supply / water supply nozzle 11, and 15 denotes a tip end main body 1 so as to communicate with the jet injection nozzle 12. Is an auxiliary water supply line formed in the
Each tube is connected to a tube (not shown) inserted therein.

As shown in FIG. 1, an objective optical system 16 is disposed inside the observation window 7 so as to be fixed inside a metallic lens frame 17. An insulating ring 21 made of an electrically insulating plastic material is joined to the outer peripheral portion of the front half of the lens frame 17.

The outer peripheral surface of the insulating ring 21 is fitted in a hole formed in the plastic block portion 1b of the tip end body 1, and an O-ring 23 for sealing is attached to the fitting portion. .

A shield pipe 25 made of metal is fitted and joined to the outer periphery of the rear portion of the lens frame 17, and a solid-state image pickup device 26 made of, for example, a charge coupled device (CCD) serves as an image receiving surface in the shield pipe 25. It is fixed facing forward.
On the outer peripheral surface of the shield pipe 25, the metal block 1a
Insulating tape is wrapped around to provide electrical insulation between and.

A transparent cover glass 27 is arranged in close contact with the front side thereof, and a low pass filter 28 and a YAG laser light cut filter 29 are further provided on the front side thereof.
Is affixed.

An observation light image is formed on the image receiving surface of the solid-state image pickup device 26 by the objective optical system 16 through the transparent members 27, 28 and 29. Reference numeral 30 is a light shielding mask for shielding unnecessary light around the optical path.

In the shield pipe 25, electronic parts for processing signals input to and output from the solid-state image pickup device 26 are mounted on the wiring board 32 and arranged, and the signal cable 33 is drawn rearward therefrom. .

The present invention is directed to such a solid-state image pickup device 2
It may be applied to an endoscope using an optical image transmitting means using an image guide fiber bundle instead of the electronic image transmitting means using 6, and may be applied to a rigid endoscope.

As shown in FIG. 1, the tip cap 50.
On the inner peripheral surface of the latter half of the above, a locking projection 51 that fits into and engages with the circumferential groove 1c formed by circumferentially recessing the outer peripheral surface of the tip end main body 1 projects inward. It is provided to prevent the tip cap 50 from coming off when it is attached to the tip body 1.

The connecting portion between the metal block portion 1a and the plastic block portion 1b is connected to the rear end portion of the plastic block portion 1b formed in a cylindrical shape as shown in FIG. 1 and FIG. 4 which is an exploded view of both portions. The front end portion of the cylindrical metal block portion 1a is fitted and connected. 1
Reference numeral d denotes a fitting portion on the plastic block portion 1b side, and 1e denotes a cylindrical portion on the metal block portion 1a side.

The signal cable 3 is attached to the metal block 1a.
3 and a light guide fiber bundle for illumination, a hole for inserting various built-in objects such as tubes, etc. are bored through in the axial direction.

Two through-holes 41 and 42 having different diameters for connecting with the plastic block portion 1b are provided in parallel with the holes, respectively, so as to contact the plastic block portion 1b. It is straightly bored rearward so that one end is opened at the contact surface and the other end is opened at the rear end surface.

Then, in the plastic block portion 1b, rod-shaped projections 43 and 44 are aligned with the two connecting holes 41 and 42 and fitted into the connecting holes 41 and 42.
Is provided so as to project straight rearward from a rear end surface which is a contact surface with the metal block portion 1a. The protrusions 43 and 44 are molded by the same mold when molding the plastic block portion 1b.

The lengths of the protrusions 43 and 44 are the same as the connecting holes 41 and
Since it is formed longer than the length of 42, the projections 43, 4
The projecting end portion 4 further projects rearward from the rear ends of the connecting holes 41 and 42.

The original shape of the projections 43 and 44 is a rod shape having a uniform diameter as shown in FIG.
44 is inserted into the connection holes 41, 42 to firmly bring the plastic block portion 1b and the metal block portion 1a into close contact, and then the projections 43, 44 protruding from the connection holes 41, 42.
Is melted by heating.

As a result, the tips of the protrusions 43 and 44 are
As shown in FIG. 1, the connecting holes 41 and 42 are formed to have a diameter larger than that of the connecting holes 41 and 42, and the portion is in close contact with the rear end surface of the metal block portion 1a.

As a result, the metal block portion 1a and the plastic block portion 1b are mechanically and firmly connected so as not to come off. An adhesive may be applied to the contact surface between the plastic block portion 1b and the metal block portion 1a.

Further, in this embodiment, the connecting holes 41, 42 are
The projections 43 and 44 are both displaced from the central axis position of the tip end main body 1, whereby the relative rotation between the metal block portion 1a and the plastic block portion 1b is also restricted. In this way, the fitting position is set to the tip body 1
If shifted from the central axis position of the connection holes 41, 42 and the protrusion 4
There may be only one 3,44.

FIG. 5 shows a second embodiment of the present invention, in which a counterbore portion having a large diameter is formed at the rear end portions of the connection holes 41, 42 so that the tip end fusion portions of the protrusions 43, 44 are formed. The protrusions 43 and 44 are housed in the spot facing portion so that the protrusions 43 and 44 do not project backward from the rear end surface of the metal block portion 1a.

6 to 9 show a third embodiment of the present invention. FIG. 6 is a side sectional view, FIG. 7 is a VII-VII sectional view, FIG. 8 is a VIII-VIII sectional view, and FIG. FIG. 3 is an exploded perspective view. Since the optical system and other built-in components are the same as those in the first embodiment, they are not shown.

In this embodiment, the first protrusion 47
However, as shown in FIG. 9 and the like, the plastic block portion 1b is formed so as to partially project outward from the fitting surface 1d.

Therefore, when a force in the direction of relatively rotating the metal block portion 1a and the plastic block portion 1b is applied, a concentrated shearing stress does not act on the first protrusion 47, so that the first protrusion 47 is unlikely to be damaged.

Further, the thickly formed second protrusion 48 is
It is formed in a tubular shape surrounding the shield pipe 25 of the imaging unit, and the shield pipe 25 is inserted into the second protrusion 48. The second connecting hole 46 on the side of the metal block portion 1a is formed in alignment with the second protrusion 48.

By forming in this way, the space required for forming the protrusion can be reduced and the metal block portion 1a and the plastic block portion 1b can be firmly connected.

Further, the shield pipe 25 has the tip end main body 1
Since it does not come into contact with the metal block 1a, it is not necessary to wind an insulating tape or the like around the outer peripheral surface of the shield pipe 25.
Then, by filling the rear end opening of the shield pipe 25 with an insulating putty or the like, the wiring board 32 and the signal cable 3
The connection with 3 is sealed.

The present invention is not limited to the above embodiment, and for example, three or more connecting holes and protrusions inserted therein may be provided.

[0042]

According to the present invention, a rod-shaped protrusion protruding from a plastic portion is fitted into a through hole formed in a metal portion forming a tip end main body, so that a protrusion protruding from the inside of the through hole is formed. By melting the protruding end portion so as to make it thicker than the diameter of the through hole and bringing it into close contact with the metal portion, the metal portion and the plastic portion can be mechanically and reliably connected by simple processing and work.

By providing the projection and the through hole at positions displaced from the central axis of the tip end main body, relative rotation of the plastic portion and the metal portion is prevented, and a plurality of projections and through holes are provided for connection. Strength increases.

Further, if the projection is provided with an insertion hole for inserting the built-in object of the endoscope and the built-in object is passed through the hole, space can be saved, and at the same time, the metal portion of the tip body can be saved. If the projection is formed by protruding outward from the outer peripheral surface of the rear end of the plastic part that fits with the metal part, the electrical stress between the internal part and the built-in part is secured , Hard to break.

[Brief description of drawings]

FIG. 1 is a side sectional view of a distal end of an insertion portion of a first embodiment.

FIG. 2 is a perspective view of the tip of the insertion portion of the first embodiment.

FIG. 3 is a front view of the distal end of the insertion portion of the first embodiment.

FIG. 4 is an exploded perspective view of a tip body of the first embodiment.

FIG. 5 is a side sectional view of the tip of the insertion portion of the second embodiment.

FIG. 6 is a side sectional view of a distal end of an insertion portion of a third embodiment.

FIG. 7 is a sectional view taken along line VII-VII of the third embodiment.

FIG. 8 is a sectional view taken along the line VIII-VIII of the third embodiment.

FIG. 9 is an exploded perspective view of a tip portion main body according to a third embodiment.

[Explanation of symbols]

 1 Tip part main body 1a Metal block part 1b Plastic block part 41, 42 Connection hole (through hole) 43, 44 Rod-shaped protrusion

Claims (5)

[Claims] 1. An endoscope in which an inner part of a distal end body connected to the distal end of an insertion part, which incorporates an objective optical system and the like, is made of metal, and a part exposed on the surface is made of plastic. At the tip of the rod, a through hole that opens at the boundary between the metal portion and the plastic portion is formed in the metal portion, and the rod shape is fitted into the through hole and protrudes to the other end side of the through hole. Of the protrusion protruding from the inside of the through hole, and the protrusion end portion of the protrusion protruding from the inside of the through hole is melted to be thicker than the diameter of the through hole and brought into close contact with the metal part. The tip of the endoscope. 2. The distal end portion of the endoscope according to claim 1, wherein the projection and the through hole are provided at positions displaced from the central axis of the distal end portion main body. 3. The distal end portion of the endoscope according to claim 1, wherein a plurality of said projections and through holes are provided. 4. The distal end portion of the endoscope according to claim 1, wherein the projection has an insertion hole for inserting an internal component of the endoscope. 5. A rear end outer peripheral surface of the plastic portion is formed so as to be fitted in a cylindrical portion formed on the front end side of the metal portion, and the protrusion is a rear end outer peripheral surface of the plastic portion. The projection is formed so as to project further outward.
The distal end portion of the endoscope according to 2, 3, or 4.