JP2016202754A - Connection method and connection structure of piping member of endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable piping members of complicated shape to be water-tightly joined by laser welding without using complicated devices.SOLUTION: The connection method of the piping members of an endoscope according to one embodiment of the present invention includes: a sealing step in which the respective metal connection parts of a first piping member and a second piping member are bonded with a sealing layer and the ducts formed in the first piping member and the second piping member are communicated; and a welding step in which at least a part of the connection part formed in the sealing step is irradiated with a laser beam and the first piping member and the second piping member are welded.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a connection method and a connection structure for a piping member of an endoscope.

  An endoscope having an air supply / water supply function and a suction function includes a pipeline (air supply channel, water supply channel) for transporting a fluid such as air or water. Many of such pipelines are configured by connecting a plurality of piping members formed of a corrosion-resistant alloy material such as stainless steel. The plurality of piping members are connected by water-tightly connecting the piping members by welding or silver brazing. In recent years, so-called laser welding by laser beam irradiation has come to be used from the viewpoint of ease of work and certainty of welding (for example, Patent Document 1).

  In the conventional laser welding described in Patent Document 1, a laser beam is irradiated to a joint portion of two piping members, and an injection port of a laser irradiation device (hereinafter simply referred to as an irradiation device) is connected to a central axis of a pipeline. This is done by rotating 360 degrees around and welding the entire circumference of the joint.

  Also, in recent years, the endoscope ducts have become increasingly complicated in shape due to the complexity of the internal structure accompanying the reduction in diameter and multifunction of the endoscope.

JP 2009-172081 A

  For example, when the pipe member 2 that is largely bent is connected as shown in FIG. 5, the pipe member 2 blocks the irradiation of the laser beam to the portion indicated by the symbol X of the joint. Therefore, in the conventional laser welding method of irradiating while rotating the injection port of the irradiation device, it is not possible to perform laser welding completely over the entire circumference of the joint, and it is possible to ensure the water tightness of the joint. could not. In order to completely laser weld the entire circumference of the joint, it is necessary to introduce a laser welding apparatus equipped with an elaborate mechanism such as an articulated robot or a scanning optical system, and the laser welding apparatus becomes complicated and large. In addition, there is a problem that a new expensive equipment cost is required.

  The present invention has been made in view of the above circumstances, and the object of the present invention is to allow watertight joining of piping members having complicated shapes by laser welding without using a complicated device. It is providing the connection method of the piping member of an endoscope.

  In the method for connecting a piping member of an endoscope according to an embodiment of the present invention, the connecting portion of the first piping member made of metal and the connecting portion of the second piping member are joined via a sealing layer, respectively. A sealing step for connecting the pipes formed respectively to the first piping member and the second piping member, and irradiating at least a part of the joint formed by the sealing step with a laser beam; A welding step for welding the two piping members.

  In the above connection method, the sealing step may include an application step of applying a sealing material to at least one of the connection portions of the first piping member and the second piping member.

  In the above connection method, the sealing step may include a mounting step of mounting the sealing member on at least one of the connection portions of the first piping member and the second piping member.

  In the above connection method, the welding step may be performed after the sealing step.

  In the above connection method, the sealing step may include a retraction forming step in which the sealing layer is formed at a position separated from the position where the weld is formed by a predetermined retraction distance or more.

  In the above connection method, a sealing layer is provided between the fitting portion that fits the connecting portion of the first piping member with the connecting portion of the second piping member without a substantial gap and the connecting portion of the second piping member. It is good also as a structure including the step which forms the recessed part which forms the space formed.

  In the above connection method, the sealing layer may be formed of an adhesive.

  In the welding step in the above connection method, when irradiation of the laser beam to one place of the joint is blocked by the second piping member, the laser beam may be irradiated to at least a part of the joint except for the one place. Good.

  In the above connection method, the welding step irradiates the laser beam while rotating the path of the laser beam around the central axis of the joint, and the rotation angle range in which the laser beam irradiation is blocked by the second piping member. The method may include a step of stopping the irradiation of the laser beam.

  Moreover, the connection structure of the piping member of the endoscope according to the embodiment of the present invention is formed in the annular first connecting portion formed in the metal first piping member and the metal second piping member. An annular second connecting portion, and a joining portion that joins the first connecting portion and the second connecting portion, and the joining portion is joined to a sealing layer formed over the entire circumference of the joining portion, A welded portion formed by laser beam irradiation on at least a part of the portion.

  According to one embodiment of the present invention, it is possible to join pipe members having complicated shapes by laser welding without using a complicated apparatus.

It is a flowchart which shows the procedure of the connection method of the piping member of the endoscope which concerns on embodiment of this invention. It is a figure explaining the connection method of the piping member of the endoscope concerning the embodiment of the present invention. It is a figure explaining the connection method of the piping member of the endoscope concerning the embodiment of the present invention. It is a figure explaining the modification of embodiment of this invention. It is a figure explaining the connection method of the piping member of the conventional endoscope.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In the embodiment described below, a cylinder member (first piping member 1) of an air / water supply operation valve provided in an operation unit of an endoscope and pressurized air (or water) are transported to the cylinder member. It is an example which applied this invention to the connection with a conduit | pipe (2nd piping member 2).

  FIG. 1 is a flowchart illustrating a procedure of a method for connecting a piping member of an endoscope according to an embodiment of the present invention.

[Adhesion process S1]
In the connection method of the present embodiment, the bonding step S1 is first performed.
FIG. 2 is a diagram showing a state of the bonding step S1 of the present embodiment. The first piping member 1 and the second piping member 2 are each formed of a corrosion-resistant alloy material such as stainless steel (for example, SUS304).

  The first piping member 1 and the second piping member 2 (particularly the second piping member 2), which are the connection targets of the present embodiment, are the same as the members 1 and 2 shown in FIG. 5 (prior art), respectively. Thus, the conventional connection method cannot be connected well.

  In the bonding step S1 (FIG. 2), first, an annular connecting portion 2a that is the outer periphery of one end of the second piping member 2 and an annular connecting portion that is the inner periphery of the insertion hole provided in the first piping member 1 Adhesive is applied to substantially the entire at least one of la. And the connection part 2a (one end part of a conduit | pipe) of the 2nd piping member 2 is engage | inserted by the connection part 1a (insertion hole) of the 1st piping member 1. FIG. Furthermore, if necessary, heat treatment or the like is performed to cure the adhesive, so that the connection portion 1a of the first piping member 1 and the connection portion 2a of the second piping member 2 are fitted around the entire circumference of the joint portion 3. The adhesive layer 4 is formed over the entire area. Thereby, the gap between the joint portions 3 is completely sealed by the adhesive layer 4. By the bonding step S1, the pipe line (hollow portion) of the first pipe member 1 and the pipe line of the second pipe member 2 are connected in a watertight (or airtight) manner.

  Various types of adhesives can be used as the adhesive used in the bonding step S1. For example, an adhesive having excellent water resistance and heat resistance such as an epoxy adhesive is used. In this embodiment, an adhesive having biocompatibility is used.

[Welding step S2]
Next, a welding step S <b> 2 is performed in which the joint 3 is welded (seam welding) by irradiation with the laser beam L.

  FIG. 3 is a diagram showing a state of the welding step S2 of the present embodiment. In the welding step S <b> 2, laser welding is performed only on a portion of the portion exposed to the outside of the joint portion 3 where the irradiation (path) of the laser beam L is not blocked by the second piping member 2. Specifically, in the welding step S2, an irradiation port (not shown) of the irradiation device is rotated around the central axis Ax of the pipe line in the joint 3 while irradiating the exposed surface of the joint 3 with the laser beam L. (That is, the path of the laser beam L is rotated). At this time, the irradiation of the laser beam L is stopped in the rotation angle range in which the irradiation (path) of the laser beam L is blocked by the second piping member 2. Further, a welded portion 5 is formed at a location where the laser beam L of the joint portion 3 is irradiated.

  As the irradiation device, an irradiation device including a high-power infrared laser device such as a YAG laser or a carbon dioxide laser is used. The types of laser devices are not limited to these, and various types of laser devices suitable for laser welding can be used.

  Further, the irradiation device supplies a shielding gas (for example, an inert gas such as argon or helium, or a mixed gas of inert gas and carbon dioxide) to the welded portion, and shield means for shielding the welding surface from the air. It has. By using the shielding means, the oxidation of the surface of the welded portion 5 is suppressed.

  The shield means is connected to the first ejection nozzle 11 that blows the shield gas A1 from the outside to the joint 3 and the other end of the second piping member 2, and is placed in the pipe lines of the first piping member 1 and the second piping member 2. And a second ejection nozzle 12 for introducing the shield gas A2. Oxidation of the surface exposed to the outside of the welded portion 5 is suppressed by the shield gas A1. Further, the shield gas A <b> 2 suppresses oxidation of the surface exposed to the pipe line of the welded portion 5 or the surface exposed to the gap between the first piping member 1 and the second piping member 2. During welding, a substantially constant amount of shielding gas A1 and A2 is ejected from the first ejection nozzle 11 and the second ejection nozzle 12, respectively. Further, during welding, the first ejection nozzle 11 rotates together with the laser beam L around the central axis Ax of the pipe line in the joint portion 3. With this configuration, the welded portion 5 is always shielded from oxygen during welding, and oxidation of the welded portion 5 is reliably prevented. Moreover, since the environment of the welded part 5 (for example, the flow rate of the shielding gas flowing around the welded part 5) is kept substantially constant during welding, welding with high uniformity is possible.

[Features of this embodiment]
As shown in FIG. 2, the second piping member 2 is greatly bent. Therefore, ideally, the joint portion 3 (more specifically, the portion exposed to the outside of the joint portion 3) to be laser-welded over the entire circumference is a part of the circumferential direction (for example, in FIG. 3). The irradiation path of the laser beam L to the portion indicated by the symbol X is blocked by the second piping member 2, and the laser beam L cannot be irradiated. That is, the joint portion 3 between the first piping member 1 and the second piping member 2 cannot be completely welded over the entire circumference.

  In this embodiment, although the part which is not welded remains in a part in the circumferential direction of the junction part 3, if sufficient welding length is ensured, required connection strength will be obtained. However, there is a possibility that a small gap connecting the inside and outside space of the pipe line may be left in the part that is not welded. Therefore, welding alone is a junction part of the endoscope pipe line (especially the air supply channel and the water supply channel). There is a risk that the watertightness (water-stopping) and airtightness required for the above may not be obtained.

  Therefore, in the present embodiment, the bonding step S1 is performed before the welding step S2, and an adhesive layer (sealing layer) is formed over the entire circumference of the joint portion 3 between the first piping member 1 and the second piping member 2. The process which forms 4 is performed and sealing is assumed to be reliable.

  Moreover, in this embodiment, as above-mentioned, adhesion process S1 is performed before welding process S2. And welding process S2 is performed in the state in which the 1st piping member 1 and the 2nd piping member 2 were adhere | attached and fixed by predetermined adhesive by the adhesive agent. Therefore, it is not necessary to use a jig for keeping the first piping member 1 and the second piping member 2 in a predetermined positional relationship during the welding step S2. As a result, the welding location (the movable range of the laser beam L) is not restricted by the arrangement of the jig.

  The above is the description of the exemplary embodiments of the present invention. Embodiments of the present invention are not limited to those described above, and various modifications are possible within the scope of the technical idea of the present invention. For example, the embodiments of the present invention also include embodiments or the like that are exemplarily specified in the specification, or contents that are appropriately combined with embodiments that are obvious from the description.

  In the above embodiment, in the bonding step S1, the adhesive is applied to substantially the entire joint 3 including the portion where the laser beam L is irradiated and the weld 5 is formed, but the present invention is limited to this configuration. Not. For example, as in a first modified example and a second modified example described below, a configuration in which the adhesive layer 4 is provided away from a position where the welded portion 5 is formed may be employed.

[First Modification]
FIG. 4 shows a modification of the embodiment of the present invention.
FIG. 4A is a diagram showing a first modification of the embodiment of the present invention. The first modified example is an example in which the adhesive layer 4 is formed at a predetermined retraction distance D or more from the position where the weld 5 is formed. In such a configuration, the adhesive is applied only to the connecting portion 1a of the first piping member 1 at a predetermined retraction distance D or more from the position where the welded portion 5 is formed, and the second piping member is applied to the connecting portion 1a. It is obtained by inserting the two connecting portions 2a and performing laser welding.

[Second Modification]
FIG. 4B is a diagram showing a second modification of the embodiment of the present invention. In the second modification, the fitting portion 1c that fits with the connection portion 2a of the second piping member 2 on the opening side of the connection portion 1a of the first piping member 1 (on the right side in FIG. 4B) with almost no gap. An annular groove (expanded diameter portion) 1e having an inner diameter wider than the fitting portion 1c is formed on the opposite side of the opening (left side in FIG. 4B). The annular groove 1e is filled with an adhesive before the connection portion 2a of the second piping member 2 is inserted, and the adhesive layer 4 is formed. By providing the annular groove 1e, the formation position of the adhesive layer 4 can be accurately managed.

  By adopting a configuration in which the adhesive layer 4 is provided apart from the position where the welded portion 5 is formed as in the first and second modified examples described above, poor welds and welded portions due to the adhesive remaining after welding Corrosion of the pipe line due to the corrosion of 5 and the decomposition of the adhesive (spattering of components) due to heat during welding is prevented or reduced.

[Other variations]
The above embodiment is an example in which the present invention is applied to the connection between the cylinder member and the conduit of the air / water feeding operation valve. However, the present invention is not limited to this configuration, and airtightness and watertightness are required. The present invention can be applied to connection of various piping members (for example, connection between conduits). Further, the present invention is not limited to a pipeline that transports fluid, but can be applied to, for example, a pipeline through which a communication line or a power line is passed, or a connection of a treatment instrument insertion channel. Further, the present invention can be applied not only to an endoscope but also to connection of conduits provided in various medical devices and medical analysis devices.

  Moreover, in said embodiment, although sealing (sealing of airtightness or watertightness) is made | formed by providing an adhesive layer over the perimeter of the junction part of two piping members to weld, this book The invention is not limited to this configuration. For example, a sealing material (sealing material) having a sealing function such as silicone resin as a main function can be used instead of the adhesive. Further, the sealing material is not limited to a solidified solid and may be a liquid (or gel). Alternatively, the sealing portion may be formed by mounting a solid (for example, elastic elastomer or sponge-like foamed resin) on the connection portion.

  Moreover, in said embodiment, although welding is performed by irradiating the junction part 3 with the laser beam L from the outside, this invention is not limited to this structure. If possible depending on the shape of the pipe member to be welded, the laser beam L may be applied to the joint portion 3 from the pipe line side (inner side). Moreover, you may irradiate the laser beam L to the junction part 3 from both the outer side and inner side.

  Moreover, in said embodiment, although a welding process is performed after an adhesion process, an adhesion process can also be performed after a welding process. In this case, you may provide the groove | channel used as the flow path for flowing an adhesive agent into a junction part after a welding process in the connection part 1a of the 1st piping member 1, or the connection part 2a of the 2nd piping member 2. FIG.

  In the above embodiment, the present invention is applied when laser welding cannot be performed over the entire circumference of the joint. However, when laser welding is possible over the entire circumference of the joint. The present invention can also be applied effectively. Even when laser welding can be performed over the entire circumference, it is not always easy to perform laser welding completely and reliably over the entire circumference. Further, even when laser welding is complete at the time of manufacture of an endoscope, a defect (gap) may occur in the weld due to aging or the like. Even when laser welding is possible over the entire circumference of the joint, by applying the present invention, the water stop integrity of the weld can be improved.

DESCRIPTION OF SYMBOLS 1 1st piping member 2 2nd piping member 3 Joining part 4 Adhesive layer (sealing layer)
5 Welding part 11 1st ejection nozzle 12 2nd ejection nozzle A1, A2 Shielding gas L Laser beam

Claims (10)

The connecting portion of the first piping member made of metal and the connecting portion of the second piping member are joined via a sealing layer, and the pipe lines formed in the first piping member and the second piping member are connected to each other. A sealing step,
A welding step of irradiating at least a part of the joint formed by the sealing step with a laser beam and welding the first piping member and the second piping member;
including,
Endoscope piping member connection method. The sealing step comprises:
An application step of applying a sealing material to at least one of the connection portions of the first piping member and the second piping member;
The connection method of the piping member of the endoscope according to claim 1. The sealing step comprises:
A mounting step of mounting a sealing member on at least one of the connection portions of the first piping member and the second piping member;
The connection method of the piping member of the endoscope according to claim 1. The welding step is performed after the sealing step;
The connection method of the piping member of the endoscope as described in any one of Claims 1-3. The sealing step comprises:
Including a retraction forming step of forming the sealing layer at a position away from a position where the weld is formed by a predetermined retraction distance or more,
The connection method of the piping member of the endoscope as described in any one of Claims 1-4. In the connection part of the first piping member,
A fitting portion that fits with the connection portion of the second piping member without a substantial gap;
A recess that forms a space in which the sealing layer is formed between the connection portion of the second piping member,
Including the step of forming
The connection method of the piping member of the endoscope as described in any one of Claims 1-5. The sealing layer was formed from an adhesive;
The connection method of the piping member of the endoscope as described in any one of Claims 1-6. In the welding step,
When irradiation of the laser beam to one place of the joint is blocked by the second piping member, the laser beam is irradiated to at least a part of the joint excluding the one place.
The connection method of the piping member of the endoscope as described in any one of Claims 1-7. The welding step comprises:
Irradiating the laser beam while rotating the path of the laser beam around the central axis of the joint; and
Stopping the laser beam irradiation in the rotation angle range in which the laser beam irradiation is blocked by the second piping member;
including,
The connection method of the piping member of the endoscope as described in any one of Claims 1-8. An annular first connecting portion formed on the first piping member made of metal;
An annular second connecting portion formed in the second pipe member made of metal;
A joining portion joining the first connecting portion and the second connecting portion;
With
The joint is
A sealing layer formed over the entire circumference of the joint;
A weld formed by irradiation of a laser beam on at least a part of the joint;
Having
Connection structure for piping members of an endoscope.

Images