JP2011067384A - Connector used to manufacture flexible tube for endoscope and method of manufacturing flexible tube for endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connector having high identification performance of connecting position and a method of manufacturing a flexible tube for an endoscope using the connector. <P>SOLUTION: A continuous molding machine 25 includes: an extruding portion 27; a head portion 28; a cooling portion 29; a carrying portion 30; and a control portion 31. The carrying portion 30 feeds a connected flexible tube raw material 23 formed by connecting a plurality of flexible tube raw materials 14 into one by connecting members 19, 20 into the head portion 28. Resin is extruded from the extruding portion 27 to a molding passage 41 of the head portion 28, and the connected flexible tube raw material 23 covered with the skin layer is delivered from an outlet hole 41a of the molding passage 41. The outlet hole 41a has a minimum passage inside diameter D<SB>1</SB>minimized in diameter in the whole section of the molding passage 41. A clearance between the minimum passage inside diameter D<SB>1</SB>and the outside diameters D<SB>2</SB>of large-diameter portions of the connecting members 19, 20 is 0.1 mm or less, and the skin layer is not formed on the outer peripheral surfaces of the large-diameter portions of the connecting members 19, 20. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a connector used when a flexible tube for an endoscope is manufactured by connecting a plurality of flexible tube materials and extruding an outer skin layer, and using the connector, the endoscope is flexible. The present invention relates to a manufacturing method for manufacturing a pipe.

  A medical endoscope for observing the inside of a body cavity of a patient is known. This endoscope includes an insertion portion to be inserted into a patient's body cavity and an operation portion provided at the proximal end of the insertion portion. The flexible tube, which is the main part that constitutes the insertion section, is made up of a spiral tube formed by winding a metal strip in a spiral shape, a cylindrical net covering the spiral tube, and a resin such as urethane. It is comprised from the outer skin layer coat-molded on the surface of the cylindrical net.

  The outer skin layer is coated and formed by extrusion molding on the outer peripheral surface of a flexible tube material in which a spiral tube is covered with a cylindrical net. In order to efficiently perform the molding process of the outer skin layer, a plurality of flexible tube materials are connected and fed into a molding passage of an extrusion molding machine, and the plurality of connected flexible tube materials are melted while being conveyed. An outer skin layer is extruded by supplying the resin in a state to the molding passage.

  In order to connect a plurality of flexible tube materials to one, for example, as described in Patent Documents 1 to 3, a connector that engages and connects the ends of two flexible tube materials. Is used. The connector is attached to the flexible tube material before molding, passes through the molding passage together with the flexible tube material, and is detached from the flexible tube material after the molding is completed. Since the connector passes through the molding passage, the outer skin layer is covered in the same manner as the flexible tube material. After forming, the connected flexible tube materials are separated by removing the connector, but the connector is covered with an outer skin layer together with the flexible tube material, so it is difficult to find the connection position. .

  Therefore, in the couplers described in Patent Documents 1 to 3, a large-diameter portion having a larger diameter than the other parts of the coupler is provided in the central portion in the axial direction. Since the outer diameter layer of the large-diameter portion is raised as compared with other portions, the connection position can be found by identifying the rise by visual observation or tactile sense.

JP-A-8-304712 Patent registration 3641221 Japanese Patent Registration No. 3542782

  However, the conventional method of searching for a connection position by relying on the rise of the surface of the outer skin layer has a problem in that it takes much time to confirm the connection position because of poor identification.

  In addition, it has been studied to automatically separate a plurality of connected flexible tube materials after the formation of the outer skin layer. In that case, since the connection position is automatically identified using a photo sensor or the like, further improvement in the identification of the connection position has been demanded.

  The present invention has been made in view of the above circumstances, and an object thereof is to improve the identifiability of the connection position.

  In order to achieve the above object, a connector used in the manufacture of a flexible tube for an endoscope according to the present invention connects a plurality of flexible tube materials in a row and feeds them into a molding passage of an extrusion molding machine. This is used when extruding the outer skin layer covering the outer periphery of each flexible tube material by supplying molten resin material to the molding passage while conveying the plurality of flexible tube materials. A connector for connecting a flexible tube material, wherein the connector passes through the molding passage together with the flexible tube material and is detached from the flexible tube material after the molding is completed. A large-diameter portion having a diameter larger than the diameter of the outer skin layer as compared with the diameter and having a clearance with respect to the smallest passage inner diameter in all sections of the molding passage is 0.1 mm or less. It is characterized by.

  It is preferable that an inclined surface that is inclined so that the diameter gradually decreases along the axial direction from the large diameter portion is provided. Moreover, it is preferable to provide a small diameter portion having a smaller diameter than the large diameter portion. Furthermore, it is preferable that a concave portion for receiving the resin supplied toward the large diameter portion is formed on the outer peripheral surface of the small diameter portion.

  The large diameter portion is preferably a separate member from the main body. The large-diameter portion is a C-ring having a substantially C-shaped cross section perpendicular to the axial direction, and is preferably detachably attached to the main body. Furthermore, the large diameter portion is preferably annular.

  Or it consists of a 1st and 2nd pair of connecting member with which each one end part of two flexible tube materials is attached, and when each 1st and 2nd connecting member couple | bonds, two possible It is preferable to connect the flexible tube materials. Moreover, it is preferable that the boundary of each connection member is located in the said large diameter part when the said 1st and 2nd connection member is couple | bonded. The large diameter portion is preferably provided on one of the first and second connecting members.

  The endoscope flexible tube manufacturing method according to the present invention includes a connecting tool having a large-diameter portion whose clearance from the minimum inner diameter of the molding passage of the extrusion molding machine is 0.1 mm or less. A step of connecting a plurality of flexible tube materials, and supplying a molten resin material into the molding passage while conveying the plurality of flexible tube materials connected in the molding passage, And a step of extruding an outer skin layer covering the outer periphery of each flexible tube material.

  According to the present invention, a plurality of flexible tube materials are connected using a connector having a large-diameter portion whose clearance from the smallest inside diameter of the molding passage is 0.1 mm or less. Since the outer skin layer covering the outer periphery of the flexible tube material is extruded, the outer diameter surface of the large-diameter portion is not formed and the outer peripheral surface is exposed, so that the identification of the connection position is improved.

It is an external view which shows the structure of an electronic endoscope. It is a fragmentary sectional view showing a schematic structure of a flexible tube. It is a perspective view which shows the structure of a coupling tool. It is explanatory drawing which shows the structure of a connection flexible tube raw material. It is a block diagram which shows the structure of a manufacturing apparatus schematically. It is sectional drawing which shows the structure of a shaping | molding die. It is explanatory drawing which shows each process of skin layer shaping | molding. It is a top view which shows the example which formed the inclined surface where a diameter becomes small gradually from the flange to the outer peripheral surface of a small diameter part. It is a top view which shows the example which formed the flange only in one side of the connection member. It is a perspective view which shows the example of the connection tool which consists of a connection member and the flange attached to a connection member. It is sectional drawing which shows the state which attached the flange to the connection member. It is a perspective view which shows the example of the coupling tool which consists of a coupling member and the flange pinched | interposed into a coupling member. It is sectional drawing which shows the state by which the flange was pinched | interposed into the connection member. It is sectional drawing which shows the example which formed the recessed part which receives the resin which flows in from the flange side in the connection member. It is sectional drawing which shows the example which formed the through-hole which penetrates the center of a connection member from the recessed part which receives the resin which flows in from the flange side in a connection member, and a recessed part. It is sectional drawing which shows an example of the connection member which formed the bottom face of the recessed part which receives the resin which flows in from the flange side in gear shape.

  In FIG. 1 showing an electronic endoscope incorporating a flexible tube according to the present invention, an electronic endoscope 2 widely used for medical purposes includes an insertion portion 3 to be inserted into a body cavity, and a base of the insertion portion 3. A main body operation unit 5 connected to the end portion and a universal cord 6 connected to the processor device and the light source device are provided.

  The insertion section 3 is provided with a flexible tube portion 3a provided continuously with the main body operation portion 5, an angle portion 3b provided continuously with the flexible tube portion 3a, and an imaging device for photographing inside the body cavity. (Not shown) is comprised from the front-end | tip part 3c with which it was incorporated. The flexible tube portion 3a, which is the length of most of the insertion portion 3, has flexibility over almost the entire length thereof, and in particular, the portion inserted into the body cavity or the like has a more flexible structure. .

  As shown in FIG. 2, the flexible tube 10 (endoscopic flexible tube) constituting the flexible tube portion 3a is a spiral formed by spirally winding a metal strip 11a on the innermost side. A tube 11 is covered with a cylindrical mesh body 12 formed by braiding metal wires, and a base 13 is fitted to both ends of the tube 11. Further, an outer skin layer made of a resin such as urethane is provided on the outer peripheral surface of the tube 11. 15 is covered. The outer surface of the outer skin layer 15 is coated with a coating film 16 containing, for example, fluorine having chemical resistance.

  The outer skin layer 15 is formed by extrusion molding. In extrusion molding, a plurality of flexible tube materials 14 are connected to each other and fed into a molding passage of a continuous molding machine 25 (see FIG. 5) which is an extrusion molding machine. Done.

  As shown in FIG. 3, the two flexible tube materials 14 are connected by a connecting tool 18. The connector 18 includes a pair of connecting members 19 and 20 having a circular cross section perpendicular to the axial direction. Each connecting member 19, 20 is attached to the base 13 attached to the end portion of the two flexible tube materials 14 by screws 21, and by connecting each connecting member 19, 20, The flexible tube material 14 is connected.

  The connecting members 19 and 20 are smaller in diameter than the small-diameter portions 19a and 20a and the small-diameter portions 19a and 20a, and flanges 19b and 20b having a maximum outer diameter among the connecting members 19 and 20 (corresponding to the large-diameter portion). It consists of. The small diameter portion 19a and the flange 19b, and the small diameter portion 20a and the flange 20b are integrally formed, respectively. The small-diameter portions 19a and 20a have an outer diameter that is substantially the same as that of the base 13 so that a step difference from the base 13 is not possible. A fitting portion is provided. The fitting portion has a smaller diameter than the outer diameter of the main body portion of the small diameter portions 19a and 20a. In addition, an engagement hole that engages with the screw 21 is formed in the fitting portion.

  A female screw 19c (FIG. (A)) and a male screw 20c (FIG. (B)) are respectively formed on the contact surfaces 19d, 20d that contact when the connecting members 19, 20 are joined. When the female screw 19c and the male screw 20c are screwed together, the connecting members 19 and 20 are coupled.

  As shown in FIG. 4, a connecting member 19 attached to one end of one flexible tube material 14 and a connecting member 20 attached to one end of another flexible tube material 14 are coupled to each other. The connected flexible tube material 23 is formed by connecting the flexible tube materials 14 in a row. In the state of the connected flexible tube material 23, the plurality of flexible tube materials 14 and the connecting tool 18 are fed into the forming passage 41 of the continuous forming machine 25 (see FIG. 5).

  As shown in FIG. 5, the continuous molding machine 25 includes a well-known extrusion unit 27 including a hopper and a screw, a head unit 28 for covering and molding the outer skin layer 15 on the outer peripheral surface of the flexible tube material 14, cooling A section 29, a transport section 30 that transports the connected flexible tube material 23 to the head section 28, and a control section 31 that controls them.

  The conveyance unit 30 includes a feeding drum 33 and a take-up drum 34. The above-described connecting flexible tube material 23 is wound around the feeding drum 33, and then sequentially drawn, and the outer skin layer 15 is formed. Is wound around the winding drum 34 through the head portion 28 and the cooling portion 29 where the outer skin layer 15 after cooling is cooled. The rotation of the feeding drum 33 and the winding drum 34 is controlled by the control unit 31, and the conveyance speed for conveying the connected flexible tube material 23 is switched.

  As shown in FIGS. 5 and 6, the head portion 28 includes a nipple 37, a die 38, and a support 39 that supports these fixedly. The support 39 includes a gate 39a for supplying molten resin extruded from the extrusion portion 27 to a resin passage 42 described later.

  The nipple 37 and the die 38 are each provided with a molding passage 41 penetrating substantially the center. The molding passage 41 is connected to a resin passage 42 formed from a space sandwiched between the nipple 37 and the die 38. The connected flexible tube material 23 is fed into the molding passage 41, and the outer skin layer 15 is formed on the outer peripheral surface of the flexible tube material 14 by the resin supplied from the extrusion portion 27 to the molding passage 41 through the gate 39 a and the resin passage 42. It is formed.

  The nipple 37 is provided with a conical recess 37 a that is connected to the right end of the forming passage 41 in the drawing and guides the insertion of the connecting flexible tube material 23. Further, at the left end of the nipple 37 in the figure, a conical convex portion 37 b that forms the resin passage 42 together with the conical concave portion 38 a at the right end of the die 38 is formed.

An outlet hole 41 a of the molding passage 41 formed in the die 38 is continuous with the conical recess 38 a, that is, the resin passage 42. The outlet holes 41a has a minimum passage inner diameter D ₁ of diameter in all sections of the molding passage 41 is minimized.

As the section with the smallest passage inner diameter D ₁ that minimizes the total section of the molding passage 41 is not limited to the outlet hole 41a described above, the minimum inner diameter in the entire interval of the molding passage 41 passage inner diameter D ₁ it may become, or the inner diameter before and after the interval molding passage 41 and the resin passage 42 intersect may be set to the minimum passage inner diameter D _1.

A clearance C (= D ₁ −D ₂ ) between the inner diameter D ₁ of the outlet hole 41 a and the outer diameter D ₂ of the flanges 19 b and 20 b provided in the connecting members 19 and 20 is 0.001 mm or more and 0.1 mm or less. Is set in the range. The outer diameter D ₂ of the flanges 19 b and 20 b has a larger diameter than the outer diameter D ₃ of the flexible tube material 14, and the difference is equal to or greater than the thickness T of the outer skin layer 15. Here, the thickness T of the outer skin layer 15 is a thickness formed on the outer peripheral surface of the flexible tube material 14.

The thickness T of the outer skin layer 15 is determined by the extrusion amount per unit time of the resin supplied from the resin passage 42 to the molding passage 41 and the conveying speed of the connected flexible tube material 23. Between the molding passage 41 including the inner diameter D ₁ of the outer diameter D ₃ and the outlet hole 41a of the tubular structure 14, the volume of only forming the outer skin layer 15 of thickness T is secured, the resin passage 36 The resin supplied toward the outer peripheral surface of the flexible tube material 14 adheres to the outer peripheral surface, and an outer skin layer 15 having a thickness T is formed on the outer peripheral surface of the flexible tube material 14.

In contrast, the flange 19b, the outer diameter _{D 2} of the 20b, the thickness T min or more skin layers 15 is larger than the outer diameter _{D 3} of the tubular structure 14. Therefore, the flanges 19 b and 20 b do not have a volume enough to form the outer skin layer 15 having a thickness T between the flanges 19 b and 20 b. Therefore, the resin supplied toward the flanges 19b and 20b flows before and after the flanges 19b and 20b in the axial direction. Since the clearance C is narrowed (set to 0.001 mm or more and 0.1 mm or less), almost all of the resin supplied to the outer peripheral surfaces of the flanges 19b and 20b does not adhere to the flanges 19b and 20b. , Flows in the axial direction. Therefore, the outer peripheral surface of the connecting flexible tube material 23 discharged from the forming passage 41 is exposed only in the portions of the flanges 19b and 20b without the outer skin layer 15 being formed.

Specific examples of the dimensions of the inner diameter _{D 1} and an outer diameter _{D 2,} the inner diameter _{D 1} of the outlet hole 41a of the head portion 28 is 6.1 mm, the flange 19b of the connecting member 19, the outer diameter _{D 2} of 20b is 6. The clearance C is 0.05 mm. Experiments have confirmed that when extrusion molding is performed under such molding conditions, the resin is not exposed to the outer peripheral surfaces of the flanges 19b and 20b. The other dimensions of the flexible tube material 14 and the connecting members 19 and 20 are such that the outer diameter of the flexible tube material 14 (the portion covered with the cylindrical mesh body 12) excluding the base 13 is 5.6 mm. The outer diameters of the small diameter portions 19a and 20a of 19 and 20 are 5.8 mm. Further, the extrusion speed (conveyance speed) when the connecting flexible tube material 23 passes through the outlet hole 41a is set to 2.7 m / min.

  The connected flexible tube material 23 formed with the outer skin layer 15 passes through the head portion 28 and then passes through the cooling portion 29. The cooling unit 29 stores a cooling liquid 40 such as water, and cools and hardens the outer skin layer 15 by passing through the cooling liquid 40. Note that the cooling is not limited thereto, and cooling may be performed by spraying the coolant 40 or air onto the outer skin layer 15.

  A process when the outer skin layer 15 is continuously formed on the flexible tube material 14 by the continuous molding machine 25 will be described with reference to FIG. First, the connecting members 19 and 20 are respectively attached to the caps 13 of the two flexible tube materials 14 to be connected using screws 21. Next, the connecting members 19 and 20 are joined to connect the two flexible tube materials 14 to create a connected flexible tube material 23 (state shown in FIG. 7A). When the number of links is two or more, the above operation is repeated.

After the connected flexible tube material 23 is set in the continuous molding machine 25, the continuous molding machine 25 starts to be driven. The extruded portion 27 discharges molten resin through the gate 39 a to the resin passage 36, and the resin is laminated on the peripheral surface of the connected flexible tube material 23. As described above, the clearance C (= D ₁ −D ₂ ) between the inner diameter D ₁ of the outlet hole 41 a of the molding passage 41 and the outer diameter D ₂ of the flanges 19 b and 20 b provided in the connecting members 19 and 20. , 0.001 mm or more and 0.1 mm or less. In such a clearance C, the outer skin layer 15 is not formed on the flanges 19b and 20b. Therefore, as shown in FIG. 7B, the connected flexible tube material 23 is a flexible tube material excluding the flanges 19b and 20b. 14 and the small diameter portions 19a and 20a are discharged from the molding passage 41 of the continuous molding machine 25 in a state where the outer skin layer 15 is formed on the outer peripheral surface.

  The connected flexible tube material 23 in which the outer skin layer 15 is formed up to the last end is removed from the continuous molding machine 25. The connecting flexible tube material 23 is separated into each flexible tube material 14 by removing the connecting tool 18 by an operator. At the time of separation, the connection position where the connector 18 is located is found by visual observation or tactile sense. Since the outer skin 15 of the flanges 19b and 20b is not molded, the outer peripheral surfaces of the flanges 19b and 20b are exposed, and the identification of the connection position is high. For this reason, the worker can find the connection position in a short time and easily.

  The flanges 19b and 20b are provided on the connecting members 19 and 20, and the boundaries of the flanges 19b and 20b coincide with the boundaries of the contact surfaces 19d and 20d of the connecting members 19 and 20. For this reason, the operation | work which peels the outer skin layer 15 with a cutter etc. and exposes the boundary part of the connection members 19 and 20 becomes unnecessary, and the operation | work which cancel | releases the connection of the connection members 19 and 20 is also easy.

  After the coupling members 19 and 20 are disconnected, the flexible tube material 14 is separated. The outer skin layer 15 covered with the portions other than the flanges 19b and 20 of the connecting members 19 and 20 is peeled off and discarded. Then, the screws 21 are loosened with a screwdriver, and the connecting members 19 and 20 are removed from the separated flexible tube materials 14. Next, the separated flexible tube material 14 is coated with a coating film 16 on the outer skin layer 15 to complete the flexible tube 10. The completed flexible tube 10 is conveyed to the assembly process of the electronic endoscope 2.

  In the above embodiment, in the flanges 19b and 20b, the surface opposite to the opposing surface is formed perpendicular to the axial direction. For example, as shown in FIG. Inclined surfaces 19e and 20e may be provided that incline so that the diameter gradually decreases toward the outer peripheral surfaces of the small-diameter portions 19a and 20a arranged in the direction. As a result, when the connecting flexible tube material 23 is fed into the head portion 28, the inclined surfaces 19e and 20e advance as guides, so that the flanges 19b and 20b are not caught inside the head and the outer skin layer 15 is covered and molded. Is done.

  In the above embodiment, the flanges are integrally formed on each of the pair of connecting members 19 and 20, but as shown in FIG. 9, the flange 20 b may be integrally formed on either one, for example, only the connecting member 20. . In this case, as the other connecting member 19, a conventional connecting member having no flange and having a small diameter portion 19a and a female screw 19c can be used.

  In the above embodiment, the flange and the coupling member constituting the main body of the coupling tool are integrally formed. However, for example, as in the coupling tool 50 shown in FIGS. 10 and 11, the flange may be a separate member from the coupling member. Good. The connector 50 includes connecting members 51 and 52 and a flange 53. The connecting members 51 and 52 have a columnar shape that is substantially the same diameter as the base 13, and the connecting member 51 is formed with a female screw 51 a, and the connecting member 52 is formed with a male screw 52 a that is screwed with the female screw 51 a. The connecting members 51 and 52 are screwed to the base 13 in the same manner as the connecting members 19 and 20 of the above embodiment.

  The flange 53 is a C ring bent in a C shape, and is detachably attached to a position covering the boundary between the connecting members 51 and 52. As shown in FIG. 11A, the flange 53 is caulked and fixed so as to be in close contact with the connecting members 51 and 52.

  When the outer skin layer 15 is formed by the continuous molding machine 25 with respect to the connected flexible tube material 54 in which the plurality of flexible tube materials 14 are connected to one by the connecting tool 50, as shown in FIG. Further, the outer skin layer 15 is formed on the outer peripheral surface of the portion excluding the flange 53, and the flange 53 is exposed to the outside. When the flexible tube material 14 is separated, for example, an operator removes the flange 53 from caulking using pliers or the like. As a result, the boundary between the connecting members 51 and 52 is exposed and the connecting members 51 and 52 are separated. When the flange 53 is separated from the connecting members 51 and 52 as described above, a conventional connecting member can be used as the connecting members 51 and 52.

  Moreover, when providing a flange separately, as shown in FIG.12 and FIG.13, the coupling tool 60 which uses the annular flange 61 may be sufficient. The connection tool 60 includes connection members 51 and 52 and an annular flange 61 in which a through hole 61 a penetrating the male screw 52 a is formed in the approximate center, and the flange 61 is sandwiched between the connection members 51 and 52. Fixed. For example, a commercially available washer is used as the flange 61. If a commercially available washer is used as the flange 61, the cost can be reduced.

  Moreover, as shown in FIG. 14, you may provide the recessed part 70 which receives resin supplied toward the flanges 19b and 20b in the vicinity of the flanges 19b and 20b. Thereby, surface roughness due to unevenness or wrinkles can be prevented on the surface of the outer skin layer 15 formed on the flexible tube material 14. The reason is as follows.

While the connecting flexible tube material 23 passes through the molding passage 41, the amount of resin extruded per unit time supplied from the resin passage 36 to the molding passage 41 is substantially constant. As described above, since the clearance C (= D ₁ −D ₂ ) between the inner diameter D ₁ of the outlet hole 41 a and the outer diameter D ₂ of the flanges 19 b and 20 b is very small, the outer peripheral surfaces of the flanges 19 b and 20 b are The outer skin layer 15 made of resin is not formed.

  Therefore, the resin supplied toward the flanges 19b and 20b flows before and after the flanges 19b and 20b in the axial direction (conveying direction), and the resin flows to the outer skin layer 15 formed on the flexible tube material 14. In some cases, the surface of the outer skin layer 15 may be roughened and wrinkled to cause surface roughness. The degree of surface roughness varies depending on the amount of extrusion of resin per unit time, the widths of the flanges 19b and 20b, the overall length of the connecting member 18 in the axial direction, and the like. The greater the amount of extrusion and the greater the width of the resin flanges 19b, 20, the greater the amount of resin that flows in, and the greater the amount of resin, the worse the surface roughness. Even if the amount of resin flowing in is the same, the shorter the overall length of the connector 18, the greater the influence on the outer skin layer 15 of the flexible tube material 14.

  The recesses 70 provided in the front and rear of the flanges 19b and 20b in the axial direction receive the resin flowing into the front and rear of the flanges 19b and 20b, and prevent the surface of the outer skin layer 15 of the flexible tube material 14 from being rough. The capacity of the recess 70 is determined according to the amount of resin flowing into the recess 70. For example, the larger the axial width of the flanges 19b and 20b, the greater the amount of resin that flows in. Therefore, the capacity of the recess 70 is increased, and the smaller the width of the flanges 19b and 20b, the smaller the capacity of the recess 70.

  As a measure for preventing the surface roughness, there is a method in which, for example, the axial length of the small diameter portions 19a and 20a of the connecting members 19 and 20 is increased in addition to providing the recess 70. If the axial length of the small diameter portions 19a and 20a is increased, the distance between the flanges 19b and 20b and the flexible tube material 14 is increased. Therefore, even if the resin flows from the flanges 19b and 20b side, It is considered that the influence of surface roughness on the outer skin layer 15 is small.

  However, when the axial length of the small diameter portions 19a and 20a is increased, the amount of the outer skin layer 15 formed on the outer peripheral surfaces of the connecting members 19 and 20 increases. Since the outer skin layer formed on the connecting members 19 and 20 is discarded, if the axial length of the small diameter portions 19a and 20a is long, the resin material is wasted, and there is a lot of loss in terms of production cost. Further, since the connected flexible tube material 23 is wound around the feeding drum 33 and the take-up drum 34, if the axial length of the small diameter portions 19a and 20a is long, the flexibility of winding of the connected flexible tube material 23 is achieved. It will also reduce. This is disadvantageous from the viewpoint of smooth feeding and winding.

  In consideration of such circumstances, the method of increasing the axial length of the small-diameter portions 19a and 20a is effective as a measure for preventing surface roughness, but has other disadvantages. The recess 70 can be said to be a very effective measure since it can prevent surface roughness without increasing the axial length of the small diameter portions 19a, 20a.

  As shown in FIG. 14A, the recess 70 is a groove formed over the entire circumference of the small diameter portions 19a and 20a, and is provided at a position adjacent to the flanges 19b and 20b. The width of the recess 70 and the depth of the groove are determined according to the amount of resin flowing from the flanges 19b and 20b side. As shown in FIG. 14B, since the resin flowing from the flanges 19b and 20b side flows into the recesses 70 and is absorbed when the outer skin layer 15 is coated, the flexible tube does not cause surface roughness. An outer skin layer 15 of the material 14 can be formed.

  Further, the recess 70 may be formed with a through hole 71 as shown in FIG. 15 in addition to the groove. If the through hole 71 is provided, the volume of the resin is increased correspondingly, so that the depth of the groove can be reduced. If the depth of the groove is too deep, the rigidity of the connecting members 19 and 20 is lowered. Therefore, from the viewpoint of securing the rigidity of the connecting members 19 and 20, it is effective to provide the through holes 71. As shown in FIG. 15A, the through hole 71 is formed so as to pass through the center of the small diameter portions 19a and 20a from the groove of the recess 70, for example. Then, when the outer skin layer 15 is coated and formed on the connected flexible tube material, as shown in FIG. 15B, the resin flows into the recess 70 and the through hole 71, and the surface roughness of the outer skin layer 15 is prevented.

  The concave portion 70 may not be a groove having a uniform depth over the entire circumference, and may be formed with unevenness such as a gear shape on the bottom surface 72 as in the concave portion 70 shown in FIG. Such a recess 70 is formed by knurling, for example.

In the above embodiment, the example in which the small diameter portions 19a and 20a and the flanges 19b and 20b (large diameter portions) are provided as the connecting members 19 and 20 has been described, but the small diameter portions 19a and 20a may not be provided. That may be only the large diameter portion of the outer diameter D _2. In addition, the outer diameter of the large-diameter portion may not be constant, and irregularities and grooves may be formed on a part of the peripheral surface of the large-diameter portion, or it may face one end like a conical shape. The diameter may be small. In other words, the large diameter portion need not entire axial length has all outside diameter D _2, the maximum outer diameter may be a D _2.

  In the above embodiment, the outer skin layer is formed of one type of resin. However, the present invention is not limited to this, and for example, two types of hard and soft resins are used. Two layers are molded so that the thickness is thicker than the hard resin, and the hard resin is thicker than the soft resin on the main body operation part side of the insertion part, and the angle part side of the insertion part is on the main body operation part side. It may be made softer. The present invention may be applied not only to the flexible tube constituting the insertion portion, but also to an endoscope flexible tube such as a universal cord having a similar structure to the insertion portion.

  Moreover, in the said embodiment, although the connection member connected mutually by screwing of a female screw and a male screw is mentioned as an example, this invention is not limited to this, For example, by mutually fitting A connecting member to be connected may be used.

  Moreover, although the connection tool was demonstrated in the example comprised from a pair of connection member, a connection member may be one member. In this case, when connecting the two flexible tube materials, the connecting members are not connected to each other, but one end of the connector is attached to one flexible tube material and the other is connected to the other end. The flexible tube material is attached.

  In the above-described embodiment, an electronic endoscope that observes an image obtained by imaging the state of the subject using the imaging apparatus is described as an example. However, the present invention is not limited to this, and an optical image is not limited thereto. The present invention can also be applied to an endoscope that employs a guide and observes the state of a subject.

2 Electronic endoscope (endoscope)
DESCRIPTION OF SYMBOLS 3 Insertion part 10 Flexible pipe 13 Base 14 Flexible pipe raw material 15 Outer layer 18, 50, 60 Connection tool 19, 20, 51, 52 Connection member 19b, 20b, 53, 61 Flange (large diameter part)
23, 54 Connected flexible tube material 25 Continuous molding machine (manufacturing equipment)
28 Head (molding die)
30 Conveying part 41 Molding passage 41a Outlet hole 42 Resin passage 70 Concave

Claims (11)

A plurality of flexible tube materials are connected in a row and fed into a molding passage of an extrusion molding machine, and a molten resin material is supplied to the molding passage while conveying the plurality of flexible tube materials. Used when extruding the outer skin layer covering the outer periphery of the flexible tube material, is a connector for connecting a plurality of flexible tube material, passing through the molding passage together with the flexible tube material, After the molding, in the connector to be removed from the flexible tube material,
A clearance that is larger than the outer diameter of the flexible tube material by the thickness of the outer skin layer or more and that has a minimum clearance of 0.1 mm or less with respect to the inner diameter of the passage that is the smallest in all sections of the molding passage. A connector used for manufacturing a flexible tube for an endoscope, comprising a diameter portion.   The connection used for manufacturing the flexible tube for an endoscope according to claim 1, wherein an inclined surface is provided so as to be gradually reduced in diameter along the axial direction from the large diameter portion. Ingredients.   The connecting tool used for manufacturing the flexible tube for an endoscope according to claim 1, further comprising a small-diameter portion having a smaller diameter than the large-diameter portion.   The concave portion for receiving the resin supplied toward the large-diameter portion is formed on the outer peripheral surface of the small-diameter portion, and used for manufacturing a flexible tube for an endoscope according to claim 3. Coupling tool.   5. The connector used for manufacturing a flexible tube for an endoscope according to any one of claims 1 to 4, wherein the large-diameter portion is a separate member from the main body.   6. The endoscope flexible tube according to claim 5, wherein the large-diameter portion is a C-ring having a substantially C-shaped cross section orthogonal to the axial direction, and is detachably attached to the main body. The connecting tool used.   6. The connector used for manufacturing a flexible tube for an endoscope according to claim 5, wherein the large-diameter portion has an annular shape.   It consists of a pair of 1st and 2nd connecting members with which each one end part of 2 flexible tube materials is attached, and the 1st and 2nd connecting members couple | bond together, and 2 flexible tubes The connection tool used for manufacturing the flexible tube for an endoscope according to claim 1, wherein the materials are connected.   9. The endoscope flexible tube according to claim 8, wherein when the first and second connecting members are joined, a boundary between the connecting members is located in the large-diameter portion. Coupling tool.   9. The connector used for manufacturing an endoscope flexible tube according to claim 8, wherein the large-diameter portion is provided on one of the first and second connecting members. A step of connecting a plurality of flexible tube materials by using a connecting tool having a large diameter portion in which the clearance between the smallest passage inner diameter and the smallest passage inner diameter in all sections of the extrusion molding machine is 0.1 mm or less. When,
Supplying a molten resin material into the molding passage while conveying a plurality of flexible tube materials connected in the molding passage, and extruding the outer skin layer covering the outer periphery of each flexible tube material The manufacturing method of the flexible tube for endoscopes characterized by including these.

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