Multi-lumen tube extrusion molding equipment

Abstract

To provide an extrusion molding apparatus capable of manufacturing a multi-tube whose outer shape of its cross section is close to a complete round.SOLUTION: An extrusion molding apparatus of a multi-lumen tube includes: a resin supply part; a mold having an extrusion port at its lower end part for molding a multi-lumen tube while extruding a resin supplied from the resin supply part vertically downwardly; and an outside surface molding device for molding an outside surface of the extruded tube. In a state in which the resin is supplied to the mold from the resin supply part, the outside surface molding device moves a first mold block and a second mold block vertically downwardly in a state in which an extruded tube is accommodated in a columnar molding space formed by the first mold block and the second mold block, and in accordance with extrusion of the tube, by reducing a pressure of the molding space formed by the first mold block and the second mold block, the outside surface of the accommodated multi-lumen tube is brought into tight contact with an inner surface of a groove.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an extrusion molding device for a multi-lumen tube having two or more ducts. [Background technology]

[0002] Multi-lumen tubes having multiple ducts (lumens) are used in medical applications such as catheter surgery and endoscopic surgery. The multiple ducts of a multi-lumen tube are used for electrode placement, guidewire insertion, balloon inflation, drug injection, and suction of body fluids and blood clots. Utilizing a multi-lumen tube makes it possible to use multiple devices and perform multiple procedures with a single tube. For example, Patent Document 1 describes an extrusion molding device that can thicken the resin layer separating flow channels without increasing the thickness of the resin layer between the outer surface of the tube and the flow channel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6771313 Summary of the Invention [Problem to be solved by the invention]

[0004] An extrusion molding device for multi-lumen tubes, such as that described in Patent Document 1, includes a tubular conduit-forming member and can form multiple conduits by extruding resin while spraying air from the conduit-forming member. However, when extrusion molding is performed while spraying air from the conduit-forming member, the pressure of the sprayed air deforms the uncured tube immediately after extrusion molding, making it difficult to achieve a perfect circular outer shape. Tubes with non-perfect circular outer shapes are not suitable for medical applications where they are inserted into the body, and therefore multi-lumen tubes with cross-sectional outer shapes that are closer to perfect circles are desired. Furthermore, attempts to reduce the outer shape of the tube or increase the number of conduits provided in the tube result in a thinner resin portion from the outer surface of the tube to the conduits formed near the outer surface, which makes the resin portion more susceptible to fracture and reduces yield.

[0005] Therefore, an object of the present invention is to provide an extrusion molding apparatus capable of manufacturing a multi-tube having a cross-sectional outer shape that is nearly a perfect circle. [Means for solving the problem]

[0006] The extrusion molding apparatus according to the present invention is used to extrude a multi-lumen tube having two or more conduits, and includes a resin supply unit that extrudes molten resin, a mold having an extrusion port at its lower end that molds the multi-lumen tube by extruding the resin supplied from the resin supply unit vertically downward, an outer surface molding device that molds the outer surface of the multi-lumen tube extruded from the mold, a gas supply unit, and a pressure reducing unit. The mold includes an inner mold, two or more tubular conduit molding members that are provided corresponding to each of the conduits of the multi-lumen tube, each having a tip that protrudes from the lower end of the inner mold and the remainder that is located inside the inner mold, and each having a through hole and a tip portion with an outer shape corresponding to the cross-sectional shape of each of the conduits, and a tubular outer mold that surrounds the inner mold and the portions that protrude from the lower end of the inner mold and forms a resin flow path between its inner surface and the outer surface of the inner mold. The outer surface molding device includes a plurality of first mold blocks each having a flat surface with a rectangular outer shape, a linear groove formed on the flat surface and having a semicircular cross section perpendicular to the flat surface, and a slit or small hole penetrating the groove, a same number of second mold blocks each having the same shape as the first mold blocks, and a drive mechanism for circulating the first and second mold blocks in pairs. The drive mechanism brings the flat surfaces of the paired first and second mold blocks into surface contact with each other in a molding zone provided vertically below the mold so that the grooves of the paired first and second mold blocks overlap, forming molding spaces between the overlapping grooves whose cross sections are perfectly circular and whose centers approximately coincide with the central axis of the mold, and linearly moves the consecutive pairs of first and second mold blocks vertically downward along the central axis of the mold, separating the paired first and second mold blocks from each other outside the molding zone.While resin is being supplied from the resin supply unit to the mold, gas is supplied from a gas supply device to each of the duct molding members, and the supplied gas is sprayed from the tip of the through hole.The drive mechanism, with the multi-lumen tube extruded from the mold housed in the molding space of each of several consecutive pairs of first and second mold blocks, moves the first and second mold blocks vertically downward in time with the extrusion of the multi-lumen tube, and reduces the pressure in the molding space using a pressure reducing device, thereby tightly adhering the outer surface of the multi-lumen tube housed in the molding space to the inner surface of the groove.

[0007] In another embodiment, the outer surface molding device includes a first belt formed of a flexible material and having a flat surface, a linear groove formed on the flat surface and having a semicircular cross section in a direction perpendicular to the flat surface, and a slit or pore penetrating the groove, and a second belt formed of the same material as the first belt and having the same shape as the first belt. to and a drive mechanism for circulating the first belt and the second belt. In this case, the drive mechanism brings the flat surfaces of the first belt and the second belt into surface contact with each other in a molding zone provided vertically below the mold so that the grooves of the first belt and the second belt overlap, forms a molding space between the overlapping grooves that has a perfect circular cross section and whose center substantially coincides with the central axis of the mold, moves the first belt and the second belt linearly vertically downward along the central axis of the mold, and separates the first belt and the second belt from each other outside the molding zone. While resin is being supplied from the resin supply unit to the mold, gas is supplied from the gas supply device to each of the duct molding components, and the supplied gas is sprayed from the tip of the through hole.The drive mechanism, with the multi-lumen tube extruded from the mold contained in the molding space formed by the first belt and the second belt, moves the first belt and the second belt vertically downward in accordance with the extrusion of the multi-lumen tube, and reduces the pressure in the molding space using a pressure reducing device, thereby tightly adhering the outer surface of the multi-lumen tube contained in the molding space to the inner surface of the groove. [Effects of the Invention]

[0008] According to the present invention, an extrusion molding apparatus capable of manufacturing a multi-tube having a cross-sectional outer shape that is nearly a perfect circle can be provided. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view showing an example of a multi-lumen tube according to a first embodiment. [Figure 2] FIG. 1 is a diagram showing a schematic configuration of an extrusion molding device for a multi-lumen tube according to a first embodiment. [Figure 3] A longitudinal cross section of the mold shown in Figure 1 [Figure 4] End view of the extrusion opening of the die shown in Figure 1 [Figure 5] A diagram showing the pipe forming member shown in Figure 4. [Figure 6] A diagram showing the pipe forming member shown in Figure 4. [Figure 7] A diagram showing the pipe forming member shown in Figure 4. [Figure 8] A diagram showing the mold block shown in Figure 3. [Figure 9] Enlarged view of the outer molding device shown in Figure 1 [Figure 10] FIG. 10 is a cross-sectional view showing an example of a multi-lumen tube according to a second embodiment. [Figure 11] A diagram showing the belt shown in Figure 10. DETAILED DESCRIPTION OF THE INVENTION

[0010] (First embodiment) FIG. 1 is a cross-sectional view showing an example of a multi-lumen tube according to a first embodiment.

[0011] The multi-lumen tube 1 is a resin tube used in medical applications such as catheter surgery and endoscopic surgery, and has multiple lumens 2-5b extending in the longitudinal direction of the tube. The lumens 2-5b are used for inserting various instruments such as guide wires, balloons, and signal lines, injecting medicinal solutions, and aspirating bodily fluids. The cross-sectional shape of the lumens 2-5b is not particularly limited, and may be circular like lumens 2, 4a, 4b, 5a, and 5b, or irregular like lumens 3. The size (inner diameter) of the lumens 2-5b can be appropriately set depending on the application. The number and arrangement of the lumens are also not particularly limited. The material of the multi-lumen tube 1 is not particularly limited, and examples include polyethylene, polypropylene, polyamide, polyurethane, polyether, polyester, polyimide, fluororesin, and silicone rubber. The cross-sectional outer shape of the multi-lumen tube 1 is a perfect circle, and in the case of a tube for medical applications, the diameter is, for example, 10 mm or less.

[0012] FIG. 2 is a diagram showing a schematic configuration of an extrusion molding device for a multi-lumen tube according to the first embodiment.

[0013] The extrusion molding apparatus 100 is an apparatus for extrusion molding a multi-lumen tube 1 using a resin, and includes an extruder 11, a mold 12, an outer surface molding device 13, a gas supply device 14, a pressure reducing device 15, and a control device 16. Each component unit of the extrusion molding apparatus 100 is fixed to a predetermined stand or the like. Although not shown, a cooling device for cooling the extruded multi-lumen tube 1, a take-up device for taking up the multi-lumen tube 1, and the like are appropriately provided downstream of the mold 12.

[0014] The extruder 11 is, for example, a screw extruder, and can melt resin pellets and extrude them from a discharge port at the tip at a predetermined speed. A gear pump for adjusting the flow rate of the resin may be provided between the extruder 11 and the mold 12.

[0015] Fig. 3 is a vertical cross-sectional view of the mold shown in Fig. 1, Fig. 4 is an end view of the extrusion port of the mold shown in Fig. 1, and Figs. 5 to 7 are views showing the pipe molding member shown in Fig. 4. More specifically, Fig. 5 corresponds to a right side view of the pipe molding member 22 shown in Fig. 4, Fig. 6(a) corresponds to a right side view of the pipe molding member 23 shown in Fig. 4, Fig. 6(b) corresponds to a bottom view of the pipe molding member 23 shown in Fig. 6(a), and Fig. 7 corresponds to a right side view of the pipe molding members 24a, 24b, 25a, and 25b shown in Fig. 4.

[0016] The mold 12 has a resin flow path 18 that allows the resin extruded from the extruder 11 to flow, and an extrusion port 19 at its lower end, and molds the multi-lumen tube 1 while extruding the resin supplied from the extruder 11 vertically downward. The mold 12 includes an inner mold 21, a plurality of conduit molding members 22 to 25 b that are partially located inside the inner mold 21, and a tubular outer mold 26. In this embodiment, the inner mold 21 is made up of two members, but the structure of the inner mold 21 is not particularly limited as long as it can hold the conduit molding members 22 to 25 b and can form the resin flow path 18 between the inner mold 21 and the outer mold 26.

[0017] The conduit molding members 22 to 25b are all tubular members having through holes for injecting gas. The conduit molding members 22, 23, 24a, 24b, 25a, and 25b are provided corresponding to the conduits 2, 3, 4a, 4b, 5a, and 5b of the multi-lumen tube 1, respectively. As shown in FIGS. 4 to 7, the conduit molding members 22, 23, 24a, 24b, 25a, and 25b have distal end portions with outer shapes corresponding to the cross-sectional shapes of the conduits 2, 3, 4a, 4b, 5a, and 5b of the multi-lumen tube 1, respectively. The distal end portions of the conduit molding members 22 to 25b protrude from the lower end of the inner mold 21, and the remaining portions of the conduit molding members 22 to 25b are housed inside the inner mold 21. The conduit molding members 22 to 25b are fixed to the inner mold 21 via members not shown. The duct molding members 22 to 25b are connected to a gas supplying device 14 via tubes or the like (not shown), and a gas such as air is supplied from the gas supplying device 14 when the multi-lumen tube 1 is extrusion-molded.

[0018] As shown in Figure 3, the lengths of the pipe molding members 22, 24a, and 24b are different. For convenience of illustration, only three pipe molding members 22, 24a, and 24b are shown in Figure 3, but all of the pipe molding members 22 to 25b are different lengths, and their upper end positions are offset from each other. By making the upper end positions of the pipe molding members 22 to 25b different, it becomes easy to identify the pipe molding members 22 to 25b, which makes it easier to manufacture and maintain the device.

[0019] In this embodiment, each of the conduit molding members 22-25b is formed as a single member, but at least one of the conduit molding members 22-25b may be composed of a tubular first member of a predetermined length including a tip portion, and a tubular second member whose lower end is detachably connected to the first member. The outer shape and size of the tip portions of the conduit molding members 22-25b vary depending on the shape (specifications) of the multi-lumen tube 1 to be molded, but if the tip portions are configured to be separable, it becomes possible to mold multi-lumen tubes 1 of different shapes by replacing the tip portions.

[0020] The outer die 26 is a tubular member that surrounds the inner die 21 and the portions of the pipe molding members 22 to 25b that protrude from the lower end of the inner die 21. The inner diameter of the outer die 26 is larger than the outer shape of the inner die 21. As a result, a resin flow path 18 consisting of a predetermined gap is formed between the outer surface of the inner die 21 and the inner circumferential surface of the outer die 26.

[0021] The outer surface molding device 13 will be described in detail below with reference to FIGS. 2, 3, 8 and 9. FIG.

[0022] Fig. 8 is a diagram showing the mold block shown in Fig. 3, and Fig. 9 is an enlarged view of the outer surface molding device shown in Fig. 1. More specifically, Fig. 8(a) is a plan view of the mold block, and Fig. 8(b) is a right side view of the mold block shown in Fig. 8(a). Since the first mold block 31 and the second mold block 32 have the same shape, they will not be distinguished from each other in the description of Fig. 8, and will simply be referred to as "mold blocks."

[0023] The outer surface molding device 13 is a device that molds the outer surface of the multi-lumen tube 1 extruded from the mold 12 into a perfect circle. The outer surface molding device 13 includes a plurality of first mold blocks 31, the same number of second mold blocks 32 as the first mold blocks 31, and a drive mechanism 35 that circulates the first mold blocks 31 and the second mold blocks 32.

[0024] As shown in FIG. 8 , mold blocks 31 and 32 each have a block portion 40 having a flat surface 36 with a generally rectangular outer shape, linear grooves 37 formed in the flat surface 36, and multiple slits 38 formed in the block portion 40. The grooves 37 formed in the block portion 40 are used to mold the outer surface of the multi-lumen tube 1 into a perfect circle, and each groove 37 has a uniform semicircular cross-sectional shape in the direction perpendicular to the extension direction of the groove 37 and the flat surface 36. In other words, the grooves 37 have a semicylindrical shape. Each of the slits 38 extends in a direction transverse to the groove 37 (a direction perpendicular to the extension direction of the groove 37) and penetrates the block portion 40 from the flat surface 36 to the surface behind the flat surface 36. These slits 38 are used to reduce the pressure inside the grooves 37 using a pressure reducing device 15 during extrusion molding. The block portion 40 is also provided with recesses 39 used to secure the mold blocks 31 and 32 to a mold block base 42 (see FIG. 3) of the drive mechanism 35. Instead of or together with the slits 38, a small hole may be provided that penetrates the block portion 40 in a direction perpendicular to the flat surface 36.

[0025] The drive mechanism 35 includes a motor 41, and the rotational force of the motor 41 circulates the first and second mold blocks 31 and 32 in pairs along a track-shaped orbit. As shown in FIGS. 2 and 9, as the drive mechanism 35 circulates the first and second mold blocks 31 and 32, the flat surfaces 36 of the separated first and second mold blocks 31 and 32 come into surface contact vertically below the mold 12. At this time, the entire flat surfaces 36 of the first and second mold blocks 31 and 32 come into contact with each other so that the grooves 37 of the paired first and second mold blocks 31 and 32 completely overlap, forming a cylindrical molding space 43 with a perfectly circular cross section between the overlapping grooves 37 (see FIG. 8(b)). The center of the cross section of the molding space 43 approximately coincides with the central axis of the mold 12. The drive mechanism 35 moves the first and second mold blocks 31 and 32 vertically downward along the central axis of the mold 12, with a cylindrical molding space 43 formed between the pair of first and second mold blocks 31 and 32. At this time, the first and second mold blocks 31 and 32 are moved so that multiple consecutive pairs of first and second mold blocks 31 and 32 are connected without any gaps, thereby resulting in a continuous molding space 43 formed by multiple pairs of first and second mold blocks 31 and 32. The portion where the flat surfaces 36 of the first and second mold blocks 31 and 32 come into surface contact with each other and move vertically downward along the central axis of the mold 12 is called the "molding zone." Thereafter, the pair of first and second mold blocks 31 and 32 separate again and circulate along a track-shaped orbit.

[0026] As shown in FIG. 9, the outer surface molding device 13 according to this embodiment is further provided with a lifting mechanism 45.

[0027] The lifting mechanism 45 includes a motor, an air cylinder, etc., and is capable of moving the outer surface molding device 13 in the vertical direction (up and down direction) as shown in Figures 9(a) and 9(b). By changing the vertical position of the outer surface molding device with the lifting mechanism 45, the vertical distance from the extrusion outlet 19 of the mold 12 to the molding zone in the outer surface molding device 13 can be changed.

[0028] In the extrusion molding apparatus 100 according to this embodiment, the outer diameter of the multi-lumen tube 1 to be molded is determined by the radius of the grooves 37 formed in the first mold block 31 and the second mold block 32. A typical extrusion molding apparatus uses a mold having an extrusion port with an inner diameter equal to the outer diameter of the tube to be molded, and a mold must be prepared for each outer diameter of the tube to be molded. In this embodiment, the exterior surface molding device 13 is moved downward by the lifting mechanism 45, lengthening the time from when the multi-lumen tube 1 is extruded from the mold 12 until it is accommodated in the molding space 43 of the first mold block 31 and the second mold block 32, thereby allowing the uncured multi-lumen tube 1 to be stretched by its own weight and reduce its outer diameter. Therefore, in the extrusion molding apparatus 100 according to this embodiment, the outer diameter of the multi-lumen tube 1 to be molded can be changed by replacing the first mold block 31 and the second mold block 32 and changing the vertical position of the exterior surface molding device 13, eliminating the need to prepare a mold 12 for each outer diameter. Therefore, the cost required to change the dimensions of the multi-lumen tube 1 can be reduced.

[0029] The gas supply device 14 is connected to the upper end of each of the duct molding members 22 to 25 b of the mold 12 via a tube or the like (not shown), and supplies gas to the through holes of the duct molding members 22 to 25 b. The gas supply device 14 includes a pump, a valve, a regulator for adjusting the flow rate, etc. The gas supplied by the gas supply device 14 is not particularly limited, but it is preferable to use air.

[0030] The pressure reducing device 15 is, for example, a vacuum pump, and is connected to the outer surface molding device 13 via tubes, piping, etc. (not shown). The pressure reducing device 15 draws a vacuum from the back surfaces (surfaces opposite to the flat surface 36) of the first mold block 31 and the second mold block 32 through the slits 38 during extrusion molding.

[0031] The control device 16 is equipped with a computer including a CPU, memory, storage device, communication interface, etc., and is connected to the extruder 11, outer surface molding device 13 (drive mechanism 35), gas supply device 14, and pressure reduction device 15 via signal lines (not shown). The control device 16 controls the operation of each device connected via the signal lines. The control device 16 may also control various devices arranged upstream and downstream of the extrusion molding device 100.

[0032] Hereinafter, a method for extrusion molding of a multi-lumen tube 1 using an extrusion molding device 100 will be described with reference to FIGS.

[0033] While resin is being supplied from the extruder 11 to the mold 12, air is supplied from the gas supply device 14 to the hollow portions (through holes) of the conduit molding members 22 to 25b, and the air is sprayed from the tips of the conduit molding members 22 to 25b. The multi-lumen tube 1 immediately after extrusion has conduits 2 to 25b each having a shape corresponding to the outer shape of the tip of the conduit molding members 22 to 25b. As a result, the shapes of the formed pipelines 2 to 5b are formed, respectively, but because air is sprayed from the tips of the pipeline molding members 22 to 25b, the shapes of the formed pipelines 2 to 5b can be maintained until the resin hardens.

[0034] Next, the multi-lumen tube 1 extruded from the mold 12 is placed in a molding space 43 formed between consecutive pairs of first mold blocks 31 and second mold blocks 32 in the molding zone. With the extruded multi-lumen tube 1 placed in the molding space 43, the drive mechanism 35 moves the first mold block 31 and the second mold block 32 vertically downward in accordance with the extrusion of the multi-lumen tube 1 (i.e., at approximately the same speed as the extrusion speed of the multi-lumen tube 1).

[0035] The molding space 43 (molding section) between at least one pair of first mold block 31 and second mold block 32 in the molding zone is depressurized by the decompression device 15. Therefore, the outer surface of the multi-lumen tube 1 housed in the molding space 43 is in close contact (adsorbed) with the inner surface of the groove 37 that forms the molding space 43. The first mold block 31 and the second mold block 32 are moved vertically downward while the outer surface of the multi-lumen tube 1 remains in close contact with the entire inner surface of the groove 37. While the first mold block 31 and the second mold block 32 are moved vertically downward, the resin hardens, and a multi-lumen tube 1 having a perfectly circular cross-sectional outer shape is obtained.

[0036] As described above, the extrusion molding apparatus 100 according to this embodiment makes it possible to manufacture a multi-lumen tube having a cross-sectional outer shape that is close to a perfect circle, since the outer surface molding device 13 is used to mold the cross-sectional outer shape of the multi-lumen tube 1 immediately after extrusion. The extrusion molding apparatus 100 according to this embodiment is particularly suitable for manufacturing tubes for medical applications that require a cross-sectional outer shape to be a perfect circle.

[0037] Furthermore, in the extrusion molding apparatus 100 according to this embodiment, the outer surface of the flexible multi-lumen tube 1 immediately after extrusion is in close contact with the inner surfaces of the grooves 37 of the first mold block 31 and the second mold block 32 due to the vacuum. Therefore, even if the number of conduits provided is increased or the diameter of the tube is reduced, the pressure of the air ejected from the conduit molding members 22-25b can be prevented from rupturing the resin portion between the outer surface of the tube and the conduit. Therefore, the extrusion molding apparatus 100 according to this embodiment is particularly suitable for manufacturing multi-lumen tubes 1 for medical applications with small diameters, such as 10 mm or less, 8 mm or less, or 5 mm or less.

[0038] (Second embodiment) Fig. 10 is a cross-sectional view showing an example of a multi-lumen tube according to the second embodiment, and Fig. 11 is a view showing the belt shown in Fig. 10. The following description will focus on the differences between this embodiment and the second embodiment.

[0039] The extrusion molding device 200 according to this embodiment includes an outer surface molding device 50 instead of the outer surface molding device 13 according to the first embodiment. The outer surface molding device 50 includes a first belt 51, a second belt 52, and a drive mechanism 53 that circulates the first belt 51 and the second belt 52.

[0040] The first belt 51 and the second belt 52 are tubular members made of a flexible material such as rubber, resin, or silicone. As shown in FIG. 11 , the first belt 51 and the second belt 52 have a flat surface 56, a groove 57 formed in the flat surface 56, and a plurality of pores 58 penetrating the groove 57. The groove 57 is a portion for molding the outer surface of the multi-lumen tube 1 into a perfect circle, and has a uniform semicircular cross-sectional shape in the extension direction of the groove 57 and in a direction perpendicular to the flat surface 56. In other words, the groove 57 has a semicylindrical shape when the first belt 51 and the second belt are linearly extended. The plurality of pores 58 are formed at predetermined intervals in the extension direction of the first belt 51 and the second belt 52. The pores 58 are used to reduce the pressure inside the groove 57 using a pressure reducing device 15 during extrusion molding. Instead of or together with the pores 58, slits may be provided which extend in the direction perpendicular to the extending direction of the first belt 51 and the second belt 52 and the flat surface 56 and penetrate the grooves 57.

[0041] The first belt 51 and the second belt 52 may be gear belts. In this case, gears that engage with gears (not shown) of the drive mechanism 53 are formed at a constant pitch on the side opposite to the flat surface 56.

[0042] The drive mechanism 53 includes a motor (not shown) and circulates the first belt 51 and the second belt 52 along a track-shaped path by the torque of the motor. As shown in FIG. 10 , as the first belt 51 and the second belt 52 circulate, the drive mechanism 53 brings the flat surfaces 56 of the separated first belt 51 and the second belt 52 into surface contact vertically below the mold 12. At this time, the grooves 57 of the first belt 51 and the second belt 52 completely overlap, and a cylindrical molding space 43 with a perfectly circular cross section is formed between the overlapping grooves 57. The center of the cross section of the molding space 43 approximately coincides with the central axis of the mold 12. The drive mechanism 35 circulates the first belt 51 and the second belt 52 while maintaining the cylindrical molding space 43 formed by the first belt 51 and the second belt 52 within the molding zone. The drive mechanism 53 separates the first belt 51 and the second belt 52 again outside the molding zone.

[0043] During extrusion molding of the multi-lumen tube, the multi-lumen tube 1 extruded from the mold 12 is accommodated in the molding space 43 between the first belt 51 and the second belt 52. With the extruded multi-lumen tube 1 accommodated in the molding space 43, the drive mechanism 53 circulates the first belt 51 and the second belt 52 in accordance with the extrusion of the multi-lumen tube 1 (that is, at approximately the same speed as the extrusion speed of the multi-lumen tube 1).

[0044] The interior of the molding space 43 is decompressed by the decompression device 15 through the fine holes 58 that penetrate the first belt 51 and the second belt 52. The outer surface of the uncured multi-lumen tube 1 housed in the molding space 43 is in close contact with the inner surfaces of the grooves 57 of the first belt 51 and the second belt 52. While the first belt 51 and the second belt 52 are circulating with the outer surface of the multi-lumen tube 1 in close contact with the entire inner surface of the grooves 57, the resin hardens, and a multi-lumen tube 1 with a cross-sectional outer shape that is a perfect circle can be obtained.

[0045] As described above, even in the extrusion molding device 200 according to this embodiment, it is possible to use the outer surface molding device 50 to mold the outer surface of the pre-cured multi-lumen tube 1 into a cylindrical shape, thereby producing a multi-lumen tube having a cross-sectional outer shape that is close to a perfect circle. In this embodiment, the outer surface molding device 50 uses the first belt 51 and the second belt 52, and therefore, unlike when discontinuous mold blocks are used, there is no need to align the first belt 51 and the second belt 52. Furthermore, because there are no seams in the grooves 57 of the first belt 51 and the second belt 52, the outer surface of the multi-lumen tube 1 can be made smoother.

[0046] (Variation) In the above embodiments, an example in which the resin supply unit is configured with a single extruder 11 has been described. However, the resin supply unit may also be configured with a first extruder that extrudes a first resin, a second extruder that extrudes a second resin having a different hardness from the first resin, and a valve mechanism that controls the supply of resin to the mold. The valve mechanism may be switchable between a first state in which the first resin extruded from the first extruder is supplied to the mold and the second resin extruded from the second extruder is not supplied to the mold, and a second state in which the first resin extruded from the first extruder is not supplied to the mold and the second resin extruded from the second extruder is supplied to the mold. For example, the configuration described in International Publication No. 2020 / 262480 can be used as this valve mechanism. Alternatively, the valve mechanism may supply a mixed resin of the first resin extruded from the first extruder and the second resin extruded from the second extruder to the mold while changing the mixing ratio of the first resin and the second resin. For example, the configuration described in International Publication No. 2019 / 177018 can be used as this valve mechanism. The operation of the valve mechanism can be controlled by the above-mentioned control device 16. By using a resin supply unit equipped with two extruders and valve mechanisms, it is possible to mold a multi-lumen tube with different hardnesses on one end and the other end. [Industrial Applicability]

[0047] The present invention can be used in a manufacturing apparatus for a multi-lumen tube. [Explanation of symbols]

[0048] 1 multi-lumen tube 2, 3, 4a, 4b, 5a, 5b conduit 11 Extruder 12 Mold 13 External molding equipment 14 Gas supply device 15 Pressure reducing device 18 Resin flow path 19 Extrusion port 21 Inner mold 22, 23, 24a, 24b, 25a, 25b Pipe molding components 26 External mold 31 First mold block 32 Second mold block 35 Drive mechanism 36 Flat surface 37 Groove 38 Slit 40 Block section 43 Molding space 45 Lifting mechanism 50 External molding equipment 51 First Belt 52 Second Belt 53 Drive mechanism 56 Flat surface 57 Groove 58 pores 100, 200 Extrusion molding equipment

Claims

1. An extrusion molding device for a multi-lumen tube having two or more ducts, a resin supply unit that extrudes molten resin; a mold having an extrusion port at a lower end thereof, for molding the multi-lumen tube while extruding the resin supplied from the resin supply unit vertically downward; an outer surface molding device that molds the outer surface of the multi-lumen tube extruded from the mold; a gas supply device; a pressure reducing device; The mold is Inner mold and two or more tubular conduit molding members provided to correspond to the conduits of the multi-lumen tube, with their tip portions protruding from the lower end of the inner mold and the remaining portions located inside the inner mold, and each having a through hole and a portion at its tip portion having an outer shape corresponding to the cross-sectional shape of each of the conduits; a tubular outer mold that surrounds the inner mold and a portion of the inner mold that protrudes from the lower end portion thereof and forms a resin flow path between the inner surface of the outer mold and the outer surface of the inner mold; The outer surface molding device a plurality of first mold blocks each having a flat surface with a rectangular outer shape, a linear groove formed on the flat surface and having a semicircular cross section in a direction perpendicular to the flat surface, and a slit or a pore penetrating the groove; second mold blocks having the same shape and number as the first mold blocks; a drive mechanism for circulating the first mold block and the second mold block in pairs; The drive mechanism includes: In a molding zone provided vertically below the mold, the flat surfaces of the paired first and second mold blocks are brought into surface contact with each other so that the grooves of the paired first and second mold blocks overlap, forming molding spaces between the overlapping grooves that have a circular cross section and whose centers substantially coincide with the central axis of the mold, and moving the consecutive pairs of the first and second mold blocks linearly vertically downward along the central axis of the mold, separating the pair of first and second mold blocks from each other outside the molding zone; In a state where resin is being supplied from the resin supply unit to the mold, a gas is supplied from the gas supply device to each of the pipe molding members, and the supplied gas is sprayed from a tip of the through hole; the drive mechanism moves the first mold block and the second mold block vertically downward in accordance with the extrusion of the multi-lumen tube, with the multi-lumen tube being housed in the molding space of each of the consecutive pairs of the first mold block and the second mold block; An extrusion molding device for a multi-lumen tube, wherein the molding space is decompressed by the decompression device, thereby causing the outer surface of the multi-lumen tube housed in the molding space to adhere tightly to the inner surface of the groove.

2. An extrusion molding device for a multi-lumen tube having two or more ducts, a resin supply unit that extrudes molten resin; a mold having an extrusion port at a lower end thereof, for molding the multi-lumen tube while extruding the resin supplied from the resin supply unit vertically downward; an outer surface molding device that molds the outer surface of the multi-lumen tube extruded from the mold; a gas supply device; a pressure reducing device; The mold is Inner mold and two or more tubular conduit molding members provided to correspond to the conduits of the multi-lumen tube, with their tip portions protruding from the lower end of the inner mold and the remaining portions located inside the inner mold, and each having a through hole and a portion at its tip portion having an outer shape corresponding to the cross-sectional shape of each of the conduits; a tubular outer mold that surrounds the inner mold and a portion of the inner mold that protrudes from the lower end portion thereof and forms a resin flow path between the inner surface of the outer mold and the outer surface of the inner mold; The outer surface molding device a first belt formed of a flexible material, the first belt having a flat surface, a linear groove formed on the flat surface and having a semicircular cross section in a direction perpendicular to the flat surface, and a slit or pore penetrating the groove; a second belt formed of the same material as the first belt and having the same shape as the first belt; a drive mechanism that circulates the first belt and the second belt, The drive mechanism includes: In a molding zone provided vertically below the mold, the flat surfaces of the first belt and the second belt are brought into surface contact with each other so that the grooves of the first belt and the second belt overlap, forming a molding space between the overlapping grooves having a perfectly circular cross section and a center of the cross section substantially coinciding with a central axis of the mold, and moving the first belt and the second belt linearly vertically downward along the central axis of the mold, separating the first belt and the second belt from each other outside the molding zone; In a state where resin is being supplied from the resin supply unit to the mold, a gas is supplied from the gas supply device to each of the pipe molding members, and the supplied gas is sprayed from a tip of the through hole; the drive mechanism moves the first belt and the second belt vertically downward in accordance with the extrusion of the multi-lumen tube, with the multi-lumen tube extruded from the mold housed in the molding space formed by the first belt and the second belt; An extrusion molding device for a multi-lumen tube, wherein the molding space is decompressed by the decompression device, thereby causing the outer surface of the multi-lumen tube housed in the molding space to adhere tightly to the inner surface of the groove.

3. The extrusion molding device for a multi-lumen tube according to claim 1 or 2, further comprising an elevation mechanism for vertically elevating the outer surface molding device.

4. 3. The extrusion molding device for a multi-lumen tube according to claim 1, wherein the positions of the upper ends of the respective conduit molding members are different.

5. 3. The multi-lumen tube extrusion molding device according to claim 1 or 2, wherein at least one of the conduit molding members includes a tubular first member including the tip portion and a tubular second member, and the upper end of the first member is detachably connected to the lower end of the second member.

6. 3. The extrusion molding device for a multi-lumen tube according to claim 1, wherein the inner diameter of the outer mold is 10 mm or less.

7. 3. The extrusion molding device for a multi-lumen tube according to claim 1, wherein the multi-lumen tube is a medical tube.

8. 3. The multi-lumen tube extrusion molding device according to claim 1, wherein the resin supply unit includes a single extruder that extrudes molten resin.

9. The resin supply unit a first extruder that extrudes a first resin; a second extruder for extruding a second resin having a hardness different from that of the first resin; 3. The extrusion molding device for a multi-lumen tube according to claim 1, further comprising a valve mechanism capable of switching between a first state in which the first resin extruded from the first extruder is supplied to the mold and the second resin extruded from the second extruder is not supplied to the mold, and a second state in which the first resin extruded from the first extruder is not supplied to the mold and the second resin extruded from the second extruder is supplied to the mold.

10. The resin supply unit a first extruder that extrudes a first resin; a second extruder for extruding a second resin having a hardness different from that of the first resin; 3. The extrusion molding device for a multi-lumen tube according to claim 1, further comprising a valve mechanism that supplies a mixed resin of the first resin extruded from the first extruder and the second resin extruded from the second extruder to the mold while changing the mixing ratio of the first resin and the second resin.

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