JP3556555B2 - Equipment for manufacturing hollow extrusion products - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an improvement in an apparatus for manufacturing a multilayer hollow extruded product in which a second molding layer made of a synthetic resin material is provided on the outer surface of at least a first molding layer made of a rubber material.
[0002]
[Prior art]
FIG. 5 shows this type of manufacturing apparatus. As shown in FIG. 4, this manufacturing apparatus has a hollow hose having a circular cross section having a middle layer y made of a synthetic resin material between an inner layer x made of a rubber material and an outer layer z (hereinafter referred to as a three-layer hose Q). A first extrusion head A for extruding the inner layer x, a second extrusion head B for extruding the intermediate layer y, and a third extrusion head for extruding the outer layer z. And a head C.
[0003]
These extrusion heads A, B, and C are not shown in the drawing, but each have a cylindrical shape, and a material supplied from the outer peripheral surface is extruded from the inner peripheral surface at one end, so-called extrusion heads. It is of a type called a crosshead, which is juxtaposed with their axes aligned. The first extruding head A and the third extruding head C are each connected to a rubber extruder D for supplying a rubber material at about 120 ° C., while the second extruding head B is A synthetic resin extruder E for supplying a synthetic resin material of about 200 ° C. is connected.
[0004]
In this manufacturing apparatus, first, the cylindrical inner layer x extruded from the first extrusion head A is sequentially supplied to the second extrusion head B, and the outer periphery of the inner layer x is provided with the second extrusion head The intermediate layer y extruded from B is covered.
[0005]
Next, the inner layer x covering the intermediate layer y is sequentially supplied to the third extrusion head C, and the outer layer z extruded from the third extrusion head C is coated on the outer periphery of the intermediate layer y. , And the inner layer x, the intermediate layer y, and the outer layer z are stacked on each other.
[0006]
Thereafter, the three molded layers x, y, and z are cooled in the cooling tank F, and the inner layer x and the outer layer z, which are rubber materials, are vulcanized, so that the three-layer hose Q having desired physical properties is obtained. You can get it.
[0007]
[Problems to be solved by the invention]
By the way, the inner layer x extruded from the first extrusion head A is a rubber material before vulcanization and therefore has extremely low rigidity, and it is difficult to maintain its own shape.
[0008]
Therefore, there is a possibility that the inner layer x extruded from the first extrusion molding head A hangs down due to gravity before reaching the second extrusion molding head B, a hollow portion is crushed, and the like, and there is a possibility that deformation occurs. This will greatly affect the shape and dimensions of the three-layer hose Q.
[0009]
For this reason, in the conventional manufacturing apparatus, the mandrel G is applied as a core material to prevent the above-mentioned situation from occurring. That is, a mandrel G having a predetermined rigidity is supplied to the first extrusion molding head A, and the inner layer x is extruded on the outer periphery of the mandrel G to form the inner layer x up to the second extrusion molding head B. This prevents a situation such as drooping or crushing from occurring.
[0010]
According to the manufacturing apparatus to which such a mandrel G is applied, the inner diameter of the three-layer hose Q is accurately defined by the outer diameter of the mandrel G, which is extremely advantageous in terms of dimensional accuracy.
[0011]
However, in the above-described manufacturing apparatus, an apparatus H for supplying the mandrel G and an apparatus J for applying a predetermined tension to the mandrel G must be arranged upstream of the first extrusion head A. Therefore, the installation space is significantly increased. Further, after vulcanizing the inner layer x and the outer layer z, an operation of pulling out the mandrel G from the three-layer hose Q becomes essential, which is not preferable in terms of productivity.
[0012]
In view of the above circumstances, an object of the present invention is to provide a manufacturing apparatus capable of obtaining a hollow extruded product having a desired shape without increasing the installation space and lowering productivity.
[0013]
[Means for Solving the Problems]
The invention according to claim 1 of the present application is directed to an apparatus for manufacturing a hollow extruded product in which a second molding layer made of a synthetic resin material is provided on an outer surface of at least a first molding layer made of a rubber material. A first extrusion head for extruding the first molding layer and a second extrusion head for extruding the second molding layer are integrated into a unit with a heat insulating material interposed therebetween. The second extrusion layer is immediately extruded from the second extrusion head on the outer surface of the first extrusion layer extruded from the first extrusion head, When extruding the second molding layer from the second extrusion head, the second molding layer made of a synthetic resin material that is heated to a temperature higher than that of the first molding layer made of a rubber material, Unvulcanized rubber material that becomes the molding layer of 1. The first molded layer so as not to affect due to heat for Thickness To reduce the thickness of the second molding layer From the heat capacity of the first molded layer, the heat capacity of the second molded layer Heat capacity is reduced.
[0014]
Further, in the invention according to claim 2 of the present application, a hollow in which a second molding layer made of a synthetic resin material and a third molding layer made of a rubber material are sequentially provided on at least the outer surface of the first molding layer made of a rubber material. In an apparatus for manufacturing an extruded product, a first extrusion head for extruding the first molding layer and a second extrusion head for extruding the second molding layer are interposed between each other. A first extruding head for extruding and forming the third molded layer is disposed near the unit, wherein the first extruded head is formed as an integral unit with a heat insulating material interposed therebetween; Immediately extruding the second molded layer from the second extrusion molding head on the outer surface of the first molded layer extruded from the third molded layer, and immediately forming the third molded layer on the outer surface of the second molded layer Extrusion head And the third molded layer is extruded from the second extrusion head. When the second molded layer is extruded from the second extrusion head, the first molded layer made of rubber material or the third molded layer is extruded. The second molding layer made of a synthetic resin material having a high temperature with respect to the first molding layer does not affect the uncured rubber material serving as the first molding layer or the third molding layer due to heat. First molded layer Thickness To reduce the thickness of the second molding layer From the heat capacity of the first molded layer, the heat capacity of the second molded layer Heat capacity is reduced.
[0015]
In these manufacturing apparatuses, a ventilation passage may be provided to open a space defined between the outer peripheral surface of the first molding layer extruded from the first extrusion molding head and the unit to the outside of the unit. preferable.
[0016]
Further, in the invention according to claim 2 of the present application, it is preferable to provide an adjusting means for adjusting a separation distance between the unit and the third extrusion head. It is preferable to extrude the third molding layer from the third extrusion head so as to support the outer periphery of the second molding layer extruded from the second extrusion head. In the third extrusion molding head, if the extrusion port of the rubber material serving as the third molding layer is located closer to the unit than the supply port of the rubber material, the third molding layer is extruded near the unit. It is possible to do. In this case, it is preferable to provide a supporting means for supporting the outer periphery of the third molding layer in the third extrusion head.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings showing the embodiments.
FIGS. 1 to 3 show an embodiment of the production apparatus according to the present invention. As shown in FIG. 4, an inner layer (first molded layer) made of a rubber material is formed as a hollow extruded product. An apparatus for manufacturing a three-layer hose Q having a circular cross section, in which an intermediate layer (second molded layer) y made of a synthetic resin material is provided as a gas barrier layer between x and an outer layer (third molded layer) z. Is exemplified. As an example of specific dimensions of the three-layer hose Q manufactured by the manufacturing apparatus of the present embodiment, the inner diameter of the inner layer x is 11.52 to 11.64 mm, the wall thickness is 2.24 to 2.33 mm, and the middle is The thickness of the layer y is 0.13 to 0.14 mm, and the outer diameter of the outer layer z is 18.10 to 18.20 mm.
[0018]
As shown in FIG. 1, the manufacturing apparatus includes an inner layer extrusion head 10 serving as a first extrusion head, an intermediate layer extrusion head 20 serving as a second extrusion head, and a third extrusion head. And an outer layer extrusion head 30 as shown in FIG.
[0019]
The inner layer extrusion head 10 is for extruding the inner layer x of the above-described three-layer hose Q, and includes an inner layer torpedo 12, an inner layer collar 13, and an inner layer die holder 14 in a center hole of a cylindrical inner layer head body 11. ing.
[0020]
The inner layer torpedo 12 is provided with a spider 12b at the base end of a substantially columnar base 12a. The spider 12b is connected to the base 12a with the axis of the base 12a being aligned with the axis of the inner layer head main body 11. It is held at the base end of the inner layer head main body 11. An inner layer nipple 15 is held at the tip of the base 12a of the inner layer torpedo 12. The inner layer nipple 15 has a substantially cylindrical shape whose outer diameter decreases toward the tip, and extends from the tip of the inner layer torpedo 12 with its axis aligned with the axis of the inner layer head body 11. I have. The distal end of the inner nipple 15 is configured so that the outer diameter thereof defines the inner diameter of the inner layer x in the above-described three-layer hose Q.
[0021]
The base 12a of the inner layer torpedo 12 and the inner layer nipple 15 are provided with blow holes 12c and 15a that communicate with each other at positions that are the respective axes. The blow holes 12c and 15a are open at the distal end face of the inner nipple 15 and closed at the base end of the base 12a. The blow holes 12c and 15a are provided in the communication passage 12d provided in the spider 12b of the inner torpedo 12 and the inner head body 11. It opens to the outer peripheral surface of the inner layer head main body 11 through the communication passage 11a. Although not explicitly shown in the drawings, an air blow device for injecting air from the distal end openings of the blowing holes 12c and 15a may be connected to the communication passage 11a of the inner layer head main body 11.
[0022]
The inner layer collar 13 and the inner layer die holder 14 are each formed in an annular shape, and are provided in the center hole of the inner layer head main body 11 so as to be continuous with the above-described spider 12b of the inner layer torpedo 12. The center holes of the inner layer collar 13 and the inner layer die holder 14 are configured such that the inner diameter gradually decreases toward the tip, and forms a tapered flow path. As is clear from the figure, the tip of the inner layer die holder 14 projects further from the tip of the inner layer head main body 11 toward the tip, and its outer peripheral portion is surrounded by the inner layer die holder retainer 16, while its inner periphery is The part holds the inner layer die 17. The inner layer die holder retainer 16 has an annular shape, and is attached to the distal end surface of the inner layer head main body 11 in a state of being engaged with the distal end portion of the inner layer die holder 14. The inner layer die 17 has an annular shape so as to surround the outer peripheral portion of the inner layer nipple 15. The center hole of the inner layer die 17 is provided so as to be continuous with the center hole of the inner layer die holder 14, and the inner diameter of the most distal end thereof is configured to define the outer diameter of the inner layer x in the above-described three-layer hose Q. It is.
[0023]
The inner layer die 17 has a plurality of ventilation passages 17a. Each of the ventilation passages 17a extends obliquely from the base outer peripheral surface of the inner layer die 17 toward the center of the distal end surface of the inner layer die 17. These ventilation passages 17a communicate with each other through annular passages 17b provided on the outer peripheral surface of the base end of the inner layer die 17, and further have communication passages 14a provided in the inner layer die holder 14 and communication holes provided in the inner layer die holder retainer 16. An opening is formed in the outer peripheral surface of the inner die holder holder 16 through the passage 16a. Although not explicitly shown in the figure, a vacuuming device for sucking gas from the distal end surface of the ventilation passage 17a may be connected to the communication passage 16a of the inner die holder retainer 16.
[0024]
Reference numeral 18 in the drawing denotes an inner layer head adjustment bolt screwed from the outer peripheral surface of the inner layer head main body 11 to the inner layer die holder 14. The inner layer head adjusting bolt 18 is for adjusting the position of the inner layer die 17 with respect to the inner layer nipple 15 via the inner layer die holder 14. Reference numeral 19 in the drawing denotes a warm water circulation jacket provided on the outer peripheral surface of the inner layer head main body 11.
[0025]
The inner layer extrusion head 10 is connected to the inner layer rubber extruder 100 with the center hole of the inner layer head body 11 aligned with the center hole of the liner 101 and a breaker plate 102 interposed therebetween. . The inner layer rubber extruder 100 is a 60 mm rubber uniaxial vent type extruder (L / D = 16), drives the screw 103 at 6.5 rpm, and is about 120 to 130 ° C. with respect to the inner layer extrusion head 10 described above. And supplies unvulcanized rubber material.
[0026]
The intermediate layer extrusion molding head 20 is for extruding the intermediate layer y of the three-layer hose Q described above, and has an intermediate layer nipple 22 and an intermediate layer die holder 23 in a center hole of a cylindrical intermediate layer head body 21. Have.
[0027]
The intermediate layer nipple 22 has a bottomed annular shape and has a through hole 22a in the center of the bottom wall. The center hole in the intermediate layer head main body 21 with the bottom wall facing outward is formed. It is fitted to the base end. The through hole 22 a provided in the bottom wall of the intermediate layer nipple 22 has an inner diameter slightly larger than the inner diameter of the inner die 17 in the inner extrusion head 10.
[0028]
The intermediate layer die holder 23 has a substantially columnar shape having substantially the same length as the intermediate layer head main body 21, and holds the intermediate layer die 24 at the base inner peripheral portion, while holding the intermediate layer die 24 at the distal end outer peripheral portion. It has a flange 23a, and is attached to the intermediate layer head main body 21 in a state where the flange 23a is in contact with the tip end surface of the intermediate layer head main body 21. The intermediate layer die 24 has a bottomed cylindrical shape and has a center hole slightly larger in diameter than the through hole 22a of the intermediate layer nipple 22 at the center of the bottom wall. It is attached to the intermediate layer die holder 23 in a state facing the side. The base end surface of the intermediate layer die holder 23 and the base end surface of the intermediate layer die 24 are located on the same plane at a position slightly separated from the bottom wall of the intermediate layer nipple 22.
[0029]
As shown in FIG. 2, the intermediate layer die holder 23 has an outer diameter at the base end slightly smaller than the outer diameter at the distal end, and a central hole of the intermediate layer head main body 21 at the distal end. , While being slightly separated from the center hole of the intermediate layer head main body 21 at the base end. Further, a spiral groove 23b is provided on the outer peripheral surface of the intermediate layer die holder 23, and the spiral groove 23b is formed between the outer peripheral surface of the intermediate layer die holder 23 and the inner peripheral surface of the intermediate layer head main body 21 from the distal end side to the proximal end side. A flow path is configured. In this flow path, the downstream end located on the base end side of the intermediate layer head main body 21 is a space defined between the base end surfaces of the intermediate layer die holder 23 and the intermediate layer die 24 and the bottom wall of the intermediate layer nipple 22. And is opened so as to be substantially perpendicular to the axis of the intermediate layer head main body 21. On the other hand, the upstream end located on the front end side of the intermediate layer head main body 21 in the flow path is opened to the outer peripheral surface of the intermediate layer head main body 21 through the communication passage 21 a provided in the intermediate layer head main body 21.
[0030]
Reference numeral 25 in FIG. 1 denotes an electric heater surrounding the outer periphery of the intermediate layer head main body 21.
[0031]
The intermediate layer extrusion head 20 has the axial center of the intermediate layer head main body 21 coincident with the axis of the inner layer head main body 11 and the heat insulating material 40 interposed therebetween. The unit is configured as an integral unit. That is, in a state where the heat insulating material 40 is interposed between the distal end face of the inner die holder 14 in the inner extrusion head 10 and the base end face of the intermediate head body 21 in the intermediate extrusion head 20, both are firmly fixed by the unit bolt 41. It is stuck to. As the heat insulating material 40, a material having sufficient rigidity to maintain the connection between the two and heat resistance sufficient to withstand a high temperature of 250 ° C. or more may be used. As is clear from FIG. 2, the heat insulating material 40 has a plate thickness larger than the amount of protrusion of the inner layer die 17 from the inner layer die holder 14, and the front end face of the inner layer die 17 and the intermediate layer nipple 22 are formed. A heat insulating space α is secured between the base end face.
[0032]
Further, the intermediate layer extrusion head 20 is connected to a synthetic resin extruder 200 via an intermediate layer relay head 50. The intermediate layer relay head 50 is a portion that communicates with the communication passage 21 a of the intermediate layer head main body 21 and extends radially outward from the intermediate layer head main body 21. The intermediate layer relay head 50 is provided with an electric heater 51 at a position to be an outer peripheral portion of the flow path. The synthetic resin material extruder 200 is a 40 mm plastic extruder. The screw 201 is driven at 1.65 rpm, and the synthetic resin material at about 200 to 240 ° C., such as THV (fluoro Thermoplastic) is applied. Reference numeral 202 in the drawing denotes a breaker plate interposed between the intermediate layer relay head 50 and the synthetic resin extruder 200.
[0033]
The outer layer extrusion head 30 is for extruding the outer layer z of the above-described three-layer hose Q, and includes an outer layer nipple holder 32 and an outer layer die holder 33 in a central hole of a cylindrical outer layer head main body 31.
[0034]
The outer layer nipple holder 32 has an annular shape in which the diameter at the base end is smaller than that at the tip, and is attached to the base end of the outer layer head main body 31 via the outer periphery at the tip. The center hole of the outer layer nipple holder 32 is configured so as to be continuous with the center hole of the outer layer head body 31 at the distal end and to gradually decrease the inner diameter toward the base end. The outer layer nipple holder 32 holds an outer layer nipple 34 at an inner peripheral portion of the base end. The outer layer nipple 34 has an annular shape, and has a center hole having two inner peripheral surfaces 34a and 34b. An inner peripheral surface (hereinafter, referred to as an introduction-side inner peripheral surface 34a) located on the proximal end side of the outer layer nipple 34 extends so that the inner diameter gradually decreases toward the distal end. The inner diameter of the most proximal portion of the introduction-side inner peripheral surface 34a is larger than the inner diameter of the most distal portion of the center hole of the intermediate layer die holder 23 described above. On the other hand, an inner peripheral surface (hereinafter, referred to as a flow path defining inner peripheral surface 34b) located on the distal end side of the outer layer nipple 34 extends so that the inner diameter gradually decreases toward the proximal end, and then returns to the proximal end side. And is associated with the tip of the introduction-side inner peripheral surface 34a. The flow path defining inner peripheral surface 34 b is configured such that the inner diameter of the leading end portion is continuous with the center hole of the outer layer nipple holder 32.
[0035]
The outer layer die holder 33 has a substantially columnar shape having substantially the same length as the outer layer head main body 31 and holds an outer layer die 35 at a base end thereof. The outer layer die 35 faces the outer layer nipple 34. In this state, it is fitted and held in the center hole of the outer layer head main body 31. In the outer layer die holder 33, a thin portion 33 a is formed from the outer peripheral side to the base end side portion including the outer layer die 35, and from the inner peripheral surface of the outer layer head main body 31 to the flow path defining inner peripheral surface 34 b of the outer layer nipple 34. A flow path from the distal end to the proximal end is formed between the leading portions. The downstream end of this flow path located on the base end side of the outer layer head main body 31 is formed by a gap between the inner end of the flow path defining inner peripheral surface 34 b of the outer layer nipple 34 and the base end of the outer layer die 35. It is open toward the axis of the outer layer head main body 31 through the outlet 36. On the other hand, the upstream end located on the tip side of the outer layer head main body 31 in the flow path has a portion serving as the supply port 33b on the outer peripheral surface of the outer layer head main body 31 through a communication passage 31a provided in the outer layer head main body 31. It is open.
[0036]
Further, the outer layer die holder 33 is configured such that the inner diameter of the center hole gradually increases toward the front end, and includes an outer layer guide roller 37 as a support means therein. The outer layer guide roller 37 supports the three-layer hose Q passing through the inside of the outer layer extrusion head 30 from below inside the outer layer extrusion head 30.
[0037]
Reference numeral 38 in the drawing denotes an outer layer head adjustment bolt screwed from the outer peripheral surface of the outer layer head main body 31 toward the outer layer nipple holder 32. The outer layer head adjustment bolt 38 is for adjusting the position of the outer layer nipple 34 with respect to the outer layer die 35 via the outer layer nipple holder 32. Reference numeral 39 in the drawing denotes a jacket for circulating hot water provided on the outer peripheral surface of the outer layer head main body 31.
[0038]
The outer layer extrusion molding head 30 is disposed on the extension of the tip of the intermediate layer head main body 21 in a state where the axis of the outer layer head main body 31 matches the axis of the intermediate layer head main body 21. It is connected to the outer layer rubber extruder 300 via 60. The outer layer relay head 60 is a portion that communicates with the communication passage 31a of the outer layer head main body 31 and extends radially outward from the outer layer head main body 31. The outer layer relay head 60 is provided with a hot water circulation jacket 61 at a position that is an outer peripheral portion of the flow path. The outer layer rubber extruder 300 is a 90 mm rubber uniaxial vent type extruder (L / D = 16), drives the screw 301 at 0.7 rpm, and is about 120 to 130 ° C. with respect to the outer layer extrusion molding head 30 described above. And supplies unvulcanized rubber material. As shown in FIG. 3, the outer layer rubber extruder 300 is installed on a table (adjusting means) 310 movable along the direction in which the three extrusion heads 10, 20, and 30 are arranged. By moving the table 310, it is possible to adjust the distance between the outer layer extrusion head 30 and the intermediate layer extrusion head 20. Reference numeral 302 in the drawing denotes a breaker plate interposed between the outer layer relay head 60 and the outer layer rubber extruder 300.
[0039]
In the manufacturing apparatus configured as described above, when the inner layer rubber extruder 100 is driven, the rubber material supplied to the inner layer extrusion head 10 is sequentially extruded and formed from between the inner layer die 17 and the inner layer nipple 15. The inner layer x having the shape is supplied to the intermediate layer extrusion head 20. During this time, it is preferable that the air blow device (not shown) is driven to constantly inject air from the tip openings of the blowing holes 12c and 15a so that the inner layer x maintains a desired shape by the pressure of the air.
[0040]
In the intermediate layer extrusion molding head 20 to which the inner layer x is supplied, the synthetic resin material is sequentially extruded and formed from between the intermediate layer nipple 22 and the intermediate layer die 24 by driving the synthetic resin material extruder 200, and the intermediate layer is drawn down. It becomes y to cover the outer periphery of the inner layer x. During this time, it is preferable that a gas is prevented from entering between the inner layer x and the intermediate layer y by driving a vacuum device (not shown) and sucking the gas in the heat insulating space α through the ventilation passage 17a.
[0041]
The inner layer x covered by the intermediate layer y is further supplied to the outer layer extrusion head 30. In the outer layer extrusion molding head 30, the rubber material is sequentially extruded and formed between the outer layer nipple 34 and the outer layer die 35 by driving of the outer layer rubber extruder 300, and becomes the outer layer z to cover the outer periphery of the intermediate layer y. As a result, the inner layer x, the intermediate layer y, and the outer layer z are in a state of being stacked on each other.
[0042]
Thereafter, the three molded layers x, y, and z are cooled in the cooling tank 400, and the inner layer x and the outer layer z, which are rubber materials, are vulcanized to obtain a three-layer hose Q having desired physical properties. become able to.
[0043]
Here, according to the manufacturing apparatus, the inner layer extrusion head 10 and the intermediate layer extrusion head 20 are configured as an integral unit, and the inner layer x extruded from the inner layer extrusion head 10 is immediately formed by the intermediate layer y. Since the coating is performed, the inner layer x, which is a rubber material before being vulcanized and extruded from the inner layer extrusion molding head 10, is not likely to be deformed such as hanging down by gravity or crushing a hollow portion. Further, since the outer layer extrusion head 30 is arranged near the intermediate layer extrusion head 20 and the intermediate layer y is immediately covered with the outer layer z, the above-described effects are more remarkable. Further, since the outer layer guide roller 37 is provided inside the outer layer extrusion head 30, the outer layer z extruded from the outer layer extrusion head 30 can be supported at a position closer to the outer layer guide roller 37. Therefore, a three-layer hose Q having a desired shape can be obtained without using a mandrel as before, and there is no possibility that the installation space and the productivity may be reduced due to the use of the mandrel. . In this case, a non-contact type outer diameter measuring device s is installed between the intermediate layer extrusion head 20 and the outer layer extrusion head 30 and on the downstream side of the outer layer extrusion head 30, respectively. If dimensional control such as controlling the driving of the extruders 100, 200, 300 is performed based on this, it is possible to further improve the dimensional accuracy of the three-layer hose Q. In addition, if the curved core rod is inserted into the inside of the inner layer x in a state where the inner layer x, the intermediate layer y and the outer layer z are stacked on each other, and then the inner layer x and the outer layer z are vulcanized, along the core rod, It is also possible to obtain a curved three-layer hose Q.
[0044]
Further, according to the manufacturing apparatus, the heat insulating material 40 is interposed between the inner layer extrusion head 10 and the intermediate layer extrusion head 20, and the heat insulation space α is secured. This causes problems such as that the rubber material of the inner layer extrusion molding head 10 is vulcanized due to high temperature, and conversely, the synthetic resin material of the intermediate layer extrusion molding head 20 cools and the fluidity deteriorates. There is no danger. Further, the intermediate layer y, which has a higher temperature than the inner layer x and the outer layer z, is cooled before covering the inner layer x, and has a small thickness of 0.13 to 0.14 mm and a small heat capacity. There is no possibility that heat will affect the unvulcanized rubber material that becomes the outer layer z. In particular, regarding the outer layer z, since the outer layer extrusion head 30 for extruding the outer layer z can be moved with respect to the intermediate layer extrusion head 20, the influence of the heat of the intermediate layer y can be reduced by adjusting the position thereof as appropriate. It is possible to reliably prevent it.
[0045]
Further, in the outer layer extrusion molding head 30, since the outer layer z is extruded toward the axis of the outer layer head main body 31, the inner layer x covered with the intermediate layer y is extruded by the extrusion force of the outer layer z. Thus, the intermediate layer y can be prevented from being scratched due to contact with the outer layer nipple 34.
[0046]
Note that, in the above-described embodiment, an apparatus for manufacturing a three-layer hose having a circular cross section is illustrated, but the cross section of the hollow extruded product does not necessarily have to be circular. Further, the number of the formed layers does not need to be three, and may be any number such as four layers or five layers as long as it is at least two or more.
[0047]
Further, in the above-described embodiment, since the outer extrusion head, which is the third extrusion head, extrudes the third molding layer at a position on the base end side, the second extrusion head is formed. It is possible to cover the second molded layer extruded from the extrusion molding head at a position closer to the second molded layer, but it is necessary to extrude the third molded layer at a position closer to the base end side. No need. Although only the third extrusion head is provided so as to be movable, only the first and second extrusion heads configured in the unit are provided so as to be movable, or both are provided so as to be movable together. May be provided.
[0048]
Furthermore, in the above-described embodiment, a so-called centering type, in which the gap between the die and the nipple is adjusted by an adjustment bolt, is illustrated as the first and third extrusion molding heads. A non-adjustable core may be applied as in the intermediate layer extrusion head exemplified as the second extrusion head. In addition, as the first extrusion head, a so-called straight head type is illustrated, but a so-called cross head type head may be applied. In this case, it is possible to manufacture a hollow extruded product using a mandrel in the same manufacturing apparatus.
[0049]
【The invention's effect】
As described above, according to the present invention, the outer surface of the first molding layer, which is a rubber material before vulcanization extruded from the first extrusion molding head, is immediately applied to the second extrusion molding head. Since the first molding layer is covered with the second molding layer which is a synthetic resin material extruded from the first molding layer, there is no possibility that the first molding layer hangs down due to gravity or a hollow portion is deformed. Therefore, a hollow extruded product having a desired shape can be obtained without using a mandrel as in the past, and there is no fear that the use of the mandrel will increase the installation space or lower the productivity. .
In addition, since the heat insulating material is interposed between the first extrusion head and the second extrusion head, the temperatures of both can be appropriately maintained. There is no danger that the rubber material will be vulcanized due to high temperature, or conversely, the synthetic resin material of the second extrusion molding head will cool and the fluidity will deteriorate.
[Brief description of the drawings]
FIG. 1 is a sectional view showing one embodiment of a manufacturing apparatus according to the present invention.
FIG. 2 is an enlarged sectional view of a main part of the manufacturing apparatus shown in FIG.
FIG. 3 is a diagram conceptually showing the manufacturing apparatus shown in FIG.
FIG. 4 is a perspective view of a three-layer hose shown as an example of a hollow extruded product.
FIG. 5 is a conceptual diagram showing a conventional manufacturing apparatus.
[Explanation of symbols]
10 Inner layer extrusion head
11 Inner layer head body
11a Access passage
12 inner layer torpedo
12a base
12b Spider
12c, 15a Blow hole
12d access passage
13 Inner layer color
14 Inner layer die holder
14a Access passage
15 Inner layer nipple
16 Inner die holder holder
16a Access passage
17 Inner layer die
17a Ventilation passage
17b Annular passage
18 Inner layer head adjustment bolt
20 Intermediate layer extrusion head
21 Middle layer head body
21a Access passage
22 Middle layer nipple
22a Through hole
23 Interlayer die holder
23a flange
23b spiral groove
24 Interlayer die
25 Electric heater
30 Outer layer extrusion head
31 Outer layer head body
31a Access passage
32 Outer layer nipple holder
33 Outer die holder
33a Thin part
33b Supply port
34 Outer layer nipple
34a Inner side inner surface
34b Channel inner surface
35 Outer Die
36 extrusion port
37 Outer layer guide roller
38 Outer layer head adjustment bolt
40 Insulation
41 unit bolt
50 Intermediate layer relay head
51 Electric heater
60 Outer layer relay head
100 Inner layer rubber extruder
101 Liner
102 Breaker plate
103 screw
200 Synthetic resin extruder
201 Screw
300 Outer Rubber Extruder
301 screw
310 table
400 cooling tank
Q Three-layer hose
s Non-contact type outer diameter measuring instrument
x inner layer
y middle layer
z outer layer
α Insulated space

Claims (7)

An apparatus for manufacturing a hollow extruded product in which a second molding layer made of a synthetic resin material is provided on an outer surface of at least a first molding layer made of a rubber material, wherein the first molding layer is extruded. The first extrusion head and the second extrusion head for extruding the second molding layer are formed as an integral unit with a heat insulating material interposed therebetween. The second extrusion layer is immediately extruded from the second extrusion head onto the outer surface of the first extrusion layer extruded from the extrusion head, and the second extrusion layer is extruded from the second extrusion head. When the second molded layer is extruded, the second molded layer made of a synthetic resin material having a higher temperature than the first molded layer made of a rubber material is used as an unvulcanized non-vulcanized material serving as the first molded layer. Does not affect the rubber material due to heat Hollow extruded, characterized in that to reduce the heat capacity of the first first molded layer second molded layer than the heat capacity of and reducing the thickness of the second molded layer against the wall thickness of the molded layer of such Equipment for manufacturing molded products. An apparatus for manufacturing a hollow extruded product in which a second molding layer made of a synthetic resin material and a third molding layer made of a rubber material are sequentially provided on an outer surface of at least a first molding layer made of a rubber material, An integrated unit comprising a first extrusion head for extruding the first molding layer and a second extrusion head for extruding the second molding layer with a heat insulating material interposed therebetween. And a third extrusion head for extruding the third molding layer is arranged near the unit, and the first extrusion layer extruded from the first extrusion head is formed of the first extrusion layer. Immediately extruding the second molding layer from the second extrusion head on the outer surface, and immediately applying the third molding layer from the third extrusion head to the outer surface of the second molding layer. Extrusion When the second molding layer is extruded from the second extrusion head, the temperature of the first molding layer or the third molding layer made of a rubber material is higher than that of the second molding layer. The second molding layer made of a resin material has a thickness equal to the thickness of the first molding layer so that the uncured rubber material serving as the first molding layer or the third molding layer is not affected by heat. On the other hand, an apparatus for manufacturing a hollow extruded product, wherein the heat capacity of the second molded layer is made smaller than the heat capacity of the first molded layer by reducing the thickness of the second molded layer . The ventilation passage which opens the space defined between the outer peripheral surface of the first molding layer extruded from the first extrusion molding head and the unit to the outside of the unit is provided. 3. An apparatus for manufacturing a hollow extruded product according to 2. 3. The apparatus for manufacturing a hollow extruded product according to claim 2, further comprising an adjusting unit for adjusting a separation distance between the unit and the third extrusion head. The hollow extrusion according to claim 2, wherein the third extrusion layer is extruded from the third extrusion head so as to support the outer periphery of the second extrusion layer extruded from the second extrusion head. Equipment for manufacturing molded products. The manufacturing of the hollow extruded product according to claim 2, wherein the third extrusion head has a rubber material extrusion port serving as the third molding layer at a position closer to the unit than the rubber material supply port. 4. apparatus. 7. The apparatus for manufacturing a hollow extruded product according to claim 6, wherein said third extrusion head is provided with support means for supporting an outer periphery of said third molded layer.

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