JP2003103599A - Extrusion molding machine and extrusion molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an extrusion molding machine which can mold a molding of a prescribed size without a cutting device made different in form while space saving is attempted. SOLUTION: The extrusion molding machine for molding a tubular molding 1 having a prescribed length is provided with a molding die 21 having a gate 35 to be an extrusion hole 34 for extruding a supplied molding material, a support pin 200 which faces the middle part of the extrusion hole 34 to be a die inner mold and has an air introduction hole 201 at the tip, and a cylindrical movable pin 56 which is engaged with the outside of the support pin 200, is fitted freely movably along the axis, and opens/closes the gate 35.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extrusion molding apparatus and an extrusion molding method, and relates to a technique suitable for use in producing a molded product having a predetermined length dimension by performing extrusion molding.

[0002]

2. Description of the Related Art Conventionally, in the extrusion molding of synthetic resin material, the synthetic resin material is plasticized by an extrusion molding machine, kneaded, and then extruded from a molding die to give a predetermined cross-sectional shape such as a circle, and further through a sizing die. The outer or inner diameter is finished and cured to obtain a molded product continuously.
The continuous molded body that passed through the molding die and the sizing die was cut into a predetermined length by a cutting device provided on the downstream side of the sizing die, and molded bodies having a predetermined length were manufactured one after another.

[0003]

However, in order to cut a molded product, in addition to an extrusion molding machine for extrusion molding, a cutting device different from this extrusion molding machine is required, and there is a problem that space saving is desired. there were.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an extrusion molding machine capable of forming a molded product of a predetermined size without a cutting device which is a separate body, in order to save space. Is to achieve.

[0005]

The extrusion molding apparatus of the present invention is an extrusion molding apparatus for molding a tubular molded article of a predetermined length, and a molding die having a gate serving as an extrusion hole for extruding the supplied molding material. A support pin having an air blow-in hole at its tip and facing the central portion of the extrusion hole, and a support pin fitted to the outside of the support pin and movable along the axis; The above-described problem is solved by including a cylindrical movable pin that opens and closes the gate. In the present invention, it is desirable that a cooling means be provided near the extrusion hole, on the extrusion direction side of the support pin. Further, in the present invention, it is possible to employ a means in which a plurality of the extrusion holes are provided and the support pins and / or the movable pins provided in the respective extrusion holes can be driven in synchronization. The extrusion molding method of the present invention is an extrusion molding method for molding a tubular molded article of a predetermined length, which comprises a molding die having a gate serving as an extrusion hole for extruding the supplied molding material, and a central portion of the extrusion hole. A support pin that faces the inside of the die and has an air blow-in hole at the tip, and a support pin that fits outside the support pin and is movable along the axis to open and close the gate. An extrusion molding device comprising a pin and
The above-described problem is solved by inserting and removing the movable pin into and from the gate to open and close the extrusion hole, and start and stop extrusion of the molding material.

The extrusion molding apparatus of the present invention comprises a cylindrical movable pin which is fitted to the outside of a support pin serving as an in-die mold and is movable along an axis line to open and close the gate.
By moving the movable pin in the axial direction of the support pin to open the gate, the molding material supplied from the material passage communicating with the gate is extruded from the gate (extrusion hole) to form a tubular shape having a predetermined cross-sectional shape. Forming a molded article of
By moving the movable pin in the axial direction of the support pin to close the gate, the extrusion of the molding material from the gate can be stopped and the extrusion of the molded product can be stopped at any position. It is possible to mold tubular moldings having length dimensions of Also, with the above configuration,
Molded products with different inner diameters (internal dimensions) can be molded simply by exchanging the support pins.
Alternatively, by exchanging the movable pin, it is possible to easily form a molded product having a different wall thickness.

In the present invention, cooling means is provided in the vicinity of the extrusion hole on the extrusion direction side of the support pin so that the molding material extruded from the extrusion hole is cooled on the downstream side by the cooling means. Then, a predetermined shape and dimensions are given to the molten resin (molding material) extruded on the downstream side of the extrusion hole as the sizing die, and it is preliminarily cooled so as not to be deformed by the next cooling step.
Alternatively, as the cooling step, the molding material extruded by the cooling means may be cooled to cool the molding material (resin) to give the molded article a predetermined shape and size.

Further, in the present invention, a plurality of the extrusion holes are provided, and the support pin and / or the movable pin provided in each extrusion hole can be synchronously driven, so that the same length is obtained. It is possible to simultaneously form a plurality of the tubular molded articles. Thereby, the molding efficiency can be improved.

In the extrusion molding method of the present invention, the movable pin is inserted into and removed from the gate to open and close the extrusion hole to start and stop extrusion of the molding material.
Extrusion of molded products can be stopped at any position,
As a result, a tubular molded product having a predetermined length dimension can be molded.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an extrusion molding apparatus and an extrusion molding method according to the present invention will be described below with reference to the drawings. 1 is a schematic sectional view of an extrusion molding apparatus according to the present embodiment, and FIG. 2 is an enlarged view of the vicinity of an extrusion hole of the extrusion molding apparatus shown in FIG. In the present embodiment, it is the cylindrical molded product 1 that is manufactured, and the extrusion hole (gate forming hole) 3 provided in the mold body (fixed mold) 21 that becomes the molding die.
4 is continuously extruded.

As shown in FIG. 1 and FIG.
Is a fixed-side attachment plate 26 attached to a fixed portion (not shown), and a fixed-side template 27 fixed to a surface of the fixed-side attachment plate 26 on the extrusion direction side (left side in the figure) via a spacer block (not shown). I have it. Also,
A manifold 28 is provided between the fixed-side mounting plate 26 and the fixed-side mold plate 27. A heater for heating (not shown) is provided in the manifold 28, and a runner 29 that is a material passage is formed. . The runner 29 communicates with a sprue in a sprue bush (not shown) to which a nozzle of the extruder is connected. A cavity block 30 is embedded and fixed to the surface of the fixed-side template 27 on the extrusion direction side.

A gate bush 32 is fitted and fixed in a gate bush mounting hole 31 formed in a surface of the fixed side template 27 or the cavity block 30 on the extrusion direction side. An assembling hole 33 is formed through the gate bush 32, and a tip end portion of the assembling hole 33 on the extrusion direction side (the left side in the drawing) has a columnar shape which opens to a position corresponding to the hollow portion of the molded product 1 ( Extrusion hole) 34 and is used as a molding die. The axial direction of the gate forming hole 34 coincides with the pushing direction.

In the gate bush 32 in the vicinity of the extrusion hole (gate forming hole) 3, as will be described later, the gate forming hole 34 is formed.
Cooling holes 202, 202 are provided so as to be located on the extrusion direction side of the gate 35 formed by the core pin 200 and the core pin 200. The cooling hole 202 is provided so as to circulate around the gate forming hole 34. Cooling hole 2 as cooling means
A cooling medium such as water supplied from a cooling medium supply means (not shown) is circulated inside 02, and by cooling the periphery of the gate forming hole 34 in this state, the downstream side of the gate 35 serves as a sizing die from the gate 35. The extruded molten resin (molding material) is given a predetermined shape and size, and is preliminarily cooled so as not to be deformed by the next cooling step.

A valve device 41 for opening and closing the gate 35 formed by the gate forming hole 34 is incorporated in the fixed mold 21. The structure of the valve device 41 will be described. The fixed-side mold plate 27 is formed with an assembling hole 42 that penetrates in the extrusion direction and communicates with the assembling hole 33 in the gate bush 32. A valve body 43 having a substantially cylindrical shape is incorporated in the assembling holes 33 and 42. This valve body 4
One end of 3 is a flange 44, which is sandwiched and fixed between the manifold 28 and the fixed-side mold plate 27.

Inside the valve body 43, the manifold 2
Material passage 45 that connects the runner 29 in 8 to the gate
Is provided. The material passage 45 is formed in a substantially linear shape along the extrusion direction except for a part on the manifold 28 side, and as shown in FIG. 2, near the lower end portion of the material passage 45, that is, at the tip end portion on the gate 35 side, A valve sleeve support portion 46 is formed as a valve body support portion having a smaller diameter than the other parts of the material passage 45. On the inner surface of the peripheral portion of the valve sleeve support portion 46, a plurality of recessed grooves 47 which are equally spaced apart from each other are formed so as to penetrate in the extrusion direction, and the recessed grooves 47 pass through the material passage 45 in the valve body 43 through the gate 35. Is in communication with. A band heater 48 for heating the material passage 45 and a substantially cylindrical heater cover 49 for covering the heater 48 from the outside are fitted to the outer peripheral surface of the valve body 43.

On the outer peripheral side of the valve body 43, a short annular heat insulating seal ring 51 located closer to the gate 35 than the heater cover 49 is fitted and fixed, and the outer peripheral surface of the heat insulating seal ring 51 is assembled with the gate bush 32. It is fitted into a cylindrical surface of the same diameter formed in the hole 33. Thus, the valve body 43 is supported by the gate bush 32 at the tip of the gate 35. Built-in holes 33, 42
Between the inner surface of the valve and the valve body 43, or between the assembling holes 33, 42 and the heater cover 49, a gap is formed for heat insulation at a portion other than the fitting surface of the heat insulating seal ring 51 and the gate bush 32. Has been done.

The material passage 45 of the valve body 43 also penetrates the central shaft portion, moves in the pushing direction, and is inserted into and removed from the gate forming hole 34. The cylindrical valve sleeve (movable pin) ) 56 and this valve sleeve 56
A cylindrical core pin (support pin) 200 is slidably provided therein. The tip of the valve sleeve 56 on the gate 35 side is always slidably fitted into the valve sleeve support 46. An end of the valve sleeve 56 on the manifold 28 side of the valve body 43 is supported by a guide bush 57 fixed in the valve body 43 and slidably penetrates through the guide bush 57. The valve sleeve 56 is driven by a fluid pressure cylinder 58 such as a hydraulic cylinder as a drive source provided on the fixed side mounting plate 26 and is movable in an axial direction that coincides with the pushing direction. In addition, the core pin 200 includes the fixed side mounting plate 26.
It is driven by a fluid pressure cylinder 58A such as a hydraulic cylinder serving as a drive source provided in the above and is movable in an axial direction that coincides with the extrusion direction. The core pin 20, which is an in-die mold, is provided with an air blowing hole 201A for blowing air into the hollow portion of the molded product 1 extruded from the extruding hole 34 so as to open at the tip in the extruding direction. It is connected to an air supply means (not shown) via an air supply pipe 201A.

As shown in FIGS. 1 and 2, the valve sleeve support portion 46 is integrally formed with three support blades 101 extending in the extrusion direction on the inner peripheral surface of the material passage 45 on the gate 35 side. A groove 47 is formed between the support wings 101. The support wing 101 is 1 with respect to the central axis of the material passage 45.
The support wings 10 are radially arranged at intervals of 20 °.
The inner edge of No. 1 has a convex curved edge 10 on the base end side on the upper side in the extrusion direction.
2, the gate 35 side is a sliding edge 103 that slides on the outer peripheral surface 56b of the valve sleeve 56 in parallel with the pushing direction. The outer peripheral surface 56b of the valve sleeve 56 is slidably supported by the three support blades 101. A gate closing portion 111 that fits into the gate 35 to open and close the gate 35 is provided at the gate-side tip portion of the valve sleeve 56. The gate closing portion 111 has a diameter larger than that of the base end portion of the valve sleeve 56. Small tip 1
The reference numeral 12 forms a plane orthogonal to the extrusion direction.

An extrusion molding method of the molded article 1 by the extrusion molding apparatus in the above embodiment will be described. During extrusion molding of the molded product 1, a cylindrical gate 35 is formed between the inner peripheral surface of the gate forming hole 34 and the outer peripheral surface of the core pin 200. In this state, the valve cylinder 56 is moved in the pushing direction side by driving the fluid cylinder 58, and the gate 35 is moved.
To block. Air blowing is started from the air blowing hole 201 at the tip of the core pin 200 which is the in-die type.

In addition, the material passage 4 is provided by the band heater 48.
Heat 5. At the same time, cooling holes 202 as cooling means
A cooling medium such as water supplied from a cooling medium supply unit (not shown) is circulated in the inside of the gate forming hole 34.
Cools the surrounding area. In this state, a molten thermoplastic resin such as nylon, which is a molding material, is supplied into the sprue from a nozzle (not shown) of the extruder. This resin is
From sprue to runner 29 of manifold 28, material passage 45 of valve body 43 and valve sleeve support 4
It is injected into the vicinity of the gate forming hole 34 through the concave groove 47 of 6.

Next, the fluid cylinder 58 is driven to move the valve sleeve 56 to the side opposite to the extrusion direction to open the gate 35, and the molten resin (molding material) is continuously supplied from the gate 35 formed in the extrusion hole 34. The molten resin (molding material) extruded from the gate 35 as a sizing die is given a predetermined shape and size while being extruded in a tubular shape, and is preliminarily cooled so as not to be deformed by the next cooling step.

When the extruded molding material has a predetermined length as the molded article 1, the fluid cylinder 58 is driven to move the valve sleeve 56 toward the extrusion direction side to close the gate 35. As a result, the pushing out from the gate 35 is stopped. Then, the tubular molded article 1 having a predetermined length is cooled and solidified by a cooling means (not shown).

According to the extrusion molding apparatus and the extrusion molding method of this embodiment, the gate forming hole 34 as an extrusion hole provided in the die and the valve body which is removably fitted into the gate forming hole 34 are provided. A cylindrical valve sleeve (movable pin) 56 and a cylindrical core pin (support pin) 200 having a closed end slidably provided in the valve sleeve 56, and the valve sleeve 56 serves as a gate 35 as an extrusion hole. Since it can be opened and closed, the molded product 1 having a predetermined length can be molded without providing a cutting device as a separate body. As a result, it is possible to achieve space saving as an extrusion molding device.

Further, cooling holes 202, 2 as cooling means
By providing 02, a predetermined shape and size are given to the molten resin (molding material) extruded as the sizing die by using this cooling hole 202, and it is preliminarily cooled so as not to be deformed by the next cooling step. Alternatively, the molded product 1 can be cooled and solidified by the cooling pipe 202 to give the resin a predetermined shape and size.

Further, with the structure of this embodiment, the core pin 200 and the valve sleeve 56 are simply replaced.
It is possible to easily mold the molded products 1 having different inner diameters (internal dimensions) and the molded products 1 having different wall thicknesses.

In the present embodiment, the extrusion hole 34
However, as shown in FIG. 3, a plurality of extrusion holes 34 can be provided, and a valve sleeve (movable pin) 56 and a core pin (support pin) 200 can be provided in each of them. In this case, from the molding material supply means 300, 4
An air supply pipe 201A which supplies a molding material through a supply pipe 29A which communicates with one extrusion hole 34 and which communicates with an air blowing hole 201 at the tip of each core pin 200.
Air is supplied through each of the air blowing holes 2
A state of blowing air from 01 is set. Then, as shown in FIG. 3, the valve sleeve 56 and the core pin 200 can be configured to be capable of being driven in synchronization with each other.
A molded product 1 having the same length dimension can be molded at the same time.

Further, by making the cross-sectional shapes of the extrusion hole 34, the core pin 200 and the valve sleeve 56 into predetermined shapes, it becomes possible to mold a tubular body having a cross section other than a circular shape.

[0028]

According to the extrusion molding apparatus and the extrusion molding method of the present invention, a tubular shape is provided which is fitted to the outside of a support pin serving as an in-die mold and is movable along an axis line to open and close the gate. The movable pin is provided, and by moving the movable pin in the axial direction of the support pin to open the gate, the molding material supplied from the material passage communicating with the gate is pushed out from the gate (extrusion hole). By forming a tubular molded product having a predetermined cross-sectional shape and moving the movable pin in the axial direction of the support pin to close the gate, the extrusion of the molding material from the gate is stopped and the molded product The extrusion can be stopped at an arbitrary position, which has the effect of forming a tubular molded product having a predetermined length dimension.

[Brief description of drawings]

FIG. 1 is a schematic configuration sectional view showing an embodiment of an extrusion molding apparatus according to the present invention.

FIG. 2 is an enlarged view of the vicinity of an extrusion hole of the extrusion molding device shown in FIG.

FIG. 3 is a schematic configuration sectional view showing another embodiment of the extrusion molding apparatus according to the present invention.

[Explanation of symbols]

1 ... Molded product 21 ... Fixed type (molding die) 34 ... Gate forming hole (extrusion hole) 35 ... Gate 47 ... Material passage 56 ... Valve sleeve (movable pin) 200 ... Core pin (support pin) In-die type 201 ... Air blowing hole 202 ... Cooling hole (cooling means)

Claims (4)

[Claims] 1. An extrusion molding apparatus for molding a tubular molded product of a predetermined length, the molding die having a gate serving as an extrusion hole for extruding a supplied molding material, and a die facing the center of the extrusion hole. A support pin that is an inner mold and has an air blowing hole at the tip, and a cylindrical movable pin that is fitted to the outside of the support pin and is movable along the axis line to open and close the gate. An extrusion molding apparatus, which comprises: 2. The extrusion molding apparatus according to claim 1, wherein cooling means is provided in the vicinity of the extrusion hole on the extrusion direction side of the support pin. 3. A plurality of said extrusion holes are provided, and said support pin and / or said movable pin provided in each extrusion hole can be driven in synchronization. Extrusion molding equipment. 4. An extrusion molding method for molding a tubular molded product of a predetermined length, comprising a molding die having a gate serving as an extrusion hole for extruding the supplied molding material, and a die facing the center of the extrusion hole. A support pin that is an inner mold and has an air blowing hole at the tip, and a cylindrical movable pin that is fitted to the outside of the support pin and is movable along the axis to open and close the gate. An extrusion molding apparatus comprising: an extrusion molding apparatus, wherein the movable pin is inserted into and removed from the gate to open and close the extrusion hole to start and stop extrusion of a molding material.