JPH0686088B2 - Manufacturing method of multi-extrusion wire and its extrusion head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a method for producing a multi-extrusion wire, and an extrusion head thereof.

Wire material shall include both hollow material and solid material.

<Prior art> A typical example of a wire material with a coating layer made by extruding rubber and plastics in multiple layers is to prevent damage to the surface during the vulcanization process of the rubber when the insulating copper is coated on the copper wire for electric wire. In order to prevent this, there are cases in which protective plastic is extruded and coated at the same time as insulating rubber, and when forming a rubber hose, protective plastic is also extruded together. In both cases, the protective plastic is removed after the vulcanization process, but as an example of leaving it, a rubber containing an identification dye on a colorless insulating rubber,
There are cases where plastics are stacked.

<Problems to be solved by the invention> For example, a rubber hose and protective plastic are simultaneously extruded in a multiplex manner, and after the rubber vulcanization process is completed, the protective plastic is cut open and removed, and a product rubber hose is taken out and a product inspection is performed. It was not uncommon for the hose to be defective with minor scratches on its surface. Since the surface of the hose was covered with a protective plastic at the same time as it was extruded, it was initially unknown how the surface was scratched.

In order to solve this incomprehensible phenomenon, the present inventor has conducted research and found that the cause of scratches on the surface of the rubber hose is that the die for extruding protective plastic and the nipple do not match the die for rubber and the nipple. It was Initially, the operation was started after aligning, but the cause of the inconsistency is that the extrusion temperature of the plastic is as high as 250 ° to 300 ° C and the extruder is long, so the extrusion head at the tip extends due to thermal expansion. , Because it deviates from the initial alignment position. Although the inner diameter of the nipple of the extrusion head for plastic is such that it does not touch the outer surface of the extruded rubber hose, the extrusion head is displaced from the alignment position, so that the one side surface of the still soft rubber is pressed to create a scratch.

From the above research results, when the extrusion heads of multiple extruders are arranged side by side and heated rubber and plastics are extruded simultaneously and in multiple layers, it is important to avoid defective products and to keep them at room temperature. It was concluded that rather than aligning the extrusion heads coaxially, each extruder had to be positioned and aligned under conditions where each material was heated to the required temperature and extruded. By embodying this conclusion, by further matching, even if the material temperature changes a little after starting operation, the material used and the required temperature change to some extent,
The challenge was to develop equipment that does not require re-adjustment and the extrusion head for that purpose.

<Means for Solving the Problem> The method for producing a multi-extruded wire rod of the present invention is a method of producing a multi-extruded wire rod, in which a plurality of extruders are used to simultaneously extrude rubber and plastics in a multiple manner to form a wire rod with a coating layer, The traveling line of the wire toward the inlet of the cooling tank, so that each extruder is temporarily installed so as to pass through the extrusion head at the tip of each extruder,
The material heating unit of each extruder is heated to a state during operation, each extruder is allowed to freely expand, and in this state, from the cooling tank side, an extrusion nipple and cooling of each head prepared in advance Through a straight rod-shaped centering gauge with a multi-stage outer diameter that matches each inner diameter of the tank inlet, align each extrusion head with the wire running line, fix the orientation and front end of each extruder at that position, and then operate it. Characterize.

In the extrusion head for producing a multi-extrusion wire of the present invention, the extrusion head main body has a mounting portion for connecting and fixing to the extrusion opening of the extruder at one location on the outer periphery thereof, and a through hole extending in the front-rear direction in the central portion. The lid body that is attached to the front surface of the main body has
The die has an opening coaxial with the through hole of the body, the rear end of the die is attached to the periphery of the opening of the lid, and the nipple is attached to the periphery of the through hole of the body. In addition, an arcuate material passage coaxial with the through hole is formed in multiple stages from the outer circumference to the inner circumference, which is a semi-circular passage for branching the material coming from the extrusion port to the left and right, and branched from both ends of the semi-circular passage. A pair of 1/4 circular passages, and the respective tip portions of the 1/4 circular passages are spread to the left and right on the inner peripheral side to form a smaller diameter 1/4 circle width axial passage inlet, and the inlet thereof. Each of the passages extending a little in the axial direction from the above is communicated between the die and the nipple to form a cylindrical passage.

<Operation> Based on the above-mentioned research results, the method for producing the multi-extrusion wire of the present invention is based on the above-mentioned research results. First, the extruders are arranged in a conventional manner, and after provisionally installed so that the running line passing through each extrusion head enters the cooling tank, The material heating part of the extruder is heated to the operating state. Temporary installation is performed so that each extruder can freely expand due to the temperature rise.

In this state, the present invention uses a straight rod-shaped centering gauge as a means for aligning each extrusion head with the traveling line toward the inlet of the cooling tank. This gauge is a multi-stage outer diameter dimension, the thickest part fits the cooling tank inlet, the next stage is the nipple inner diameter of the extrusion head that makes the outermost layer, the next stage is the nipple inner diameter of the extrusion head that makes the layer below, It is a gauge that has a part that fits the inside diameter of each nipple. After adjusting each extruder temporarily installed and adjusted so that the gauge fits each extrusion head, fix the orientation and front end of each extruder. Specifically, only the front end of the extruder is fixed by the gauge when each extrusion head is aligned, and the rear end is constrained so that it cannot move laterally by changing the direction of the extruder.

As a result, even if the extruder expands and contracts, the position of the extrusion head attached to its front end does not change.

In other words, each extruder is positioned at the operating temperature, and even if the operating temperature changes to some extent, the expansion and contraction of the extruder caused by this does not cause misalignment of the extrusion heads.

Since the extruder for producing a multi-extrusion wire of the present invention is an extruder used for carrying out the above-mentioned production method, only the front end thereof is fixed,
The rear end can be restrained so as not to move laterally to change the direction of the extruder. That is, one extruder is placed on one base, placed at a required position on the floor of the factory, and only the front end of the extruder is fixed to the base via the support legs. . Since the rear end of the extruder is mounted on the rear support and is mounted movably only in the screw axial direction on the base, the extruder cannot be moved laterally to change its direction.

That is, since the extruder fixed only at the front end can expand and contract backward, the extrusion head attached to the front end is not displaced by the temperature rise and fall of the extruder.

The extrusion head for producing a multi-extrusion wire according to the present invention has remarkably shortened its axial length and reduced the thermal influence between the multi-extrusion materials. As described below, the conventional extrusion head fits a coaxial guide tube into the hollow portion of the main body in the wire running direction,
By attaching a die to the main body and a nipple to the guide tube, the material passage dug in the fitting surface of the main body and the guide tube is divided into left and right, each of which spreads in a semicircular shape so that it can pass between the die and nipple. Since the head as a whole is long in the axial direction and the material passage is also long in the axial direction, the thermal effect on the inner layer material is large.

On the other hand, the extrusion head of the present invention is composed of a thick plate-shaped main body that is perpendicular to the wire running line and a lid body that is wrapped around the main body. A die is attached to the main body and a nipple is attached to the lid body. On the tying surface of, make multiple steps from the outer circumference to the inner circumference and spread it evenly, and proceed between the dies and the nipple,
Both the whole and the passages are extremely short in the axial direction, reducing the thermal effect on the inner layer material.

<Examples> Fig. 1 is a schematic plan view of a rubber hose manufacturing facility to which the present invention is applied, in which 1 is a rubber extruder, 1a is its extrusion head,
1b is a material supply unit, 1c is a screw drive mechanism, and 1d is its base. 2 is a protective plastic extruder, 2a is its extrusion head, and 2d is its base. 3 is a cooling tank and 4 is a take-off machine. L is a wire rod running line, and in this case, a hose core material passes through.

FIG. 2 shows a place where the hose core material O is first coated with the rubber G, and then the protective plastic P is coated thereon, and the hose core material O is put into the cooling tank 3. The die of the rubber extruder head 1a is 10, the nipple is 11, the die of the plastic extrusion head 2a is 20, and the nipple is 21. These will be described later with reference to FIG.

FIG. 3 shows the present invention, in which each extruder head 1a, 2a and cooling tank 3 are shown.
In the embodiment of the centering gauge 5 for aligning, the multi-stage outer diameter dimensions a, b, c are respectively the inner diameter of the nipple 11 of the head 1a, the inner diameter of the nipple 21 of the head 2a, and the inner diameter of the inlet of the cooling tank 3. It is matched.

First, as shown in FIG. 1, each extruder 1 and 2 is temporarily installed at room temperature in accordance with the material running line L passing through the cooling tank 3 and the take-up machine 4, and each is heated to an operating state, The centering gauge 5 shown in FIG.
Insert into 2a and 1a. The method of adjusting the position of each extruder 1 and 2 is arbitrary, and it is left to the factory technician, but generally the basis of each extruder is
When 2d (Fig. 4) is temporarily installed, press the vertical and horizontal adjustment block fixed at the required position on the floor with the set screw on the base 2d to finely adjust the position of the base itself. , Gauge 5 outer diameter a
If the part of (1) fits the inner diameter of the nipple 11 of the extrusion head 1, the part of the outer diameter (b) fits the inner diameter of the nipple 21 of the extrusion head 2, and the part of the outer diameter (c) fits the inlet of the cooling tank 3 Are aligned, which facilitates centering during heating.

4 and 5 show an embodiment of the plastic extruder 2, in which an extrusion head 2a is provided at the front end, a material supply section 2b is provided at the rear end, and a screw drive mechanism 2 is provided.
The c is attached, and one set of extruders is put together on one base 2d.

The screw cylinder of the extruder 2 is surrounded by an electric heater 6 for almost the entire length and is equipped with a cooling wind turbine 7. This extruder 2
The front end of is fixed on the support leg 8 fixed on the base 2d,
The rear end including the material supply unit 2b is supported by the rear support base 9. The rear support base 9 and the screw drive mechanism 1c are mounted on the screw axial rail 13 on the base 2d via the common movable base plate 12, so that the rear support base 9 is expanded or contracted according to the expansion and contraction of the screw cylinder. Can be easily moved, and the extrusion head 2a is extruded by the expansion of the screw cylinder unlike the conventional case, and there is no risk of the extrusion head 2a coming off the traveling line.

In the embodiment shown in FIG. 4, the intermediate portion of the screw cylinder is received by the intermediate receiving plate 14, but this is merely received and does not prevent expansion and contraction.

Next, the extrusion heads 2a and 1a shown in FIG. 6 and thereafter will be described. The plastic extrusion head 2a shown in FIGS. 6 and 7 is the present invention, and the rubber extrusion head 1a (FIGS. 8 and 9) is a conventional type. Of course, the rubber extrusion head may be the same as that shown in FIGS. 6 and 7, but in this embodiment, since it does not affect the heat of other extruded materials, it is a conventional one.

First, the structure of the conventional extrusion head 1 will be described with reference to FIGS. The head main body 17 is connected and fixed to the extrusion port 15 of the extruder 1 by a mounting portion 16, and a guide cylinder 18 is fitted in a hollow portion of the main body in the traveling direction of the wire. On the outer circumference of the guide tube 18,
A material passage 19 for guiding the material extruded from the extrusion port 15 to between the die 10 and the nipple 11 is dug. This passage 19 is divided into the left and right peripheral surfaces of the guide cylinder 18, gradually changing its direction to the traveling line direction, widening the passage width in a semicircular shape, and attached to the nipple 11 attached to the guide cylinder 18 and the main body 17. The gap with the die 10 has been reached. It goes without saying that the rubber extruded from the gap between the die 10 and the nipple 11 adheres to the outer periphery of the core material C.

This conventional extrusion head 1a uses a guide tube 18 that is long in the traveling line direction and has a long material passage in the same direction. When the material is coated, it has a considerable thermal effect on the material.

The extrusion head 2a of the present invention is shown in FIGS. 6 and 7 in which this is made small so that the lower layer material is not much affected by heat. The head main body 22 connected and fixed to the extrusion port 15 of the extruder 2 through the mounting portion 16 is a thick plate shape standing at a right angle to the traveling line, and the lid 23 tying to the front surface thereof is also the same. A through hole 24 communicating in the front-rear direction is provided at the center of the main body 22, and the lid 23 has an opening 25 coaxial with the through hole 24. The die 20 has its rear end attached to the periphery of the opening 25, and the nipple 21 has its rear end attached to the periphery of the through hole 24.

Arc-shaped material passages 26, 27, 28 coaxial with the through hole 24 are formed in multiple stages from the outer circumference to the inner circumference on the tying surfaces of the head body 22 and the lid body 23. That is, it is a semi-circular passage 26 that branches the material coming from the extrusion port 15 to the left and right, a pair of quarter circular passages 27 that branch from both ends of the passage 26, and spreads each tip part to the inner peripheral side left and right, It serves as an inlet for the axial passage 28 having a smaller diameter and having a quarter circle width. 4 extending axially from the entrance
Four passages 28 with a width of one-half each lead to between the die 20 and the nipple 21. From there, a cylindrical material, in this case plastic P, is extruded and covers the outer circumference of the rubber hose G.

In this embodiment, the semicircular passage 26 and the left and right quarter circular passages 27 are on a tie surface perpendicular to the through hole 24 (axial direction), and the inlet of the axial passage 28 is located slightly forward of the surface. Has become. In other words, the tying surface protrudes slightly like a cone near the inner diameter. And from the end of passage 27 to the axial passage
28 The reason for narrowing the area toward the entrance is to make the extruded plastic uniform in thickness all around.

Although the method for producing the multi-extrusion wire rod and the extrusion head thereof according to the present invention have been described above with reference to the respective embodiments, it goes without saying that they can be variously changed and applied by a technique well known to those skilled in the art depending on the implementation conditions.

By utilizing the features of the extrusion head of the present invention, the extrusion head may be utilized for extruding a wire rod other than the multi-extruded wire rod.

<Effects of the Invention> The method for producing a multi-extrusion wire of the present invention is a method in which a plurality of extruders simultaneously extrude rubber and plastics simultaneously and in a multiple manner to form a wire with a coating layer. It was determined that the cause was the displacement of the extrusion head due to the thermal expansion of the extruder for multilayer materials. As a countermeasure, the material heating part of each extruder is heated to the operating state and positioned. At that time, a straight bar centering gauge having a multi-stage outer diameter was used to easily align the extrusion head of each extruder even in a heated state. Then, the orientation and front end of each extruder were fixed so that the extruder temperature may slightly change during the operation so that the extrusion head is not pushed or pulled by the expansion and contraction of the machine body.

The extrusion head for producing a multi-extrusion wire according to the present invention has solved the problem that the material extrusion passage of the conventional extrusion head is long in the axial direction, and thus has a large thermal effect on the lower layer material. That is, the extrusion head main body is made into a thick plate standing at right angles to the wire running line, the lid is tied to the front surface, dies and nipples are attached to each, and arcuate material passages in multiple stages from the outer circumference to the inner circumference of the mating surface. Because of the provision of the four, the material passage already surrounds the running line with a tie surface that is almost perpendicular to the running line.
It becomes a one-round circular axial passage inlet and exits between the die and the nipple with a very short axial passage, so the axial length of the extrusion head is extremely reduced compared to the past, and the thermal effect on the inner layer material is also significant. It has decreased.

[Brief description of drawings]

FIG. 1 is a schematic plan view of an embodiment in which the present invention is applied to a rubber hose manufacturing apparatus, FIG. 2 is a sectional explanatory view of the same multi-extrusion coating portion, and FIG. 3 is an elevational view of an embodiment of a straight bar-shaped centering gauge, 4 and 5 are front views of one embodiment of the extruder of the present invention,
A side view, FIGS. 6 and 7 are an elevational view and a cross sectional view of an embodiment of the extrusion head of the present invention, and FIG. 6 shows a sectional view taken along line XX of FIG. Figures 8 and 9 are elevation views showing a conventional extrusion head,
FIG. In the figure, 2 is an extruder, 2a is an extrusion head, 2d is a base, 8 is a support leg, 20 is a die, 21 is a nipple, 22 is a head body, and 23.
Is a lid, and 26, 27 and 28 are material passages.

Claims (2)

[Claims] 1. In a method for producing a multi-extruded wire rod, wherein a plurality of extruders simultaneously extrude rubber and plastics in multiple layers to form a wire rod with a coating layer, the running line of the wire rod toward the cooling tank inlet is the above-mentioned. Each extruder is temporarily installed so as to pass through the extrusion head at the tip of each extruder, and the material heating section of each extruder is heated to the operating state, and each extruder is allowed to freely expand, In this state, from the cooling tank side, align each extrusion head with the wire rod running line through a pre-prepared extrusion nipple of each head and a straight bar-shaped centering gauge with a multi-stage outer diameter that matches each inner diameter of the cooling tank inlet. ,
A method for producing a multi-extrusion wire rod, which comprises operating the extruder after fixing the direction and front end of each extruder at that position. 2. The extrusion head main body is provided at one place on the outer periphery thereof.
A lid part that is connected to and fixed to the extrusion port of the extruder, and has a through hole that extends in the front-rear direction in the center part, and the lid body that is tied to the front surface of the main body has an opening portion that is coaxial with the main body through hole. The die has a rear end attached to the peripheral edge of the lid opening, and the nipple is attached to the peripheral edge of the main body through hole. The arc-shaped material passage is formed in multiple stages from the outer circumference to the inner circumference. It is a semicircular passage for branching the material coming from the extrusion port to the left and right, and a pair of quarter circular passages branched from both ends of the semicircular passage. , Each of the quarter circular passages has its front end expanded to the left and right on the inner peripheral side to form a smaller diameter quarter circle width axial passage inlet, and each passage slightly extended in the axial direction from the inlet. Is a cylindrical passage that leads between the die and the nipple. Multiple press extrusion head for outgoing material manufacturing to.