JPH0343253Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a rotary pot spinning device used for producing carbon fibers using pitch and tar, which are by-products of petroleum refining, as raw materials. More specifically, in a pot spinning device that spins and winds yarn with low tension, the pot itself is a device that also has a heating function, and is maintained at a required temperature to achieve molecular polymerization of the yarn wound inside. The present invention relates to an induction heating device for a rotary pot spinning device, which has the function of winding the spun yarn while promoting the strength of the yarn.

(Prior technology) Carbon fiber, which is called carbon fiber, has extremely high strength in its final state, and demand has increased because it can use inexpensive raw materials such as pitch and tar, which are obtained in large quantities as by-products of oil refining. Development and research into improving manufacturing methods and equipment is being carried out by many companies in the petroleum refining and textile fields both domestically and internationally. Pot spinning is a method of spinning and winding yarn at low tension, but carbon fibers are heated in the pre-spinning process or inside the spinning pot to promote polymerization and develop a strength that can withstand the spinning process. As a method and device for improving the spinning speed, there existed a horizontally arranged cylindrical roller type as a pre-process to the spinning pot, but until now there has been no example in which the spinning pot itself is configured to be heated. I can't find it.

An example of a conventional long fiber spinning method is shown in FIG.

In this spinning method, raw materials such as pitch and tar are transferred from a raw material hopper 21 to an extruder 2.
2, where it is kneaded and extruded by the screw mechanism, and further sent to the spinneret 24 by the gear pump 23. Therefore, the raw material is extruded from the spinneret 24 in the form of a thick string, and is then extruded from the feed roller 24.
5 at an appropriate speed and wound onto a winding bobbin 26. In this method, the tension applied to the yarn during winding is determined by the difference ΔV between the feed speed V ₁ determined by the rotation speed of the feed roller 25 and the winding speed V ₂ by the winding bobbin 26 .

When V ₁ − V ₂ = △V, if △V>0, the tension applied to the thread becomes negative tension and the thread becomes slack; on the other hand, if △V<0, the tension applied to the thread becomes a tensile force and the thread becomes taut.

Moreover, if the value exceeds the limit value, the thread will break. Therefore, in this method, in order to perform proper spinning, it is necessary to always maintain the relationship ΔVlim>ΔV>0.

(Problem to be solved by the invention) In the conventional method as described above, the speed difference △V between feeding and winding, including instantaneous fluctuations, is
A control method that can accurately, stably, and maintain a constant value is required; in other words, this method is unsuitable for spinning low-tension yarn with large fluctuations in yarn tension. I can do it. When spinning yarns such as carbon fibers, which have low strength in the pre-spinning process, it has been desired to introduce a process that improves the strength of the yarns as a pretreatment for the spinning process.

(Means for solving the problem) In the present invention, a pot method is adopted as a spinning method in which the spinning tension is low and the size can be controlled. To improve this, the fibers are heated within the rotary spinning pot itself to promote polymerization of the fibers. That is, the above problem was solved by controlling the environmental temperature of the fibers housed inside with high precision by induction heating the inside of the rotary spinning pot like a heating furnace.

(Embodiments) Hereinafter, embodiments of the present invention shown in the drawings will be described. In FIG. 1, a fiber bundle 1 in an initial state in the form of a string or filament aggregate of a suitable thickness is guided from a spinneret (not shown) through a guide funnel 2 to a rotary spinning pot 3. The spinning pot 3 is made of metal and is rotated coaxially with the guide funnel 2 by an electric motor 4.

The guide funnel 2 is moved up and down in a predetermined cycle by a known mechanism (not shown) with a stroke having a width (height H in the drawing) for winding the thread. Due to the rotation by the pot 3 and the vertical movement of the guide funnel 2, the yarn receives a centrifugal force and a vertical force when leaving the guide funnel 2, and is given a traverse motion that draws a sine curve. It is evenly sprayed onto the inner circumferential surface of the film and laminated with a predetermined width (H). By winding the yarn in this manner, the spun fiber bundles 1 are prevented from concentrating on a specific portion of the inner peripheral surface of the pot 3, and can be layered uniformly.

The fiber bundle 1 accommodated in the inner peripheral surface of the pot 3 in this way is heated by induction heating.
Heated and maintained at an environmental temperature of 400-500℃ by
The polymerization of molecules is promoted and the strength of the fiber is improved.

Next, the induction heating method and apparatus for the rotary spinning pot 3 will be explained in detail.

As shown in FIG. 1, around the metal (aluminum or iron) pot 3, a yoke portion for forming a magnetic path, that is, an iron core 5 is provided on a base plate 13, and the iron core 5 is not shown in the figure. A plurality of excitation coils 6 are provided in a distributed manner or in a concentrated manner.

Excitation coils 6A and 6B constitute a pair of coils, and similarly 6C, 6D and 6E, 6F form a pair, and coil 6E is a donut-shaped coil.

The main alternating magnetic flux Φ, which is the source of induction heating, runs as shown by the dotted line in the figure, and as a result, the cylindrical part 3A and bottom part 3B of the pot 3 have a direction (○・,○×) as shown in the figure.
Eddy currents are generated, which generates Joule heat. This allows the pot itself to become a heat source, allowing efficient and clean heating.

Furthermore, the temperature gradient (temperature distribution) inside the pot can be adjusted arbitrarily by providing a copper material 7 with low electrical resistance by plating, thermal spraying, or inserting a copper plate ring in areas where the temperature should be raised locally. Is possible. In order to prevent the heat of the heated pot 3 from being conducted to the electric motor 4 via the motor shaft 4A and causing a malfunction, it is desirable to use a coupling 8 made of a heat insulating material such as ceramic.

The temperature of this pot 3 needs to be controlled with high accuracy of approximately ±1°C relative to the set temperature, similar to the conventional horizontal heat roller. This will be explained by.

The set temperature command signal _T1 and the output signal from the temperature detector 10 provided in the pot 3 are inputted to the temperature controller 9, and the two are compared to generate a control signal such that the temperature difference ΔT becomes zero. S is input to the coil voltage controller 11.

As a result, the voltage applied to the excitation coil 6 is controlled, thereby controlling the intensity of the alternating magnetic flux, and ultimately controlling the amount of Joule heat generated. The temperature detector 10 can be installed at a suitable location inside the pot 3, thereby measuring the temperature of the pot 3 or the environmental temperature inside the pot 3.

FIG. 3A is a block diagram showing another embodiment of the present invention, in which the same reference numerals are used for parts that are the same as or equivalent to those shown in FIG. 1.

The difference from the embodiment shown in FIG. 1 is the direction of the main magnetic flux, that is, the shape and arrangement of the excitation coil.

As is clear from the side view of FIG. 3A and the plan view of FIG. It is located in
The alternating magnetic flux Φ generated in each coil generates eddy currents, as described above, thereby generating Joule heat.

In order to show the eddy currents generated on the cylindrical surface of the pot, a developed view of the cylindrical surface of the pot is shown in FIG. 3B, and the eddy currents E ₁ ,
E ₂ and E ₃ are shown.

As mentioned above, in the embodiment shown in FIG. 1, the main magnetic flux Φ is of the magnetic path axial direction type (axial type), which is the same as the rotation axis of the pot, whereas in the embodiment shown in FIG. This is a radial type magnetic path in which the magnetic flux is directed in the radial direction.

The former requires an iron core magnetic path to guide the magnetic flux, so the structure is somewhat complicated and larger, but it has the advantage of uniform temperature distribution. On the other hand, the latter has the advantage of not particularly requiring an iron core and has a simple configuration, but on the other hand, eddy currents are generated locally, and the former is superior in terms of uniformity of temperature distribution.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view showing one embodiment of the present invention;
Figure 2 is a flowchart of the temperature control of the present invention.
3A is a schematic side view showing another embodiment of the present invention, FIG. 3B is a top view and partially exploded view showing the exciting coil and generated eddy current in the embodiment of FIG. 2, and FIG. 4 1 is a schematic side view of a spinning method according to the prior art; FIG. Codes in the drawings: 1: fiber bundle, 2: guide funnel,
3: Rotating spinning pot, 3A: Cylindrical part, 3B: Bottom part, 4: Electric motor, 4A: Motor shaft, 5: Iron core, 6: Excitation coil, 6A, 6B, 6C, 6D,
6E, 6F: Coil, 7: Copper ring, 8: Coupling, 9: Temperature controller, 10: Temperature detector, 1
1: Coil voltage controller, 13: Base plate.

Claims (1)

[Claims for Utility Model Registration] (1) A metal rotary spinning pot rotated by an electric motor about a vertical axis; for generating an alternating magnetic field to form a magnetic circuit passing through the rotary spinning pot; a coil; and a controller for controlling a voltage applied to the coil in order to control the environmental temperature of the fibers accommodated in the rotary spinning pot, the eddy current flowing in the metal surface of the rotary spinning pot. 1. An induction heating device for a rotary spinning pot, characterized in that the rotary spinning pot itself is heated by induction using Joule heat generated by the spinning pot. (2) Utility model registration In the induction heating apparatus according to claim 1, the control device includes a temperature sensor provided in a part of the rotary spinning pot, and output data and settings from the temperature sensor. Induction heating of a rotary spinning pot, which is equipped with a temperature regulator that inputs and compares temperature data, and a coil voltage controller that controls the voltage applied to the coil according to the output data from the temperature regulator. Device.