JPH0466936B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat setting device for a false twisting machine, which has a fast response speed for temperature control, can accurately control temperature, efficiently transmits heat to the yarn, and has a heat setting device for a false twisting machine. It is an object of the present invention to provide a heat setting device that consumes less power and has a smaller amount of heat escaping from the device to the outside of the device.

Figure 1 shows an example of the structure of a false twisting machine.
1 is a burn before false twisting, 2 is a guide, 3 is a supply roller, 4 is a heat setting device, 5 is a cooling device, 6 is a guide, 7 is a false twisting section, 8 is a take-up roller, 9 is a guide, 10 is a false twisting device This is a package of yarn that has been made. The yarn 11 supplied from the burn 1 to the false twisting process via the guide 2 and the supply roller 3 is transferred to the false twisting section 7.
The yarn is twisted by a take-off roller 8 and wound into a package 10. At this time, the false twist generated in the yarn between the false twisting section 7 and the supply roller 3 is heated by the heat setting device 4. It is cooled and fixed in the cooling section 5. The temperature of the heat-setting device 4 is set at about 210 degrees, although the temperature varies depending on the type and thickness of the yarn 11, the yarn speed, the structure of the device, etc., and the yarn 11 is placed on the heating surface 12 of the heat-setting device 4. It is heated by sliding contact or close running.

FIG. 2 is a sectional view showing the structure of a conventional heat setting device 4, in which 13 is a heat storage plate, 14 is a heat-resistant insulating plate, 15 is a heater, 16 is a heat insulating material, and 17 is a case. The heat storage plate 13 is heated by the heater 15 via the insulating plate 14, and the threads 11 slide on the heating surface 12 of the heat storage plate 13 and are indirectly heated from the heater 15 via the insulator 14 and the heat storage plate 13. It's starting to heat up. However, this heat storage plate
It has a surface area 300 to 1000 times that of the yarn 11, and the amount of heat transferred to the yarn 11 is less than 5% of the amount of heat generated by the heater 15, and most of it is dissipated to the surroundings. It will be done. As a result, the temperature inside the room where the false twisting machines are installed increases, to the extent that when operating a large number of false twisting machines, it is necessary to cool the room with an air conditioner not only in summer but also in winter. Furthermore, since heating of the yarn 11 is performed indirectly via the insulating plate 14 and the heat storage plate 13, there are problems in that heat transfer is very slow, heat loss is large, and the responsiveness of temperature control is also poor. Therefore, in order to compensate for the poor responsiveness of temperature control, the heat capacity of the heat storage plate 13 must be increased to some extent, and as a result, the surface area of the heat storage plate 13 becomes large, increasing heat loss to the surroundings. A vicious cycle was occurring.

This invention was made in order to solve the above-mentioned drawbacks of the conventional heat setting device, and uses a conductive ceramic molded body as a heater, and heats the conductive ceramic molded body by applying an electric current to the yarn 11. Direct heating improves the thermal response of the heat-setting device, allowing temperature control to be performed accurately and quickly, and also allows heat from the heater to be efficiently transferred to the yarn. be.

That is, the heat setting device for the false twisting machine of the present invention has the following features:
Conductive ceramic molded bodies 18a, 18b, 1 in the shape of elongated strips or circular tubes are formed along the path of the thread 11.
8c, and the yarn 11 is directly heated by applying electricity to the conductive ceramic molded body and causing the ceramic molded body to generate heat. This will be further explained with reference to examples.

FIG. 3 is a sectional view showing one embodiment of the heat setting device of the present invention, in which 18a is a strip-shaped conductive ceramic molded body, 16 is a heat insulating material, 17 is a case, 1
9 is a bolt screwed into the case 17, and 20 is a short cylindrical holding piece. The holding piece 20 is made of a heat-resistant insulating material, and the bolt 19 is inserted into the center hole thereof, and the conductive ceramic molded body 18a is pressed by the stepped portion 21, and the holding piece 20 is made of a heat-resistant insulating material. It is fixed on top. Furthermore, this presser piece 2
0 also serves as a side guide for the yarn 11 running along the conductive ceramic molded body 18a.

Conductive ceramic molded body 18a (and 18b,
18c) is mainly composed of oxide ceramic materials, non-oxide ceramic materials such as silicides and borides of carbides and nitrides, or blended materials of these oxide materials and non-oxide materials. A fine powder made by mixing these materials with a metal component of 5% or less is tightly sintered, or a conductive ceramic layer is coated on the surface of an insulating ceramic molded body. As for its characteristics, it must have a uniform, fine, and dense structure, and must have higher hardness and wear resistance than metal heater materials. For example, the strip-shaped conductive ceramic molded body 18a of the illustrated embodiment is
Thickness of uniform fine material fine powder under 2000 atm pressure
It is formed into a strip shape of 0.7 mm, width 6 mm, and length 100 mm, and is made of Al ₂ O ₃ −
Products molded from TiC-based materials or SiC-based materials, or products whose surface is coated uniformly with a conductive ceramic layer of TiN or TiC to a thickness of 10 microns on the surface of an insulating ceramic molded object molded from Al ₂ O ₃ -based material, etc. is used. In addition to these materials, for example, materials such as zirconium titanate, or these materials
A conductive ceramic molded body 18 is made using a material containing 5% or less of metal fine powder such as Ni and Cr.
a (and 18b, 18c) can be manufactured. The above-mentioned fine metal powder is blended to adjust the resistance value of the conductive ceramic molded body, but if it is blended in an amount of 5% or more,
The abrasion resistance of the molded body is sharply reduced, and there is a risk that the molded body will be damaged due to the difference in thermal expansion coefficient between the materials.

If the conductive ceramic molded body 18a (and 18b, 18c) constructed as described above has a grain-sized material structure, its strength and hardness will inevitably decrease, and it will suffer from sudden heat or thermal shock when energized. This increases the possibility of breakage, and when the threads are brought into sliding contact, the sliding contact surface tends to become rough due to abrasion, which causes fuzzing, etc., to occur in the processed threads. Furthermore, if the hardness of the ceramic molded body is low, the abrasion resistance will be reduced, making it difficult to obtain twisted yarn of a certain quality, and the life of the heater will also be shortened. Furthermore, if the internal structure of the ceramic molded body is not dense and there are many spots, the threads will fluff, and the glue, oil, etc. contained in the threads will adhere to the spots and minute recesses on the sliding surface. This is not preferable because it impairs its function as a heater and makes it difficult to remove. The electrical resistance value of such a conductive ceramic molded body is
It is about 500 to 2000 times stronger than nichrome wire. In order to improve the responsiveness of temperature control and to reduce heat dissipation from the surface, it is better to make the surface area of the conductive ceramic molded body as small as possible.

The strip-shaped conductive ceramic molded body 18a is arranged along the path of the thread 11, as shown in FIG. 4, and current is applied between both ends a and b to form a heating section A of a predetermined length. Reference numeral 22 denotes a metal plate that electrically connects the ends of the plurality of conductive ceramic molded bodies 18a. Of course, the entire length of the heating section A may be formed of one conductive ceramic molded body, but if the heating section A is to have a temperature gradient or local temperature control is to be performed, a plurality of conductive ceramic molded bodies may be formed as in the illustrated embodiment. It is better to have a structure in which they are arranged in series. The temperature of the conductive ceramic molded body 18a is detected by a temperature sensor 23 such as a thermistor or an infrared sensor, and then sent to a voltage regulator 2 via a controller 24.
5 to control the applied voltage. Al ₂ O ₃ −
In a test using a conductive ceramic molded body 18a whose main component is TiC-based material, when 12V was applied to both ends, heat generation that could be felt in the hand was obtained, considerable heat generation was obtained at 30V, and 1 second at 100V. about 200
It was possible to heat up to 1.5 degrees Celsius, and the temperature fluctuation from the set temperature could be kept to less than 1.5 degrees Celsius. In addition, the conductive ceramic molded body 18a
The surface area of is about 25 times that of the thread 11,
In tests using conductive ceramic molded bodies made of the various materials mentioned above, the set temperature was reached in a very short time, and the power consumption was approximately 30% of that of conventional equipment.

In the above embodiment, the conductive ceramic material was formed into a rectangular shape in consideration of the convenience of molding, but as shown in FIG. It may have a guiding shape, or it may have a circular tubular shape as shown in FIG. 6, and the thread 11 may be passed through the center hole 27 thereof. Furthermore, by changing the cross-sectional area of the conductive ceramic molded body along the yarn path, or by changing the cross-sectional area of the conductive ceramic molded body along the yarn path, it is possible to create an independent voltage regulator and temperature for each of a plurality of conductive ceramic molded bodies arranged along the yarn path. It is also possible to freely set the temperature of each part of the heating section A by providing a sensor and controlling the temperature separately.

As described above, the heat setting device of the present invention uses a conductive ceramic molded body as a heater, and directly heats the yarn by sliding the yarn into sliding contact with or running close to the conductive ceramic molded body. As a result, heat is efficiently and quickly transferred to the yarn, making it possible to accurately control the heating temperature, and the heat generating part can be made smaller, significantly reducing heat dissipation to the surroundings. This makes it possible to obtain uniform, high-quality twisted yarn, and to significantly reduce the power consumed by the heat setting device of the false twisting machine.

[Brief explanation of the drawing]

Fig. 1 is a side view showing an example of the structure of a false twisting machine, Fig. 2 is a sectional view of a conventional heat setting device, Fig. 3 is a sectional view showing an embodiment of the heat setting device of the present invention, and Fig. 4 is a sectional view showing an example of the structure of a false twisting machine. FIGS. 5 and 6 are diagrams schematically showing the arrangement of the conductive ceramic molded body and its control system, and FIGS. 5 and 6 are diagrams showing other shapes of the conductive ceramic molded body. In the figure, 3 is a supply roller, 4 is a heat setting device, 7 is a false twisting section, 8 is a take-up roller, 11 is a yarn,
16 is a heat insulating material, 17 is a case, 18a, 18b,
18c is a conductive ceramic molded body, 20 is a holding piece, 23 is a temperature sensor, 24 is a controller, 25 is a voltage regulator, and A is a heating section.

Claims (1)

[Scope of Claims] 1. A conductive ceramic molded body in the form of an elongated strip or a circular tube is arranged along the path of the yarn, and electricity is applied to the conductive ceramic molded body to cause the ceramic molded body to generate heat. A heat setting device for a false twister, which is characterized by directly heating the strips. 2. The heat setting device according to claim 1, wherein the conductive ceramic molded body is molded from an oxide ceramic material, a non-oxide ceramic material, or a blend of these materials. 3. The heat-setting device according to claim 2, wherein the conductive ceramic molded body is formed from a material in which 5% or less of a metal component is blended with the material described in the preceding paragraph. 4. The heat setting device according to claim 1, wherein the conductive ceramic molded body is formed by coating the surface of an insulating ceramic molded body with a conductive ceramic layer.