JPS609279Y2 - Core of cord heater - Google Patents

Description

[Detailed Description of the Invention] Cord-shaped heaters are used as heating elements in defrosting heaters for electric refrigerators, heat-retaining heaters for electronic jars, etc., and the structure thereof is usually as shown in FIG.

In the figure, reference numeral 1 denotes a string-like winding core made by twisting or braiding glass fiber or Tetoron fiber threads.

Reference numeral 2 denotes a resistance wire spirally wound on the winding core, and a nichrome wire or a copper-nickel wire is wound at an appropriate pitch depending on the amount of heat generated.

3 is an insulator extruded and coated on the spirally wound resistance wire to insulate it.

In order to manufacture a heater that generates a large amount of heat, such as a heater for keeping electronic jars warm, the constituent materials need to have good heat resistance properties. It is required to reduce the resistance value of the material and to cover it with an insulating material such as silicone rubber or fluororubber having a heat resistance of 200C or more.

The resistance wire is generally stretched with a constant tension (the winding of the resistance wire is greater than the tension), as shown in Figure 3.
The winding is performed by being unwound from a bobbin 4 that rotates at high speed around a moving winding spool 1.

In this case, as mentioned above, since a nichrome wire with a relatively thick wire diameter is used, it is wound with strong tension.

As a result, the glass fibers on the surface of the roll are broken and the surface becomes fluffy, which not only hinders the next process, but also causes the broken fibers to fly into the air, making the work environment worse.

Next, the completed cord-shaped heater is cut to a predetermined length, the insulating liquid coated at both ends is removed, and lead wires are connected thereto before being attached to a device.

Crimp terminals are usually used to connect these lead wires, but connection failures often occur due to breakage when the terminals are crimped.

This is because the strength of glass fiber cannot withstand the impact force of the crimping tool.

To reduce this problem, glass fiber wrapping sheets are impregnated with varnish and dried beforehand, but due to problems such as the flexibility required for the wrapping sheets and the misalignment of the resistance wire during the resistance wire winding process. As a result of the limited degree of treatment, satisfactory effects have not yet been achieved.

On the other hand, in order to manufacture a heater with a low calorific value, the selection range of constituent materials is relatively wide, and glass fibers, which have the above-mentioned drawbacks, are avoided for the winding material, and Tetron fibers, which have high curl and knot strength, are used.

However, since Tetron fibers shrink when heated, it is necessary to undergo heat treatment in advance to prevent shrinkage due to the heat received during the process, especially during the blunting process to remove resistance wire strain after winding the resistance wire, or during the insulation technology process. There is a drawback.

The present invention improves these drawbacks, and eliminates environmental pollution due to fluff and fiber breakage during the winding process even when used as a winding wire for a heater with a high calorific value. To provide a cord-shaped heater winding which is free from the fear of cutting and which does not require a heat setting process even when used as a winding of a heater with a low calorific value.

The cord-shaped heater winding of the present invention is characterized by the use of aromatic polyamide fibers alone or in combination with glass fibers.

Next, embodiments of the present invention will be described, but the present invention is not limited thereto, and as long as they fall within the scope of the technical idea, they are of course a part of the present invention.

Example #1 Aromatic polyamide fiber Kepler 49 (trade name)
1500 denier outer diameter approximately 0.5 mm #2 Aromatic polyamide fiber Kepler 49 (trade name) and non-alkali glass fiber 225 denier are first twisted with a thread holder 2 x 3 and the outer diameter is 287/US S1 and final twist 166/US 2. Approximately 0.
It was made with a 4mm string.

#3 The yarn composition was the same as #2, with a lower twist of 431/rice S1 and a final twist of 249/rice 2, resulting in a string with an outer diameter of approximately 0.42rrrtt+.

#4 225 denier non-alkali glass fiber thread holding 3x
3, the first twist is 431/US S1, the final twist is 249/US 2, and the outer diameter is about 0.42rrr! It was made into a string of n and was impregnated with silicone varnish.

0.1X of nickel chromium on #1 to #4 rolls 0
．． A 4 mm ribbon wire was wound to give a resistance of 40 ohms/meter.

As a result, good resistance conductors were obtained for #1 to #3, but #
Sample No. 4 was so fluffy that it was cut several times and a long piece could not be obtained.

Further, silicone rubber was extruded and covered (vulcanized) on the conductor obtained as described above to obtain a cord-shaped heater having an outer diameter of 1.4 to 1.5 mm.

Next, these heaters were cut into 1-meter pieces, the coverings at both ends were removed, and the lead wires were crimped with crimp terminals to measure the connection strength.

As a result, all of #1 to #3 were able to withstand a tensile force of 20 kg, but only #4 was cut at 9 to 5 to 10.

Furthermore, as a result of measuring the resistance value of the product, it was found that there was almost no change in the resistance value, even though the heater setting process was not performed on the rolled shin.

Further, when the tensile strength of the rolled sheet was measured after being left in a thermostatic oven at 200° C. for 96 hours, there was no change in flexibility or appearance, and almost no decrease in tensile strength was observed.

As mentioned above, the cord-shaped heater winding of the present invention can obtain a stable resistance value without requiring heat setting compared to the conventional Telolon fiber products.

In addition, compared to glass fiber products, it does not require varnish treatment, does not cause fuzz or scattering of fibers during the winding process, has extremely low drop in tensile strength when crimping terminals, and is comparable in terms of heat resistance to conventional products. It has various advantages that cannot be found in the conventional ones.

The second advantage is that the diameter of the winding can be reduced.

The material of the wrapping paper of this invention uses aromatic polyamide fiber with high modulus, so it can easily be made into a thin diameter of 0.5 m or less due to restrictions on elongation and strength. The point is that it has become similar.

Therefore, the finished outer diameter of the cord-shaped heater can be made thinner, which is advantageous in terms of material consumption, heat conduction, and use.

As mentioned above, the winding of the cord-shaped heater of the present invention has many advantages and is of great industrial value.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway view of the cord-shaped heater, FIG. 2 is a side view of the cord-shaped heater, and FIG. 3 is an explanatory diagram of resistance wire winding.

Claims (1)

[Claims for Utility Model Registration] 1. A cord-like heater in which a resistor is wrapped around a core of a string-like material, which is better than insulating fibers, and the resistor is covered with an insulator. A winding core of a cord-shaped heater characterized by its use. 2. The winding core according to claim 1, which uses aromatic polyamide fiber as the winding core. 3. The winding core according to claim 1 of the utility model registration claim, which uses a twisted yarn of aromatic polyamide fiber yarn and glass fiber yarn as the winding core. 4. The winding core according to claim 1, in which aromatic polyamide fiber threads and glass fiber threads are used in the winding core without being aligned and twisted.