JPH0229962B2 - TANGUSUTENGOKUBOSOSENNORENZOKUSENKEISOKUTEIHOHO - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for continuously measuring the deviation in wire diameter of an ultra-fine tungsten wire by measuring the electrical resistance of the ultra-fine tungsten wire. The wire diameter of ultrafine tungsten wire, which is generally used in display lamps for digital watches, is difficult to measure with mechanical measuring instruments, so it is usually measured continuously using a method called the MG method. this
The MG method is a method of measuring the wire diameter by the weight of the obtained wire rod per unit length.
The wire diameter is measured (displayed) using the MG value. However, since this MG method determines the wire diameter by the weight per predetermined length, it is not possible to continuously reproduce the measurement results of the measured wire diameter, so the reproducibility cannot be confirmed. In addition, the measurement results are intermittent point data with large deviations and are uneven, and the maximum and minimum values of the wire diameter cannot be obtained, making it impossible to perform precise and reliable wire diameter measurements. . Furthermore, in the case of tungsten, the MG method measures the weight per predetermined length, which is usually 200 mm, and has extremely low reliability when measuring wire diameters within a range considerably shorter than the unit length. As a result of repeated research on wire diameter measurement of ultra-fine tungsten wire, the inventors found that the wire diameter and wire electrical resistance are inversely proportional to each other.
Focusing on the fact that the electrical resistance changes depending on the tensile force acting on the wire, we have found a precise and reliable method for measuring the wire diameter by measuring the electrical resistance while applying a predetermined tensile force to the wire. The present invention was made based on the above research,
The measurement results can be reproduced continuously, and the maximum and minimum values can be obtained with small deviations.
The purpose of the present invention is to provide a method for continuously measuring the wire diameter of ultra-fine tungsten wire, which compensates for the shortcomings of the MG method and can perform accurate and reliable wire diameter measurements. The present invention will be explained below. The continuous wire diameter measuring method according to the present invention involves running a tungsten ultra-fine wire, which is a wire to be measured, and applying a tensile force equal to or less than the MG value of the wire x 50 g (excluding zero) to the running ultra-fine tungsten wire. However, the deviation in the wire diameter is measured by measuring the electrical resistance between a plurality of predetermined points on the wire. In the wire diameter measuring method according to the present invention, the tungsten ultra-fine wire to be applied is one having an MG value of 0.05 or less. In addition, applying a tensile force corresponding to the MG value of the wire to the ultra-fine tungsten wire may cause the wire to break if the tensile force is too large.
This is also because if it is small, the reliability of the measurement results will be low. Furthermore, when measuring the electrical resistance of the tungsten ultra-fine wire in a predetermined range, the measurement is performed between two locations with an interval within at least the length of the tungsten ultra-fine wire that is actually used.
This makes it possible to accurately measure the wire diameter of the short tungsten ultra-fine wire that is actually used. Since the change in electrical resistance in the tungsten ultra-fine wire can be replaced by a deviation (change) in the wire diameter, it is possible to measure the deviation in wire diameter in each part of the tungsten ultra-fine wire, and also to measure the maximum and minimum values of the wire diameter. When measuring the wire diameter of the ultra-fine tungsten wire, the MG value of the drawn ultra-fine tungsten wire is measured in advance by the MG method. As shown in FIG. 1, the tungsten ultra-fine wire 1 is wound around a pay-out reel 2, and the tungsten ultra-fine wire 1 is wound around a take-up reel 3, and the take-up reel 3 is rotated by an electric motor to form the tungsten ultra-fine wire 1. Wind it up while running. As a means for applying tensile force to the traveling ultrafine tungsten wire 1,
For example, tension rollers 4, 4' are provided in the middle of the tungsten ultra-fine wire 1, and the tension rollers 4, 4'
4' is brought into elastic contact with the ultrafine tungsten wire 1 using a spring or the like to tension the wire 1. In this case, a predetermined tensile force corresponding to the MG value of the wire 1 is constantly applied to the ultra-fine tungsten wire 1 that the tension rollers 4, 4' run by adjusting the spring force. Note that other methods may be used to apply the tensile force. For example, a constant current DC power supply 5
A pair of power supply terminals 6, 6' connected to the tungsten wire 1 are brought into contact with points at predetermined intervals in the axial direction of the tungsten wire 1 to pass current through these sections, and a pair of measurement terminals 8, 8' is brought into contact with the ultrafine tungsten wire 1 between the power supply terminals 6 and 6' at a predetermined distance in the axial direction, and the electrical resistance of this section is measured. The recorder 7 measures and records the electrical resistance of the ultrafine tungsten wire 1 by replacing it with its wire diameter, and can continuously measure and record changes in electrical resistance as wire diameter deviations. For example, if the recorder 7 is of a type that records the wire diameter by moving a pen on a running recording paper, the running ultrafine tungsten wire 1
The deviation of the wire diameter in each part can be continuously recorded as a line graph. Note that this measuring means may be other methods. Therefore, the tension roller 4,
At 4', a predetermined tensile force corresponding to the MG value is applied to improve measurement accuracy, and the change in electrical resistance can be continuously recorded in response to the deviation (change) in the wire diameter. By measuring the electrical resistance of the tungsten ultra-fine wire 1 with the measuring terminals 8 and 8', the deviation in wire diameter of each portion of the running tungsten ultra-fine wire 1 can be continuously measured and recorded by the recorder 7. The obtained measurement results are recorded and reproduced as a graph, so you can check the reproducibility, and the wire diameter deviation of each part of the ultra-fine tungsten wire 1 becomes continuous data, so it is highly reliable and has no deviation. Furthermore, the maximum and minimum values of the wire diameter can be determined by the deviation of the wire diameter in each portion, resulting in accurate data. An example in which the diameter of a tungsten ultrafine wire was measured using the measuring method of the present invention will be described in combination with a comparative example. As an embodiment of the present invention, the wire length is 3~
It is applied to a lamp used for lighting a 5 mm clock dial display, and the electric resistance is measured by applying a predetermined tensile force to two ultrafine tungsten wires with MG values of 0.02 and 0.04, respectively, as shown in the table below. was measured.
The measurement results of the electrical resistance of each wire are shown in the table below.
Furthermore, a diagram of the measurement results for W line 2 is shown in FIG.

[Table] According to this table and FIG. 2, it can be said that in the case of the method of the present invention, it is possible to accurately measure the change in electrical resistance of the ultrafine tungsten wire, that is, the deviation in the wire diameter.
According to FIG. 2, it can be said that the conventional MG method measures the average value of the graph in FIG. Note that during measurement, since the ambient temperature affects the electrical resistance of the wire, it is preferable to maintain the ambient temperature at an optimal constant temperature, and in this example, the ambient temperature was 20°C. As described above, the method for continuously measuring the diameter of an ultra-fine tungsten wire according to the present invention can continuously measure the diameter of an ultra-fine tungsten wire and obtain accurate and reliable measurement results.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an example of measuring the wire diameter of an ultra-fine tungsten wire by the method of the present invention;
FIG. 2 is a diagram showing an example of the measurement results. 1...Tungsten ultra-fine wire, 2...Feeding reel, 3
...Take-up reel, 4, 4'...Tension roller, 5
...DC power supply, 6, 6'...power terminal, 7...recorder,
8, 8'...Measurement terminal.

Claims (1)

[Claims] 1. Run a wire to be measured whose MG (weight per specified length) is 0.05 or less, and apply a tensile force of MG of the wire to 50 g or less (not including zero) to the wire to be measured. A continuous wire diameter measuring method for ultra-fine tungsten wire, characterized in that the deviation in wire diameter of the wire to be measured is measured by measuring electrical resistance at a plurality of predetermined locations on the wire.