JPH0618287Y2 - Material anisotropy measuring device - Google Patents

Description

The present invention relates to an anisotropy measuring apparatus for materials using high frequency, and particularly to an apparatus suitable for continuously measuring long continuous materials. However, the device can also be used for individual measurement of separated samples.

(B) Conventional technology In a sheet-shaped or linear material, when the fibers or molecules constituting the material are aligned in one direction, anisotropy appears in the mechanical and physical properties of the material. This anisotropy may be inconvenient because the expansion ratio or strength of the material differs depending on the direction.
On the contrary, in some cases, anisotropy is intentionally given such that the fibers or molecules are oriented to increase the tensile strength. In any case, it is important for the quality control of the material to detect the degree of orientation of molecules or fibers of the sheet-shaped or linear material.

The method conventionally used as the above-mentioned anisotropy measuring method is a method in which a tensile test is performed by cutting a test piece from a material, so it is a destructive test, and it takes time to determine the result. Although it is useful for the final inspection of products, it cannot be used for continuous quality monitoring of sheets in the manufacturing process.

Since the molecules of the material or the orientation of the constituent fibers also appear as the anisotropy of the dielectric constant or dielectric loss of the material, a method of measuring the anisotropy using high frequency has been proposed by the present applicant. In this method, a slit is provided in the cavity resonator, a sample is inserted, and the resonance frequency of the cavity resonator or the change in the Q value of the cavity resonator when the sample is rotated are measured. This method can obtain results in a much shorter time than the method of cutting the test piece from the material in various directions and conducting the tensile test.
Since it is necessary to rotate the cavity resonator and the sample relative to each other, mechanical accuracy is difficult when used for measurement at an intermediate stage of the continuous manufacturing process of the sheet material. That is, the cavity resonator is divided into upper and lower halves in order to allow a continuous sheet-shaped material to pass across the cavity resonator, but since the sheet cannot be rotated, You have to rotate one. Since the cavity resonator is divided into upper and lower parts, the machine for rotating it integrally becomes very complicated and large, and it is very susceptible to vibrations and highly accurate measurement. Is not obtained at present.

(C) Problems to be solved by the invention The present invention is mainly intended to solve the above-mentioned problems when continuously measuring the anisotropy of a continuous material with a material anisotropy measuring apparatus using a cavity resonator. The purpose is
The present invention provides an extremely simple structure and quickness of measurement even in general anisotropy measurement.

D. Means for solving the problem A cavity resonator having a square cross section is used, and electric vibrations that excite the cavity resonator are generated in two directions so that the directions of the electric vibrations are orthogonal to each other. The electric vibrations in the two directions inside the cavity resonator are separately detected, and the deviation of the resonance frequency in each direction and the difference in the Q of the cavity resonator or the difference in the amount of microwave transmission are measured. I decided to do it.

E action Figure 2 shows the cross section of the cavity resonator. If the cavity resonator has a square cross-section and the cavity cross-section is exactly overlapped when rotated by 90 ° as shown in the figure, the electrical vibration in the x direction and the electrical vibration in the y direction in the figure are the same resonance. Indicates the frequency. According to the present invention, a standing wave of such electrical vibration in two orthogonal directions is formed in the cavity resonator, and the sample is set across the cavity resonator and parallel to the plane of the drawing. Then, since the sample is subjected to electrical vibration in two orthogonal directions, it is possible to detect a difference in permittivity, dielectric loss or microwave transmission amount in two orthogonal directions without rotating the sample by 90 °.

F. Embodiment FIG. 1 shows an embodiment of the present invention. Reference numeral 1 denotes a cavity resonator having a square cross section, which is divided into upper and lower parts by a slit 2 which crosses the cavity at the center of its length, and each is fixed to a frame 3 to be integrated. Reference numeral 4 is a strip-shaped material of the sample to be measured, which is transported in the direction of the arrow through the slit 2. Coaxial waveguide converters 5 and 6 are connected to both ends of the cavity resonator, and antennas 7 and 8 are inserted in two adjacent side surfaces of the coaxial waveguide converter 5 in directions orthogonal to each other. . The output of the oscillator 9 is divided into two by a magic T10 and supplied to these antennas via a coaxial cable. Due to this high frequency, two resonance states in which the electric fields are orthogonal to each other in the cavity resonator 1 are determined. A standing wave is formed, and the slit 2 is positioned just at the antinode of the standing wave of this electric field. The phase relationship of the high frequencies supplied to the antennas 7 and 8 is arbitrary. Two receiving antennas 11 and 12 are inserted in the lower coaxial waveguide converter 6 in the same direction as the antennas 7 and 8, and are arranged in the x direction y.
The directional electric vibrations are received separately. The antennas 11 and 12 are detection circuits 13 and 13 using coaxial cables, respectively.
The output voltage of the detection circuits 13 and 14 is connected to the differential amplifier 15, and is input to the differential mamp 15. The output of the detection circuit 13 out of the two inputs of the differential amplifier 15 can be adjusted in attenuation rate by the sliding resistance 16. With this configuration, a standard sample is inserted into the slit 2 and the sliding resistance is adjusted so that the deflection of the galvanometer 17 connected to the output side of the differential amplifier 15 becomes 0. When passing through the slit, it is possible to immediately read whether the orientation of the material to be measured is over or under the reference due to the deflection of the needle of the galvanometer 17 in the positive and negative directions. Further, the output of the differential amplifier 15 may be continuously recorded.

Next, an example of obtaining the anisotropy of the material from the resonance frequency value, the Q value, the dielectric constant value, the dielectric loss value or the like obtained by sweeping the frequency will be shown. As shown in FIG. 3, the oscillator 9 shown in FIG.
0 is changed to the directional coupler 18, and a calculation unit 19 is provided to input the signal detected through the receiving antennas (11 and 12) and the frequency value from the oscillator 9.

For example, a linearly polarized wave is oscillated while sweeping the frequency from the oscillating antennas (7 and 8) to a saw blade type. The signals received by the receiving antennas (11 and 12) are detected, and the values are input to the arithmetic unit 19. Therefore, the arithmetic unit first calculates the resonance frequency value and the Q value from the input values, and then From these values, the dielectric constant value and the dielectric loss value are obtained. The anisotropy of the material is obtained by the ratio or difference of the resonance frequency value, Q value, dielectric constant value, dielectric loss value, etc. in these two directions.

In the above embodiment, the phases of the electric vibrations in the two directions are arbitrary,
Since some electric vibrations in the orthogonal direction are also received by the receiving antenna, it is better to set the phase difference to 90 ° when it is desired to detect a slight orientation of the sample with high sensitivity. With this configuration, when the electric field in one direction is maximum and the electric field in the other direction is 0, it is possible to prevent electric vibrations in two directions from interfering with each other on the detection side. The phase of the excitation high frequency may be adjusted by changing the lengths of the coaxial cables from the magic T to the antenna.

In the above-mentioned embodiment, the electric vibrations in two directions are simultaneously applied to the cavity resonator, but the electric vibrations in two directions are alternately applied mechanically or electrically to the cavity resonator by the switching means. Good.

G. Effect Since the device of the present invention does not need to rotate the sample with respect to the cavity resonator in the above-described structure, it is mechanically very simple and the anisotropic property of the continuous strip that is continuously transferred. What is called continuous measurement can be easily performed.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention, and FIG. 2 is a sectional view for explaining the direction of an electric field in a cavity resonator. Figure 3 shows
FIG. 7 is a perspective view showing another embodiment of the present invention.

Claims (1)

[Scope of utility model registration request] 1. A slit crossing a cavity resonator having a square cross section is provided, and a sample is inserted into the slit, and an electric field in the cavity resonator is parallel to two side surfaces of the cavity resonator and orthogonal to each other. The two-direction electric vibrations in the cavity resonator are provided by providing means for separately exciting the two-direction electric vibrations in the cavity resonator by exciting the two-direction electric vibrations.
An apparatus for measuring anisotropy of materials, which detects a resonance frequency or an amount of microwave transmission with respect to electric vibration in a direction and compares the detected data.