JPS61139762A - Apparatus for detecting electric properties of resin - Google Patents

Abstract

PURPOSE:To make it possible to detect the change in capacity with high accu racy, by arranging a counter electrode in a single layer or plural laminated layers in a opposed relation to each of parallel electrodes and providing a liquid resin pervious electric insulating layer between electrodes while allowing the counter electrode to face to the surface of an article to be measured. CONSTITUTION:Electrodes 3, 4 are parallelly arranged to the single surface of an electric insulating substrate 1 and lead-out wire terminal 5, 6 are arranged to the opposite surface thereof. Counter electrodes 7, 8 are arranged in opposed relation to the electrodes 3, 4 through a layer pervious to a flowable resin and having an electric insulating property such as a glass cloth layer 9 and counter electrodes 10, 11 are arranged through a glass cloth layer 2. The counter electrodes 10, 11 are faced to the surface of a reinforced resin product 14 through a glass cloth layer 13 and the electrode 3 is connected to the counter electrodes 8, 10 while the electrode 3 is connected to the counter electrodes 7, 11. The connection between electrodes is brought to a such a form that plural condensers are connected in parallel and highly accurate measurement is enabled by a small electrode.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an apparatus for detecting electrical properties of resin.

(Prior Art) In the production of reinforced resin products, it is already known that the degree of hardening of a matrix resin material impregnated into reinforcing fibers can be detected by electrical measurement. That is, during the curing reaction process of the resin material, electrical properties such as dielectric properties and electrical conductivity change, so by detecting these changes, it is possible to know the state of curing of the resin material. Measurement of such electrical properties is performed using a pair of electrode plates, but for high-precision detection, the area of the electrode plates should be made sufficiently large, or the gap between the electrode plates should be made as small as possible. It is necessary to lower the impedance or electrical resistance between the electrodes. In reality, increasing the area of the electrode plates is not practical, so attempts have been made to insert or embed the electrodes in the material to be measured in order to reduce the gap between the electrode plates. However, this method has a practical problem because the inserted or buried electrodes and their lead wires become product defects. Therefore, a pair of electrodes is arranged in parallel with a gap on one side of an electrically insulating substrate, and the electrical properties are measured by applying the electrodes directly to the surface of the resin or through a liquid resin permeable electrically insulating layer such as glass cloth. That is also suggested.

(Problems to be Solved by the Invention) In the above-mentioned device having a pair of parallel electrodes on an electrically insulating substrate, the size of the electrodes must be set to several 1 for accurate detection.
It needs to be 3mm square, and one side of the board is 100mm.
It also depends on the degree. A device of such dimensions is very inconvenient to use when manufacturing small parts or when the product has a curved shape, and it also poses a problem when it is desired to minimize the bonding marks of the electrodes. Furthermore, in measurement results obtained using a device with parallel electrodes, the peak may be reversed where it should normally be shown, resulting in a trough-like change. be.

(Means for Solving the Problems) In order to solve the above-mentioned problems of parallel electrodes, the present invention arranges one or more layers of counter electrodes in a stacked manner facing each of the parallel electrodes. Between each of the parallel electrodes and the counter electrode, and between the counter electrodes, an electrically insulating layer permeable to liquid resin, such as a thin layer of glass cloth or ceramic fiber cloth, is arranged. Preferably, each counter electrode further has an electrically insulating layer permeable to liquid resin below it in the stacking direction.

(Function) When using the detection device of the present invention having the above configuration, the counter electrode is made to face the surface of the object to be measured either directly or through an electrically insulating layer permeable to liquid resin. Since the fluid resin during the curing reaction permeates the electrical insulating layer between the opposing electrodes, the electrical properties of the resin can be measured by the electrical signal generated between the electrodes. Since the connection between the electrodes is in the form of a plurality of capacitors connected in parallel, a larger capacitance can be obtained compared to measurement using a pair of parallel electrodes, and the electrodes can be made smaller accordingly.

(Effects) As described above, according to the present invention, counter electrodes are arranged at positions facing each of a pair of electrodes arranged in parallel with a gap on an electrically insulating substrate, and a liquid resin is placed between these electrodes. Since a permeable electrically insulating layer is provided, the state of curing of the resin can be determined from the electrical properties of the resin that has permeated into this electrically insulating layer.

Furthermore, the connection between the electrodes eliminates the risk of connecting multiple capacitors in parallel.

(Embodiment) FIG. 1 is a cross-sectional view showing an embodiment of the present invention, in which two pairs of electrodes 3.4 are arranged in parallel with an interval on one surface of an electrically insulating substrate 1, and on the opposite surface. A lead wire terminal 5.6 is arranged to be connected to each of these electrodes 3.4. A pair of counter electrodes 7.8 are arranged opposite to the electrodes 3.4 with a layer, such as a glass cloth layer 9, permeable to the fluid resin and having electrical insulation properties interposed therebetween. Furthermore, another pair of counter electrodes 1O111 are arranged with the glass cloth layer 12 in between, at positions facing each of the counter electrodes 7.8. The counter electrode 10.11 is placed facing the surface of the reinforced resin product 14 via the glass cloth layer 13.

If the reinforcing fibers of the reinforced resin product 14 do not have electrical conductivity, the glass cloth layer 13 may be omitted. Electrode 3.
7.10 forms one electrode stack array, electrode 4.8.1
1 forms another electrode stack array. Electrode 3 is a counter electrode 8.
10 and the electrode 4 is connected to the counter electrode 7.11.

10.11 is approximately rectangular as shown in FIG. 3, and lead pieces 16 are formed at both ends at positions offset in the width direction from the center line 15 in the long sleeve direction of the rectangle.

The electrodes can be arranged as shown in FIG. 2, the lead piece 16 can be folded back, and the desired connection can be completed with solder. If the lead piece 16 is eccentric in the width direction, the position of the lead piece can be changed by turning the dark-shaped electrode upside down and using it, making the connection work convenient. Note that, as shown in FIG. 3, a large number of holes 17 are formed in the counter electrode 7.8.10.11 for passage of the fluid resin.

Figures 4 and 5 show measurement results when only one layer of opposing electrodes is used in a conventional device consisting of only a pair of parallel electrodes and the device of the present invention. , and FIG. 5 respectively show changes in interelectrode capacitance.

As is clear from FIG. 4, according to the present invention, the dielectric loss coefficient can be detected with much higher sensitivity than the conventional device even if the counter electrode is only one layer, and the dielectric loss coefficient can be detected with much higher sensitivity than the conventional device. Noise (ASB, C, and D are shown in FIG. 4). It has been experimentally confirmed that the above-mentioned effects of the present invention can be further improved by using a plurality of opposing electrodes.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an example of a resin electrical property detection device according to the present invention, Fig. 2 is an exploded perspective view thereof, Fig. 3 is a plan view showing an example of a counter electrode, and Fig. 4 is a measurement of dielectric loss coefficient. FIG. 5 is a chart showing the results of measuring the interelectrode capacitance. 1... Insulating substrate 3.4... Electrode 7.8.10.11... Counter electrode 9.12.
13... Electric insulation layer 14... Reinforced resin product Figure 1 Figure 3

Claims (7)

[Claims] (1) A first electrode and a second electrode are arranged in parallel with an interval on one surface of an electrically insulating substrate, and are placed at a position opposite to the first electrode with an electrically insulating layer permeable to liquid resin interposed therebetween. A fourth electrode is disposed at a position where the third electrode faces the second electrode, the first electrode and the fourth electrode are placed in an electrically connected relationship with each other, and the second electrode and the fourth electrode are placed in an electrically connected relationship with each other. 3
A device for detecting electrical properties of resin, characterized in that electrodes are placed in an electrically connected relationship with each other. (2) The detection device according to item (1) above, wherein holes for resin penetration are formed in the third and fourth electrodes. (3) The detection device according to item (1) or item (2) above, wherein the electrically insulating layer permeable to liquid resin is constituted by a glass fiber layer. (4) In the detection device according to any one of paragraphs (1) to (3) above, the other surface of the substrate has an external drawer connected to the first electrode and the second electrode, respectively. A detection device equipped with a wire terminal. (5) A pair of electrodes are arranged in parallel with an interval on one side of an electrically insulating substrate, and a pair of counter electrodes is arranged in a position opposite to these pairs of electrodes through an electrically insulating layer permeable to liquid resin. A device for detecting electrical physical properties of a resin, characterized in that a plurality of layers are arranged in a laminated manner, and electrodes arranged at overlapping positions in the lamination direction are electrically connected to each other every other electrode when viewed in the lamination direction. (6) The detection device according to item (5) above, wherein each of the counter electrodes is formed with a hole for resin penetration. (7) The detection device according to item (5) or item (6), wherein the uppermost opposing electrode of each stacked row is connected to the electrode on the substrate of the adjacent stacked row.