JPH0652206B2 - Capacitance type pressure distribution measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Object of the invention [Industrial application] The present invention relates to an apparatus for measuring a distribution of a load acting on an object.

It may be necessary to measure the distribution of loads acting on the object. For example, in the case of performing a performance evaluation test of a car seat, conventionally, a driver actually sits down on a seat of a car and mainly evaluates the performance based on the feel of the seat. BACKGROUND ART A seat performance evaluation test is performed by measuring a load distribution in which part and how a seat of a cab receives weight and other loads.

[Prior Art] However, the load distribution measuring device used here is one in which load cells are arranged at a large number of points on the seat, the device becomes large, and an evaluation test in a laboratory is possible, but it is actually running. Unsuitable for use in a car.

Therefore, the applicant of the present application has previously proposed a load distribution measuring device using a sensor using pressure-sensitive conductive rubber (see Japanese Patent Application Publication No. 100331 in 1982).

This newly proposed load distribution measuring device is provided with electrodes on both sides of a pressure-sensitive conductive rubber sheet, and measures the load and its distribution from the change in electrical resistance when a load acts on the pressure-sensitive conductive rubber sheet. is there.

[Problems to be Solved by the Invention] However, the pressure-sensitive conductive rubber sheet used here is configured by dispersing conductive particles in a rubber sheet base material, but the dispersion is not always uniform. For this reason, uniform pressure-sensitive conductivity is not guaranteed over the entire surface, and the recoverability when unloading again is not always good, which causes a decrease in measurement accuracy.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a small and inexpensive device capable of easily and highly accurately measuring a load distribution on an object. Is.

(B) Structure of the Invention [Means for Solving the Problem] To this end, the capacitance type pressure distribution measuring device of the present invention has a structure in which a plurality of electrode elements are arranged in a matrix on one surface. A flexible sheet-shaped first electrode plate and a flexible sheet-shaped second electrode plate having a plurality of electrode elements arranged on one surface in the matrix are provided on both surfaces of a spring material sheet made of a dielectric material. A sheet-like sensor formed by laminating the two electrodes so that the one surface faces each other, and an exciting device that excites the electrode element of the first electrode plate, and an electrode element of the second electrode plate. A processing device that processes the output of the first electrode plate and the second electrode, the electrostatic capacity of the spring material sheet between the electrode elements facing each other at a designated measurement location is detected. Each plate is made of a flexible sheet of insulating material A base, and a shield window layer made of a conductive ink formed by printing on one surface of the base in a state where the measurement points located in a matrix are in the shape of a white window, and on the shield window layer. A surface insulating layer made of an insulating ink formed by printing, an electrode layer made of a conductive ink formed on the surface of the surface insulating layer along the rows or columns of the matrix by printing, and the electrode. It is characterized by comprising a back surface insulating layer made of an insulating ink formed on the surface of the layer by printing and a shield layer made of a conductive ink formed on the surface of the back surface insulating layer by printing.

Hereinafter, details of the present invention will be described with reference to the drawings illustrating an embodiment.

In FIG. 1, reference numeral 1 is a pressure distribution measuring device, and the pressure distribution measuring device 1 includes a sensor 2 and a measuring unit 3.
The measuring unit 3 includes an excitation device 4 and a processing device 5.

The sensor 2 includes a first electrode plate 6, a spring plate 7, and a second electrode plate 8.
It is configured by stacking and integrally bonding. The sensor 2 has a plurality of measurement points 11 arranged in a matrix as shown in FIG.

The spring material 7 is in the form of a sheet, and is made of a flexible elastic material made of a dielectric material and having good linearity and restoration. Examples of the material forming the spring material 7 include natural rubber,
Silicon rubber can be mentioned.

The first electrode plate 6 and the second electrode plate 8 have substantially the same structure. That is, as shown in FIGS. 3 and 4, both electrode plates 6 and 8 are provided on the base 12 with a shield window layer 13, a front surface insulating layer 14, an electrode layer 15, a back surface insulating layer 16 and a shield layer 1.
7 is formed by printing.

The base 12 has, for example, a rectangular sheet shape, and is made of a flexible insulating material such as polyester or polyethylene terephthalate. The shield window layer 13 is formed by printing on the base 12 using a conductive ink. As shown in FIG. 5, the shield window layer 13 is almost solid, except that white windows 18 are formed in a matrix shape in correspondence with the measurement points.

The surface insulating layer 14 is formed on the shield window layer 13 by using an insulating ink by solid printing, as shown in FIG.

The electrode layer 15 is formed by printing on the insulating layer 14 using a conductive ink. As shown in FIG. 7, the electrode layer 15 is formed in a plurality of lines along the rows or columns of the measurement points 11 of the matrix. The back surface insulating layer 16 is formed by printing on the electrode layer 15 using an insulating ink. The back surface insulating layer 16 is formed by solid printing as shown in FIG. 8 and cooperates with the surface insulating layer 14 to form the electrode layer 1
Although the front and back surfaces and the edge portion of 5 are covered, the extraction portion 21 of the electrode layer 15 is exposed without being covered.

The shield layer 17 uses a conductive ink to form the back surface insulating layer 1
6 is formed by printing. The shield layer 17 is formed by solid printing as shown in FIG. 9, and cooperates with the shield window layer 13 to form the front surface insulating layer 14 and the back surface insulating layer 1.
6 is covered, but the extraction portion 21 of the electrode layer 15 is exposed without being covered.

The two electrode plates 6 and 8 configured as described above are bonded to the front and back surfaces of the spring material 7 with the base 12 facing the spring material 7. At this time, the first electrode plate 6 is arranged so that the electrode layers 15 are aligned with the rows of the matrix of the measurement points 11, and the electrode plate 8 is arranged so that the electrode layers 15 are aligned with the columns of the matrix.

Therefore, the electrode layer 15 in the row direction of the first electrode plate 6 and the electrode layer 15 in the column direction of the second electrode plate 8 face each other through the window 18 provided at the measurement point 11, and through the respective windows 18. The electrode layers 15 of the two electrode plates facing each other form an electrode element, and each pair of the electrode elements forms an electrode 10 (FIG. 12) at the measurement location.

In the sensor 2 thus configured, the extraction portions 21 of the electrode layers 15 of the first electrode plate 6 and the second electrode plate 8 are electrically connected to the printed boards 22 and 23 and are connected to the measurement unit 3.

That is, the electrode layer 15 in the row direction of the first electrode plate 6 is connected to the multiplexer 24, and the multiplexer 24 is connected to the high frequency generator 25.

On the other hand, the electrode layer 15 in the column direction of the second electrode plate 8 is connected to the wave detector 27 constituting the wave detector array 26. A heterodyne detector can be used as the detector 27. The output of the detector array 26 is the changeover switch 28.
Is input to the processing device 5.

[Operation] In the pressure distribution measuring device configured as described above, the operation when detecting the distribution of the pressure acting on the sensor 2 is as follows.

The high frequency generator 25 is excited. The multiplexer 24 is used to connect the plurality of electrode lines 20 in the row direction of the first electrode plate 6.
Select one of them to excite. Multiplexer 24
Is controlled by a switching signal from the processing device 5. When the selected electrode wire 20 is excited, an AC electric field is formed in the vicinity of the electrode wire 20, and the electrode wire 20 facing the window 18 of the corresponding electrode plate in the column direction of the second electrode plate 8 is To receive. This reception voltage includes information on the capacitance of the electrode 10 that changes according to the thickness of the spring material 7 interposed between the first electrode plate 6 and the second electrode plate 8 at the measurement location. .

The signal received by the electrode wire 20 of the second electrode plate 8 is simultaneously detected by the detector 27 and AD-converted, and the processing device 5
Entered in.

Similarly, by switching the multiplexer 24, all the electrode wires 20 of the first electrode plate 6 are sequentially excited,
When the capacitance at the electrodes 10 is measured, those signals are input to the processing device 5, and the electrodes 10 are calculated by calculation.
The dielectric constant of the measurement location of each electrode 10 is calculated from the electrostatic capacitance at, and the pressure acting on the measurement location is specified from the dielectric constant.

(C) Effect of the Invention According to the pressure distribution measuring device of the present invention, it is possible to accurately and rapidly detect a change in the capacitance of the electrode due to a change in the thickness of the spring material between the orthogonal grid electrodes. On the basis of this, the state of pressure acting on the spring material of the sensor can be detected from the distribution of the dielectric constant. In the present invention, the electrode grid is constructed by using the electrode lines that are shielded except for the grid points that form the electrode part, thereby suppressing the electrostatic induction noise from the outside and suppressing the local change of the dielectric constant. It has become possible to detect it as a change in capacity.
Since the electrode wire and the electrode plate can be manufactured by a printing technique, the thickness can be reduced, the manufacturing is easy, and the cost is low. Moreover, in the pressure distribution measuring device of the present invention, since the spring material is used for the sensor and the pressure-sensitive conductive sheet mixed with the conductive particles is not used, it is possible to ensure homogeneity as a sensor and to perform high-precision measurement. Along with
Recovery after unloading is quick, and high-speed measurement is possible.

[Brief description of drawings]

FIG. 1 is a structural explanatory view of a pressure distribution measuring device, FIG. 2 is a plan explanatory view of a sensor showing a measurement position, FIG. 3 is a plan explanatory view of an electrode plate, FIG. 4 is a sectional explanatory view of the electrode plate, and FIG. 5 is an explanatory plan view showing a print pattern of a shield window layer, FIG. 6 is an explanatory plan view showing a print pattern of a surface insulating layer, FIG. 7 is an explanatory plan view showing a print pattern of an electrode layer, and FIG. FIG. 9 is a plan explanatory view showing a printed pattern of a back surface insulating layer, FIG. 9 is a plan explanatory view showing a printed pattern of a shield layer, FIG. 10 is a plan explanatory view of a sensor, FIG. 11 is a sectional explanatory view of the sensor, and twelfth. The figure is a pressure distribution measurement circuit diagram. 1 ... Pressure distribution measuring device, 2 ... Sensor, 3 ... Measuring unit, 4 ... Excitation device, 5 ... Processing device, 6 ... First electrode plate, 7 ... Spring material, 8 ... 2 electrode plate, 10 ... electrode, 11 ... measurement location, 12 ... base, 13 ... shield window layer, 14 ... surface insulating layer, 15 ... electrode layer, 16
...... Back insulating layer, 17 ...... Shield layer, 18 ...... Window, 2
0 ... Electrode wire, 21 ... Extraction part, 24 ... Multiplexer, 25 ... High frequency generator, 26 ... Detector array, 27 ... Detector.

 ─────────────────────────────────────────────────── ─── Continuation of the front page Examiner Masayuki Mori (56) Bibliographic references Kohei 5-31540 (JP, Y2)

Claims (1)

[Claims] 1. A flexible sheet-shaped first electrode plate having a plurality of electrode elements arranged in a matrix on one surface, and a flexible sheet having a plurality of electrode elements arranged in the matrix on one surface. A sheet-shaped sensor formed by laminating a sheet-like second electrode plate on both surfaces of a spring material sheet made of a dielectric material so that the one surfaces face each other, and the first electrode plate is provided with the sheet-like sensor. An electrostatic device for exciting the electrode element and a processing device for processing the output from the electrode element of the second electrode plate, and the electrostatic force of the spring material sheet between the electrode elements facing each other at a designated measurement point. The first electrode plate and the second electrode plate are configured to detect capacitance, and each of the first electrode plate and the second electrode plate has a base made of a flexible sheet-shaped insulating material, and a measurement point located in a matrix shape with white windows. One of the bases in the A conductive ink shield window layer formed by printing on a surface, an insulating ink surface insulating layer formed by printing on the shield window layer, and a matrix of the matrix on the surface of the surface insulating layer. A plurality of conductive ink electrode layers formed by printing along rows or columns, a back insulating layer made of an insulating ink formed by printing on the surface of the electrode layer, and a surface of the back insulating layer An electrostatic capacitance type pressure distribution measuring device, comprising: a conductive ink shield layer formed by printing on the.