JPH08159706A - Interval sensor - Google Patents

Abstract

PURPOSE: To enable the interval to be set highly accurately while hardly damaging member on both sides of the interval to be set by arranging a piezo-electric polymer layer and a pair of detection electrodes formed thereon. CONSTITUTION: An interval sensor 11 has detection electrodes 13 and 14 formed on both sides of a piezo-electric polymer layer 12. The polymer layer 12 is made of a polymer material exhibiting a piezo-electric property and the detection electrodes 13 and 14 are made of a metal material as thin film on both sides of the polymer layer 12 by a thin formation method such as evaporation method and leads 15 and 16 are connected thereto. An interval sensor 11 is arranged between rolls 21 and 22 to set an interval and the rolls 21 and 22 are brought into contact with the sensor 11. By this contact of the rolls, the piezo-electric polymer layer 12 of the sensor 11 is distorted physically and as a result, a potential difference is caused on both sides of the polymer layer 12 by a piezo-electric effect to be drawn from the detection electrodes 13 and 14. On the other hand, the potential difference has a fixed relationship with a force applied and thus, when the relationship is checked between the thickness of the sensor 11 and the potential difference generated beforehand, the interval of the rolls can be learned from the potential difference.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distance sensor capable of measuring or setting a distance between objects, and more particularly to a distance sensor characterized by using a piezoelectric polymer.

[0002]

2. Description of the Related Art When manufacturing a ceramic multilayer electronic component such as a multilayer capacitor, a plurality of ceramic green sheets having internal electrodes are prepared, and the plurality of ceramic green sheets are laminated and fired. I was getting a union. By the way, in order to obtain a ceramic laminated electronic component having stable characteristics and excellent reliability,
The thickness of the ceramic green sheet must be controlled with high accuracy.

A method using a plurality of rolls such as a reverse roll method is used for manufacturing the ceramic green sheet. For example, in the reverse roll method, as shown in FIG. 1, a plurality of rolls 1 to 3 that are rotationally driven are used. That is, the ceramic slurry 4 is supplied between the rolls 1 and 2 which rotate in the direction of the arrow shown in the drawing, and the rolls 1 and 2 are rotated to form a ceramic slurry layer having a predetermined thickness due to the gap between the rolls 1 and 2. To do. Then, the ceramic slurry 4 layer on the surface of the roll 2 is transferred onto the carrier sheet 6 supplied from the roll 3, and the transferred ceramic slurry layer is dried to obtain a ceramic green sheet 5. In this case, the thickness of the ceramic green sheet 5 is mainly controlled by the distance between the rolls 1 and 2.

That is, in order to stably obtain the ceramic green sheet 5 having a predetermined thickness, the distance between the rolls 1 and 2 must be controlled with high precision. Conventionally, in order to set the interval between the rolls 1 and 2 with high accuracy, among these, a method of setting the interval using a gap gauge, and irradiating a laser beam from one side of the gap between the rolls,
A method is adopted in which the light transmitted through a light receiving element arranged on the other side is detected and the interval is measured thereby.

[0005]

The gap gauge is usually
It is composed of a metal plate having a thickness corresponding to the interval to be set. Therefore, the gap gauge is set to, for example, rolls 1 and 2.
By inserting the gap gauge between the rolls 1 and 2, narrowing the gap between the rolls 1 and 2, and pulling out the gap gauge from the gap between the rolls 1 and 2 when the outer surfaces of the rolls 1 and 2 come into contact with the gap gauge, The interval between the two was set. In this method, the gap between the rolls is set with high accuracy by the thickness of the gap gauge.

However, since the gap gauge is made of a metal plate, there is a problem that the outer surfaces of the rolls 1 and 2 may be damaged, resulting in deterioration of the surface properties of the ceramic green sheet 5. In addition, in the gap setting method using the gap gauge, although the gap between the rolls is set according to the thickness of the gap gauge as described above, it is not possible to accurately know the actually set gap between the rolls. could not.

On the other hand, in the method using laser light,
In the case of an inexpensive measuring device, the resolution was low, so that the interval between the rolls could not be set with high accuracy. However, if an expensive measuring device is used, the distance between the rolls can be controlled with a high degree of accuracy, but a very expensive device is required to set the distance between the rolls, which results in a high cost. was there.

An object of the present invention is to provide a distance sensor which is less likely to damage members on both sides of the distance to be set and which can set the distance with high accuracy and at low cost.

[0009]

SUMMARY OF THE INVENTION The present invention is a gap sensor capable of measuring a gap between objects and setting a gap having a desired size. The gap sensor includes a piezoelectric polymer layer and the piezoelectric polymer layer. And a pair of detection electrodes formed in layers.

The piezoelectric polymer layer is composed of a polymer material exhibiting piezoelectricity. Such a piezoelectric polymer layer has a function of applying a force from both sides of the piezoelectric polymer layer. An appropriate piezoelectric polymer material capable of taking out an electrical output having a certain relationship with the size can be used. Examples of such a piezoelectric polymer include polyvinylidene fluoride, polyvinyl fluoride, polyvinyl chloride, etc., but the piezoelectric polymer used in the present invention is not limited thereto.

In the distance sensor of the present invention, a pair of detection electrodes are formed on the piezoelectric polymer layer. The pair of detection electrodes are provided to take out an electrical output generated according to the force applied to the piezoelectric polymer layer. The pair of detection electrodes may be dispersed and formed on both surfaces of the piezoelectric polymer layer, that is, may be formed so as to face each other with the piezoelectric polymer layer interposed therebetween. Alternatively, as long as the electric output corresponding to the force applied when the force is applied from both surfaces of the piezoelectric polymer layer can be taken out as described above, the piezoelectric polymer layer is separated by a predetermined distance on one main surface. A pair of detection electrodes may be formed. That is, even in the mode in which the pair of detection electrodes are formed on the surface of the piezoelectric polymer layer, as long as the electric output corresponding to the force applied to both main surfaces of the piezoelectric polymer layer can be taken out,
There is no particular limitation, and the detection electrode may be embedded in the piezoelectric polymer layer.

Further, in the distance sensor of the present invention, preferably, a support layer made of a flexible material is laminated on at least one surface of the piezoelectric polymer layer so as to support the piezoelectric polymer layer. The material having flexibility includes a relatively soft material such as a synthetic resin, a synthetic rubber or a natural rubber, and widely includes an appropriate material that is hard to damage the surface of the object whose distance is measured.

The support layer may be laminated on one side or both sides of the piezoelectric polymer layer, or the support layer may be constituted so as to cover the piezoelectric polymer layer.

[0014]

When the interval sensor of the present invention is used to measure and set the interval, the interval sensor is inserted at the interval to be set.
Then, the objects on both sides are brought close to each other and brought into contact with the distance sensor of the present invention. This contact causes a physical strain in the piezoelectric polymer layer, and the physical strain is taken out from the pair of detection electrodes as an electrical output by the piezoelectric effect. In this case, the extracted electrical output has a value corresponding to the force applied to the piezoelectric polymer layer.

Therefore, the distance between the objects can be known from the electrical output of the pair of detection electrodes. Moreover, since the piezoelectric polymer layer is made of a polymer material, there is no possibility of damaging the surface of an object to be contacted.

Further, in the structure in which the support layer is laminated on the piezoelectric polymer layer, the support layer is made of a flexible material, so that the risk of scratching the surface of the object is more effectively reduced. can do. In addition, when the distance between the objects to be measured is narrow, the thickness of the piezoelectric polymer layer must be very thin, but when the thickness of the piezoelectric polymer layer is very thin, the piezoelectric polymer layer When the shape retention is likely to be impaired, the shape retention of the distance sensor can be improved by laminating a support layer having higher strength than the piezoelectric polymer layer but having flexibility.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be clarified by describing embodiments with reference to the drawings.

FIG. 2 is a perspective view of a distance sensor according to an embodiment of the present invention, and FIG. 3 is a sectional view thereof. The space sensor 11 includes detection electrodes 13, 1 on both surfaces of the piezoelectric polymer layer 12.
4 is formed. The piezoelectric polymer layer 12 is made of a polymer material having piezoelectricity, such as polyvinylidene fluoride, polyvinyl fluoride, or polyvinyl chloride. The detection electrodes 13 and 14 are the piezoelectric polymer layer 1 described above.
It is formed by applying a metal material to both surfaces of No. 2 by a thin film forming method such as vapor deposition, plating or sputtering, or by applying and curing a conductive paste.

The detection electrodes 13 and 14 have lead wires 15 and
16 are connected. A method of using the distance sensor 11 of this embodiment will be described with reference to FIGS. 4 and 5. For example,
A case of setting the interval between the rolls 21 and 22 shown in FIG. 4 will be described.

First, the gap sensor 1 is provided between the rolls 21 and 22.
Place 1 After that, bring the rolls 21 and 22 closer together,
As shown in FIG. 5, the rolls 2 are provided on both sides of the gap sensor 11.
Abut 1, 22. When the rolls 21 and 22 are brought into contact with both surfaces of the distance sensor 11, the distance sensor 1
Physical distortion is given to the piezoelectric polymer layer 12 of No. 1. As a result, a potential difference occurs on both surfaces of the piezoelectric polymer layer 12 due to the piezoelectric effect. This potential difference is taken out from the detection electrodes 13 and 14.

On the other hand, in the piezoelectric polymer layer 12, the potential difference between both surfaces generated when the physical strain is applied has a constant relationship with the applied force. That is, the rolls 21 and 2
As the outer surface of 2 comes into contact with the interval sensor 11 and a force is applied to further reduce the thickness of the piezoelectric polymer layer 12, the generated potential difference increases. Therefore,
The force applied to the distance sensor 11 in advance, that is, the distance sensor 1 changed by the pressure contact of the rolls 21, 22.
If the relationship between the thickness of No. 1 (corresponding to the interval between the rolls 21 and 22) and the potential difference generated in that case is investigated, the roll 2 can be determined by the potential difference extracted from the detection electrodes 13 and 14.
The distance between 1 and 22 can be known.

As described above, if the distance sensor 11 is used, the distance between the rolls 21 and 22 can be measured by the electric output taken out from the detection electrodes 13 and 14. Further, when setting the interval between the rolls 21 and 22, the rolls 21 and 22 are brought close to the interval sensor 12 as described above, and when the desired interval is reached, the interval sensor 11 is placed between the rolls 21 and 22. It can be removed from the gap.

Further, in the interval sensor 11 of this embodiment,
Since the piezoelectric polymer layer 12 is mainly used, even if the thin electrodes 13 and 14 as described above are formed on the surface, there is almost no possibility of scratching the surface of the rolls 21 and 22 in the above work.

However, preferably, the rolls 21 and 22
The detection electrode may be formed only in a region distant from the region in contact with, or may be embedded and formed inside the piezoelectric polymer layer 12.

Further, like the distance sensor 31 of the second embodiment shown in FIG. 6, the support layer 32 may be laminated on one main surface of the piezoelectric polymer layer 12. Similarly, as shown in FIG. 7, the first and second support layers 33 and 34 may be laminated on both main surfaces of the piezoelectric polymer layer 12.

Examples of the material forming the support layers 32 to 34 are materials having flexibility, for example, synthetic resins such as silicone resin and soft vinyl chloride resin, synthetic rubber or natural rubber. Such a support layer 32 to
In the structure in which 34 is laminated on the piezoelectric polymer layer 12, since the support layers 32 to 34 are made of a material having flexibility, the outer surfaces of the support layers 32 to 34 have metal rolls 21 and 2.
It is unlikely that the outer surfaces of the rolls 21, 22 will be damaged when contacted with 2.

In addition, when the spacing to be set is very narrow and the thickness of the piezoelectric polymer layer 12 is very thin, and when the piezoelectric polymer layer 12 alone is not sufficient in shape retention, the piezoelectric Support layer 32 having higher strength than the polymer layer 12
By using ~ 34, it is possible to provide a distance sensor capable of setting a very small distance.

Further, the interval between the long rolls can be set by using a plurality of interval sensors of the present invention. That is, as shown in the perspective view of FIG. 8, when setting the interval between the long cylindrical rolls 35 and 36, a plurality of the above-described interval sensors 11 are prepared, and the interval between the rolls 35 and 36 is appropriately set. The distance between the rolls 35 and 36 can be set accurately by inserting them at a distance of.

That is, by using a plurality of the distance sensors of the present invention and arranging them linearly or two-dimensionally as described above, it is possible to surely set the intervals having various plane shapes. it can.

Further, as shown in FIG. 8, when a plurality of gap sensors 11 are used in setting the gap between the long rolls 35 and 36, the gap between the rolls 35 and 36 is set to the roll 35. , 36 can be easily made constant over the lengthwise direction.

Further, the distance sensor of the present invention can be widely used not only for setting the distance between the pair of rolls as described above but also for setting the distance between various objects. For example, it can be suitably used also when setting the interval A between the molds 41 and 42 shown in FIG. In this case, the distance sensor of the present invention is installed between the molds 41 and 42, and
By dimensionally arranging, the intervals between the molds 41 and 42 can be set to be constant, and the front and rear / right and left inclinations of the molds 41 and 42 can be easily adjusted, that is, parallel alignment can be easily performed.

[0032]

As described above, in the distance sensor of the present invention, the distance between the members to be measured is electrically measured by utilizing the piezoelectric effect in the piezoelectric polymer layer. Therefore, the interval between the members can be set with high accuracy, and the dimension of the interval can be known. Moreover, since the piezoelectric polymer layer is the main component, it is relatively soft, and therefore
The surface of the member contacting the distance sensor is hardly damaged.

In addition, since the detection electrode is merely formed on the piezoelectric polymer layer, an inexpensive distance sensor can be provided. Further, in the structure in which the support layer is laminated on the piezoelectric polymer layer, when the support layer is made of a flexible material, it is possible to more effectively prevent damage to the surface of the member contacting the distance sensor. You can In addition, the support layer is made of a material having higher strength than the piezoelectric polymer layer, so that when the piezoelectric polymer layer is thin, the support layer can supplement the shape retention of the distance sensor. Therefore, even if the piezoelectric polymer layer is thinned to measure a relatively small distance, it is possible to configure the distance sensor having sufficient shape retention.

[Brief description of drawings]

FIG. 1 is a schematic side view for explaining a configuration in which a ceramic green sheet is obtained by a reverse roll method.

FIG. 2 is a perspective view showing a distance sensor according to an embodiment of the present invention.

FIG. 3 is a sectional view of the distance sensor according to the embodiment shown in FIG.

FIG. 4 is a side view for explaining a process of measuring a gap between rolls using the gap sensor of the embodiment.

FIG. 5 is a cross-sectional view for explaining a process of measuring the distance between rolls using the distance sensor according to the embodiment.

FIG. 6 is a sectional view for explaining a distance sensor according to a second embodiment.

FIG. 7 is a sectional view for explaining a distance sensor according to a third embodiment.

FIG. 8 is a perspective view for explaining a method for measuring a distance between long rolls.

FIG. 9 is a partially cutaway cross-sectional view for explaining a distance between a pair of molds measured by a distance sensor of the present invention.

[Explanation of symbols]

 11 ... Interval sensor 12 ... Piezoelectric polymer layer 13, 14 ... Detection electrode 31 ... Interval sensor 32 to 34 ... Support layer

Claims (1)

[Claims] 1. A distance sensor comprising a piezoelectric polymer layer and a pair of detection electrodes formed on the piezoelectric polymer layer.