JPS62245904A - Sensor element - Google Patents

Abstract

PURPOSE:To obtain an element capable of detecting flexural and torsional behavior including elongation and compression from a fine quantity to a considerable quantity by fitting a plate type body to a deforming conductive element formed by providing electrode end parts at two positions of a deforming conductive sheet. CONSTITUTION:The element has the electrode end parts 12 provided on both sides of one surface of the deforming conductive sheet 11 and also has the plate type body 14 adhered to the other surface across an adhesive layer 13. This sheet 11 decreases in electric resistance by >=1 digit owing to considerable elongating deformation and compressing deformation. Thus, the plate type body 14 made of a leaf spring with large toughness is fitted thereto and then external stress is applied indirectly to the sheet 11 through the plate type body 14, so the mechanical strength and durability of the element increase greatly. This, element is therefore superior in durability against inflection, torsion, compression, etc., and deformation from a fine quantity to a considerable quantity is obtained as a large change in resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sensor element. More specifically, the present invention relates to a sensor element made of a deformable conductive sheet that can easily and elastically undergo three-dimensional bending deformation accompanied by expansion, compression and twisting by external force, and whose electrical resistance value decreases with the deformation.

(Prior art) Conventionally, materials whose electrical resistance value decreases due to elongation deformation are not widely known. Therefore, by capturing the decrease in electrical resistance value caused by elongation deformation, it is possible to determine whether or not the object to be measured has elongated, and the amount of elongation. However, an element capable of detecting the frequency of expansion and compression had not been developed.

On the other hand, a strain gauge is known as an element that utilizes the property that electrical resistance increases with elongation deformation. That is, when a thin metal wire such as Constance, Advance, or Nichrome is pulled, its electrical resistance increases. However, the change in resistance of this type of metal wire is extremely small, so in order to extract it as an electrical signal, the circuit must have filter functions such as signal amplification and averaging, resulting in a complex and high-cost circuit. . Furthermore, since the elongation rate of strain gauges is extremely small (1% or less), the strain gauges can only handle minute deformations of the object to be measured, and cannot detect large elongation deformations such as those of bent parts of the human body such as elbows and knees. It is not suitable for

There are also elements using piezoelectric elements and pressure-sensitive conductive rubber. Piezoelectric elements are used to detect mechanical strain deformation and voltage changes, but like strain gauges, they require complex and high-cost circuits and are only suitable for applications involving minute deformations. On the other hand, in the latter type of pressure-sensitive conductive rubber, the electrical resistance value decreases with respect to pressure wI deformation, but the electrical resistance value does not decrease with respect to elongation deformation.

As mentioned above, the conventionally known elements are circuit-complicated and expensive, and can only be used for minute deformations or cannot be used for compressive deformation. Therefore, if there is an element that can detect the presence or absence, frequency, and amount of deformation of objects that undergo bending or twisting deformation with minute to considerable amounts of elongation or compression, it is expected that there will be a wide range of applications. However, the current situation is that nothing that satisfies this requirement has yet appeared.

[Problem that the invention seeks to solve]

The present invention is capable of bending and bending, which involves slight deformation to considerable elongation and compression deformation, which cannot be achieved using conventionally known materials.
The object is to provide a sensor element capable of detecting torsional behavior.

[Means for solving problems]

The object of the present invention is to provide a sensor element characterized in that a plate-like object is attached to a part or the entire surface of at least one side of a deformed conductive element having electrode ends at at least two places. achieved.

The first feature of the present invention is that a small amount of the deformed conductive element (partially or the entire surface of one side of the deformed conductive element is attached to a plate-like object). It means an element having electrode ends in at least two places.

The electrode ends are usually provided at both ends of the deformed conductive sheet. However, one or more electrode ends may be provided in the middle of the deformed conductive sheet other than at both ends, or one or more electrode ends may be provided on the front and back surfaces of the sheet. In this case, by detecting a decrease in the electrical resistance value of the deformed conductive sheet at an arbitrary end of the electrode, it is possible to grasp the deformation behavior of the corresponding portion of the object to be measured.

That is, the ends of the electrodes for detecting the electrical resistance value of the deformed conductive sheet only need to be provided at intervals;
The position, number, shape, etc. may be appropriately selected depending on the purpose and method of use.

The electrode end can be made by applying a conductive adhesive containing a conductive substance such as nickel, copper/silver, or carbon directly onto the surface of the deformed conductive sheet by coating, transferring, screen printing, or other means. There are shapes printed, metal plates normally used as electrodes bonded with the conductive adhesive, mechanically attached with rivets, grommets, hooks, etc., and combinations of these. This list is not limited to this list.

In addition, the deformable conductive sheet referred to here means that when stretched or compressed deformation is applied, or when the sheet is bent with elongated or compressed deformation,
When a deformation action such as twisting is applied, the electrical resistance value of the knitted fabric in the direction of deformation decreases by more than an order of magnitude [! It means fi thing. For example, in March 1985, the same applicant as the present invention
The patent application No. 60-41024 was filed on May 4th.
Examples include sheet-like knitted fabrics included in "modified conductive knitted fabrics". Also, by the same applicant as the present invention,
This sheet is included in the "Deformable Conductive Polymer Elastomer" filed as Japanese Patent Application No. 59-20057 on September 27, 2005.

Note that the deformed conductive sheet and the extensible insulating reinforcing material may be partially or completely buried or bonded together. If a stretched conductive sheet reinforced in this way is used as a sensor element,
Deterioration in conductive performance and physical destruction after repeated stretching are significantly improved.

Next, the plate-like object referred to in the present invention refers to a material with high toughness, that is, a metal with an insulating coating on the surface (for example, phosphor bronze or beryllium copper, etc.), a plastic with high rigidity (
(polyacetal, polycarbonate, nylon 66, vinyl chloride, fluororesin, etc.), various FRP (for example, a combination of reinforcing fibers such as glass fiber, carbon fiber, aramid fiber, or fiber fabric with epoxy resin, unsaturated polyester resin, etc.) , or all materials commonly used as temporary springs, such as ceramics. Further, the shape of the plate-like object is determined as appropriate depending on the purpose and use of the object, but usually a flat or curved object is easy to handle. However, we are not particular about this.

In addition, it is possible to create a more compact and flat sensor element than by drawing a circuit directly on the surface of a plate-shaped object by means such as coating with conductive adhesive, dipping, printing, transfer, screen printing, vapor deposition of metal, or pasting of metal foil. Therefore, it is suitable for light, thin, short and small applications such as in the electronics field.

The present inventors have invented a sensor element in which the electric resistance value is reduced by one order of magnitude or more due to an unprecedented amount of elongation deformation or compressive deformation by providing electrode ends at at least two locations on a deformed conductive sheet. However, in areas where the external stress during compression or bending is directly applied to the deformed conductive sheet (for example, the center of the deformed conductive sheet), undulation and destruction progress, resulting in poor mechanical properties such as strength and stretch bankability, and durability. However, it was found to be inferior in terms of performance, and no significant improvement was observed simply by laminating the elastomer reinforcing material with a deformable conductive sheet.

Therefore, when a deformed conductive sheet is attached to the above-mentioned plate-like object, external stress is indirectly applied to the deformed conductive sheet through the plate-like object, so the mechanical strength and durability of the sensor are significantly increased, especially for bending sensors. It has been found to be effective when used in push-in type switches.

As a means for attaching a deformed conductive sheet to a plate-like object,
Although this may be done mechanically with rivets or hooks, it is preferable to use an adhesive because it is simpler in terms of operability and also in terms of durability because it adheres to the plate-like object over a wider area. Adhesives include commonly used epoxy and amide plastic adhesives, urethane adhesives,
Any latex adhesive may be used.

Further, the attachment point may be on one side or both sides of the deformed conductive sheet, or may be on a part or the entire surface of the deformed conductive sheet. In particular, when &I fabric is used as the deformable conductive sheet when adhesive is applied to the entire surface, the bending/twisting sensor element can detect a wide range of bending angles ranging from minute deformation to large deformation.

The reason for this is that when bending stress is applied, stress is applied uniformly to each point on the surface of a product bonded over the entire surface, and the stress component in the direction perpendicular to the surface increases along with the parallel component. This is thought to be because the resistance value decreases as the contact pressure increases at the intertwined portion of the threads. Furthermore, when attaching a plate-like object to one side of the deformed conductive sheet, it is more preferable to coat the other side with silicone resin or fluororesin, since this improves environmental resistance.

In addition, when using a deformable conductive knitted fabric as a deformable electrically conductive sheet, if the electrode end is installed in the yarn axis direction, it will become a highly sensitive bending, torsion, or compression sensor, and if it is installed in the bias direction, it will become a highly sensitive bending, torsion, and compression sensor. The sensor element can handle even larger deformations.

Next, the sensor element of the present invention will be further explained using the drawings. FIGS. 1 to 5 show schematic diagrams of the sensor element of the present invention.

FIG. 1 shows a sensor element in which electrode ends are provided at both ends of one side of a deformed conductive sheet, and both ends of the other side are attached to a plate-like object via an adhesive layer. Further, FIG. 2 shows a sensor element in which the entire surface of one side of the sheet is adhered to a plate-like object, and electrode ends are provided not only at both ends but also at the center. FIG. 3 shows a sensor element in which plate-like objects are attached to the entire surfaces of both sides of the sheet. In addition, Fig. 4 a) and b) show a temporary spring with electrodes printed on it, the center part of the sheet with electrically insulating adhesive, and both ends with sensor elements glued with conductive adhesive. The other side is coated with silicone resin or fluororesin to improve environmental resistance. Note a)
b) is a side sectional view and b) is a plan view. Figure 5 a)
, b) represents a sensor element in which electrode ends are installed at intervals on both the front and back surfaces of a deformed conductive sheet, and both surfaces are bonded to a plate-shaped object, a) is a side sectional view, and b) is a plan view. represent.

In addition, in the figure, 11, 21. 31. 41. 41', 51.
51' is a deformed conductive sheet, 12, 22, 32, 42.
42', 52°52' is the electrode end, 13, 23,
33, 43, 53 are adhesive layers, 14.24.34,
44.44', 54.54', 54'' are plate-shaped objects, 1
5.25.35, 45.45', 55 is the lead wire,
46 represents a circuit printed on a plate-like material, and 47 and 47' represent silicone resin or fluororesin, respectively.

These inventions detect minute to considerable deformations such as bending, twisting, and compression as large changes in resistance, and are detected by an unprecedented detection circuit and have particularly excellent mechanical durability. It becomes a sensor element.

The sensor element of the present invention will be further explained below using Examples, but it is clear that the sensor element is not limited to these Examples or the previous drawings.

〔Example〕

Polyester taffeta manufactured by Asahi Kasei Corporation (50 d
/24 f, latitude 75 d/36 f) was treated with a sodium hydroxide aqueous solution (80 g) at 100°C (weight loss rate 2).
0%) and sensitized in a bath with a weight ratio of 5nC1t:hydrochloric acid of 3:10, and after washing and dehydration, activated in a bath with a weight ratio of PdC1z:hydrochloric acid of 1:15, and after washing and dehydration with NiCl.
z ・6 HzO, NaHPOz HzO.

Sodium citrate, NH4, (1, ammonia water 1
A Ni-plated ester taffeta was produced by treatment at 90° C. for 2 minutes in a bath with a weight ratio of: 1:3:2:2.

Cut this into 10cm x IQcm size samples,
Put water into a double cylindrical laminar flow generator (inner cylinder rotates at high speed, outer cylinder inner diameter 25cm, inner cylinder outer diameter 10c+++) and process at inner cylinder rotation speed 200 rpm for 300 minutes to deform. A conductive sheet was obtained. Next, 5% of commercially available urethane elastomer resin (solvent DMF, solid content 10wt%) was added.
After coating on release paper with 0μm gauge, 100℃ x 5
n+in was dried, and thermal adhesive transfer was performed on both sides of a sheet-shaped deformed conductive Wm object at 110° C. under a pressure of 4 kg/ci. This was cut in the bias direction and warp direction to a size of 1 cI 11 width x 5 cm length.

Next, a commercially available Ni-based conductive adhesive was coated on both ends of the deformed conductive sheet, which had been cut in the bias direction, together with the lead wires, and dried and cured to produce element (2). Next, using a commercially available two-component epoxy adhesive on a commercially available polycarbonate resin plate (thickness 300 μm), glue both ends of one side of the above element The sample 11hl, which is a product of the present invention, was prepared by elongating the film to a certain degree (7%) and curing the adhesive. Similarly, one entire surface of element (1) was adhered to the resin plate and cured to prepare sample 11h2, which is a product of the present invention.

In addition, in the same manner as Sample Magnet 2, one side of the element was adhered to a resin plate on its entire surface, and the other side was coated with a commercially available condensed silicone resin, and left to harden at room temperature for 24 hours to prepare sample PlkL5 of the present invention. did.

On the other hand, an element (2) was prepared by coating both ends of the deformed conductive sheet, which had been cut in the warp direction, with a conductive adhesive along with lead wires in the same manner as in the element (2).

Sample 11h3, which is a product of the present invention, was prepared by adhering and curing the entire surface of one side of element 1 to the resin plate in the same manner as sample 11h2.

In addition, the entire surfaces of both sides of the element (1) were similarly adhered to a resin plate using an epoxy adhesive to prepare sample No. 4 of the present invention. Next, electrodes were placed with conductive adhesive at 6 locations with a width of 1 cm and an interval of 1 cm on both ends of the front and back sides and the center of the deformed conductive sheet cut in the bias direction, and the resistance value was 4.5 x 10".
Sample 6 of the present invention was prepared by elongating it to an elongation just below Ω and bonding the entire surface of both surfaces with an adhesive.

These samples Nal~6 were set in a bending tester (bagging tester manufactured by Yamaguchi Kagaku Co., Ltd.) and
The resistance values at each bending degree of 0.15, 20, and 30.45" were measured and shown in Table 1 with element 0--20' to 6
The resistance value at 20' was compared before and after repeated bending, and the resistance value was expressed as the number of times the resistance value was 5 times or more. Table 1
The results are shown below.

As can be seen from Table 1, the sensor elements of the sample levels 1 to 6 of the present invention have excellent bending fatigue resistance compared to the comparative example (element ■) that is not bonded to a plate-like object, and exhibits small deformation to large deformation. It can be seen that the sensor element can sense the entire deformation.

[Effects of the Invention] The sensor element according to the present invention having the above-mentioned configuration has excellent durability against bending, twisting, compression, etc., and can be interpreted as a large change in resistance value, from minute deformation to considerable deformation. Therefore, it can be used as a sensor element that can perform detection with a simple circuit, which cannot be done using conventionally known sensor elements.

[Brief explanation of drawings]

1 to 5 show schematic diagrams of embodiments of the sensor element of the present invention. In the figure, 11.21, 31.41.41', 51.51
'...Deformed conductive sheet, 12.22, 32, 42.42', 52.52'.
... Electrode end, 13 , 23 , 33 , 43 , 53
...adhesive layer, 14.24, 34, 44.44',
54.54'... plate-like object, 15.25, 35, 45.
45', 55...Lead wire, 46...Circuit printed on plate-shaped material, 47...Silicone resin or fluorine resin. 1111 figure #! J3 figure procedural amendment (voluntary) November 12, 1985 Commissioner of the Japan Patent Office Kuro 1) Akio Yu 1, Indication of the case 1989 Patent Application No. 089207 2, Name of the invention Sensor element 3, Person making the amendment Relationship to the case Patent applicant name (003) Asahi Kasei Kogyo Co., Ltd. 4, Agent address 4-8-10 Toranomon-chome, Minato-ku, Tokyo 105 tct 4) 5. Column 6 of "Detailed Description", Contents of Amendment 1) "Along with elongation, compression, and twisting" in the 12th line of page 1 of the specification is corrected to "Along with elongation, compression, and twisting." 2) "The deformed conductive sheet has extensibility" on page 6, line 5 of the specification is corrected to "the deformed conductive sheet has extensibility." 3) A flexible printed circuit board (e.g. ester film, By attaching a polyimide film (made of polyimide film) to a plate-like object, it can be corrected compactly. 4) "It becomes an element." written in the 8th line of page 11 of the specification becomes an r element. These products of the present invention can be used in the following applications. For example, as a pedometer, it can be attached to joints such as elbows and knees, or the sensor element of the present invention (hereinafter referred to as the element) can be incorporated into shoes to detect the number of steps taken by bending the element as you walk. It is possible to detect the number and degree of flexion by attaching the element to the bending part of various training equipment and equipment for muscle strengthening, shake-up, and rehabilitation, or to the human body. In addition, by appropriately selecting the type of plate-like element, it can be used as a load cell that can handle from minute stress to large stress, and by propagating the motion of an object that vibrates or accelerates to the element, it can be used as a vibrometer or accelerometer. Can be used. Furthermore, by appropriately selecting the shape and spacing of the connecting ends of the element according to the shape and size of the test object, it is possible to bond it to not only flat surfaces but also rigid materials with curved surfaces (such as metal and wood). ,
It can be used for various measurement purposes such as strain and stress in a wide range of fields, such as detecting strain deformation such as minute elongation and warping. In addition, the bending conductivity of the element can be used to create tactile sensors for robots, non-contact switches for keyboards and handwriting input, seating detection sensors that can be used in seats to confirm seating, and window frames and handrails for crime prevention and safety purposes. It can be used for crime prevention and danger prediction sensors installed (pressure sensors such as touch sensors, danger prediction sensors for power windows of automobiles, etc.). Next, as an industrial sensor, it is attached to the rotating or bending part of an industrial robot to detect the direction of the robot hand, position control sensor for position control, limit switch, micro switch, etc. It can be used as a safety switch to prevent a robot from running out of control, and by placing a sheet-like (mat-like) sensor element in a dangerous area, it can be used as a safety switch that detects the intrusion of a worker and stops the robot in an emergency. used. Further, it can be used as a diaphragm, a pressure gauge, a sensor for detecting the expansion rate of an expanding body, a pulse meter, a blood pressure meter, and various flow rate meters (for fluids such as liquids and gases). Furthermore, by attaching an element made of a plate-like material with low bending stress directly to the hand or arm or attaching it to a glove, etc., we can create a finger switch that directly responds to finger movements, that is, a joystick for games that provides a sense of realism. First, it can be used as a sign language voice conversion device in combination with a computer, and furthermore, as an input device that allows remote control of robot hands for dangerous or precision work. Note that the uses of the sensor element of the present invention are not limited to the above-mentioned uses. Correct to j.

Claims (1)

[Claims] 1. A sensor element comprising a deformed conductive element having electrode ends provided at at least two locations on a deformed conductive sheet, and a plate-like object attached to a part or the entire surface of at least one side.