JP2009079976A - Apparatus for measuring road surface strain - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a strain measuring apparatus which has a structure resistant to damage on a wheel grounded area and can measure strain distribution occurring on a road surface with high precision. <P>SOLUTION: The apparatus 1 has a sensor section 6. The sensor section 6 is configured by fixing a gauge base 4 to which a resistive strain gauge 3 (or a strain-sensitive section) is fixed to the backside of a flexible substrate 2 and fixing a sheet insulating member 5 to the front side of the flexible substrate 2. The flexible substrate 2 is provided with a thin film conductor 18 which electrically communicates with a wire connecting section 14a out of wire connecting sections (tabs) 14a, 14b on the both sides of the strain-sensitive section of each resistive gauge 3 and thin film conductors 19, 20 which electrically communicate with the wire connecting section 14b. The gauge base 4 of the sensor section 6 is fixed to the road surface so that the strain gauge 3 is positioned on the wheel grounded area out of the road surface and that end sections 18b, 19b, 20b of the thin film conductors 18, 19, 20 are positioned on an area which deviates from the grounded area in the wheel width direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an apparatus for measuring strain on a road surface on which a moving body having wheels such as an automobile and an aircraft travels.

  2. Description of the Related Art In recent years, tires with high contact pressure and tires with reinforced sidewalls are frequently used for wheels of automobiles and airplanes as the size of the vehicle body or body increases. And, road surfaces such as asphalt pavement that travels moving bodies using such tires are susceptible to damage because large strains are generated, and the strain distribution generated on the road surface for maintenance and management of the road surface, etc. It is desired to accurately measure

  In this case, it is conceivable to attach a plurality of resistance strain gauges (hereinafter sometimes simply referred to as strain gauges) to the ground contact area of the wheel on the road surface (the area where the wheel can be grounded).

  However, since individual strain gauges are very small compared to the ground contact area of the wheel, a large number of strain gauges are required to properly measure the distribution of strain generated on the road surface. It is necessary to wire a large number of lead wires for connecting the gauge to the measuring device (multi-point measuring device) so as to cross the grounding region of the wheel in the width direction of the wheel. In addition, strain measurement using a strain gauge is generally performed by a one-gauge three-wire method in which three lead wires are connected to one strain gauge in order to compensate for the influence of changes in the resistance value of the lead wires. In such a case, the number of lead wires that is three times the number of strain gauges fixed to the road surface is required. Furthermore, it is difficult to arrange these many leads uniformly on the road surface.

  For this reason, when a large number of strain gauges are attached to the road surface and the strain distribution of the road surface is to be measured, the bundle of lead wires connected to these strain gauges is partially bulky in the ground contact area of the wheel. It will be expensive. In such a case, it has been confirmed by experiments of the present inventor that the lead wire is likely to be disconnected when the tire of the traveling vehicle wheel is grounded on the bundle of the lead wires. It was.

  The reason is considered as follows. That is, when a wheel tire comes in contact with the bundle of lead wires, each lead wire receives a tensile force and a compressive force accompanying elastic deformation of the tire. More specifically, the lead wire receives a tensile force in the width direction of the wheel at a contact portion of the bundle of lead wires with the tire, and the lead wire receives a compressive force in the width direction of the wheel at the groove portion on the outer peripheral surface of the tire. Further, since the bundle of lead wires is bulky, the ground load received from the wheel is locally concentrated on the bundle of lead wires, and as a result, the above-described tensile force and compressive force tend to be locally large. As a result, it is considered that the bundle of lead wires is likely to be deformed when the wheel tire is grounded, and consequently the lead wires are likely to be disconnected.

  Therefore, in order to appropriately measure the strain distribution on the road surface while avoiding such inconvenience, it is desirable to adopt a structure that is as flat and thin as possible in the ground contact area of the wheel.

  On the other hand, for example, as seen in FIG. 5 or FIG. 6 of Patent Document 1, on a single sheet-like gauge base, a plurality of strain sensitive portions and a thin-film wiring pattern connected to both ends of each strain sensitive portion There is known a strain gauge that is integrally formed by photoetching or the like. In such a strain gauge, a plurality of strain sensing parts and a thin film-like wiring pattern connected to the plurality of strain sensitive parts are integrally formed on one gauge base, so that the strain gauge is flat and thin.

  Therefore, it is conceivable to attach such a strain gauge to the grounding area of the wheel so that no lead wire is wired in the grounding area.

However, in the strain gauge found in Patent Document 1, the wiring patterns connected to both ends of each strain sensing part are integrally formed of the same material as the strain sensing part that is a resistance element. And, since the ground contact area of the wheel on the road surface is an area having a larger width than each strain sensing part, if a wiring pattern is formed on the gauge base so as to cross the ground contact area, individual contact areas are obtained. The variation width of the length of the wiring pattern for each strain sensing part becomes large, and as a result, the variation of the resistance value of these wiring patterns becomes large. As a result, the substantial gauge factor or sensitivity of each individual strain sensing unit varies relatively, and it becomes difficult to accurately measure the strain distribution on the road surface.
JP 2003-97906 A

  The present invention has been made in view of such a background, and an object thereof is to provide a strain measuring device that can measure a strain distribution generated on a road surface with high accuracy with a structure that is not easily damaged in a ground contact region of a wheel. To do.

  In order to achieve this object, the road surface strain measuring device of the present invention has four basic modes. The first aspect is a strain measuring device for measuring strain on a road surface that grounds a traveling wheel of a moving object, and includes a front surface and a rear surface of a sheet-like gauge base (both surfaces in the thickness direction of the gauge base). A single layer fixed to the one surface of the gauge base with a plurality of resistance strain gauges fixed to one surface of the gauge base and the plurality of resistance strain gauges interposed between the gauge base and A sensor structure comprising: a multilayer flexible substrate; and a plurality of thin film conductors provided at the flexible substrate and having one end connected to a conductive wire connecting portion of each resistance strain gauge. The plurality of resistance strain gauges are located in the ground contact area of the wheel on the road surface, and the strain on the road surface is transmitted to each resistance strain gauge via the gauge base. As described above, the gauge base is interposed between the road surface and the flexible substrate, and the thin film conductors are fixed to the road surface. It is provided on the flexible substrate so as to be located in a region deviating in the direction, and the other end is exposed so that wiring can be connected (first invention).

  According to the first invention, the sensor structure has a structure in which a plurality of strain gauges are sandwiched between a sheet-like gauge base and a flexible substrate (so-called FPC substrate (flexible printed circuit board)). Therefore, it becomes a thin flat plate as a whole. Then, the sensor structure unit is configured such that the plurality of resistance strain gauges are positioned in a ground contact area of the wheel on the road surface, and the gauge base is interposed between the road surface and the flexible substrate. Since it is fixed to the road surface, the strain generated on the road surface in the ground contact area of the wheel is transmitted to each resistance type strain gauge via the gauge base. As a result, a strain corresponding to the strain generated on the road surface is generated in each resistance type strain gauge, and the resistance of the strain sensitive part of the resistance type strain gauge (resistance element whose resistance value changes according to the strain). A value change will occur. The gauge base is used as a base of a general resistance-type strain gauge (a base to which a resistance element serving as a strain sensing part is fixed), and one of the front and back surfaces of the gauge base. When the surface is fixed to the object, the strain generated on the surface of the object is transmitted to the other surface side of the gauge base.

  In this case, since the other end portions of the plurality of thin film conductors whose one end portions are electrically connected to the conductive wire connecting portions of the respective resistance strain gauges are exposed, lead wires or the like are connected to the other end portions of the respective thin film conductors. Wiring can be connected, and by connecting each resistance type strain gauge to the measuring instrument via the wiring, the strain generated in each resistance type strain gauge, and consequently, on the road surface immediately below the resistance type strain gauge. The strain can be measured in the same way as general strain measurement. Further, in this case, since the other end of each thin film conductor is located in a region deviating from the grounding region of the wheel in the width direction of the wheel, a bundle of wires connected to the other end of each thin film conductor is formed. The wheel never touches the ground. Therefore, a situation in which the wiring is disconnected due to contact with the wheel is prevented. In addition, since the sensor structure in the ground contact area of the wheel is a thin flat plate, the ground contact surface is relatively wide even if the wheel of the moving moving object is grounded. The situation where the force received from the wheels is concentrated locally is prevented. As a result, it is possible to prevent the sensor structure from being damaged when the wheel is grounded.

  In addition, since each of the thin film conductors is a conductor (for example, a conductor such as copper, gold, silver, or aluminum) whose specific resistance is sufficiently smaller than that of the strain sensitive part of the resistance strain gauge, Each resistance value and its variation width are very small. For this reason, the substantial gauge factor or sensitivity for each resistance type strain gauge can be made substantially uniform. As a result, it is possible to accurately measure the change in the resistance value of the strain sensing part of each resistance type strain gauge, and hence the strain generated on the road surface immediately below the resistance type strain gauge.

  Therefore, according to the first aspect of the present invention, it is possible to accurately measure the strain distribution generated on the road surface with a structure that is not easily damaged in the ground contact area of the wheel.

  The resistance strain gauge according to the first aspect of the present invention is such that a resistance element whose resistance value changes according to strain is fixed to one of the front and back surfaces of the gauge base smaller than the gauge base by photoetching or the like. In general, a commercially available resistance strain gauge can be used. The same applies to the third invention described later.

  Moreover, the second aspect of the road surface strain measuring device of the present invention is a strain measuring device for measuring the road surface strain for grounding the traveling wheel of the moving body, and the front and back surfaces of the sheet-like gauge base ( A plurality of resistance-type strain-sensitive parts fixed to one surface of the gauge base and the plurality of resistance-type strain-sensitive parts interposed between the gauge base and the gauge base. A single-layer or multi-layer flexible substrate fixed to the one surface of the gauge base, and a plurality of thin films provided on the flexible substrate, each of which is electrically connected to the conductive wire connection portion of each resistance strain sensing portion A plurality of resistance-type strain sensing parts are located in the ground contact area of the wheel on the road surface, and the strain on the road surface is the sensor structure part. Through the gauge base The plurality of thin-film conductors are connected to the other end portions of the plurality of thin film conductors so as to be transmitted to each resistance strain sensing portion with the gauge base interposed between the road surface and the flexible substrate. Is provided on the flexible substrate so as to be located in a region deviating from the ground contact region of the wheel in the width direction of the wheel, and the other end portion is exposed so that wiring can be connected. (Second invention).

  According to the second aspect of the present invention, the sensor structure portion sandwiches a plurality of resistance type strain sensing portions (resistance elements whose resistance values change according to strain) between the sheet-like gauge base and the flexible substrate. Since it has such a structure, it becomes a thin flat plate as a whole like the first invention. And this sensor structure part has these resistance type strain sensing parts located in the ground contact area of the wheel in the road surface, and interposes the gauge base between the road surface and the flexible substrate. Therefore, the strain generated on the road surface in the ground contact area of the wheel is transmitted to each resistance type strain sensing part via the gauge base. As a result, a strain corresponding to the strain generated on the road surface is generated in each resistance-type strain-sensitive portion, and the resistance value of the resistance-type strain-sensitive portion is changed.

  In this case, since the other end portions of the plurality of thin-film conductors whose one end portions are electrically connected to the conductive wire connecting portions of the resistance-type strain sensing portions are exposed, Each resistance type strain sensitive part can be connected to a measuring instrument via wiring, and by extension, the strain generated on the road surface immediately below each resistance type strain sensitive part can be measured. Further, in this case, since the other end of each thin film conductor is located in a region deviating from the wheel ground region in the width direction of the wheel, a bundle of wires connected to the other end of each thin film conductor. The wheel never touches the ground. Therefore, a situation in which the wiring is disconnected due to contact with the wheel is prevented. Further, since the sensor structure in the ground contact area of the wheel is a thin flat plate, it is possible to prevent the sensor structure from being damaged when the wheel is grounded, as in the first invention.

  Further, each of the thin film conductors has a small resistance value and its variation width, as in the first invention, so that the change in the resistance value of the strain sensing part of each resistance strain gauge, Strain generated on the road surface directly under the resistance strain gauge can be measured with high accuracy.

  Therefore, according to the second aspect of the present invention, it is possible to accurately measure the strain distribution generated on the road surface with a structure that is not easily damaged in the ground contact area of the wheel.

  Further, a third aspect of the road surface strain measuring device of the present invention is a strain measuring device for measuring road surface strain for grounding a traveling wheel of a moving body, and a single-layer or multi-layer flexible substrate, A plurality of resistance strain gauges fixed to one of the front surface and the back surface of the flexible substrate, and a plurality of resistance strain gauges provided on the flexible substrate, each of which is electrically connected to a conductive wire connecting portion of each resistance strain gauge. A thin film conductor and a sheet structure insulating member fixed to one surface of the flexible substrate so as to cover one surface of the flexible substrate and the plurality of strain gauges, In the sensor structure, the plurality of resistance-type strain gauges are located in a ground contact area of the wheel on the road surface, and the strain on the road surface passes through the flexible substrate. The flexible substrate is interposed between the road surface and the sheet-like insulating member so as to be transmitted to a resistance strain gauge, and is fixed to the road surface. It is provided in the flexible substrate so as to be located in a region deviating from the wheel ground contact region in the width direction of the wheel, and the other end portion is exposed so that wiring can be connected ( Third invention).

  According to the third invention, the sensor structure has a structure in which a plurality of resistance strain gauges are sandwiched between the sheet-like insulating member and the flexible substrate. It will be a thin flat plate. And this sensor structure part has these resistance type strain gauges located in the earthing | grounding area | region of the said wheel among the said road surfaces, and interposes the said flexible substrate between this road surface and the said sheet-like insulating member. Thus, the strain generated on the road surface in the ground contact area of the wheel is transmitted to each resistance strain gauge via the flexible substrate. As a result, a strain corresponding to the strain generated on the road surface is generated in the resistance strain gauge, and the resistance value of the strain sensing part of the resistance strain gauge is changed. The flexible substrate generally has a function of transmitting strain in the same manner as the gauge base.

  In this case, since the other end portions of the plurality of thin film conductors whose one end portions are electrically connected to the conductive wire connecting portions of the respective resistance strain gauges are exposed, as in the first invention, wiring such as a lead wire is provided. Each resistance strain gauge can be connected to a measuring instrument, and consequently the strain generated on the road surface immediately below each resistance strain gauge can be measured. Further, in this case, since the other end of each thin film conductor is located in a region deviating from the wheel ground region in the width direction of the wheel, a bundle of wires connected to the other end of each thin film conductor. The wheel never touches the ground. Therefore, a situation in which the wiring is disconnected due to contact with the wheel is prevented. Further, since the sensor structure in the ground contact area of the wheel is a thin flat plate, it is possible to prevent the sensor structure from being damaged when the wheel is grounded, as in the first invention.

  Further, each of the thin film conductors has a small resistance value and its variation width, as in the first invention, so that the change in the resistance value of the strain sensing part of each resistance strain gauge, Strain generated on the road surface directly under the resistance strain gauge can be measured with high accuracy.

  Therefore, according to the third aspect of the present invention, the strain distribution generated on the road surface can be accurately measured with a structure that is not easily damaged in the ground contact area of the wheel.

  According to a fourth aspect of the road surface strain measuring apparatus of the present invention, there is provided a strain measuring apparatus for measuring road surface strain for grounding a traveling wheel of a mobile body, and comprising a front surface and a rear surface of a sheet-like insulating member. The one surface of the sheet-like insulating member by interposing the plurality of resistance-type strain-sensitive portions between the plurality of resistance-type strain-sensitive portions fixed to one surface of the sheet and the sheet-like insulating member And a single-layer or multi-layer flexible substrate fixed to the plurality of resistance-type strain gauges, and a plurality of one-side conductive portions provided on the flexible substrate, each of which is electrically connected to the conductive wire connecting portion of each resistance-type strain sensing portion. A sensor structure comprising a thin film conductor, wherein the plurality of resistance strain sensitive parts are located in a ground contact area of the wheel on the road surface, and the road surface has a strain. Flexible substrate Via the flexible substrate interposed between the road surface and the sheet-like insulating member, and the plurality of thin-film conductors are respectively The other end of the wheel is provided in the flexible substrate so as to be located in a region deviating from the wheel contact area in the width direction of the wheel, and the other end is exposed so that wiring can be connected. (4th invention).

  According to the fourth invention, the sensor structure has a structure in which a plurality of resistance strain sensitive parts are sandwiched between the sheet-like gauge base and the flexible substrate. Similarly, it becomes a thin flat plate as a whole. And this sensor structure part positions the said flexible substrate between the said road surface and the said sheet-like insulating member, and the said some resistance type strain sensing part is located in the earthing | grounding area | region of the said wheel among the said road surfaces. Since it is interposed and fixed to the road surface, the strain generated on the road surface in the ground contact area of the wheel is transmitted to each resistance type strain sensing part via the flexible substrate, as in the third invention. As a result, a strain corresponding to the strain generated on the road surface is generated in the resistance-type strain-sensitive portion, and the resistance value of the resistance-type strain-sensitive portion is changed.

  In this case, since the other end portions of the plurality of thin-film conductors whose one end portions are electrically connected to the conductive wire connecting portions of the resistance-type strain sensing portions are exposed, Each resistance type strain sensitive part can be connected to a measuring instrument via wiring, and by extension, the strain generated on the road surface immediately below each resistance type strain sensitive part can be measured. Further, in this case, since the other end of each thin film conductor is located in a region deviating from the wheel ground region in the width direction of the wheel, a bundle of wires connected to the other end of each thin film conductor. The wheel never touches the ground. Therefore, a situation in which the wiring is disconnected due to contact with the wheel is prevented. Further, since the sensor structure in the ground contact area of the wheel is a thin flat plate, it is possible to prevent the sensor structure from being damaged when the wheel is grounded, as in the first invention.

  In addition, since each thin film conductor has a small resistance value and its variation width, as in the first invention, the resistance value change of each resistance type strain sensing part, and hence the resistance type strain. It is possible to accurately measure the strain generated on the road surface immediately below the sensing part.

  Therefore, according to the fourth aspect of the invention, it is possible to accurately measure the strain distribution generated on the road surface with a structure that is not easily damaged in the ground contact area of the wheel.

  Supplementally, the sheet-like insulating member in the third invention or the fourth invention may be a gauge base, but may be a soft film having poor strain transmission.

  In the first invention or the second invention, the sensor structure section may further include a sheet-like insulating member fixed to a surface opposite to the surface on the gauge base side among the front surface and the back surface of the flexible substrate. You may make it (5th invention).

  According to the fifth aspect of the invention, even if any thin film conductor is provided on the opposite surface of the flexible substrate, the thin film conductor can be prevented from being damaged or insulated. Can be secured.

  In the third or fourth aspect of the invention, the sensor structure portion includes a sheet-like gauge base fixed to a surface opposite to the surface on the sheet-like member side of the front and back surfaces of the flexible substrate. You may make it provide further (6th invention).

  According to the sixth aspect of the invention, since the flexible substrate is fixed to the road surface via the gauge base, the strain generated on the road surface is each resistance type strain gauge or each resistance type via the gauge base and the flexible substrate. It is transmitted to the strain sensing part. In this case, even if any thin film conductor is provided on the opposite surface of the flexible substrate, damage to the thin film conductor is prevented or insulation is ensured. Can do.

  In the first to fourth aspects of the invention, the strain sensitive part of each resistance strain gauge or the resistance value change of each resistive strain sensitive part (and hence the strain on the road surface) is measured, for example, by the strain sensitive part. This can be done using a Wheatstone bridge circuit built into the edge. In this case, in the first invention or the third invention, the thin film conductor to be conducted to the conductor connection portion of each resistance strain gauge is a conductor provided at one end of the strain sensing portion of each resistance strain gauge. It consists of the 1st thin film-like conductor connected to a connection part, and the 2nd thin film-like conductor and 3rd thin film-like conductor connected to the conducting wire connection part provided in the other end part of this distortion | strain sensitive part. Desirable (seventh invention).

  Similarly, in the second or fourth aspect of the invention, the thin film conductor that is conducted to each of the resistance strain sensitive parts is conducted to a conductor connecting portion provided at one end of each resistance type strain sensitive part. It is desirable to comprise a first thin film conductor and a second thin film conductor and a third thin film conductor that are electrically connected to a conductive wire connecting portion provided at the other end of the resistance-type strain sensing portion. 8 invention).

  According to these seventh and eighth inventions, three thin film conductors are conducted to the strain sensitive part of each resistance type strain gauge, or to each resistance type strain sensitive part. It is possible to measure strain by the 1-gauge 3-wire method, change in resistance value of each thin film conductor due to changes in environmental temperature, and change in resistance value of wiring connected to the other end of each thin film conductor Therefore, it is possible to perform accurate strain measurement.

  As described above, when the first to third thin film conductors are provided for each resistance strain gauge or for each resistance strain sensing part, the first to third to the flexible substrate. Various ways of providing the thin film conductor are conceivable. For example, the first to third thin film conductors are preferably provided on the flexible substrate in the following manner.

  That is, the flexible substrate is a two-layer flexible substrate obtained by polymerizing the first layer substrate and the second layer substrate, and the first to third thin film conductors corresponding to the respective resistance strain gauges. The first thin film conductor is formed on the surface of the first layer substrate on the opposite side of the surface of the first layer substrate and the second layer substrate side, and the second thin film conductor and the third thin film are formed. And the second thin film conductor and the third thin film conductor are respectively formed on the front surface and the back surface of the second layer substrate so as to face each other through the second layer substrate. It is preferable that conduction is made through a conductor member provided in a through hole formed in the flexible substrate so as to penetrate through the respective one end portions in the thickness direction of the flexible substrate (Ninth Invention). .

  According to the ninth aspect of the invention, since the first layer substrate is interposed between the first thin film conductor and the second thin film conductor, the first thin film conductor and the second thin film conductor are interposed. The thin-film conductors are formed on the first-layer substrate in a pattern that causes partial overlap with the thin-film conductors in the thickness direction of the first-layer substrate (thickness direction of the flexible substrate). Insulation between them can be secured. Further, since the third thin film conductor faces the second thin film conductor via the second layer substrate, the third thin film conductor overlaps in the thickness direction of the second layer substrate (thickness direction of the flexible substrate). The insulation between those thin film conductors can be ensured. For this reason, the area of the flexible substrate (area seen in the thickness direction) can be kept to a minimum while ensuring the insulating properties of the first to third thin film conductors. It can be kept to the minimum necessary. As a result, it is possible to reduce the material cost of the sensor structure, and consequently the manufacturing cost. At the same time, the second thin film conductor and the third thin film conductor are opposed to each other, and the second thin film conductor and the third thin film conductor are formed by the conductor member provided in the through hole passing through one end of the second thin film conductor and the third thin film conductor. Conductivity with the conductor can be easily secured. Examples of the conductor member include metal plating applied to the inner peripheral surface of the through hole, solder filled in the through hole, and the like.

  In the first invention or the third invention, the sensor structure portion is provided with a plurality of through holes penetrating in the thickness direction of the sensor structure portion while avoiding the resistance strain gauges and the thin film conductors. It is preferable to be provided (10th invention). Similarly, in the second invention or the fourth invention, the sensor structure part includes a plurality of penetrations that penetrate in the thickness direction of the sensor structure part while avoiding the resistance strain sensitive parts and the thin film conductors. It is preferable that a hole is formed (11th invention).

  According to these tenth or eleventh inventions, when the sensor structure is fixed to the road surface with an adhesive, the adhesive can enter each through-hole and be mixed into the adhesive. Bubbles can be passed through the through-hole, so that it is possible to prevent a situation in which a local adhesive reservoir or a bubble remains locally between the sensor structure and the road surface. . As a result, the road surface side surface of both surfaces in the thickness direction of the sensor structure can be uniformly fixed to the road surface.

[First Embodiment]
A first embodiment of the present invention will be described with reference to FIGS. 1 is a plan view of the surface side of the sensor structure 6 of the road surface strain measuring device 1 according to the present embodiment, FIG. 2 is a view taken along the arrow II in FIG. 1, and FIG. 3 is a second view of the flexible substrate 2 of the sensor structure 6. 4 is a plan view of the back side of the sensor structure 6, FIG. 5 is an exploded perspective view of a part of the sensor structure 6, and FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. FIG. 7 is a graph showing a measurement example of the road surface strain distribution by the strain measuring device 1 of the present embodiment. This embodiment is an embodiment of the first invention.

  The strain measuring apparatus 1 according to the present embodiment includes a flexible substrate 2, a plurality of resistance strain gauges 3 (hereinafter simply referred to as strain gauges 3), a sheet-like gauge base 4, and a cover film 5. 6 is provided. The entire sensor structure 6 is generally formed in a thin rectangular plate shape, and is fixed to the road surface A with its thickness direction directed vertically as shown in FIG. The road surface A is a road surface on which a moving body (not shown) having traveling wheels such as an automobile and an aircraft travels. In FIG. 2, the sensor structure 6 is shown thick for convenience of illustration and explanation, but the thickness is actually about 0.2 mm. Moreover, the moving direction of the moving body on the road surface A is a direction perpendicular to the paper surface of FIG. 2 (extending direction of two two-dot chain lines shown in FIG. 1).

  The flexible board 2 is a so-called FPC board (flexible printed board). In the present embodiment, the flexible substrate 2 is a multi-layer substrate, and a rectangular first layer substrate 7 and a rectangular second layer substrate 8 are polymerized in the thickness direction between them, The two substrates 7 and 8 are bonded to each other (fixed) with an adhesive 9 (see FIG. 2) interposed therebetween. In this case, the dimension of the second layer substrate 8 in the lateral direction (left and right direction in FIG. 1 and FIG. 2) is slightly larger than the dimension of the first layer substrate 7 in the lateral direction. One side 8a (the left side in FIGS. 1 and 2) of the substrate 8 protrudes from the side edge (the left side edge in FIG. 1) of the first layer substrate 7. Hereinafter, the one side portion 8a of the second layer substrate 8 protruding in this way is referred to as the protruding portion 8a.

  The first layer substrate 7 and the second layer substrate 8 are thin film sheets made of an insulating material such as polyester (PET), polyimide amide (AI), polyphenylene sulfide (PPS), polyether ether ketone (PEEK). The substrate is flexible.

  Supplementally, when the first layer substrate 7 and the second layer substrate 8 are made of a material having a thermoplastic polyimide as a base material, the flexible substrates can be obtained by bonding the substrates 7 and 8 together by thermal fusion. 2 can also be configured. In that case, the adhesive 9 is unnecessary.

  In the following description of the present embodiment, of the both surfaces in the thickness direction of the first layer substrate 7, the surface on the second layer substrate 8 side is the back surface of the first layer substrate 7, and the opposite surface is the first layer. It is defined as the surface of the substrate 7 or the surface of the flexible substrate 2. Of the two layers in the thickness direction of the second layer substrate 8, the surface on the first layer substrate 7 side is the surface of the second layer substrate 8, and the opposite surface is the back surface of the second layer substrate 8 or the flexible substrate. 2 is defined as the back side.

  As shown in FIGS. 1 and 2, a rectangular cover film 5 is fixed to the surface of the first layer substrate 7 (the surface of the flexible substrate 2) so as to cover the surface. However, the cover film 5 is not fixed to the side portion of the surface of the first layer substrate 7 on the side of the overhanging portion 8a of the second layer substrate 8 (the left side portion in FIGS. 1 and 2). The surface of is exposed. The cover film 5 is a film made of an insulating material such as polyester (PET), polyimide (PA), polyimide amide (AI), polyphenylene sulfide (PPS), polyether ether ketone (PEEK). This cover film 5 functions as a sheet-like insulating member in the fifth invention, and ensures the insulation of a plurality of thin film conductors 18 to be described later fixed to the surface of the first layer substrate 7, It has a function of protecting the thin film conductor 18. In the present embodiment, the cover film 5 is fixed to the surface of the first layer substrate 7 by an adhesive 10 (see FIG. 2) interposed between the cover film 5 and the surface of the first layer substrate 7.

  Supplementally, when the cover film 5 is made of a material having heat-fusibility, the cover film 5 may be fixed to the first layer substrate 7 by heat-sealing. In that case, the adhesive 10 is unnecessary.

  As shown in FIGS. 2 and 4, a square gauge base 4 is fixed to the back surface of the second layer substrate 8 (the back surface of the flexible substrate 2) so as to cover the back surface. However, of the back surface of the second layer substrate 8, the gauge base 4 is not fixed to the protruding portion 8a, and the back surface of the protruding portion 8a is exposed. This gauge base 4 generally functions as a base for fixing a strain sensitive part (resistive element) of a resistance type strain gauge (a base for transmitting strain of a measurement object to the strain sensitive part). It is formed in the shape of a thin film sheet made of a material such as epoxy. The gauge base 4 is fixed to the back surface of the second layer substrate 8 with an adhesive 11 (see FIG. 2) interposed between the gauge base 4 and the back surface of the second layer substrate 8.

  In this case, among the both surfaces of the gauge base 4 in the thickness direction, the plurality of strain gauges 3 are fixed in advance with an adhesive (not shown) on the surface on the second layer substrate 8 side (hereinafter referred to as the surface of the gauge base 4). These strain gauges 3 are arranged in a grid between the gauge base 4 and the second layer substrate 8.

  Each strain gauge 3 is generally commercially available as a single resistance strain gauge. As shown in FIG. 5, a Cu-Ni alloy or a Ni-Cr alloy is formed on a small area square gauge base 12. The strain sensing part 13 which is a resistance element made of such a material is fixed by photoetching or the like. Tabs 14 a and 14 b as conductor connection portions are formed integrally with the strain sensitive portion 13 at both ends of the strain sensitive portion 13. In the present embodiment, one gauge lead 15a, 15b is connected in advance to each tab 14a, 14b. These gauge leads 15a and 15b are sufficiently thin conductors.

  Photoetching or printing on the surface of the first layer substrate 7, the surface of the second layer substrate 8, and the back surface of the second layer substrate 8 of the flexible substrate 2, as shown in FIGS. 1, 3, and 4, respectively. A plurality of thin film conductors 18, 19, and 20 are fixed to each other. 1, 3, and 4, for convenience of illustration, the thin film conductors 18, 19, and 20 are indicated by thin lines except for both ends.

  The number of these thin film conductors 18, 19, 20 is the same as the number of the strain gauges 3, and one thin film conductor 18, 19, 20 is associated with each strain gauge 3. . Further, the material of these thin film conductors 18, 19, and 20 is made of copper (Cu), silver (Ag), gold (Au), aluminum (Al), or the like, more specific resistance than the strain sensitive part 13 of the strain gauge 3. Is a sufficiently small conductor.

  The thin film conductors 18, 19, and 20 correspond to the first thin film conductor, the second thin film conductor, and the third thin film conductor, respectively, in the present invention.

  Each thin film conductor 18 shown in FIG. 1 has one end 18 a provided in the vicinity of the tab 14 a of the strain gauge 3 corresponding to the thin film conductor 18, and the other end 18 b is the surface of the first layer substrate 7. Of the second layer substrate 8 is provided on the side of the protruding portion 8a side (the portion not covered with the cover film 5) and exposed. Each thin film-like conductor 18 is provided so as to extend on the surface of the first layer substrate 7 between both end portions 18a, 18b. The end portions 18b of the thin film conductors 18 are arranged at substantially equal intervals in the longitudinal direction of the first substrate 7 (vertical direction in FIG. 1).

  Each thin film conductor 19 shown in FIG. 3 has one end 19 a provided in the vicinity of the tab 14 b of the strain gauge 3 corresponding to the thin film conductor 19 and the other end 19 b on the surface of the second layer substrate 8. It is provided in the overhanging portion 8a and is exposed. Each thin-film conductor 19 is provided so as to extend on the surface of the second layer substrate 8 between both end portions 19a and 19b. Further, the end portions 19b of the thin film conductors 19 are arranged at substantially equal intervals in the vertical direction of the second substrate 8 (vertical direction in FIG. 1). Since the first layer substrate 7 is interposed between the thin film conductor 18 and the thin film conductor 19, they are insulated from each other. Therefore, in the present embodiment, when these thin film conductors 18 and 19 are viewed in the thickness direction of the flexible substrate 2, the intermediate portions except for both ends thereof overlap in a single line shape (the thin film conductor 19 is The thin film conductors 18 and 19 are provided so as to exist under the thin film conductor 18).

  Each thin-film conductor 20 shown in FIG. 4 has one end 20a provided near the tab 14b of the strain gauge 3 corresponding to the thin-film conductor 20 and the other end 20b. Is provided on the overhanging portion 8a of the back surface of the second layer substrate 8, and is exposed. Each thin film conductor 20 is provided so as to extend on the back surface of the second layer substrate 8 between both end portions 20a and 20b. In this case, the thin film conductors 19 and 20 corresponding to the same strain gauge 3 are provided so as to face each other through the second layer substrate 8 over the entire length thereof. Therefore, when these thin film conductors 19 and 20 are viewed in the thickness direction of the flexible substrate 2, the thin film conductors 19 and 20 corresponding to the same strain gauge 3 overlap each other. Accordingly, the intermediate portions of the three thin film conductors 18, 19, 20 for each strain gauge 3 overlap each other in a single line shape when viewed in the thickness direction of the flexible substrate 2.

  The thin film conductors 18, 19, and 20 are electrically connected to the corresponding tabs 14a and 14b of the strain gauge 3 as follows. In other words, in the present embodiment, the flexible substrate 2 is opposed to the through-hole 21 that passes through the one end portion 18a of each thin film conductor 18 in the thickness direction of the flexible substrate 2 as shown in FIG. A through hole 22 that penetrates in the thickness direction of the flexible substrate 2 is formed through the respective one end portions 19 a and 20 a of the thin film conductors 19 and 20. The through-hole 21 is filled with a solder lead (not shown) while a gauge lead 15a connected to the tab 14a of the strain gauge 3 is inserted from the back side of the flexible substrate 2, and the gauge lead 15a is filled with the solder. And the thin film conductor 18 are electrically connected. As a result, the tab 14 a of each strain gauge 3 is electrically connected to the thin film conductor 18 corresponding to the strain gauge 3.

  Further, as shown in FIG. 6, a gauge lead 15 b connected to the tab 14 b of the strain gauge 3 is inserted into the through hole 22 from the back side of the flexible substrate 2 and filled with solder 23. Thus, the gauge lead 15b and the thin film conductors 19 and 20 are electrically connected. As a result, the tab 14 b of each strain gauge 3 is electrically connected to the thin film conductors 19 and 20 corresponding to the strain gauge 3. The solder 23 corresponds to the conductor member in the ninth invention.

  Therefore, in this embodiment, only one thin film conductor 18 is conducted to the tab 14a of each strain gauge 3, while two thin film conductors 19 and 20 are conducted to the tab 14b. The reason why the two thin-film conductors 19 and 20 are electrically connected to the tab 14b is to measure the strain of each strain gauge 3 by the 1-gauge 3-wire method.

  In the present embodiment, the sensor structure 6 is provided with a plurality of through holes 24 penetrating in the thickness direction. These through holes 24 are formed at positions where the respective strain gauges 3 and the respective thin film conductors 18, 19, 20 are avoided (positions where the respective strain gauges 3 and the respective thin film conductors 18, 19, 20 do not exist). .

  The above is the structure of the sensor structure 6. As the adhesives 9, 10, and 11, an epoxy adhesive, a phenol adhesive, a polyimide adhesive, or the like may be used.

  When the strain on the road surface A is measured by the strain measuring apparatus 1 according to the present embodiment, as shown in FIG. 2, the back surface of the gauge base 4 of the sensor structure 6 (the flexible surface of both surfaces in the thickness direction of the gauge base 4 is flexible). The surface opposite to the substrate 2 side) is made to face the road surface A, and the sensor structure 6 is fixed to the road surface A by the adhesive B interposed between the gauge base 4 and the road surface A. That is, the sensor structure 6 is fixed to the road surface A so that the gauge base 4 is interposed between the flexible substrate 2 and the road surface A. At this time, since a plurality of through holes 24 are formed in the sensor structure 6, a reservoir of the adhesive B is locally formed between the sensor structure 6 and the road surface A or locally. The situation where bubbles remain is prevented. The type of the adhesive B may be the same as that of the adhesives 9, 10, and 11.

  By fixing the sensor structure portion 6 to the road surface A in this way, the strain generated on the road surface A at a location immediately below each strain gauge 3 is transmitted to the strain gauge 3 via the gauge base 4 and the gauge base 12 of the strain gauge 3. The resistance value of the strain sensing unit 13 is changed according to the strain.

  Here, in the present embodiment, the grounding area of the wheel of the moving body (the area where the wheel can be grounded when the moving body travels) in the road surface A is, for example, two two-dot chain lines shown in FIG. It is an area between. When the sensor structure 6 is fixed to the road surface A, a plurality of (14 in this embodiment) strain gauges 3 provided in the sensor structure 6 are located in the ground contact area of the wheel and are flexible. The other end portions 18b, 19b, and 20b of the thin film conductors 18, 19, and 20 of the substrate 2 are all located in a region that deviates from the grounding region in the width direction of the wheel (interval direction of the two-dot chain line shown in FIG. 1). Thus, the sensor structure 6 is fixed to the road surface A. Accordingly, the sensor structure 6 is fixed to the road surface A so that the wheels of the moving body do not come into contact with the ends 18b, 19b, 20b of the thin film conductors 18, 19, 20, respectively.

  Then, lead wires (not shown) are connected to the end portions 18b, 19b, 20b of the respective thin film conductors 18, 19, 20 by soldering or the like, and these lead wires serve as measuring instruments (not shown). Connected. Further, for each strain gauge 3, the strain generated on the road surface A immediately below the strain gauge 3 is measured by the measuring instrument by the 1 gauge 3-wire method. Thereby, the strain distribution on the road surface A in the ground contact area of the wheel is measured.

  In this case, the other end portions 18b, 19b, 20b of the respective film-like conductor portions 18, 19, 20 that connect the lead wires deviate from the grounding region of the wheel. It can be wired so that it does not pass. For this reason, even if the wheel is grounded to the sensor structure 6 within the grounding area of the wheel, the wheel is grounded to the lead wire connected to the end portions 18b, 19b, and 20b of the respective film-like conductor portions 18, 19, and 20. Therefore, disconnection of the lead wire can be prevented.

  Further, the sensor structure 6 in the wheel contact area is a sufficiently thin flat plate. Furthermore, the sensor structure 6 can be uniformly adhered to the road surface A over substantially the entire back surface (the back surface of the gauge base 4). For this reason, even if a wheel contacts the sensor structure 6, the force acting on the sensor structure 6 from the wheel concentrates locally on the sensor structure 6, and the sensor structure 6 is damaged, It is possible to prevent a situation in which the sensor structure 6 is bent and the sensor structure 6 is damaged.

  Moreover, since each thin film-like conductor part 18,19,20 is comprised with the conductors whose specific resistance is sufficiently small, such as copper, the dispersion | variation in each resistance value becomes a minute thing. For this reason, the substantial gauge factor or sensitivity can be made substantially equal for each strain gauge 3, and the strain distribution on the road surface A by these strain gauges 3 can be measured with high accuracy.

  FIG. 7 shows an example of the measurement result of the strain distribution. This example is an example of a measurement result of strain distribution when an aircraft wheel is grounded to the sensor structure 6 in the ground contact area. 7 is a coordinate axis indicating the position of the road surface A in the width direction of the wheel, and the Y axis is a coordinate axis indicating the position of the road surface A in the traveling direction of the wheel. In this case, although a maximum ground load of 910 kN acts on the sensor structure 6, the strain distribution generated on the road surface A could be measured without causing inconvenience such as breakage of the sensor structure 6. Even when the vehicle wheel sensor structure 6 is grounded, the strain distribution on the road surface A can be measured without hindrance.

In the sensor structure 6 of the present embodiment, the first layer substrate 7 is interposed between the thin film conductor 18 and the thin film conductor 19, and between the thin film conductor 19 and the thin film conductor 20. Since the second layer substrate 8 is interposed, the thin film conductors 18, 19, and 20 can be overlapped when viewed in the thickness direction of the flexible substrate 3. For this reason, in the present embodiment, as described above, the three thin film conductors 18, 19, 20 for each strain gauge 3 have a single intermediate portion excluding their both ends in the thickness direction of the flexible substrate 2. It is provided so as to overlap linearly. As a result, the area seen in the thickness direction of the flexible substrate 3 can be kept to the minimum necessary. As a result, the area of the sensor structure 6 viewed in the thickness direction can be kept to the minimum necessary, and the material cost of the components of the sensor structure 6 can be reduced. In addition, since the intermediate portions of the thin film conductors 18, 19, and 20 overlap in the thickness direction of the flexible substrate 2, the influence of electromagnetic induction noise caused by the surrounding environment can be reduced.
[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 8 is a plan view showing a gauge base and a strain sensing unit used in the sensor structure 28 of the strain measuring device of this embodiment, and FIG. 9 is a partial cross-sectional view of the sensor structure 28 (cross-sectional view similar to FIG. 6). It is. The strain measuring device according to the present embodiment is different from that of the first embodiment only in a part of the structure of the sensor structure portion 28. Therefore, the difference will be mainly described, and the sensor structure of the first embodiment will be described. The same components as those of the unit 6 are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof is omitted. Moreover, this embodiment is an embodiment of the second invention.

  In the sensor structure section 6 of the first embodiment, a plurality of strain gauges 3 having the gauge base 12 and the strain sensing section 13 are used, and these strain gauges 3 are fixed to the surface of the gauge base 4. On the other hand, in this embodiment, as shown in FIG. 8, a plurality of strain sensitive portions 13 (resistance strain sensitive portions) are directly fixed to the surface of the gauge base 4 by photoetching or the like. I made it. These strain sensing parts 13 are arranged on the surface of the gauge base 4 in the same arrangement as the strain gauges 3 of the sensor structure part 6 of the first embodiment. In addition, one gauge lead 15a, 15b is connected to each of the tabs 14a, 14b at both ends of each strain sensing part 13 in the same manner as the strain gauge 3 of the sensor structure part 6 of the first embodiment. .

  And in the sensor structure part 28 of this embodiment, the gauge base 4 to which the plurality of strain sensing parts 13 are fixed in this way is formed on the back surface of the flexible substrate 2 (the second layer substrate 8) as shown in FIG. The back surface of the flexible substrate 2 is fixed to the back surface of the flexible substrate 2 with an adhesive 11 interposed therebetween. In addition, it corresponds to the conduction form between the tab 14a of each strain sensing part 13 and the thin film conductor 18 corresponding to the strain sensing part 13, and the tab 14b of each strain sensing part 13 and the strain sensing part 13. The conducting mode with the thin film conductors 19 and 20 is exactly the same as in the first embodiment.

  The structure of the sensor structure portion 28 other than that described above is the same as the structure of the sensor structure portion 6 of the first embodiment. And when measuring the strain distribution of the road surface A, the strain sensing part 29 is located in the grounding area | region of a wheel similarly to the sensor structure part 6 of 1st Embodiment, and each thin film-like of the flexible substrate 2 is used. The gauge base 4 of the sensor structure 28 is attached to the road surface A via the adhesive B so that the respective end portions 18b, 19b, 20b of the conductors 18, 19, 20 deviate from the grounding region in the width direction of the wheel. It is fixed. Further, the other end portions 18b, 19b, and 20b of the respective thin film conductors 18, 19, and 20 are connected to a measuring instrument through lead wires (not shown) connected thereto, and in this state, strain distribution is performed. Are measured in the same manner as in the first embodiment.

Also in this embodiment, disconnection of the lead wires connected to the other end portions 18b, 19b, and 20b of the respective thin film conductors 18, 19, and 20 of the flexible substrate 2 and the sensor structure portion 28 in the grounding region of the wheel. It is possible to appropriately measure the strain distribution of the road surface A in the ground contact region without causing damage.
[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIGS. FIG. 10 is an exploded perspective view of a part of the sensor structure 35 of the strain measuring device of the present embodiment (an exploded perspective view similar to FIG. 5), and FIG. 11 is a partial cross-sectional view of the sensor structure 35 (similar to FIG. 6). FIG. The strain measuring device according to the present embodiment differs from that of the first embodiment only in a part of the structure of the sensor structure 35. Therefore, the difference will be mainly described, and the sensor structure of the first embodiment will be described. The same components as those of the unit 6 are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof is omitted. The present embodiment is an embodiment of the third invention.

  In the sensor structure 6 of the first embodiment, a plurality of strain gauges 3 are fixed to the surface of the gauge base 4 on the back side of the flexible substrate 2. On the other hand, in the sensor structure portion 35 of the present embodiment, as shown in FIGS. 10 and 11, each strain gauge 3 is arranged on the surface side of the flexible substrate 2, and the surface of the flexible substrate 2 (first layer substrate). 7) and an adhesive (not shown). 10 and FIG. 11, only one strain gauge 3 is shown, but actually, in the present embodiment (in this embodiment, the same number as the number of strain gauges 3 of the sensor structure section 6 of the first embodiment). ) Is provided in the sensor structure 35. These strain gauges 3 are fixed to the surface of the flexible substrate 2 in the same arrangement as the strain gauges 3 of the sensor structure section 6 of the first embodiment. Further, on the surface of the flexible substrate 2, the thin film conductor 18 (excluding the other end portion 18b) and the strain gauge 3 are interposed between the surface and the adhesive 10 (or by thermal fusion), A cover film 5 as a sheet-like insulating member is fixed, and each strain gauge 3 is covered with the cover film 5.

  Further, one gauge lead 15a, 15b is connected to the tabs 14a, 14b of each strain gauge 3 in the same manner as in the first embodiment. Then, the gauge lead 15a connected to the tab 14a of each strain gauge 3 is inserted from the surface side of the flexible substrate 2 into the through hole 21 passing through the one end portion 18a of the thin film conductor 18 corresponding to the strain gauge 3, The tab 14 a is electrically connected to the thin film conductor 18 by solder (not shown) filled in the through hole 21. Further, the gauge lead 15b connected to the tab 14b of each strain gauge 3 is inserted into the through hole 22 passing through the one end portions 19a and 20a of the thin film conductors 19 and 20 corresponding to the strain gauge 3 from the surface side of the flexible substrate 2. The tab 14 b is electrically connected to the thin film conductors 19 and 20 by the solder 23 inserted and filled in the through hole 22.

  In addition, although illustration is abbreviate | omitted, the several through-hole penetrated in the thickness direction is drilled in the sensor structure part 35 similarly to the sensor structure part 6 of 1st Embodiment.

  The structure of the sensor structure 35 other than that described above is the same as the structure of the sensor structure 6 of the first embodiment. Then, when measuring the strain distribution on the road surface A, the strain gauge 3 is located in the grounding region of the wheel and the thin film conductors 18 of the flexible substrate 2 are the same as the sensor structure portion 6 of the first embodiment. , 19 and 20, the gauge base 4 of the sensor structure 35 is fixed to the road surface A with an adhesive B so that the other end portions 18 b, 19 b and 20 b of the respective contact portions deviate from the ground contact area in the width direction of the wheel. Is done. That is, the sensor structure 35 is fixed to the road surface A so that the flexible substrate 2 is interposed between the cover film 5 as the sheet-like insulating member and the road surface A. Further, the other end portions 18b, 19b, and 20b of the respective thin film conductors 18, 19, and 20 are connected to a measuring instrument through lead wires (not shown) connected thereto, and in this state, strain distribution is performed. Are measured in the same manner as in the first embodiment. In this case, since the gauge base 4 and the flexible substrate 2 are interposed between each strain gauge 3 and the road surface A, the strain generated on the road surface A is applied to the gauge base 4, the flexible substrate 2, and the gauge base 12. Then, it is transmitted to the strain sensing part 13 of the strain gauge 3.

  Also in this embodiment, disconnection of the lead wires connected to the respective end portions 18b, 19b, 20b of the respective thin film conductors 18, 19, 20 of the flexible substrate 2 and damage to the sensor structure portion 35 in the grounding region of the wheel. Thus, it is possible to appropriately measure the strain distribution of the road surface A in the ground contact region.

  In this embodiment, since the flexible substrate 2 is the same as that of the sensor structure portion 6 of the first embodiment, the through-hole 21 passing through the one end portion 18a of each thin film conductor 18 is provided. 21 may be omitted, and the gauge lead 15 a connected to the tab 14 a of each strain gauge 3 may be soldered directly to one end portion 18 a of the thin film conductor 18 corresponding to the strain gauge 3.

In the present embodiment, instead of the cover film 5, a gauge base similar to the gauge base 4 is used, and the strain gauge 3 is fixed to the back surface of the gauge base (the surface on the flexible substrate 2 side). The gauge base and the strain gauge 3 may be fixed to the surface of the flexible substrate 2 with an adhesive.
[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described with reference to FIGS. 2 is an exploded perspective view of a part of the sensor structure 40 of the strain measuring device of the present embodiment (an exploded perspective view similar to FIG. 5), and FIG. 12 is a partial cross-sectional view of the sensor structure 40 (similar to FIG. 6). FIG. In addition, since the strain measuring apparatus in this embodiment is different from that of the third embodiment only in a part of the structure of the sensor structure section 40, the difference will be mainly described, and the sensor structure of the third embodiment will be described. The same components as those of the unit 35 are denoted by the same reference numerals as those of the third embodiment, and detailed description thereof is omitted. The present embodiment is an embodiment of the fourth invention.

  In the sensor structure part 35 of the third embodiment, a plurality of strain gauges 3 having the gauge base 12 and the strain sensing part 13 are used. On the other hand, in the sensor structure portion 40 of the present embodiment, as shown in FIGS. 12 and 13, instead of the cover film 5 provided in the sensor structure portion 35 of the third embodiment, a sheet having the same shape as this A gauge base 41 is provided as an insulating member, and a plurality of surfaces (back surface) on the flexible substrate 2 side in the thickness direction of the gauge base 41 are similar to the gauge base 4 of the second embodiment. The strain sensitive part 13 (resistive strain sensitive part 13) is directly fixed by photoetching or the like. Then, the gauge base 41 to which the strain sensitive portion 13 is fixed in this way is fixed to the surface of the flexible substrate 2 by the adhesive 10 with the strain sensitive portion 13 interposed between the gauge base 41 and the surface of the flexible substrate 2. I made it.

  In FIG. 12 and FIG. 13, only one strain sensing unit 13 is illustrated. However, actually, in the present embodiment, the number of strain gauges 3 in the sensor structure unit 35 of the third embodiment is plural (in this embodiment, The same number of strain sensing parts 13 are fixed to the gauge base 41. The arrangement of the strain sensing units 13 is the same as the arrangement of the strain gauges 3 in the third embodiment. In addition, one gauge lead 15a, 15b is connected to each of the tabs 14a, 14b at both ends of each strain sensing part 13 as in the third embodiment. And the conduction | electrical_connection form of the tab 14a of each distortion | strain sensitivity part 13 and the thin film-like conductor 18 corresponding to this distortion | strain sensitivity part 13, and the tab 14b of each distortion | strain sensitivity part 13 and this distortion | strain sensitivity part 13 respond | correspond. The conducting form with the thin film conductors 19 and 20 is exactly the same as in the third embodiment.

  Supplementally, the gauge base 41 covers almost the entire surface of the flexible substrate 2 except for the end portions 18 b of the respective thin film conductors 18 on the surface of the flexible substrate 2, similarly to the cover film 5. Although not shown in the drawings, the sensor structure 40 includes a plurality of through holes penetrating in the thickness direction including the gauge base 41 in the same manner as the sensor structure 35 of the third embodiment. .

  The structure of the sensor structure 40 other than that described above is the same as the structure of the sensor structure 35 of the third embodiment. When measuring the strain distribution on the road surface A, the strain sensing unit 13 is located in the grounding region of the wheel, and the other end portions 18b of the thin film conductors 18, 19, and 20 of the flexible substrate 2 are used. , 19b, 20b deviate from the ground contact area in the width direction of the wheel, and the gauge base 4 of the sensor structure 40 is fixed to the road surface A via the adhesive B. That is, the sensor structure 40 is fixed to the road surface A so that the flexible substrate 2 is interposed between the gauge base 41 as a sheet-like insulating member and the road surface A. Furthermore, the respective end portions 18b, 19b, 20b of the respective thin film conductors 18, 19, 20 are connected to a measuring instrument through lead wires (not shown) connected thereto, and in this state, the strain distribution is reduced. Measurement is performed in the same manner as in the third embodiment. In this case, since the gauge base 4 and the flexible substrate 2 are interposed between each strain sensing part 13 and the road surface A, the strain generated on the road surface A is changed through the gauge base 4 and the flexible substrate 2. It is transmitted to the strain sensing unit 13.

  Also in this embodiment, disconnection of the lead wires connected to the respective end portions 18b, 19b, 20b of the respective thin film conductors 18, 19, 20 of the flexible substrate 2 and damage to the sensor structure portion 40 in the grounding region of the wheel. Thus, it is possible to appropriately measure the strain distribution of the road surface A in the ground contact region.

  In this embodiment, since the flexible substrate 2 is the same as that of the sensor structure portion 6 of the first embodiment, the through-hole 21 passing through the end portion 18a of each thin film conductor 18 is provided. 21 is omitted, and the gauge lead 15a connected to the tab 14a of each strain sensing part 13 is directly soldered to one end 18a of the thin film conductor 18 corresponding to the strain sensing part 13. Good.

  Next, some modified modes related to the above embodiments will be described.

[Modification 1]
In each of the embodiments described above, the flexible substrate 2 is incorporated in each of the sensor structures 6, 28, 35, and 40 so that the first layer substrate 7 is located above the second layer substrate 8 (the side away from the road surface A). However, the upper and lower sides of the flexible substrate 2 are turned upside down, and the sensor structure parts 6, 28, 35, 40 are arranged so that the first layer substrate 7 is located below the second layer substrate 8 (side approaching the road surface A). It may be incorporated into.

  In this case, in the first embodiment or the second embodiment, when the flexible substrate 2 is turned upside down, the through hole 21 passing through the one end portion 18a of each thin film conductor 18 is omitted, and each tab 14a is provided with the tab 14a. The connected gauge lead 15 a may be directly soldered to the one end portion 18 a of the thin film conductor 18.

[Modification 2]
In each of the embodiments, the through hole 22 is provided so as to pass through the respective one end portions 19a and 20a of the thin film conductors 19 and 20, but in the vicinity of the one end portions 19a and 20a of the thin film conductors 19 and 20, You may make it drill a through hole in the base | substrate (the part in which the thin film-like conductors 18, 19, and 20 do not exist) of the flexible substrate 2. FIG. In this case, for example, in order to make the gauge lead 15b conductive to the thin film conductors 19 and 20 in the first embodiment or the second embodiment, the gauge lead 15b is bonded before the first layer substrate 7 and the second layer substrate 8 are bonded together. After the intermediate portion of 15b is soldered to the one end portion 20a of the thin film conductor 20 on the back surface side of the second layer substrate 8, the tip portion of the gauge lead 15b is connected to the second layer substrate 8 through the second hole. What is necessary is just to make it protrude to the surface side of the layer board | substrate 8 through a through hole, and to solder to the one end part 19a of the thin film-like conductor 19 of the surface side of this 2 layer board | substrate 8. For example, in order to make the gauge lead 15b conductive to the thin film conductors 19 and 20 in the third embodiment or the fourth embodiment, the gauge lead 15b is bonded before the first layer substrate 7 and the second layer substrate 8 are bonded together. After passing through the through hole of the first layer substrate 7, the intermediate portion of the gauge lead 15b is soldered to one end portion 19a of the thin film conductor 19 on the surface side of the second layer substrate 8, and the gauge lead 15b It is only necessary to project the tip of the second layer substrate 8 through the through hole of the second layer substrate 8 to the back side of the second layer substrate 8 and solder it to the one end portion 20a of the thin film conductor 20.

  Similarly to the above, in the first embodiment and the second embodiment, the base of the flexible substrate 2 (the thin film conductors 18, 19, 20 are also present in the vicinity of the one end 18a of the thin film conductor 18 in the through hole 21. The tip of the gauge lead 15a that has passed through this through hole may be soldered to the one end 18a of the thin film conductor 18 so as to be drilled in the portion that is not. In the third and fourth embodiments, a through hole for passing the gauge lead 15a is not necessary.

[Modification 3]
In the first embodiment or the second embodiment, for example, the inner peripheral surface of each through hole 22 is subjected to metal plating (such as solder plating) that conducts to the thin film conductors 19 and 20, and the back surface of the flexible substrate 2. On the side, the gauge lead 15b may be soldered to the metal plating. Similarly, metal plating (solder plating or the like) that conducts to the thin film conductor 18 is applied to the inner peripheral surface of each through hole 21, and the gauge lead 15 a is soldered to the metal plating on the back surface side of the flexible substrate 2. It may be.

  Similarly to the above, in the third embodiment or the fourth embodiment, the inner peripheral surface of each through-hole 22 is subjected to metal plating (such as solder plating) that conducts to the thin-film conductors 19 and 20, and the flexible substrate 2. The gauge lead 15b may be soldered to the metal plating on the surface side. In the third embodiment or the fourth embodiment, the gauge lead 15a can be directly soldered to the thin film conductor 18, so that even if the through hole 21 is provided, the inner circumference of the through hole 21 can be reduced. Applying metal plating as described above to the surface may be omitted.

[Modification 4]
In each of the embodiments described above, the gauge leads 15a and 15b are connected to the tabs 14a and 14b at both ends of each strain sensing part 13, respectively, and the conduction between the tab 14a and the thin film conductor 18 and the tab 14b and Conduction with the thin film conductors 19 and 20 is performed through the gauge leads 15a and 15b. Instead of this, without using the gauge leads 15a and 15b, it is also possible to conduct the conduction between the tab 14a and the thin film conductor 18 and conduct the conduction between the tab 14b and the thin film conductors 19 and 20. is there.

  One example will be described with reference to the cross-sectional view of FIG. 14 is a cross-sectional view representatively showing an example in which the tab 14b and the thin film conductors 19 and 20 are electrically connected without using the gauge lead 15b in the first embodiment (the same cross section as FIG. 6). Figure).

  In this example, when the gauge base 4 to which the strain gauge 3 is fixed is fixed to the back surface of the flexible substrate 2 with the adhesive 11, the tab 14 b of each strain sensitive portion 13 is attached to the thin film conductor 20 at the location of the through hole 22. Is brought into contact with one end 20a. At this time, the adhesive 11 is not applied to the tab 14b. After the gauge base 4 is fixed to the back surface of the flexible substrate 2, each through hole 22 is filled with solder 23, and the tab 14 b is electrically connected to the thin film conductors 19 and 20 by the solder 23.

  Although illustration is omitted, conduction between the tab 14a of each strain sensing part 13 and the thin film conductor 18 can be performed in the same manner as described above. In this case, the tab 14 a is brought into contact with the back surface of the flexible substrate 2 at the location of the through hole 21. Then, after the gauge base 4 is fixed to the back surface of the flexible substrate 2, the through hole 21 is filled with solder, and the tab 14 a is electrically connected to the thin film conductor 18 by this solder.

  In the second to fourth embodiments, similarly to the above, without using the gauge leads 15a and 15b, the conduction between the tab 14a and the thin film conductor 18 and the connection between the tab 14b and the thin film conductors 19 and 20 are achieved. It is possible to conduct. However, in the third embodiment, a gauge base is used instead of the cover film 5, and the strain gauge 3 is fixed to the back surface of the gauge base.

  In each embodiment, by using solder plating or conductive adhesive applied to the inner peripheral surfaces of the through holes 21 and 22, the tab 14 a and the thin film can be formed without using the gauge leads 15 a and 15 b. It is also possible to conduct the conductor 18 and conduct the conduction between the tab 14b and the thin film conductors 19 and 20.

[Modification 5]
In each of the embodiments, the flexible substrate 2 has a two-layer structure, but may have a three-layer structure, for example. For example, as shown in the exploded perspective view of FIG. 15, the first layer substrate 51 with the thin film conductor 18 fixed to the surface, the second layer substrate 52 with the thin film conductor 18 fixed to the surface, and the thin film conductor 20 on the back surface. A flexible three-layer structure in which the fixed third-layer substrate 53 is bonded to each other so that the second-layer substrate 52 is sandwiched between the first-layer substrate 51 and the third-layer substrate 53. The substrate 54 may be used instead of the flexible substrate 2. In FIG. 15, as in FIG. 5, a part of the thin film conductors 18, 19, 20 corresponding to one strain gauge 3 or the strain sensing part 13 is illustrated.

  Supplementally, the thin film conductor 20 may be fixed to the surface of the third layer substrate 53.

[Modification 6]
Further, instead of the flexible substrate 2, for example, a single-layer flexible substrate 56 as shown in a perspective view of FIG. 16 may be used. This flexible substrate 56 has a thin film conductor 18 and a thin film conductor 19 fixed to its front surface and a thin film conductor 20 fixed to its back surface. In FIG. 16, as in FIG. 5, a part of the thin film conductors 18, 19, 20 corresponding to one strain gauge 3 or the strain sensing part 13 is illustrated.

  Supplementally, in the flexible substrate 56, the thin film conductors 19 and 20 are fixed to the same surface (front surface) of the flexible substrate 56, so that the thin film conductors 19 and 20 are not in contact with each other. It is necessary to configure the pattern of the conductors 19 and 20.

[Modification 7]
Alternatively, for example, a single-layer flexible substrate 60 as shown in FIG. 17 may be used. FIG. 17 is an exploded perspective view of a part of the sensor structure 61 using the flexible substrate 60. In the flexible substrate 60, the thin film conductors 18, 19, and 20 are fixed only on the surface (one surface of both surfaces in the thickness direction of the flexible substrate 60).

  When such a flexible substrate 60 is used, for example, the sensor structure can be configured as follows. An example in that case will be described with reference to FIG. This example is an example of an embodiment of the third invention.

  The example shown in FIG. 17 is an example in which the strain gauge 3 is used, and each strain gauge 3 is fixed to the surface of the flexible substrate 60 via an adhesive (not shown) as in the third embodiment. In FIG. 17, only one strain gauge 3 and a part of the thin film conductors 18, 19 and 20 corresponding thereto are shown in the same manner as in FIG. It is fixed to the surface of the flexible substrate 60 in the same arrangement as that shown in FIG. The thin film conductors 18, 19, and 20 are provided for each individual strain gauge 3, and they extend in an appropriate pattern from the vicinity of each strain gauge 3 to one side of the flexible substrate 60. Yes.

  In this case, in addition to the gauge leads 15a and 15b being connected to the tabs 14a and 14b at both ends of the strain sensing part 13 of each strain gauge 3, the third gauge lead 15c is further connected to the tab 14b. It is connected to. The gauge leads 15a, 15b, and 15c are soldered to the one end portions 18a, 19a, and 20a of the thin film conductors 18, 19, and 20, respectively. As a result, the tab 14 a is electrically connected to the thin film conductor 18, and the tab 14 b is electrically connected to the thin film conductors 19 and 20.

  As described above, the plurality of strain gauges 3 are fixed to the surface of the flexible substrate 60, and the gauge leads 15a, 15b, and 15c for each strain gauge 3 are respectively attached to the thin film conductors 18, 19,. The cover film 5 as a sheet-like insulating member is connected to the surface of the flexible substrate 60 by an adhesive or by heat fusion (however, the other end portions of the thin film conductors 18, 19, 20 are The sensor structure portion 61 is configured by being fixed to (except). The sensor structure 61 is provided with a plurality of through holes (not shown) penetrating in the thickness direction of the sensor structure 61 as in the above embodiments.

  When the sensor structure portion 61 is configured in this way, the strain on the road surface A is flexible by fixing the flexible substrate 60 to the road surface A with an adhesive interposed between the back surface and the road surface A. It is transmitted to each strain gauge 3 through the substrate 60. In this case, each strain gauge 3 fixed to the flexible substrate 60 is positioned in the ground contact area of the wheel, and the other end portions of the thin film-like bodies 18, 19, and 20 extend from the ground contact area in the width direction of the wheel. Flexible substrate 60 is fixed to road surface A so as to be located in the deviated region. In this case, it is not necessary to interpose the gauge base between the flexible substrate 60 and the road surface A.

  And although illustration is abbreviate | omitted, by connecting the other end part of each thin film-like conductor 18, 19, 20 to a measuring device via the lead wire connected to this, road surface A is similar to each said embodiment. The strain distribution (strain distribution in the wheel contact area) can be measured.

  Supplementally, the gauge base may be fixed to the surface of the flexible substrate 60 with an adhesive instead of the cover film 5. In this case, the strain of the road surface A may be transmitted to each strain gauge 3 via the gauge base so as to be fixed to the road surface A of both surfaces in the thickness direction of the gauge base. In this way, one embodiment of the first invention is configured.

  Further, when the flexible substrate 60 is used, for example, the sensor structure can be configured as follows. An example in that case will be described with reference to FIG. FIG. 18 is a perspective view of a part of the sensor structure in this example. Moreover, this example is an example which is one embodiment of the fourth invention or the second invention.

  In the example shown in FIG. 18, the sheet-like gauge base 65 is subjected to photoetching or the like on one side (here, the back side) of both sides in the thickness direction, like the gauge base 4 of the second embodiment. It is an example provided with the some distortion | strain sensitive part 13 which adhered. In this example, as in FIG. 17, in addition to the fact that the gauge leads 15a and 15b are respectively connected to the tabs 14a and 14b at both ends of each strain sensing part 13, a third gauge is also provided. The lead 15c is connected to the tab 14b. The gauge leads 15a, 15b, and 15c are soldered to the one end portions 18a, 19a, and 20a of the thin film conductors 18, 19, and 20, respectively. Then, the back surface of the gauge base 65 is fixed to the surface of the flexible substrate 60 with an adhesive, with each strain sensing portion 13 being interposed between the flexible substrate 60 and the sensor structure portion 66. The The sensor structure 66 is provided with a plurality of through holes (not shown) penetrating in the thickness direction of the sensor structure 66 as in the above embodiments.

  When the sensor structure portion 66 is configured in this manner, the flexible substrate 60 is fixed to the road surface A with an adhesive interposed between the back surface and the road surface A, so that the distortion of the road surface A is flexible. It is transmitted to each strain sensing part 13 through the substrate 60. In this way, one embodiment of the fourth invention is configured. Alternatively, by fixing the gauge base 65 to the road surface A with an adhesive interposed between the surface and the road surface A, the strain of the road surface A is applied to each strain sensing unit 13 via the gauge base 65. Be transmitted. In this way, one embodiment of the second invention is configured.

  In any case, each strain sensing part 13 is located in the grounding area of the wheel, and the other end of each thin film conductor 18, 19, 20 deviates from the grounding area in the width direction of the wheel. The flexible substrate 60 is fixed to the road surface A so as to be located in the region.

  And although illustration is abbreviate | omitted, by connecting the other end part of each thin film-like conductor 18, 19, 20 to a measuring device via the lead wire connected to this, road surface A is similar to each said embodiment. The strain distribution (strain distribution in the wheel contact area) can be measured.

  In addition, through holes penetrating in the thickness direction of the flexible substrate 60 through the one end portions 18a, 19a, 20a of the respective thin film conductors 18, 19, 20 are formed, and the gauge leads 15a, 15b, 15c may be inserted and the through hole may be filled with solder from the back side of the flexible substrate 60. In that case, it is desirable that a cover film or a sheet-like insulating member such as a gauge base is fixed to the back surface of the flexible substrate 60 to cover the through holes.

  Further, without using the gauge leads 15a, 15b, 15c, the tab 14a of the strain sensing part 13 is electrically connected to the thin film conductor 18, and the tab 14b is electrically connected to the thin film conductors 19, 20. It is also possible to configure the part. An example will be described with reference to an exploded perspective view of FIG.

  Referring to FIG. 19, a conductive adhesive 70 is applied to the tab 14a of each strain sensing part 13 fixed to the gauge base 65 shown in FIG. 18, and a conductive adhesive 71 is applied to the tab 14b. Apply. In this case, when the back surface (upper surface in FIG. 19) of the gauge base 65 is overlapped on the surface of the flexible substrate 60, the conductive adhesive 70 contacts the thin film conductor 18, and the conductive adhesive 71 contacts the thin film conductor 19. , 20 are applied to the tabs 14a, 14b, respectively, so as to be in contact with both of them. Conductive adhesives 72a, 72b, 72c are also applied to the one end portions 18a, 19a, 19b of the thin film conductors 18, 19, 20 respectively. Then, an adhesive (not shown) is applied to a portion of the back surface of the gauge base 65 other than the conductive adhesives 70 and 71, and the back surface of the gauge base 65 is overlaid on the surface of the flexible substrate 60. In this state, the gauge base 65 and the flexible substrate 60 are heated while being pressed against each other in the thickness direction by hot pressing. As a result, the conductive adhesive 70 on the gauge base 65 side is electrically connected and joined to the conductive adhesive 72a on the flexible substrate 60 side, and the conductive adhesive 71 on the gauge base 65 side is electrically bonded to the flexible substrate 60 side. The gauge base 65 is bonded to the flexible substrate 60 at the same time as being electrically connected and bonded to the agents 72b and 72c.

  As a result, the tab 14 a is electrically connected to the thin film conductor 18, and at the same time, the tab 14 b is electrically connected to the thin film conductors 19 and 20.

  In the example of FIG. 19, an example in which the strain sensing unit 13 is directly fixed to the gauge base 65 is shown, but even when the strain gauge is fixed to the gauge base 65, the sensor structure unit similar to the above is provided. It is possible to configure.

The top view of the surface side of the sensor structure part of the distortion | strain measuring apparatus of 1st Embodiment of this invention. II arrow line view of FIG. The top view of the surface side of the 2nd layer board | substrate of the flexible substrate with which the sensor structure part shown in FIG. 1 was equipped. The top view of the back surface side of the sensor structure part shown in FIG. The disassembled perspective view of a part of sensor structure part shown in FIG. FIG. 5 is a cross-sectional view taken along line VI-VI in FIG. 1. The graph which shows the example of a measurement of the strain distribution of the road surface by the strain measuring apparatus of 1st Embodiment. The top view which shows the gauge base and strain sensing part which are used for the sensor structure part of the distortion | strain measuring apparatus of 2nd Embodiment of this invention. The fragmentary sectional view of the sensor structure part of a 2nd embodiment. The disassembled perspective view of a part of sensor structure part of the strain measuring device of the third embodiment of the present invention. The fragmentary sectional view of the sensor structure part of a 3rd embodiment. The disassembled perspective view of a part of sensor structure part of the strain measuring device of the fourth embodiment of the present invention. The fragmentary sectional view of the sensor structure part of a 4th embodiment. The fragmentary sectional view of the sensor structure part regarding the deformation | transformation aspect of embodiment of this invention. The disassembled perspective view of a part of flexible substrate regarding the deformation | transformation aspect of embodiment of this invention. The perspective view of the part of flexible substrate regarding the deformation | transformation aspect of embodiment of this invention. The disassembled perspective view of a part of sensor structure part regarding the deformation | transformation aspect of embodiment of this invention. The disassembled perspective view of a part of sensor structure part regarding the deformation | transformation aspect of embodiment of this invention. The disassembled perspective view of a part of sensor structure part regarding the deformation | transformation aspect of embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Strain measuring apparatus 2,54,56,60 ... Flexible board, 3 ... Strain gauge, 4,41,65 ... Gauge base (sheet-like insulating member), 5 ... Cover film (sheet-like insulating member), 6, 28, 35, 40, 61, 66 ... sensor structure, 7 ... first layer substrate, 8 ... second layer substrate, 14a, 14b ... tab (conductor connection portion), 18, 19, 20 ... thin film conductor, 22 ... through hole, 23 ... solder (conductor member).

The third aspect of the reference invention relating to the road surface of the strain measurement equipment of the present invention, there is provided a strain measuring device for measuring the strain of the road surface to the ground wheels for traveling of the moving body, a single-layer or A multilayer flexible substrate, a plurality of resistance strain gauges fixed to one of the front and back surfaces of the flexible substrate, and provided on the flexible substrate, each of the resistance strain gauges at the conductor connection portion A sensor comprising a plurality of thin-film conductors whose one ends are electrically connected, and a sheet-like insulating member fixed to one surface of the flexible substrate so as to cover one surface of the flexible substrate and the plurality of strain gauges. A plurality of resistive strain gauges are located in the ground contact area of the wheel on the road surface, and the road surface strain is The plurality of thin film conductors are fixed to the road surface with the flexible substrate interposed between the road surface and the sheet-like insulating member so as to be transmitted to each resistance strain gauge via the rexible substrate. Each of the other end portions is provided on the flexible substrate so as to be located in a region deviating from the wheel ground contact region in the width direction of the wheel, and the other end portion is exposed so that wiring can be connected. (3rd invention).

The fourth aspect of the reference invention relating to the road surface of the strain measurement equipment of the present invention, there is provided a strain measuring device for measuring the strain of the road surface to the ground wheels for traveling of the moving body, the sheet-like insulation The sheet-like sheet is formed by interposing the plurality of resistance-type strain-sensitive parts between the plurality of resistance-type strain-sensitive parts fixed to one of the front and back surfaces of the member and the sheet-like insulating member. A single-layer or multi-layer flexible substrate fixed to the one surface of the insulating member and the plurality of resistance strain gauges, and one end of each of the resistance strain sensing portions provided on the conductive wire connecting portion. A plurality of thin-film conductors that are electrically connected to each other, and the sensor structure is configured such that the plurality of resistance-type strain sensing portions are located in a ground contact region of the wheel on the road surface, And the strain on the road The plurality of thin films are fixed to the road surface with the flexible substrate interposed between the road surface and the sheet-like insulating member, so that each of the plurality of thin film is transmitted to the resistance strain sensitive parts via the flexible substrate. The conductive conductors are provided on the flexible substrate so that the other end portions thereof are located in regions deviating from the wheel grounding region in the width direction of the wheel, and the other end portions can be connected to wiring. It is exposed (4th invention).

Before describing the road surface strain measuring apparatus of the present invention for achieving the above object, reference inventions of four types relating to the road surface strain measuring apparatus of the present invention will be described . The first aspect is a strain measuring device for measuring strain on a road surface that grounds a traveling wheel of a moving object, and includes a front surface and a rear surface of a sheet-like gauge base (both surfaces in the thickness direction of the gauge base). A plurality of resistance-type strain gauges fixed to one surface of the gauge base, and a plurality of resistance-type strain gauges interposed between the gauge bases and a multilayer layer fixed to the one surface of the gauge base. A sensor board comprising: a flexible board; and a plurality of thin film conductors provided at the flexible board and each having one end connected to a conductive wire connecting part of each resistance strain gauge. A plurality of resistance strain gauges are located in the ground contact region of the wheel of the road surface, and the strain of the road surface is transmitted to each resistance strain gauge via the gauge base, The gauge base is interposed between the road surface and the flexible substrate, and is fixed to the road surface. Each of the plurality of thin film conductors deviates from the ground contact area of the wheel in the width direction of the wheel. It is provided on the flexible substrate so as to be located in the region, and the other end is exposed so that wiring can be connected (first invention).

A second aspect as a reference invention related to the road surface strain measuring device of the present invention is a strain measuring device for measuring a road surface strain in which a traveling wheel of a moving body is grounded. A plurality of resistance strain sensitive sections fixed to one of the front surface and the back surface (both surfaces in the thickness direction of the gauge base), and the plurality of resistance strain sensitive sections between the gauge base A multi- layer flexible substrate fixed to the one surface of the gauge base with a portion interposed therebetween, and one end portion of each flexible strain-sensitive portion provided on the flexible substrate, and one end portion thereof being electrically connected to the resistance strain sensing portion. A plurality of thin film conductors, wherein the plurality of resistance strain sensitive parts are located in a ground contact area of the wheel of the road surface, and the road surface The strain is The plurality of thin-film conductors are fixed to the road surface with the gauge base interposed between the road surface and the flexible substrate so that the resistance-type strain sensing parts are transmitted through the base. The other end of the wheel is provided in the flexible substrate so as to be located in a region deviating from the wheel contact area in the width direction of the wheel, and the other end is exposed so that wiring can be connected. (2nd invention).

A third aspect as a reference invention related to the road surface strain measuring device of the present invention is a strain measuring device for measuring road surface strain for grounding a traveling wheel of a moving body, and is a multi- layer flexible device. A substrate, a plurality of resistance strain gauges fixed to one of the front surface and the back surface of the flexible substrate, and one end portion of each of the resistance strain gauges connected to the conductive wire connection portion provided on the flexible substrate. A sensor structure comprising a plurality of thin film conductors and a sheet-like insulating member fixed to one surface of the flexible substrate so as to cover one surface of the flexible substrate and the plurality of strain gauges. In the sensor structure, the plurality of resistance strain gauges are located in the ground contact area of the wheel on the road surface, and the road surface strain is The flexible substrate is interposed between the road surface and the sheet-like insulating member so as to be transmitted to each resistance strain gauge through the substrate, and the thin film conductors are respectively fixed to the road surface. The other end of the wheel is provided in the flexible substrate so as to be located in a region deviating from the wheel contact area in the width direction of the wheel, and the other end is exposed so that wiring can be connected. (3rd invention).

Further, a fourth aspect as a reference invention related to the road surface strain measuring device of the present invention is a strain measuring device for measuring a road surface strain for grounding a traveling wheel of a moving body, and is a sheet-like insulating member The sheet-like insulation by interposing the plurality of resistance-type strain-sensitive parts between the plurality of resistance-type strain-sensitive parts fixed to one of the front and back surfaces of the sheet and the sheet-like insulating member A multi- layer flexible substrate fixed to the one surface of the member and the plurality of resistance strain gauges, and one end portion of each flexible strain sensing portion being connected to the conductive wire connection portion of the resistance strain sensing portion. A plurality of thin film conductors, wherein the plurality of resistance-type strain sensing units are located in a ground contact area of the wheel of the road surface, and the road surface The strain of The plurality of thin film conductors are fixed to the road surface with the flexible substrate interposed between the road surface and the sheet-like insulating member so as to be transmitted to each resistance-type strain sensing part via the kibble substrate. Are provided on the flexible substrate so that each other end portion is located in a region deviating from the wheel ground contact region in the width direction of the wheel, and the other end portion is exposed so that wiring can be connected. (4th invention).

Next, the road surface strain measuring apparatus of the present invention according to claims 1 and 2 of the present application will be described. Prior Symbol first to fourth invention, the measurement of the resistance change of the strain sensing part or each resistive strain sensitive portion of the resistive strain gauge (and thus distortion of the road), for example, the strain sensing part is This can be done by using a Wheatstone bridge circuit incorporated on one side. In this case, the road surface strain measuring device according to the first aspect of the present invention is a thin film conductor that conducts to the conductive wire connecting portion of each of the resistance strain gauges in addition to the specific matters of the first invention. Are connected to a first thin-film conductor to be connected to a conductive wire connecting portion provided at one end of the strain sensitive portion of each resistance strain gauge, and a conductive wire connecting portion provided to the other end of the strain sensitive portion. It consists of a second thin film conductor and a third thin film conductor to be conducted, and the flexible substrate is a two-layer flexible substrate obtained by polymerizing a first layer substrate and a second layer substrate, and each resistor Of the first to third thin film conductors corresponding to the strain gauge, the first thin film conductor is the surface on the opposite side of the surface of the first layer substrate and the back surface of the first layer substrate on the second layer substrate side. And the second thin film conductor and the third thin film Are formed on the front surface and the back surface of the second layer substrate so as to face each other with the second layer substrate therebetween, and the second thin film conductor and the third thin film conductor are respectively Is connected through a conductor member provided in a through hole drilled in the flexible substrate so as to penetrate through the flexible substrate in the thickness direction, and corresponds to each of the resistance strain gauges. Among the first to third thin-film conductors, the first thin-film conductor and the second thin-film conductor are intermediate portions except for both ends of the first thin-film conductor and the second thin-film conductor. The second thin film conductor and the third thin film conductor are single in the thickness direction of the flexible substrate over the entire length. Heavy And it is characterized in that is provided to fit Ri (seventh invention).

Similarly, in addition to the invention specific matter of the second invention, the road surface strain measuring device according to the second aspect of the present invention further includes a thin-film conductor that is electrically connected to each of the resistance-type strain sensing parts. A first thin film-like conductor that conducts to a conductor connecting portion provided at one end of each resistance strain sensing portion, and a first conductor that conducts to a conductor connecting portion provided at the other end of the resistance strain sensing portion. The flexible substrate is a two-layer flexible substrate obtained by polymerizing a first layer substrate and a second layer substrate, and each resistance type strain receiving device. Of the first to third thin film conductors corresponding to the sensitive part, the first thin film conductor is on the surface opposite to the surface on the second layer substrate side of the front and back surfaces of the first layer substrate. And the second thin film conductor and the third thin film conductor form the second layer substrate. The second thin-film conductor and the third thin-film conductor are respectively formed on the front and back surfaces of the second layer substrate so as to face each other, and the flexible substrate passes through one end of each of the flexible substrate. Are connected through a conductor member provided in a through hole formed in the flexible substrate so as to penetrate in the thickness direction, and the first to third corresponding to each of the resistance strain sensitive parts. Among the thin-film conductors, the first thin-film conductor and the second thin-film conductor are the thickness of the flexible substrate at the intermediate portion excluding both ends of the first thin-film conductor and the second thin-film conductor. The second thin-film conductor and the third thin-film conductor are overlapped in a single line in the thickness direction of the flexible substrate over their entire length. Provided It is characterized in that there (eighth invention).

According to the seventh invention (the invention according to claim 1) and the eighth invention (the invention according to claim 2), in addition to the effects of the first invention and the second invention , each resistance type Since three thin-film conductors are connected to the strain-sensitive part of the strain gauge or each resistance-type strain-sensitive part, it is possible to perform strain measurement by the so-called 1-gauge three-wire method. It is possible to perform accurate strain measurement by compensating for the effect of changes in the resistance value of each thin film conductor due to temperature changes and the resistance value change of the wiring connected to the other end of each thin film conductor. It becomes possible.

According to the seventh and eighth inventions , since the first layer substrate is interposed between the first thin film conductor and the second thin film conductor, the first thin film conductor And the second thin film conductor are formed on the first layer substrate in a pattern that causes a partial overlap in the thickness direction of the first layer substrate (thickness direction of the flexible substrate). Insulation between the thin film conductors can be ensured. Further, since the third thin film conductor faces the second thin film conductor via the second layer substrate, the third thin film conductor overlaps in the thickness direction of the second layer substrate (thickness direction of the flexible substrate). The insulation between those thin film conductors can be ensured. For this reason, the area of the flexible substrate (area seen in the thickness direction) can be kept to a minimum while ensuring the insulating properties of the first to third thin film conductors. It can be kept to the minimum necessary. As a result, it is possible to reduce the material cost of the sensor structure, and consequently the manufacturing cost. At the same time, the second thin film conductor and the third thin film conductor are opposed to each other, and the second thin film conductor and the third thin film conductor are formed by the conductor member provided in the through hole passing through one end of the second thin film conductor and the third thin film conductor. Conductivity with the conductor can be easily secured . Moreover, the influence of electromagnetic induction noise can be reduced because the intermediate part of the 1st-3rd thin film-like conductor overlaps in the thickness direction of a flexible substrate. Na us, as the conductive member, such as a solder filled in the metal plating and the through-hole was subjected to the inner peripheral surface of the through hole and the like.

[First Embodiment]
A first embodiment of the present invention will be described with reference to FIGS. 1 is a plan view of the surface side of the sensor structure 6 of the road surface strain measuring device 1 according to the present embodiment, FIG. 2 is a view taken along the arrow II in FIG. 1, and FIG. 3 is a second view of the flexible substrate 2 of the sensor structure 6. 4 is a plan view of the back side of the sensor structure 6, FIG. 5 is an exploded perspective view of a part of the sensor structure 6, and FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. FIG. 7 is a graph showing a measurement example of the road surface strain distribution by the strain measuring device 1 of the present embodiment. This embodiment is an embodiment of the first invention . More specifically, this embodiment is an embodiment of the invention (seventh invention) according to claim 1 of the present application.

Further, as shown in FIG. 6, a gauge lead 15 b connected to the tab 14 b of the strain gauge 3 is inserted into the through hole 22 from the back side of the flexible substrate 2 and filled with solder 23. Thus, the gauge lead 15b and the thin film conductors 19 and 20 are electrically connected. As a result, the tab 14 b of each strain gauge 3 is electrically connected to the thin film conductors 19 and 20 corresponding to the strain gauge 3. The solder 23 corresponds to the conductor member in the seventh invention .

In the sensor structure 6 of the present embodiment, the first layer substrate 7 is interposed between the thin film conductor 18 and the thin film conductor 19, and between the thin film conductor 19 and the thin film conductor 20. Since the second layer substrate 8 is interposed, the thin film conductors 18, 19, and 20 can be overlapped when viewed in the thickness direction of the flexible substrate 3. For this reason, in the present embodiment, as described above, the three thin film conductors 18, 19, 20 for each strain gauge 3 have a single intermediate portion excluding their both ends in the thickness direction of the flexible substrate 2. It is provided so as to overlap linearly. As a result, the area seen in the thickness direction of the flexible substrate 3 can be kept to the minimum necessary. As a result, the area of the sensor structure 6 viewed in the thickness direction can be kept to the minimum necessary, and the material cost of the components of the sensor structure 6 can be reduced. In addition, since the intermediate portions of the thin film conductors 18, 19, and 20 overlap in the thickness direction of the flexible substrate 2, the influence of electromagnetic induction noise caused by the surrounding environment can be reduced.
[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 8 is a plan view showing a gauge base and a strain sensing unit used in the sensor structure 28 of the strain measuring device of this embodiment, and FIG. 9 is a partial cross-sectional view of the sensor structure 28 (cross-sectional view similar to FIG. 6). It is. The strain measuring device according to the present embodiment is different from that of the first embodiment only in a part of the structure of the sensor structure portion 28. Therefore, the difference will be mainly described, and the sensor structure of the first embodiment will be described. The same components as those of the unit 6 are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof is omitted. Moreover, this embodiment is an embodiment of the second invention . More specifically, this embodiment is an embodiment of the invention according to claim 2 of the present application (eighth invention).

Also in this embodiment, disconnection of the lead wires connected to the other end portions 18b, 19b, and 20b of the respective thin film conductors 18, 19, and 20 of the flexible substrate 2 and the sensor structure portion 28 in the grounding region of the wheel. It is possible to appropriately measure the strain distribution of the road surface A in the ground contact region without causing damage.
[Third Embodiment]
Next, a third embodiment according to the reference invention will be described with reference to FIGS. FIG. 10 is an exploded perspective view of a part of the sensor structure 35 of the strain measuring device of the present embodiment (an exploded perspective view similar to FIG. 5), and FIG. 11 is a partial cross-sectional view of the sensor structure 35 (similar to FIG. 6). FIG. The strain measuring device according to the present embodiment differs from that of the first embodiment only in a part of the structure of the sensor structure 35. Therefore, the difference will be mainly described, and the sensor structure of the first embodiment will be described. The same components as those of the unit 6 are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof is omitted. The present embodiment is an embodiment of the third invention.

In the present embodiment, instead of the cover film 5, a gauge base similar to the gauge base 4 is used, and the strain gauge 3 is fixed to the back surface of the gauge base (the surface on the flexible substrate 2 side). The gauge base and the strain gauge 3 may be fixed to the surface of the flexible substrate 2 with an adhesive.
[Fourth Embodiment]
Next, a fourth embodiment according to the reference invention will be described with reference to FIGS. 2 is an exploded perspective view of a part of the sensor structure 40 of the strain measuring device of the present embodiment (an exploded perspective view similar to FIG. 5), and FIG. 12 is a partial cross-sectional view of the sensor structure 40 (similar to FIG. 6). FIG. In addition, since the strain measuring apparatus in this embodiment is different from that of the third embodiment only in a part of the structure of the sensor structure section 40, the difference will be mainly described, and the sensor structure of the third embodiment will be described. The same components as those of the unit 35 are denoted by the same reference numerals as those of the third embodiment, and detailed description thereof is omitted. The present embodiment is an embodiment of the fourth invention.

Claims (11)

A strain measuring device that measures strain on a road surface that grounds a traveling wheel of a moving object,
A plurality of resistance strain gauges fixed to one of the front and back surfaces of the sheet-like gauge base, and the plurality of resistance strain gauges interposed between the gauge base and the gauge base. A sensor comprising a single-layer or multi-layer flexible substrate fixed to one surface, and a plurality of thin-film conductors provided on the flexible substrate, each of which is electrically connected to a conductive wire connection portion of each resistance strain gauge. Having a structure,
In the sensor structure, the plurality of resistance strain gauges are located in a ground contact area of the wheel on the road surface, and the strain on the road surface is transmitted to each resistance strain gauge via the gauge base. As described above, the gauge base is interposed between the road surface and the flexible substrate, and is fixed to the road surface,
The plurality of thin film conductors are provided on the flexible substrate so that the other end portions thereof are located in regions deviating from the wheel ground region in the width direction of the wheel, and the other end portions are wired. The road surface strain measuring device is exposed to be connectable. A strain measuring device that measures strain on a road surface that grounds a traveling wheel of a moving object,
A plurality of resistance strain sensitive parts fixed to one of the front and back surfaces of a sheet-like gauge base, and the plurality of resistance type strain sensitive parts interposed between the gauge bases A single-layer or multi-layer flexible substrate fixed to the one surface of the gauge base, and a plurality of thin films provided on the flexible substrate, each of which is electrically connected to the conductive wire connection portion of each resistance strain sensing portion A sensor structure comprising a conductor,
In the sensor structure, the plurality of resistance-type strain sensing units are located in a ground contact area of the wheel on the road surface, and each of the resistance-type strain sensing units has a strain on the road surface via the gauge base. So that the gauge base is interposed between the road surface and the flexible substrate, and is fixed to the road surface,
The plurality of thin film conductors are provided on the flexible substrate so that the other end portions thereof are located in regions deviating from the wheel ground region in the width direction of the wheel, and the other end portions are wired. The road surface strain measuring device is exposed to be connectable. A strain measuring device that measures strain on a road surface that grounds a traveling wheel of a moving object,
Single-layer or multiple-layer flexible substrate, a plurality of resistance strain gauges fixed to one of the front and back surfaces of the flexible substrate, and a conductive wire connection of each resistance strain gauge provided on the flexible substrate A plurality of thin-film conductors, each of which is electrically connected at one end, and a sheet-like insulating member fixed to one surface of the flexible substrate so as to cover one surface of the flexible substrate and the plurality of strain gauges. Having a sensor structure with
In the sensor structure, the plurality of resistance strain gauges are located in a ground contact area of the wheel on the road surface, and the strain on the road surface is transmitted to each resistance strain gauge via the flexible substrate. As described above, the flexible substrate is interposed between the road surface and the sheet-like insulating member, and is fixed to the road surface,
The plurality of thin film conductors are provided on the flexible substrate so that the other end portions thereof are located in regions deviating from the wheel ground region in the width direction of the wheel, and the other end portions are wired. The road surface strain measuring device is exposed to be connectable. A strain measuring device that measures strain on a road surface that grounds a traveling wheel of a moving object,
A plurality of resistance strain sensitive portions fixed to one of the front and back surfaces of the sheet-like insulating member, and the plurality of resistance strain sensitive portions interposed between the sheet-like insulating members. A single-layer or multi-layer flexible substrate fixed to the one surface of the sheet-like insulating member and the plurality of resistance-type strain gauges, and a conductor connection portion of each resistance-type strain-sensitive portion provided on the flexible substrate. Each having a plurality of thin film conductors having one end conductive to each other,
In the sensor structure, the plurality of resistance-type strain sensing units are located in a ground contact area of the wheel on the road surface, and the strain on the road surface is each resistance-type strain sensing unit via the flexible substrate. So that the flexible substrate is interposed between the road surface and the sheet-like insulating member, and is fixed to the road surface,
The plurality of thin film conductors are provided on the flexible substrate so that the other end portions thereof are located in regions deviating from the wheel ground region in the width direction of the wheel, and the other end portions are wired. The road surface strain measuring device is exposed to be connectable.   3. The road surface strain measuring device according to claim 1 or 2, wherein the sensor structure portion includes a sheet-like insulating member fixed to a surface opposite to the surface on the gauge base side of the front surface and the back surface of the flexible substrate. A road surface strain measuring device further comprising:   5. The road surface strain measuring device according to claim 3, wherein the sensor structure portion is a sheet-like gauge fixed to a surface opposite to the surface on the sheet-like member side of the front and back surfaces of the flexible substrate. A road surface strain measuring device further comprising a base.   4. The road surface strain measuring device according to claim 1 or 3, wherein the thin film conductor to be conducted to the conductive wire connecting portion of each resistive strain gauge is a conductive wire provided at one end of the strain sensing portion of each resistive strain gauge. It consists of the 1st thin film-like conductor connected to a connection part, and the 2nd thin film-like conductor and 3rd thin film-like conductor connected to the conducting wire connection part provided in the other end part of this distortion | strain sensitive part. A characteristic road surface strain measuring device.   5. The road surface strain measuring device according to claim 2, wherein the thin film conductor to be conducted to each of the resistance type strain sensing parts is conducted to a conductor connecting portion provided at one end of each resistance type strain sensing part. It comprises a first thin film conductor, and a second thin film conductor and a third thin film conductor that are electrically connected to a conductive wire connecting portion provided at the other end of the resistance type strain sensing portion. Road surface strain measurement device. 9. The road surface strain measuring apparatus according to claim 7 or 8, wherein the flexible substrate is a two-layer flexible substrate obtained by polymerizing a first layer substrate and a second layer substrate, and corresponds to each resistance strain gauge. Among the first to third thin film conductors, the first thin film conductor is formed on the surface opposite to the surface on the second layer substrate side of the front surface and the back surface of the first layer substrate. The second thin film conductor and the third thin film conductor are respectively formed on the front surface and the back surface of the second layer substrate so as to face each other through the second layer substrate,
The second thin film conductor and the third thin film conductor are provided in through holes formed in the flexible substrate so as to penetrate through the respective one end portions in the thickness direction of the flexible substrate. A road surface strain measuring device, wherein the device is electrically connected via a conductor member.   4. The road surface strain measuring apparatus according to claim 1 or 3, wherein the sensor structure portion includes a plurality of through-holes penetrating in a thickness direction of the sensor structure portion while avoiding the resistance strain gauges and the thin film conductors. A road surface strain measuring device, wherein:   5. The road surface strain measuring device according to claim 2, wherein the sensor structure portion includes a plurality of penetrating through the sensor structure portion in a thickness direction avoiding the resistance strain sensitive portions and the thin film conductors. A road surface strain measuring device having a through hole.