JPS63210632A - Dynamical quantity detection element - Google Patents

Abstract

PURPOSE:To improve linearity and to expand a dynamical quantity detectable range, by applying coating generating tensile stress to the surface of a thin strip formed of a non-amorphous magnetic alloy having positive magnetostriction and preliminarily imparting compression strain to a part of the thin strip. CONSTITUTION:Coating 4 having a tendency to generate tensile stress by coating is applied to the surface of a thin strip formed of a non-amorphous magnetic alloy having positive magnetostriction. Compression strain is preliminarily applied to at least a part of the thin strip 2 by the coating relation of said coating 4. As the coating 4, a metal such as copper, an organic material or the like are used and the coating 4 is applied by a gaseous phase plating method, an electroplating method or coating.

Description

[Detailed description of the invention]

The present invention relates to a dynamic all-detection element that utilizes the stress-magnetic effect of an amorphous magnetic alloy.

[For mechanical quantity sensors that measure force, torque, etc., sensors that utilize the stress-magnetic effect of amorphous magnetic alloys have been attracting attention in recent years.According to this dynamic sensor, Contact detection is possible. (2) Force can be directly converted to zero electricity. ■The device structure as a sensor is simple and miniaturization is achieved. ■Amorphous magnetic alloys are high-strength, high-toughness materials that are corrosion-resistant and completely elastic, so they have advantages such as excellent environmental resistance and the ability to withstand a wide range of usage conditions. As an example, a ribbon 01 of an amorphous magnetic alloy with positive magnetostriction that is sensitive to the stress-magnetic effect is rotated around the rotation axis 02.
A torque sensor that detects changes in the magnetic properties of the ribbon 01 due to the stress-magnetic effect by winding it around the ribbon 01 and introducing "torsional strain" generated on the rotating shaft 02 due to the torque T into the ribbon 01, thereby detecting 1-luke T. (See Figure 1).In an amorphous magnetic alloy with positive magnetostriction, when tensile stress is applied, the magnetoelastic energy in the tensile direction decreases,
There is a phenomenon in which magnetization becomes easier in that direction, and this phenomenon is called the stress-magnetic effect. In the torque sensor, this stress-magnetic effect is used to apply magnetization to the entire surface of the ribbon 01 in the circumferential direction. A uniform easy axis of magnetization (-axis magnetic anisotropy) Ku is given in the direction of the inclination angle α (α>45°) with respect to 03. However, when torque T acts on the rotating shaft 02, the second
As shown in the figure, the angle ± with respect to the axial direction of the rotating shaft 02
A stress σ expressed by the formula σ = 16, T (however, d is the outer diameter of rotation @02 and πd3) is generated in the 45° direction, and due to the stress-magnetic effect, −@magnetic anisotropy is also generated in the +σ direction. As a result, a synthesized easy axis Ku' is given. Generally, the magnetic permeability of a magnetic material changes depending on the direction of the axis of easy magnetization with respect to the direction of the magnetic field, so the change in the axis of easy magnetization (Ku-+Ku') is regarded as a change in magnetic permeability, and the torque T Largeness can be detected. Therefore, if a change in magnetic permeability (or magnetic flux density) is detected as a voltage change using, for example, an excitation coil (-primary coil) and a detection coil (secondary coil), a torque-output curve as shown in Figure 3 can be obtained. It will be done. However, the normally used amorphous magnetic alloys have poor linearity and a narrow mechanical quantity detectable range I, so they are used as detection elements in the low torque range. The stress-output curve of the amorphous magnetic alloy is as shown in Figure 4, and the slope of the curve is large near the stress -O, so the sensitivity is very high in that part.
In Fig. 1, the thin strip 01 is on the surface of the rotation ll1I102.
Coupled with the fact that the stress distribution generated in the ribbon 01 is not uniform due to the adhesive force when joining the
When the 1 to 1 torque acting on the rotation is zero, the detection output, which should originally be zero, is detected as a relatively large value due to the difference in the stopping angle of the rotation @02. The object of the present invention is to provide good linearity of the stress-magnetic characteristic curve, expand the range in which mechanical quantities can be detected, and make it possible to detect changes in a wide range of mechanical quantities. The object of the present invention is to provide a mechanical quantity detection element in which the slope of the characteristic curve near the car O is gentle. The purpose of this is to apply a coating that tends to generate tensile stress when deposited on the surface of a ribbon made of an amorphous magnetic alloy having positive magnetostriction, and to This is achieved by applying compressive strain in advance. For example, an amorphous magnetic alloy that is provided in the form of a thin ribbon by continuously supplying molten alloy onto a high-speed rotating copper drum and ultra-quenching it is produced without grain boundaries in its structure, and mechanically compared to crystalline alloys. Amorphous magnetic alloys, which are chemically and electromagnetically excellent ferromagnetic materials, and in particular, whose main component is iron, exhibit excellent linearity in stress-magnetic characteristics. By the way, since the amorphous magnetic alloy is a material obtained by freezing a liquid structure, its atomic distribution state is similar to a liquid phase state and has a lower density than a crystalline body (crystalline alloy). Therefore, the attraction between atoms is assumed to be larger than that of a crystalline body. If this assumption is followed, the stress -〇 in the characteristic curve a shown in Fig. 4 will appear to be an upper value, and for example, as shown in Fig. 5, it can be considered that the curve connected to the characteristic curve a is latent. The stress ≥
If the characteristic curve C shown in FIG. 6 can be obtained, the stress-magnetic characteristics will be significantly improved. As a result of conducting experiments with such assumed r, the present inventors found that
By applying compressive strain (compressive stress) in advance to an amorphous magnetic alloy ribbon having positive magnetostriction, the characteristic surface I! i
It was confirmed that IC could be achieved. To impart compressive strain, it is easy to coat the surface of a ribbon made of an amorphous magnetic alloy with a metal or organic material that tends to produce tensile stress when deposited. Specifically, a synthetic coating is formed on the surface of the ribbon using a vapor phase plating method (sputtering method, vacuum evaporation method) or an electroplating method, or a resin material in the form of a melt (or slime) (preferably a resin adhesive) is formed. After being applied to the surface of the ribbon, it is cured, and compressive strain is applied to the ribbon depending on the adhesion of the coating to the ribbon. The obtained mechanical foot detection element can be used by attaching it to an object to be measured, and can also be suitably used as a single unit in a load detection device, a compression detection device, etc. When a coating is applied to the surface of a substrate by a vapor phase plating method or an electroplating method, internal stress is generated to a greater or lesser extent in the coating. In the electroplating method, it is known that internal stress can be adjusted using a brightening agent. For example, the primary brightener in a nickel plating bath functions as a Mu stress reducer, imparting compressive stress to the coating (tensile stress acts on the substrate), and adding a secondary brightener to this causes tensile stress (
(compressive stress acts on the substrate), the electrodeposition stress increases. In addition, 1 fll of a resin liquid having thermal expansion (contraction) characteristics different from those of the amorphous magnetic alloy is applied to the surface of the crystalline magnetic alloy ribbon, and the adhesion relationship relatively seals the thermal deformation of the ribbon. Compressive strain can be applied to the strip. For example, it is preferable to impart compressive strain to at least a portion of the amorphous magnetic alloy ribbon by applying a thermosetting resin film with a curing temperature of 93°C; The band is the operating temperature range of the dynamics detection element (normal dynamics detection elements are used at room temperature of 25°C, so the operating temperature refers to temperatures above or below normal temperature). The coated thin ribbon obtained by heating the resin to a curing temperature exceeding 100 mL may be returned to the operating temperature when used as a mechanical quantity detecting element. Since the internal stress of the coating applied to the ribbon increases as the thickness increases by n, it is effective to increase the thickness of the coating in order to impart a large compressive strain to the ribbon. However, it should be noted that if the thickness is increased to a certain extent, it will be easy to peel off from the thin ribbon that is the base. From this point of view,
It is recommended that the thickness of the metal plating coating be kept below 10 μm. Person 15] ■F e meeting + Bn, vS, Lq, q C2 thin strip 1.2.3 (Dimensions: thickness 25 μm, length 10r: m,
A width of 25 seconds was prepared. (2) Thin strip 1 was not coated with any coating, and both sides of thin strips 2 and 3 were each coated with copper by 4.5 degrees by sputtering (Fig. 7). The thickness of coating 4 is 500A. The film thickness of coating 5 was 800A. The sputtering conditions are as follows. (2) The stress-magnetic properties of ribbons 1.2.3 were examined using the J apparatus shown in FIG. 8 as specimens. The results are shown in FIG. 9 as a stress-relative permeability curve. In FIG. 8, reference numeral 6 indicates a hanging tool that grips the upper part of the specimen over its entire width, and a gripping tool 7 is attached to the lower side of the specimen over its entire width, and is attached to a hook 8. A variable tensile force is applied to the specimen by the stopped weight 9. In addition, coils (0.19 mmφ formal copper wire 80T) 10 were installed on both sides of the specimen, and 1 K11z
, 1. The inductance was obtained by applying an IV sine wave alternating current, determining the inductance with an impedance analyzer, and converting this into relative permeability. As described above, this relative magnetic permeability changes depending on the magnitude of the tensile stress applied to the ribbons 1, 2.3. Therefore, by measuring the induced voltage, the magnitude of the tensile force (the load on the weight 9) can be determined. The stress-relative permeability curve in Figure 9 shows the weight of the ribbon 1.2°3. ! 9 is changed, and the magnitude of the load is taken as a change in relative magnetic permeability. Evaluation of test results> ■ Comparing the characteristic curves of Young Strip 1 and Thin Strip 2.3, it can be seen that it is effective to apply a copper coating using the sputtering method to the surface of the A-band. I understand. That is, similar to curve C in FIG. 6, a curve with an expanded linear range is obtained. ■Comparing the characteristic curves of thin strips 2 and 3, the larger the thickness of the copper coating, the more effective it is, and as the I11 thickness increases, the curve shifts to the right, and the stress detection range increases (I2 < I
3) It turns out. It is clear that as the thickness of the copper cladding increases, its own internal stress increases, and this internal stress increases the compressive strain capacity of the ribbon (note that tensile stress occurs in the copper cladding). This is thought to cause the characteristic curve to shift to the right. Note that the excellent linearity of the characteristic curve means that no auxiliary computing equipment is required. Hetglas 260 manufactured by Allied Co., Ltd. by single roll method
A thin ribbon made of an amorphous magnetic alloy made of 5SC (trade name) (dimensions: 400 mm x 7 # x 25 μm) was prepared. ■ Apply epoxy resin adhesive Araldite X N 1244 (trade name) manufactured by Ciba Geigy Co., Ltd.
Thermal expansion coefficient 10X 10-5/'C)
After the resin adhesive was put into a constant temperature bath at a temperature of 150° C. and cured, it was taken out from the constant temperature bath and allowed to cool. (2) Next, the stress-magnetic characteristics (stress-output (voltage V)) of the obtained test piece were investigated in the same manner as in the case shown in FIG. The results are shown in FIG. Evaluation of test results> The curve shape in Figure 10 almost coincides with curve C shown in Figure 6, and if compared with curve a (see Figure 4), it is extremely effective to apply compressive strain. It turns out that. As is clear from the above explanation, a coating that tends to generate tensile stress by adhesion is applied to the surface of a ribbon made of an amorphous magnetic alloy with positive magnetostriction, and A dynamic detection element has been proposed in which at least a portion of a thin ribbon is subjected to compressive strain in advance due to adhesion. The mechanical m-detecting element of the present invention has improved stress-magnetic characteristics and an expanded range of mechanical quantity detection compared to an amorphous magnetic alloy piece (mechanical quantity detecting element) to which no compressive strain has been applied in advance. Because of this, it has a wide range of applications. Furthermore, since the mechanical m-sensing element of the present invention is formed by coating the surface of a thin strip, it can be expected to improve corrosion resistance, especially when the coating material is copper or gold-2 synthetic resin. Furthermore, in the mechanical m-detecting element of the present invention, by coating not only one side but both sides of the ribbon, the compressive strain m applied to the A9 band can be increased, and the mechanical m detection elements may be provided.

[Brief explanation of the drawing]

Figures 1 and 2 are diagrams explaining the principle of detecting the torque applied to the shaft by joining a ribbon made of an amorphous magnetic alloy around the shaft, and Figure 3 is a diagram showing the principle of detecting the torque applied to the shaft. A graph showing a torque-output curve as an example of shaft torque measurement by a torque sensor using a mechanical base detection element, Fig. 4 is a graph showing stress-magnetic characteristics of an amorphous magnetic alloy, Figs. 5 and 6. 7 is a graph showing stress-magnetic characteristics for detailed explanation of the present invention, and FIG. j3
Figure 8 is a cross-sectional view of the main part of a magnetic alloy ribbon;
The figure is a graph showing the stress-relative permeability characteristics of a known mechanical quantity detecting element and a mechanical quantity detecting element f of the present invention. (llas2605SC) [?Stress in band-
It is a graph showing magnetic properties. 1.2.3...Thin strip, 4,5...Copper coating, 6...
Hanging shell, 7... Gripping tool, 8... Hook, 9... Weight,
10...Coil.

Claims (4)

[Claims] (1) In a mechanical quantity detecting element that utilizes the stress-magnetic effect of an amorphous magnetic alloy with positive magnetostriction, there is a tendency for tensile stress to occur due to adhesion on the surface of a ribbon made of an amorphous magnetic alloy. 1. A mechanical quantity detecting element characterized in that the ribbon is coated with a certain coating, and at least a portion of the ribbon is subjected to compressive strain in advance due to the adhesion of the coating. (2) The mechanical quantity detecting element according to claim 1, wherein the coating is applied to both sides of the ribbon. (3) The mechanical quantity detection element according to claim 1, wherein the coating is a film of copper, gold, other pure metal, or an alloy film. (4) The mechanical quantity detecting element according to claim 1, wherein the coating is a pure metal film or an alloy film formed by vapor phase plating.