JPH05133752A - Vibrator - Google Patents

Abstract

PURPOSE:To measure the angular velocity precisely and stably by forming those two of the side faces of a vibratory body which are not parallel as surfaces having crystal grains of the same azimuth orientation. CONSTITUTION:A rolled plate 4 consisting of elinver alloy has surfaces in parallel with the rolled face, which are mostly {110}, wherein the direction parallel to the rolling is mostly <112>. Accordingly the rolled plate 4 is mostly composed of crystal grains having the <110> direction perpendicular to the plane 4a, <112> direction perpendicular to the side face 4b perpendicular to the rolling direction, and <111> direction perpendicular to the side face 4c in parallel with the rolling direction. To prepare a tuning fork type vibrator 1 in aquare column, whose face parallel to the plane 4a is the 1st side face, from the rolled plate 4, cutting-out is made while the cutout direction of the vibrator long axia direction L is inclined approx. 33-37 deg. to the rolling direction 5, two side faces 2a, 2b have majorly {110} planes, and crystals are situated in the same azimuth. The same applies to four side faces, and all surfaces can be provided with approx. identical moduli of elasticity, magneto-strictive coefficient, and temp. dependency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibrator, and more particularly to a vibration piece type vibrator for a vibrating gyroscope used in the fields of automobile navigation systems and automatic traveling robots.

[0002]

2. Description of the Related Art FIG. 5 (a) is a perspective view showing the structure of a conventional sound piece type vibrator. This conventional vibrator has piezoelectric elements 2a to 2d on side surfaces 1a to 1d of a vibrating body 1 having a rectangular cross section.
The transducer 3 is formed by attaching d.

FIG. 5 shows such a vibrator 3.
As shown in (b), a driving AC voltage is applied to the piezoelectric elements 2a and 2d to cause the vibrator 3 to bend and vibrate in the Y-axis direction, and Z
When the rotational angular velocity acts around the axis, Coriolis force is generated in the direction (X-axis direction) perpendicular to the vibration (Y-axis). The rotational angular velocity can be known by detecting this force as a voltage difference generated between the piezoelectric elements 2b and 2c attached in the X-axis direction.

As a material for such a vibrating body 1, an alloy having a constant elasticity property such as elinvar (Fe-Ni alloy) is conventionally used. These alloys are cold rolled into a plate shape, and the vibrating body 1 is cut out from the rolled plate 4 as shown in FIG. That is, after the longitudinal direction of the vibrating body 1 is cut so that the rolling direction or the direction orthogonal to the rolling direction, heat treatment is performed to adjust the temperature dependence of the elastic constant, and the vibration of the vibrator 3 is generated. It is processed and used so that the state is always stable against changes in ambient temperature.

[0005]

However, a cold-rolled sheet is a cold-rolled sheet in which each crystal grain undergoes stagnation deformation and is flattened, and therefore the rolled sheet exhibits anisotropy. become. That is, in the case of such a rolled plate, at least the crystal on the surface of the plate has the direction of a certain surface thereof substantially parallel to the rolled surface (rolling surface), and the direction of these crystals is parallel to the rolling direction of the plate. .. The crystal orientation as if it was affected by rolling can be relaxed to some extent by the heat treatment, but it is impossible to form a polycrystal aggregate having completely random crystal orientations.

Therefore, for example, the vibrating body 1 is shown in FIG.
In the case of the one used as shown in FIG. 3, since the two non-parallel side surfaces 1a, 1b have different elastic constants, magnetostriction constants, temperature dependences, etc., there is a difference in the resonance frequency and its temperature anisotropy depending on the bending direction of the vibrator 1. Then, the piezoelectric element 2 shown in FIG.
There is a problem in that the detection characteristics of b and 2c differ from each other, which makes it impossible to stably and accurately detect the rotational angular velocity.

An object of the present invention is to overcome the above-mentioned problems that conventional oscillators have. Therefore, it is possible to realize accurate and stable measurement of angular velocity by eliminating the difference in detection characteristics between so-called piezoelectric elements. To provide a simple oscillator.

[0008]

As a structure of a vibrator which meets the above-mentioned object, the present invention provides a resonator element vibrating body having a polygonal cross-sectional shape, which is manufactured by using a rolled metal material. We propose a vibrator in which at least two non-parallel sides of each side of the vibrating body are configured to have crystal grains in substantially the same orientation. This oscillator has one side surface parallel to the rolling surface, and the other side surface orthogonal to this side surface with respect to the rolling direction is 33 to 37 ° (35.3 ° ± 3 °).
It is one of the preferable modes that the vibrator is configured to be cut out at an inclination of 2 °), preferably at an inclination of 35.3 °. This oscillator has a cross section whose parallel surface is aligned with the rolling direction and has a first side surface parallel to the rolling surface and a second side surface having an inclination of approximately 60 ° or approximately 120 ° with respect to the first side surface. It is one of the preferable modes to provide a vibrator having a polygonal cross-sectional shape configured by providing the side surface of This oscillator has a cross section whose parallel surface is aligned with the rolling direction and has a first side surface having an angle of 60 ° with the rolling surface and a first side surface having an angle of approximately 60 °. It is one of the preferable modes to make a vibrator having a polygonal cross-sectional shape configured by providing two side surfaces. This oscillator is formed by cutting its transverse section into parallel planes aligned in the rolling direction, and cutting each of the first and second side faces at an angle of approximately 45 ° with respect to the rolling plane of the raw metal material. A vibrator is one of the preferable modes.

Further, each of the above-mentioned vibrators may be formed by rolling at least four side faces of a polygonal column forming a vibrator. The vibrator obtained in this manner can also be expected to have the same effects as those obtained by cutting the rolled metal material described above.

Further, in these vibrators, even if a polygonal column forming a vibrating body is manufactured by a drawing method, the same action and effect as above can be expected.

[0011]

In the vibrating body of the present invention, at least two non-parallel side surfaces of the vibrating body are formed as surfaces having crystal grains of substantially the same orientation, so that the characteristic of each side surface of the polygon, that is,
Since the elastic constants and magnetostriction constants depending on the bending direction of the vibrating body and their temperature dependences can be made the same, the resonance frequency of the detection surface can be stabilized, which in turn enables stable detection of the angular velocity. To do.

In particular, when this vibrating body is cut out from a rolled metal material, one side surface thereof is parallel to the rolling surface and the other side surface orthogonal to the side surface is 35.3 ° with respect to the rolling direction.
If the inclination is ± 2 °, or if the angle between each side surface and the rolling surface or another side surface is approximately 60 ° or 120 °, each side surface becomes {110} dominant. thing,
Further, when the angle is set to about 45 °, there is no dominant surface and the surface becomes random, and in any case, the orientational arrangement of the crystal grains on the two side surfaces becomes the same, and the above-described action and effect can be obtained.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an orientational arrangement of crystal grains of a rolled plate made of an enliver alloy which is a material of a vibrating body. In this rolled plate 4, since there are many {110} planes substantially parallel to the rolled surface 4a and many <112> directions parallel to the rolled direction, this rolled plate is perpendicular to the rolled surface 4a. Na <
Most of the crystal grains have a <110> direction, a <112> direction perpendicular to the side surface 4b perpendicular to the rolling direction, and a <111> direction perpendicular to the side surface 4c along the rolling direction.

Therefore, in the case of manufacturing the quadrangular prism-shaped vibrating piece type vibrating body 1 having the plane parallel to the rolling plane 4a as the first side surface from the rolling plate 4 having the above-mentioned azimuth arrangement, FIG. As shown, the cutting direction (θ) in the long-axis direction L of the vibrator is 33 to 37 ° with respect to the rolling direction 5, preferably about 3
It may be cut out at an inclination of 5.3 °. When such material removal is performed, for example, the rolling surface of the rolling plate 4 having the orientational arrangement shown in FIG.

[Outer 1] Therefore, by cutting out at such an angle, the other side faces orthogonal to the rolling face have a large number of (110) faces as crystal grain faces that are substantially parallel to that face. The two side surfaces 2a and 2b have crystals having substantially the same orientation.

Further, FIG. 2 (c) shows the index of the preferential surface among the crystal grain surfaces substantially parallel to the side surfaces of the quadrangular prism vibrating body 1. In this case, in the longitudinal direction of the quadrangular prism, the crystal grains having the <100> orientation increase.

Therefore, the preferential planes of the four side surfaces of the cut-out rectangular prismatic piece are both {110} planes, and the transverse plane is preferentially the {100} plane. The azimuth arrangements are almost the same, and therefore, the elastic constants and magnetostriction constants of the respective surfaces of the vibrating body or their temperature dependences can be made almost uniform.

Therefore, the piezoelectric elements 1a to 1d are attached to the respective side faces 1a to 1d of the vibrating body 1 thus manufactured,
A vibrator 3 having a quadrangular cross-sectional shape as shown in FIG.
Formed. Then, as shown in FIG. 5 (b), a driving voltage was applied to the piezoelectric bodies 2a and 2d, and this vibrator was flexurally vibrated in the Y-axis direction. Then, the arrow 9
When the rotational angular velocity (Ω) indicated by is applied, the vibrator 3 flexurally vibrates in the X-axis direction and Coriolis force is generated. There is a difference in angle, and the angular velocity can be detected.

In the structure of such a vibrator, the crystal orientations of the four side surfaces are substantially the same, so that the resonance frequencies in the two vibration directions and the temperature dependences thereof are always the same, and therefore constant. Can be stabilized.

As a method of detecting the drive of the vibrator 3, as shown in FIG. 5C, the vibrator 3 is vibrated in the Y-axis direction by the piezoelectric elements 2a and 2b attached to the adjacent surfaces which are not parallel to each other. Then, when the vibration in the X-axis direction excited by this is detected by the piezoelectric elements 2a and 2b to detect the angular velocity (Ω), the vibration direction is the combination of the vibrations of the two side surfaces of the quadrangular prism. Therefore, by making the elastic constants of the two side surfaces uniform, the vibration direction can be accurately taken in the diagonal direction of the prismatic cross section, and the deviation of the detection sensitivity of the piezoelectric elements 2a, 2b due to the temperature change of the resonance frequency can be eliminated, and the input angular velocity can be eliminated. The offset level can be stabilized at the same time when there is no error.

FIG. 3 (a) shows a modified example of the vibrator of the present invention, showing an example in which a vibrator 6 having a regular triangular cross section is cut out from the rolled plate 4, and the crystal grains It is the figure which looked at rolling plate 4 with which the direction arrangement was arranged from side 4c. When one side surface (bottom surface) of the equilateral triangle is cut out in parallel with the rolling surface 4a as shown in FIG. 4B, the crystal grain surface almost parallel to the three side surfaces of the triangular prism as shown in FIG. Since all of them are faces with a large amount of {110}, it is possible to make the crystal grains on each side surface of the triangular prism have the same orientation.

Therefore, as shown in FIG. 3D, the piezoelectric elements 7a and 7b are provided on the two side surfaces 6a and 6b of the vibrating body 6.
Are attached to form a vibrator. Then, the vibrator is vibrated in the Y-axis direction in the drawing by the piezoelectric elements 7a and 7b, and at the same time, the generated voltage of the piezoelectric elements 7a and 7b is fed back to the driving means to cause the vibrator to self-oscillate. When an angular velocity is applied to this oscillator, this oscillator vibrates in the X-axis direction in the figure, so that the angular velocity can be detected by the voltage difference generated between the piezoelectric elements 7a and 7b.

Also in this case, at the same time as described above, the vibrator is cut out from the rolled metal plate so that the crystal orientations of the two adjacent side surfaces 6a and 6b are aligned, so that the vibrator can be accurately moved in the vertical direction (X-axis and Y-axis directions). ), And the detection characteristics can be stabilized.

Next, FIG. 4 shows another modification of the present invention, in which the vibrating body has a square cross-sectional shape, and the four side surfaces are inclined by 45 ° with respect to the rolling surface. It is cut out to have. In the oscillator thus manufactured, the influence of the crystal grain orientation is small, and since there are no specific crystal axes oriented in the directions perpendicular to the four side surfaces, the elastic constants and the like are almost equal.

As described above, according to the present invention, the same effect can be obtained not only by the method of cutting the vibrating body from the rolled metal material but also by rolling and forging each of the four side faces of the square pole. So applicable. In such a vibrating body, since the four side surfaces are all rolling surfaces, the orientation of crystal grains is approximately the same.

In addition, as described above, the vibrator of the present invention may be manufactured by a method of pulling out a quadrangular prism which can be expected to have the same effect as described above. In many of the longitudinal directions, the crystal grains are oriented in the <111> direction, but the orientation of crystal grains is almost the same on each of the four side faces. As in (c), by attaching a piezoelectric element, it is possible to manufacture a vibrator with stable detection characteristics.

[0026]

As described above, in the vibrator of the present invention, the difference between the elastic constant and the magnetostriction constant depending on the direction of the bending vibration of the vibrating body having the polygonal cross-sectional shape and the difference in the temperature dependence thereof are considered. It can be lost. Therefore, stable angular velocity detection characteristics can be obtained, and such a vibrator can be easily manufactured.

[Brief description of drawings]

FIG. 1 is a diagram for explaining crystal orientations of a rolled plate used to manufacture the vibrator of the present invention.

FIG. 2 is a diagram for explaining a method of cutting out a vibrating body according to an embodiment of the present invention.

FIG. 3 is a diagram for explaining a method of cutting out a vibrating body according to another embodiment of the present invention.

FIG. 4 is a diagram for explaining a method of cutting out a vibrating body according to still another embodiment of the present invention.

FIG. 5 is a diagram for explaining a general configuration of a vibrator.

[Explanation of symbols]

 1, 6 Vibrators 2a, 2b, 2c, 2d, 7a, 7b Piezoelectric elements 3, 8 Vibrator 4 Rolled plate

Claims (5)

[Claims] 1. A vibrating piece type vibrating body having a polygonal cross-sectional shape, which is produced by using a rolled metal material as a raw material.
An oscillator that is configured as a plane with crystal grains that have almost the same orientation. 2. The vibrator according to claim 1, wherein one side surface of the vibrator is parallel to a rolling surface and the other side surface orthogonal to this side surface is 35.3 ° ± 2 ° with respect to the rolling direction. A vibrator obtained by cutting out at an inclination. 3. The vibrator according to claim 1, wherein a cross section of the vibrator is a parallel surface aligned in the rolling direction, and a surface parallel to the rolling surface is a first side surface, with respect to the first side surface. A vibrator having a polygonal cross-sectional shape with a second side surface having an inclination of approximately 60 ° or approximately 120 °. 4. The vibrator according to claim 1, wherein a cross section of the vibrator is a parallel surface aligned in the rolling direction, and a surface having an angle of 60 ° with the rolling surface is a first side surface. An oscillator having a polygonal cross-sectional shape, the second side surface of which is an angle of approximately 60 ° with the side surface of the. 5. The vibrator according to claim 1, wherein a cross section of the vibrator is a parallel surface aligned in the rolling direction, and the first and second side surfaces are substantially parallel to the rolled surface of the raw metal material. A vibrator made of a piece cut out at an angle of 45 °.