JPH04326065A - Vibration-proof apparatus of angular velocity sensor - Google Patents

Abstract

PURPOSE:To obtain a vibration-proof apparatus for reducing the phase delay to the angular velocity around the angular velocity input shaft of a vibrator. CONSTITUTION:A vibrator part 1 constituted of a cylindrical receiving part 1b and the tuning fork type vibrator 1a received in the receiving part 1b is mounted and a support part 2 protruding in a flange shape is fixed to the outer periphery of the vibrator part 1 by welding. A base member 3 having protruding parts 3b on which the support part 2 is placed formed thereto is mounted and the half of the vibrator part 1 is received in the recessed part 3a of the base member 3. The support part 2 is opposed to the base member 3 so as to provide a predetermined interval from the protruding parts 3b of the base member 3 and elastomers 4-7 are arranged to the interval parts. The periphery of the Z-axis being the angular velocity input axis of a vibrator 1a becomes rigid constitution by said elastomers 4-7 and flexible constitution is obtained with respect to the Y-axis in the vibration direction of the vibrator 1a and the X-axis in a Coriolis force acting direction.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration isolating device for an angular velocity sensor that detects the angular velocity acting on a vehicle, for example.

0002

2. Description of the Related Art Conventionally, as a sensor of this type, a vibrating angular velocity sensor that utilizes Coriolis force is known (for example, Japanese Patent Laid-Open No. 62-52410). This vibrates the vibrator at a resonance point, detects the Coriolis force acting in a direction perpendicular to the vibration direction, and outputs the angular velocity by performing synchronous detection.

[0003] If vibration near the resonant frequency of the vibrator acts on the angular velocity sensor, an output error will occur, so a vibration isolator is conventionally provided. As shown in FIG. 3, elastic bodies 4 made of rubber etc.
, 5 are arranged, and the elastic bodies 4 and 5 absorb vibrations transmitted from the base members 3 and 3' (for example, vehicle running vibrations, etc.), and the vibrations are not transmitted to the vibrator. .

0004

[Problems to be Solved by the Invention] However, in conventional devices, vibrations transmitted from the base member are absorbed by the vibration isolating material, but vibrations are also damped around the angular velocity input axis of the vibrator. Therefore, there is a problem in that a phase lag occurs between the angular velocity that is actually occurring and the angular velocity that acts on the housing section that houses the vibrator.

The object of the present invention is to provide an angular velocity vibration isolator that does not cause such phase lag.

[0006]

[Means for Solving the Problems] According to the present invention, this problem is solved in a vibrating angular velocity sensor equipped with a vibrator, in which an accommodating portion for accommodating the vibrator and an angular velocity input axis of the vibrator intersect with each other. a support part fixed to the accommodating part so as to protrude in a direction in which the base member is supported at a predetermined interval, and a base member disposed at the interval between the base member and the support part. and an elastic body whose shear direction coincides with the direction intersecting the angular velocity input axis of the vibrator.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below with reference to embodiments shown in the drawings. In FIGS. 1 and 2, reference numeral 1 denotes a vibrator section, which is composed of a tuning fork type vibrator 1a and a housing section 1b. The accommodating portion 1b has a hollow cylindrical shape made of metal, and the tuning fork type vibrator 1a is accommodated and sealed inside the accommodating portion 1b. 2
is a metal support part, which is fixed to the housing part 1b by welding or the like so as to protrude in a direction crossing the Z axis, which is the angular velocity input axis of the vibrator 1a, and has a rectangular shape. are doing. Reference numeral 3 denotes a metal base member fixed to the body of an automobile, for example, and has a concave cross-section. The lower half of the accommodating portion 1 is disposed in the recess 3a of the base member 3. Elastic bodies 4 to 7 are made of, for example, silicone rubber and have a cylindrical shape. The elastic body 4
- 7 are arranged in contact between the four corners of the support part 2 fixed to the housing part 1 and both ends of the two convex parts of the base member 3. For example, the support part 2 and the base are connected by fixing fittings (not shown). It is fixed to member 3.

[0008] Generally speaking, when considering the vibration damping effect at a certain angular frequency ω, it is sufficient to consider the natural angular frequency ωn of the vibration damping mechanism. In other words, if ωn <<ω, a sufficient vibration damping effect can be obtained. Therefore, the natural angular frequency ω1 in the X direction, which is the direction in which the Coriolis force acts in FIGS. 1 and 2, or the Y direction, which is the vibration direction of the vibrator 1a, and the natural angular frequency ω2 around the Z axis, which is the angular velocity input axis. Find ω1 <<ω
By setting the relationship 2, there is no phase delay with respect to the actual angular velocity, and it is possible to sufficiently absorb vibrations from, for example, the vehicle body.

Now, the natural frequency ω in the X direction or Y direction
1 is

0010

[Equation 1] (K is the total spring constant of the elastic bodies 4 to 7 in the shear direction, M
is the mass of the vibrator section 1). On the other hand, when finding the natural frequency ω2 around the Z-axis, we get

[0011]

[Equation 2] (R is the distance from the central axis of the vibrator section 1 to the elastic bodies 4 to 7, I is the moment of inertia around the central axis of the vibrator section 1),

0012

[Math 3] I=M×r2/2 (r is the radius of the vibrator section 1), so

0013
]

It is expressed as [Equation 4]. Now, in order to make ω1 <ω2, R>
It is understood that the elastic bodies 4 to 7 may be disposed at a distance R greater than r, that is, the radius r of the vibrator portion 1. This means that fixing the support part 2 around the outer periphery of the vibrator part 1 and arranging the elastic bodies 4 to 7 at the four corners of this support part, as in the above embodiment, leads to the above relationship R>r. become. As a result, the configuration is rigid around the Z axis, which is the angular velocity input axis of the vibrator 1a, and the structure is rigid around the Z axis, which is the angular velocity input axis of the vibrator 1a, and
It has a flexible configuration in the axial and Y-axis directions.

[0014] In general, in an angular velocity sensor using a tuning fork type vibrator 1a, vibrations in the Y axis, which is the vibration direction of the vibrator 1a, and the X axis, which is the direction in which the Coriolis force acts, are Error output is likely to occur.

Therefore, in the elastic bodies 4 to 7, the shearing direction in which the spring constant becomes smaller is made to coincide with the X-axis and the Y-axis. In addition, the elastic body 4
The lower surface 2a of the support portion 2 supported by the vibrator 1
It is aligned with the center of gravity of Further, as the material for the elastic bodies 4 to 7, silicone rubber, which does not increase its spring constant even at low temperatures, is used in consideration of the environment in which vehicles, particularly automobiles, are used.

Although four elastic bodies are used in the configuration shown in FIG. 1, by changing the shapes of the support portion 2 and the base member 3, it is possible to achieve the desired objective even with three elastic bodies. Is possible.

[0017]

In summary, in the present invention, with an extremely simple configuration, the phase delay with respect to the angular velocity around the angular velocity input axis can be reduced without reducing the vibration damping effect in the vibration direction of the vibrator and in the direction in which Coriolis acts. It has the excellent effect of reducing

[Brief explanation of drawings]

FIG. 1 is a partially transparent perspective view showing the overall configuration of a vibration isolator.

FIG. 2 is a side view of FIG. 1;

FIG. 3 is a diagram illustrating a conventional configuration.

[Explanation of symbols]

1 Transducer section 1a Vibrator 1b Storage section 2 Support part 3 Base member 4-5 Elastic body

Claims (1)

[Claims] 1. A vibrating angular velocity sensor including a vibrator, comprising: a housing part that houses the vibrator; and a housing part fixed to the housing part so as to protrude in a direction crossing an angular velocity input axis of the vibrator. a support part, a base member on which the support part is supported at a predetermined interval, and a base member disposed at the interval between the base member and the support part and relative to the angular velocity input axis of the vibrator. A vibration isolating device for an angular velocity sensor, comprising: an elastic body whose shear direction coincides with the intersecting direction.