Vibrating gyroscope

The vibrating gyroscope includes, for example, a regular triangular prism-shaped vibrating body. Piezoelectric elements are respectively formed to the three side faces of the vibrating body. An oscillation circuit is connected between two piezoelectric elements and the other piezoelectric element. Two supporting members made of metal wire are mounted to vivinity of nodal points of the vibrating body in order to support the vibrating body. Both ends of the supporting members are fixed to a supporting board. A holding portion for holding a part of the vibrating body is formed on the supporting board. The holding portion is formed by a opening or a recess. The vibrating body together with an oscillation circuit and detection circuit can be mounted on the supporting board. The opening or the recess wherein a part of the vibrating body is held can have a extended portion to enlarge exposing portion of two side faces of the vibrating body.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention is related to a vibrating gyroscope and, more 
particularly, to the type of vibrating gyroscope that can be applied for a 
navigation system providing an appropriate guidance of a vehicle by 
detecting the position of a moving body by sensing its rotational angular 
velocity, or to the type of vibrating gyroscope that can be applied for a 
damping system such as preventing device for preventing shaking of hands 
that suppresses vibration by detecting an external vibration. 
2. Description of the Prior Art 
FIG. 6 is an exploded perspective view showing an example of a conventional 
vibrating gyroscope. 
The conventional vibrating gyroscope 1 shown in FIG. 6 includes a regular 
triangular prism-shaped vibrating body 2 made of a constant-elastic metal 
material such as elinver. On three side faces of the vibrating body 2, 
piezoelectric elements 3a, 3b, 3c are secured respectively by suitable 
means such as an adhesive(not shown). 
The piezoelectric elements 3a, 3b, 3c are made, for example, by forming 
electrodes on both surfaces of a piezoelectric ceramics. An oscillation 
circuit (not shown) described later is connected between the piezoelectric 
elements 3a, 3b and the piezoelectric element 3c. 
Two supporting members 5a and 5b made of metal wire are mounted on 
ridge-line portions in the vicinity of the nodal points of the vibrating 
body 2. Each of the supporting members 5a and 5b consists of a pair of 
legs 6, 6 and a connecting member 7 between two legs 6, 6, and is shaped 
like a U-shape in cross section. The legs 6, 6 of the supporting members 
5a and 5b are mounted on a rectangular-shaped supporting board 10 and each 
of the connecting members 7 are mounted on the ridge-line portions in the 
vicinity of the nodal points of the vibrating body 2. 
The supporting board 10 has two foot members 11, 11 extending downward from 
its both ends in the longitudinal direction. Each of the foot members 11, 
11 has a projecting piece 11a extending downward from the center of the 
bottom end of the foot member 11. Two projecting pieces 11a, 11a of the 
supporting board 10 are inserted into two holes 12a, 12a formed on a 
circuit board 12. The vibrating body 2 and the supporting board 10 are 
housed in a case 15. 
Circuit components 13, 13 containing an oscillation circuit and a detection 
circuit are mounted on the circuit board 12. By a signal from the 
oscillation circuit, the vibrating body 2 bends and vibrates in the 
direction perpendicular to the face on which the piezoelectric element 3c 
is formed. In this situation, when a rotation is applied around the 
central axial direction of the vibrating body 2, a vibration direction of 
the vibrating body 2 changes by a Corioli's force, according as a change 
of the vibration direction, a difference is generated between output 
voltages of the piezoelectric elements 3a and 3b. Thus, a rotational 
angular velocity applied to the vibrating gyroscope 1 can be detected by 
measuring the difference of the output voltages. 
However, since the vibrating body 2, the supporting members 5a and 5b, the 
supporting board 10 and the circuit board 12 are constructed to a vertical 
direction in the conventional vibrating gyroscope 1, it is tall, that is 
to say, it takes a large space in the vertical direction. Thus, when 
mounting the vibrating gyroscope 1 in the other device, it occupies large 
space in the vertical direction. This had been an obstacle to 
miniaturization of the device. Moreover, a manufacturing process had been 
complicated because the above each members are constructed to the vertical 
direction in the conventional vibrating gyroscope 1. 
SUMMARY OF THE INVENTION 
A major object of the present invention is to provide a vibrating gyroscope 
which is possible to reduce a height and simplify the manufacturing 
process and thus is easily manufactured. 
In order to achieve the above object, the vibrating gyroscope related to 
the present invention has a prism-shaped vibrating body, two supporting 
members are fixed in vicinity of nodal points of the vibrating body in 
order to support the vibrating body, and a supporting board for fixing 
both ends portion of the supporting members characterized in that there 
are provided a holding portion for holding a part of the vibrating body in 
the supporting board. 
The above holding portion is constructed by a opening or a recess. On the 
supporting board, circuit components are mounted together with the 
vibrating body. 
In the above stated configuration, a part of the vibrating body is held in 
the opening or the recess provided on the supporting board, so that a 
projecting size of the vibrating body in the vertical direction is 
reduced, and thus leads to smaller size of the vibrating gyroscope in 
height. The circuit components are mounted together with the vibrating 
body on the supporting board, so that there is no necessity for 
constructing a different board on which the circuit components are mounted 
below the supporting board. In this way, the height of the vibrating 
gyroscope can be further reduced. 
According to the present invention, the height of the vibrating gyroscope 
can be reduced ; and this is a help to miniaturize a device on which the 
vibrating gyroscope is mounted. A member which fix the supporting member 
for supporting the vibrating body is configured with a single supporting 
board, so that there is no necessity for constructing a plurality of the 
members to the direction of height as the prior art. Consequently, the 
number of parts can be reduced as a whole, and the manufacturing process 
is simplified and thus it is possible to lower costs.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 is a major portion perspective view of one embodiment of the present 
invention. 
A vibrating gyroscope 20 comprises a regular triangular prism-shaped 
vibrating body 22. The vibrating body 22 is formed with a constant-elastic 
metal material such as elinver, iron-nickel alloy, or is formed with a 
material which generally generates machanical vibration, such as guartz, 
glass, crystal, ceramics. Three piezoelectric elements 24a, 24b, 24c are 
secured respectively on three side faces of the vibrating body 22. The 
piezoelectric element 24a has a piezoelectric plate 26a made of 
piezoelectric ceramics, two electrodes 28a and 30a are formed on both 
surfaces of the piezoelectric plate 26a. The electrode 30a is secured to a 
side face of the vibrating body 22. Similarly, two piezoelectric elements 
24b and 24c have piezoelectric plates 26b and 26c (not shown), and 
electrodes 28b, 30b (not shown) and electrodes 28c, 30c (not shown) are 
formed on both surfaces of piezoelectric plates 26b and 26c. The 
electrodes 30b and 30c of the piezoelectric elements 24b and 24c are 
secured to surfaces of the vibrating body 22. 
Two supporting members 32a and 32b made of metal wire are mounted on 
ridge-line portions between two side faces on which the piezoelectric 
elements 24a and 24b are formed of the vibrating body 22. Each of the 
supporting members 32a and 32b consists of a pair of legs 34, 34 and a 
connecting member 36 between two legs 34, 34, and is shaped like a U-shape 
as a whole. One supporting member 32a includes the straight connecting 
member 36 extending in the transverse direction to the vibrating body 22 
and the two straight legs 34, 34 are bent downward from both ends of the 
connecting member 36. On the other hand, the other supporting member 32b 
is in the same structure as the supporting member 32a and has the 
connecting member 36 and a pair of legs 34, 34. 
The midpoints of the connecting members 36 of the supporting members 32a 
and 32b are secured by means of welding process or an adhesive to the 
ridge-line portions of the vibrating body 22 on which the piezoelectric 
elements 24a and 24b are formed. In this embodiment, let the length of the 
vibrating body 22 in the longitudinal direction be L, then the supporting 
members 32a and 32b are secured to the points 0.224 L away from opposite 
ends of the vibrating body 22 in the longitudinal direction. 
The tips of the legs 34, 34 of the supporting members 32a and 32b are fixed 
onto a surface of the rectangular supporting board 38. The supporting 
board 38 is made of a metal or a resin. In this situation, the vibrating 
gyroscope 20 is housed in a case 40. 
A part of the vibrating body 22 is held in a holding portion provided on 
the supporting board 38. That is, the supporting board 38 has a opening 42 
in a location near one end of the supporting board 38 as holding portion 
for holding the part of the vibrating body 22. The opening 42 pierces 
through the supporting board 38 from one main surface of the supporting 
board 38 to the other main surface of the supporting board 38, and the 
opening 42 is formed to a rectangular-shaped configuration from the 
viewpoint of a plane. The opening 42 is larger than one side face 
equivalent for the bottom face of the vibrating body 22. The vibrating 
body 22 is mounted on the supporting board 38 by two supporting members 
32a and 32b while its lower portion is held in the opening 42. 
Circuit components 44 which are an oscillation circuit and a detecting 
circuit are mounted in a location near the other side end of the 
supporting board 38. In this case, the circuit components 44 are mounted 
together with the vibrating body 22 on the supporting board 38 at a 
prescribed distance from the vibrating body 22. 
In the vibrating gyroscope 20 shown in FIG. 1, since the lower part of the 
vibrating body 22 is held in the opening 42 provided on the supporting 
board 38, the height of the vibrating body 22 above the supporting board 
38 is reduced when compared with the vibrating gyroscope based on the 
prior art. This results in a smaller size of the vibrating gyroscope 20 in 
height. Since the lower portion of the vibrating body 22 is held in the 
opening 42 provided on the supporting board 38, the length of the legs 34, 
34 of the supporting members 32a and 32b are shortened and thus the 
vibrating body 22 is fixed onto the supporting board 38 more strongly. 
Moreover, since the circuit components 44 are mounted together with the 
vibrating body 22 on the supporting board 38, an additional board for 
mounting the circuit components below the supporting board 38 is not 
necessary as is needed for the conventional vibrating gyroscope 1 shown in 
FIG. 6. Consequently, the height of the vibrating gyroscope 20 shown in 
FIG. 1 is smaller than the vibrating gyroscope based on the prior art. 
Since all the components are mounted on a single supporting board 38 in the 
vibrating gyroscope 20 constructed by this embodiment and the vibrating 
body 22 does not protrude upward from the supporting board 38, the entire 
height of vibrating gyroscope 20 can be reduced. Therefore, a plurality of 
the vibrating gyroscopes 20 can be piled easily as shown in FIG. 2. 
The vibrating gyroscope 50 shown in FIG. 2 is constructed by two vibrating 
bodies 22, 22 of two vibrating gyroscopes 20, 20 are piled up in a 
vertical direction in a way two vibrating bodies 22, 22 are perpendicular 
to each other. Thus, rotational angular velocity in two directions can be 
detected by the vibrating gyroscope 50. Moreover, rotational angular 
velocity in three or more of directions can be detected by means of making 
a pile of three or more of the vibrating gyroscopes 20. 
FIG. 3 is a major portion plane view a modified example of the vibrating 
gyroscope shown in FIG. 1. 
As the opening, its shape can also be cross-shaped configuration from the 
viewpoint of a plane like the opening 52 as shown in FIG. 3. The opening 
52 has two extended portions 54, 54 to enlarge exposing portion of two 
side faces of the vibrating body 22 on which the piezoelectric elements 
24a and 24b are secured as compared with the opening 42 shown in FIGS. 1 
and 2. 
Thus, a manufacturing such as trimming for frequency adjustment can easily 
be performed on side faces of the vibrating body 22 in the vibrating 
gyroscope 20 shown in FIG. 3. 
FIG. 4 is a major portion sectional view of an another modified example of 
the vibrating gyroscope shown in FIG. 1. 
In this modified example, particularly, the upper part of the vibrating 
body 22 is held in the opening 42 of the supporting board 38, as compared 
with each of embodiments show in FIGS. 1, 2 and 3. In this case, the 
supporting members 56 are straight in shape, and both ends of them are 
fixed to end of the peripheries of the opening 42. In other words, 
supporting member 56, the members corresponding to the supporting member 
32a (32b), a pair of legs 34, 34 and connecting member 36 shown in FIGS. 
1, 2 and 3 are designed to a single straight member. 
In the vibrating gyroscope 20 shown in FIG. 4, similarly to the modified 
example shown in FIG. 3, a manufacturing can also be performed easily on 
the two side faces of the vibrating body 22, so that this facilitates 
trimming for frequency adjustment. 
FIG. 5 is a major portion expanded sectional view of an another embodiment 
of the present invention. 
In the vibrating gyroscopes shown in FIGS. 1-4, a opening is formed to the 
supporting board 38 as holding portion for holding a part of the vibrating 
body 22. However, the holding portion is not limited to a opening, but it 
can be a recess 58 as shown in FIG. 5 depending on the thickness of the 
supporting board 38. 
It will be apparent from the foregoing that, while the present invention 
has been described in detail and illustrated, these are only particular 
illustrations and example, and the invention is not limited to these. The 
spirit and scope of the invention is limited only by the appended claims.