JPH0480321B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a piezoelectric vibration type angular velocity sensor.

[Conventional technology]

Conventionally, this type of angular velocity sensor was developed by
There is one described in Publication No. 58-174854. This has the configuration shown in FIG. That is, drive parts 1, 1' formed of piezoelectric material on the front and back surfaces of a metal plate.
, and detection parts 2 and 2' formed of piezoelectric material on the front and back surfaces of a metal plate are arranged perpendicularly to each other with adhesives 3 and 3' interposed therebetween. Then, an AC voltage is applied to the driving parts 1 and 1', and the phases of the driving parts 1 and 1' are shifted by 180 degrees, and the driving parts 1 and 1' are driven in opposite directions of the arrows in the figure with respect to the central axis A. When an angular velocity is generated around the central axis A during the vibration, the detection parts 2, 2' move in a direction perpendicular to the vibration direction of the drive parts 1, 1' due to the well-known Coriolis force. The angular velocity is detected by measuring the electrical signals generated in the piezoelectric bodies of the detection parts 2 and 2' as the piezoelectric body bends.

[Problem to be solved by the invention]

However, in the conventional device described above, the drive unit 1,
1' and the detection parts 2, 2' are directly orthogonally arranged and connected, so the connection strength between the two is weak.
There is a problem in that the repeated vibration modes tend to cause fatigue in the connecting portion, and in some cases, it becomes impossible to detect the angular velocity.

The present invention attempts to solve the above-mentioned problems by improving the bonding strength between both plate-shaped parts.

[Means to solve the problem]

The present invention has been devised in view of the above points, and has a first plate-shaped portion and a second plate-shaped portion arranged in a mutually orthogonal relationship, and a piezoelectric The angular velocity sensor has a structure in which a driving part made of a body is formed and a detection part made of a piezoelectric material is formed in a second plate-like part, and both plate-like parts are substantially flat and rectangular. A connecting portion having a plate-like shape extending in a direction perpendicular to both the plate-like portions is arranged between the two plate-like portions, and the two plate-like portions are brought into an orthogonal relationship via the connecting portion. The first plate-like part, the second plate-like part, and the joint part are formed by an integrated substrate.

[Effect]

The plate-shaped parts forming the drive section and the detection section are connected by a plate-shaped joint extending in a direction perpendicular to them, so both plate-shaped parts are perpendicular to each other. Nevertheless, the connecting area between the two plate-shaped parts can be secured by the above-mentioned connecting portion.

〔effect〕

The instability of the bonding strength between the first plate-shaped portion and the second plate-shaped portion is eliminated, and fatigue failure of the bonded portion between both plate-shaped portions can be avoided, thus providing an angular velocity sensor with good durability. .

〔Example〕

In FIGS. 1 to 3, 40 and 41 are a pair of substrates according to the present invention, and have a thickness of, for example, 0.5 mm.
Made of Fe-Co-Ni alloy metal.

The substrates 40 and 41 have substantially flat and rectangular first plate portions 44 and 45 and second plate portions 46 and 47 on both sides of the substantially square connecting portions 42 and 43, respectively. It is the composition. The plate-like parts 44 to 47 are arranged in a perpendicular relationship to each other, and the coupling portion is arranged at the orthogonal part of both the plate-like parts 44 to 47 so as to extend in a direction perpendicular to both the plate-like parts. 42 and 43 are arranged. The connecting portions 42 and 43 include both plate-like portions 44 to 47.
It has a width dimension that is almost the same as that of .

These plate-like parts 44, 45 and the coupling part 42, and the plate-like parts 46, 47 and the engaging part 43 are connected to the substrate 4.
0.41.

As a method for this integration, there is a method such as cutting, which is well known as a general processing technique.

Reference numerals 50 and 51 denote driving piezoelectric bodies formed by adhesion on opposite surfaces of the first plate-like parts 44 and 45, and 52 and 53 represent the second plate-like parts 4.
6 and 47 by adhesion, and these piezoelectric bodies 50 to 53 are, for example,
Made of 0.2mm thick PZT ceramic.

The polarization directions of the driving piezoelectric bodies 50 and 51 are shown in FIG.
It is in the direction of the arrow.

60 is a metal terminal part, and the metal terminal part 60 is the first
It is fixed by welding, soldering, etc. on the plate-shaped portions 42 and 43 sides.

70, 71, and 72 are terminal portions, respectively. The terminal section 70 is connected to the piezoelectric body 5 as the detection section.
Lead wires 80, 81 electrically connected to 0, 51
The terminal portion 71 has lead wires 82, 8 electrically connected to the piezoelectric bodies 50, 51 as driving portions.
It has 3.

The lead wires 80, 81 are arranged along the side edges of the engaging portions 42, 43 and the first plate-like portions 44, 45.

The terminal portion 72 is connected to the substrates 40, 41 and the lead wires 8.
It is electrically connected to the terminal section 60, which functions as a common terminal section, through terminals 0 to 83 to apply an alternating voltage to each piezoelectric body 50, 51.

90 is an AC voltage application source, and 100 is a detection circuit.

In the above configuration, the operation will be explained next. An AC voltage is applied from an AC voltage application source 90 to the drive piezoelectric bodies 50 and 51 via the terminal portions 71 and 72 . As a result, the drive piezoelectric bodies 50 and 51 expand and contract, which causes the first plate-like portions 44 and 4 to expand and contract.
5, the plate-shaped portions 44 and 45 are driven and vibrated symmetrically in opposite directions with respect to the central axis A with a phase shift of 180° as shown in FIG.

In such a vibration state, when an angular velocity is generated around the central axis A, the second plate-like portions 52 and 53 of the sensing portion are bent as indicated by the arrows in FIG. 1 due to the well-known Coriolis force. As a result, the piezoelectric body 5 of the detection part
2 and 53 are subjected to an expansion and contraction action, and an electric signal corresponding to the expansion and contraction is sent to the detection circuit 10 via the terminal parts 70 and 72.
0, and the angular velocity is electrically detected here.

Although the drive piezoelectric bodies 50, 51 and the detection piezoelectric bodies 52, 53 are formed on one side of the first plate-like parts 44, 45 and the second plate-like parts 46, 47, as shown in FIG. Of course, it may be formed on both sides (in the figure,
Although only one side of the detection piezoelectric bodies 52 and 53 is illustrated, they are also formed on the other side.

Further, in the above embodiment, the substrate is made of metal, but it may be made of ceramic, for example. In this case, it is necessary to provide a lead wire for grounding each piezoelectric body.

Furthermore, it is also possible to form the detection section in the first plate-shaped part and the drive part in the second plate-shaped part.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing one embodiment of the present invention;
3 is a partial sectional view including an electric circuit, showing another embodiment of the present invention, and FIG. 4 is a perspective view showing a conventional technique. 40, 41... substrate, 42, 43... joint part,
44, 45...first plate-shaped portion, 46, 47...
Second plate-shaped portion, 50, 51...driving piezoelectric body,
52, 53... piezoelectric body for detection, 80-83... lead wire.

Claims (1)

[Scope of Claims] 1. A first plate-shaped part and a second plate-shaped part are arranged in a mutually orthogonal relationship, and a driving part made of a piezoelectric material is provided in the first plate-shaped part. The angular velocity sensor has a second plate-like part formed with a detection part made of a piezoelectric material, wherein both the plate-like parts are substantially flat and rectangular, and between the two plate-like parts, A connecting portion having a plate-like shape extending in a direction orthogonal to the both plate-like portions is arranged, and the both plate-like portions are connected in an orthogonal relationship via the connecting portion, and the first An angular velocity sensor characterized in that the plate-shaped portion, the second plate-shaped portion, and the coupling portion are constituted by a substrate having an integral structure. 2. The angular velocity sensor according to claim 1, wherein two sets of the substrates are arranged facing each other at symmetrical positions with respect to a central axis. 3. Claim 1, characterized in that the connecting portion has a substantially rectangular plate shape whose dimension in the extending direction is at least approximately the same as the width dimension of both the plate-shaped portions. Or the angular velocity sensor according to item 2. 4. Claims characterized in that the lead wire connected to the detection part of the second plate-shaped part is arranged along the coupling part and the side edge of the first plate-shaped part. The angular velocity sensor according to any one of Items 1 to 3.