JPS62243220A - Piezoelectric relay - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a piezoelectric relay that utilizes distortion caused by an electrical load on a piezoelectric element used as a relay circuit for various industrial electronic control devices.

Conventional technology In recent years, electronic devices have become more and more power-saving, and conventional electromagnetic relay devices consume a lot of power.Recently, there has been a trend to utilize the distortion phenomenon of piezoelectric elements in relays to save power. I'm getting stronger.

Hereinafter, a conventional piezoelectric relay will be described with reference to the drawings. Conventionally, this type of piezoelectric relay has had a configuration as shown in FIG. In Fig. 2, 1 is a piezoelectric element, 2 is a metal deflection plate bonded to the piezoelectric element 1, 3 is a movable contact attached to the deflection plate 2, and 4 is composed of the piezoelectric element 1 and the deflection plate 2. A fixed contact 6 is attached to a position facing the movable contact 3 on a support base that supports the piezoelectric unimorph. Input electric wires 6a and 6b apply voltage to the piezoelectric element 1, and are directly connected to the deflection plate 2 and the piezoelectric element 1, respectively.

Regarding the conventional piezoelectric relay configured and constructed as described above,
The operation will be explained below. Now, when a voltage is applied to the piezoelectric unimorph consisting of the piezoelectric element and the deflection plate 2 from the input electric wires 6& and 6b, the piezoelectric unimorph curves as shown by the two-dot chain line in FIG. 2 (this phenomenon is well known). Yes, the principle itself is not directly related to the present invention, so the explanation will be omitted6)
.

At this time, the movable contact 3 provided on the deflection plate 2 comes into contact with the fixed contact 5 provided on the support base 4, and another control component (not shown) wired to the movable contact 3 and the fixed contact 6, respectively. turns on and operates, and when the input voltage applied to the piezoelectric unimorph is released, the piezoelectric unimorph returns to its original state and the movable contact 3 and fixed contact 6 are separated and o
The state will be yy, and the control parts will stop operating.

In addition, the present inventors recently proposed a piezoelectric relay with a new configuration as shown in FIG. 3 as a solution to the drawbacks of the conventional piezoelectric relay shown in FIG. 2.

The piezoelectric relay proposed by the present inventors will be described below. In Fig. 3, 7 is a case made of plastic or the like having a bottom surface and a protruding piece 7& at the upper end opening, 8 is a piezoelectric element, which is bonded to a metal deflection plate 9 with a larger diameter, and is shaped like a flat plate. A piezoelectric unimorph is formed, and when a voltage is applied, the piezoelectric element 8 curves to become a convex surface, and a plurality of piezoelectric unimorphs are assembled in the case T so that they alternately curve in opposite directions. It is stored freely in the case 7. 10 is an electrode plate made of a conductive material such as a metal plate provided between the surfaces of the piezoelectric elements of the piezoelectric unimorph, and 10a is an electrode plate made of a conductive material such as a metal plate arranged at the uppermost end.

11 is the piezoelectric element 8 at the top end! A movable contact 1 and 2 are provided at the center of the upper surface of the case 7, and fixed contacts 1 and 2 are provided on the inner wall of the protruding piece 71L of the case 7, facing the movable contact 11.

13& and 13b are input electric wires for applying voltage to the pressure type element 8 (8a), and each deflection plate 9 and electrode plate 10. It is directly connected to IQIL by soldering, etc.

The operation of the piezoelectric relay proposed by the present inventors having the above structure will be described below. FIG. 3 shows a state in which a voltage is applied to the piezoelectric unimorph so that the piezoelectric unimorph bends alternately in opposite directions, and the movable contact 11 and the fixed contact 12 are in contact with each other.As with the conventional example, the bending phenomenon of the piezoelectric unimorph is well known, so it will be explained. omitted. ), the control parts (not shown) connected to contacts 11 and 12 are turned on, and when the applied voltage is released, the piezoelectric unimorph returns to its planar state and contacts 10 and 11 are separated and connected to each other. The control parts that have been removed will be in the OFF state.

Problems to be Solved by the Invention In the former conventional configuration, as shown in FIG.
The amount of displacement is only about several tens of microns, and depending on the voltage level applied to the movable contact 3 and fixed contact 6, abnormal discharge may occur, and there is no dimensional margin during assembly.
Because the piezoelectric unimorph is fixed on a cantilever, the position of the movable contact 3 attached to the tip of the deflection plate 2 is extremely unstable in front and back, left and right, or up and down, and even during bending operation, the movable contact 3 and fixed contact 6 are This is inconvenient, as it causes malfunctions such as turning OFF or, conversely, turning ON even before bending. In addition, if the total length of the piezoelectric unimorph is set long in order to increase the amount of displacement, since it is a cantilever type, cracks may occur due to vibration etc. due to the strength of the piezoelectric element. (contact pressure) was also reduced, and reliable electrical switching could not be achieved, and in the worst case, the device could no longer function.

In addition, the latter configuration proposed by the present inventors eliminates the drawbacks of the former conventional example, and because the displacement amount is the sum of the displacement amounts of the combined piezoelectric unimorphs, it is large and easy to assemble. Since they are combined in a double-supported configuration, there is an advantage that the contact pressure during bending is also strong.

However, as a voltage application stage for bending the piezoelectric unimorph, input electric wires were connected directly to the deflection plate of the piezoelectric unimorph and the electrode plate placed between the surfaces of the piezoelectric elements and at the top, by means of soldering, etc. Since the piezoelectric unimorph and electrode plate must be assembled in advance with the input wires connected, disconnections or setting errors may occur frequently.
The bending motion sometimes became unstable due to solder build-up during soldering. Additionally, when attaching the input wire to the deflection plate, the piezoelectric element is heated, which deteriorates the characteristics of the piezoelectric element itself and significantly reduces the amount of curvature (displacement). There was also an element of uncertainty in terms of performance.

Means for Solving the Problem In order to solve this problem, the present invention provides a piezoelectric unimorph in which all of the metal plates constituting one of the electrodes for applying voltage to the piezoelectric element, and the piezoelectric element surface constituting the other electrode. The structure is such that each electrode rod is provided through each electrode plate so as to be electrically connected to all of the electrode plates provided between the electrode plates and the uppermost end thereof.

OPERATION This configuration provides, in addition to the advantages of the configuration according to our previous proposal, that all metal plates and electrode plates are each separately penetrated as a means of applying voltage to each of the combined piezoelectric unimorphs. By providing an electrically connected electrode rod, the piezoelectric unimorph and electrode plate can be simply assembled into the pre-installed electrode rod during assembly, making it easy to attach the piezoelectric unimorph and the electrode plate without any work such as soldering. The surface of the piezoelectric element and the electrode plate also maintain a uniform plane, and even when bent, the operation sound is stable and constant, and the piezoelectric element itself does not heat up due to /% bending, so it is stable. A highly reliable piezoelectric relay with good characteristics and no worries about disconnection etc. can be obtained.

Embodiment FIG. 1 shows the operating state of a piezoelectric relay according to an embodiment of the present invention. The explanation will be given below according to FIG. Furthermore, the third
The same parts as those in the figures are given the same numbers and the explanation will be omitted. In the figure, 14 is a case that replaces case 7, and the fixed contact 1
2 is provided at the upper end opening of the protruding piece 141Lft. 16 has an electrode rod 171L, which will be described later, on a part of its end.
″f: A metal deflection plate constituting a piezoelectric unimorph having through holes 15 &'ii for insertion, 1θ and 18 &
is provided between the faces of the piezoelectric element 8 and on the topmost piezoelectric element 8&, and constitutes one of the application electrodes, and a through hole 161 for inserting an electrode rod 17b'i, which will be described later, into a part of its end.
The electrode plates 17a and 17b having L'i are respectively penetrated by the deflection plate 16 and the electrode plates 16, 161L, and are electrically connected to all the combined deflection plates 15 and electrode plates 19, 16&. It is.

The operation will be explained below. Now, when the voltage applied to the piezoelectric unimorph is applied to the electrode rods 171L and 17b,
The piezoelectric unimorph is curved in the state shown in FIG. 1, and as in the conventional example, the curvature of the piezoelectric unimorph is well known, so a description thereof will be omitted. ), the movable contact 11 and the fixed contact 12 come into contact and turn on, and when the voltage application is removed, the movable contact 11 and the fixed contact 12 separate and turn off.

Effects of the Invention As described above, according to the present invention, all of the metal plates constituting one of the voltage application electrodes to the piezoelectric element of the piezoelectric unimorph and the piezoelectric element constituting the other electrode are provided between the surfaces and at the top end. By providing each electrode rod penetrated so as to be electrically connected to all of the electrode plates, each electrode can be easily assembled by simply incorporating the piezoelectric unimorph and the electrode plate into the electrode rods provided in advance during assembly. can be easily connected without soldering or wiring, leading to a significant reduction in man-hours during assembly and cost reduction of the piezoelectric unimorph. In addition, by omitting soldering, the piezoelectric element is prevented from being overheated, thereby completely preventing any deterioration in its characteristics, and the lack of solder texture improves operational stability by preventing irregularities on the operating surface, and causes instability such as wire breakage. It is highly reliable and has extremely high practical value in terms of cost.

[Brief explanation of drawings]

FIG. 1 shows the operation of a piezoelectric relay according to an embodiment of the present invention (
2 is a configuration diagram showing a conventional piezoelectric relay, and FIG. 3 is a cross-sectional view showing the assembled state of the piezoelectric relay proposed by the present inventors when it is activated (ON state). FIG. 8...Piezoelectric element, 11...Movable contact,
12... Fixed contact, 14... Case,
15...Metal plate (Riyomi plate), 16,161・
...Electrode plate, 17, 171L... Electrode rod. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Case

Claims (1)

[Claims] a case, and a plurality of flat plate-like elements built into the case so that when a voltage is applied, the piezoelectric element surface curves into a convex surface, and each curves alternately in opposite directions. a piezoelectric unimorph, an electrode plate made of a conductive material such as a metal plate arranged between the surfaces of the piezoelectric elements of the combined piezoelectric unimorph and at the top end, and one of the electrodes for applying voltage to the piezoelectric elements of the piezoelectric unimorph. and each electrode rod penetrated so as to be electrically connected to all of the metal plates constituting the other electrode, and all of the electrode plates constituting the other electrode, and the electrode plate disposed at the uppermost end. A piezoelectric relay consisting of a movable contact located on the