JPS6266529A - Piezo-electric 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 [Industrial Application Field] The present invention relates to a piezoelectric relay, and in particular, it is an object to obtain a piezoelectric relay that is highly efficient, has an increased holding force, and has stable operation.

"Prior Art" FIG. 4 is a diagram showing the basic structure and operating principle of a piezoelectric relay. Reference numeral 1 is a metal plate, and 2 and 2' are piezoelectric elements bonded to the metal plate 1, which constitutes a bimorph 9. 3 is a fixed part, 4 is a card made of an insulator, 5 is a movable spring, 6 is a fixed spring, and 5a and 6a are contacts.

7.8 is a current-carrying terminal.

The distortion of the piezoelectric elements 2, 2' obtained by applying a predetermined voltage to the current-carrying terminals 7, 8 generates a displacement in the X or X' force direction, thereby driving the movable spring 5 and causing the contacts 5a, 6a.

However, when considering the dimensions and material constants of the piezoelectric material used to obtain the contact gap and contact force necessary for a relay, the problem is that it is not possible to obtain a compact and low-voltage operation, resulting in a large, inefficient relay. There was a point.

"Problems to be Solved by the Invention" In view of the above-mentioned problems, the present invention aims to provide a piezoelectric relay that is small in size, capable of low voltage operation, has high holding power, and has stable operation.

``Means for Solving the Problem'' Therefore, the present invention arranges a plurality of bimorphs adjacent to each other so that the strain direction is uniform, and at least a part of the bimorphs is fixed or supports, and the other part is constant. This is a movable part that is displaced in a direction, and a magnetic attraction force is applied to the movable part.

In other words, by applying a magnetic attraction force to the displacement force of the bimorph, the lack of energy due to low voltage drive can be compensated for, and by arranging multiple bimorphs adjacent to each other so that the strain direction is uniform, the amount of displacement can be reduced. are the same, but the stiffness is set to "dog", and the difference between the load force when applying a positive voltage and a reverse voltage is set to "dog", thereby increasing the holding force in combination with the above-mentioned magnetic attraction force.

"Embodiment" FIG. 1 shows an embodiment of a piezoelectric relay according to the present invention. 10
．． 10' is a metal substrate, 11 and 12 are piezoelectric elements each having a uniform strain direction, and these constitute a bimorph 13 and 13'. 14.14'
is a support part provided on the base 15, and an electrode plate 16 is provided on the inner surface.
．． 16' is provided, and the bimorphs 13, 13
' is fixed with support at both ends, and the electrode plate 16.
A voltage is applied to the bimorphs 13 and 13' from 16'. 17° and 18 are current-carrying terminals.

An insulating magnet (
A card 19 consisting of, for example, a plastic magnet is fixed. Reference numeral 20 denotes a U-shaped magnetic pole, which is fixed to the base 15 so that the extension 21 of the card 19 can move between its opposite ends 20a and 20b. 22 is a movable spring, 23 is a fixed spring, and 22a and 23a are contacts.

Next, a comparison of the displacement-load characteristic curves between the plurality of bimorphs 13, 13' according to the present invention and the bimorph 9 shown in FIG. 4 will be explained with reference to FIGS. 3(a) and 3(b).

(a) shows the case of bimorph 9 shown in FIG. 4, and (b) shows the case of bimorphs 13 and 13' according to the present invention.

31.32 is the load characteristic curve of the bimorph itself, 33 and 34 are the positive voltages applied to the bimorphs 9 and 13.13', 35
．． 36 is a load characteristic curve when a reverse voltage is respectively applied. xl, x', and X2. X'2 is the amount of displacement at which the load force becomes 0 when voltage is applied, and Xl and X2 (X2 and X'2) are approximately the same value.

Y and Z are the load force differences (Y<Z) when a positive voltage and a reverse voltage are applied when the contact is closed.

That is, the bimorph structure according to the present invention has the characteristic that although there is no difference in the amount of displacement due to voltage application, the stiffness is a dog, and the difference in load force when a positive voltage and a reverse voltage are applied is a dog. Therefore, within the range of the load force difference, the card extension 2m (
Bimorph 13
．． 13', the holding force can be increased.

Next, this will be explained in detail with reference to FIG. 2, which shows a displacement-load characteristic curve when spring load characteristics and magnetic attractive force are considered. 40 is a load characteristic curve due to the stiffness of the bimorphs 13 and 13', 41 is a contact load '1 curve due to the movable spring 22 and fixed spring 23, and 42 is the bimorph 13
13' and the spring load curves of the movable spring 22 and the fixed spring 23. 43 is the attractive force generated between the card extension 21 (magnet) and the magnetic pole 20. 44
and 45 are composite load characteristic curves when a positive voltage and a reverse voltage are applied to the bimorphs 13 and 13'.

As can be seen from the figure, bimorph 1 is created by applying voltage.
When the load force of 3 and 13' becomes rOJ (X31
When the displacement is made at 1, the suction force 43 increases, which promotes the displacement. Therefore, high efficiency can be achieved.

When the card extension 21 (magnet) contacts the magnetic pole 20 and the contacts 223, 23a are closed, the difference S between the attractive force 43 and the combined load force of the bimorphs 13 and 13' becomes the holding force. As described above, this holding force S can be set to be larger as the difference in load force between the positive voltage and the reverse voltage is applied is larger, so as explained in FIG. 3, the present invention can obtain a larger holding force than the conventional one.

Next, when a reverse voltage is applied, a load force difference R is generated between the reverse voltage and the composite load characteristic 45, and the bimorphs 13 and 13' are restored.

In the present invention, a comparison of a bimorph set supported at both ends has been described, but similar results can be obtained in a comparison with a bimorph set supported at both ends. It is easily understood that the extension part 21 of the card 19 may be made of a general magnetic material, and the magnets may be arranged at the open bottoms of the magnetic poles 20a and 20b.

"Effects of the Invention" As explained above, according to the present invention, a plurality of bimorphs are arranged adjacently so that the strain direction is uniform, and magnetic attraction force is applied to the movable part. A stable piezoelectric relay with high efficiency and large holding force can be obtained.

[Brief explanation of drawings]

Fig. 1 shows an embodiment of the piezoelectric relay according to the present invention, Fig. 2 shows the same displacement-load characteristic curve, and Fig. 3 (a) and (b) show the displacement-load characteristic of the bimorph shown in Figs. 1 and 2. The curve comparison diagram, FIG. 4, is a diagram showing the basic structure and operating principle of a piezoelectric relay. 13, 13'...bimorph, 2]...card extension (magnet), 20...magnetic pole, 22...movable spring, 23...fixed spring. Patent applicant: Daiko Denki Seisakusho Co., Ltd. President and CEO 1) Takehiko4ceKi(-Ltsutoi4,452)mipQj=fl!aEObD@a@
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Claims (1)

[Claims] A plurality of bimorphs are arranged adjacent to each other so that the strain direction is uniform, and at least a part of the bimorphs is a fixed or supporting part and the other part is a movable part that is displaced in a certain direction,
A piezoelectric relay characterized in that a magnetic attraction force is applied to the movable part.