JPS61176175A - Latch-type piezoelectric actuator - Google Patents

Abstract

PURPOSE:To obtain an actuator of simple structure, small size, low power, low heat generation, and without magnetic interference by using a piezoelectric element as a driving source of a flying member. CONSTITUTION:Piezoelectric elements 4 and 6 are arranged in parallel on a leaf spring 1. Another end 4b of the piezoelectric element 4 is fixed to an attachment member 3 so as to bring a movable contact 2 arranged on a concave side of bend of the leaf spring 1 in contact with a contact 5a of an actuating leaf spring 5 with a certain pilot pressure. The end part 6b of a piezoelectric element 6 is fixed so as to make a contact 7a of an actuating leaf spring 7 symmetrical to the contact 5a with respect to the leaf spring 1. When a voltage is applied to the piezoelectric element 4, the element 4 is displaced minutely, but at high speed. Then the center of the leaf spring 5 bends and the movable contact 2 as a flying member is separated from the contact 5. The leaf spring 1 is reversed and comes in contact with the contact 7a. When a voltage is applied to the piezoelectric element 6, the movable contact 2 is separated from the contact 7a and the leaf spring 1 is reversed again to be in contact with the contact 5a. Thus the alternate contact of the movable contact 2 can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a latch-type actuator using a piezoelectric element.

(Prior Art and its Problems) Conventionally, an electromagnetic actuator using a coil has been used as a latch-type actuator.

However, electromagnetic actuators generate a magnetic field by energizing a coil and use the magnetic force to move a movable member, so they require a large amount of input energy and have problems such as heat generation and magnetic interference.

Also, because it uses a coil, it was difficult to miniaturize it.

(Object of the Invention) An object of the present invention is to eliminate such conventional drawbacks and provide a latch-type piezoelectric actuator that has a simple structure, is small in size, has low power consumption, low heat generation, and is free from magnetic interference.

(Structure of the Invention) According to the present invention, a leaf spring having a flying member and the plate i
a supporting part that supports the spring in a curved manner; an electrostrictive or piezoelectric element arranged in parallel on the convex side of the curved leaf spring; one end connected to the electrostrictive or piezoelectric element and the other end connected to the plate; A latch-type piezoelectric device comprising: an actuating leaf spring that is supported so as to be curved in a convex manner with respect to the spring, and that transmits the force of the electrostrictive or piezoelectric element to the flight member through its convex surface. An actuator is obtained.

(Detailed Description of Configuration) The present invention solves the problems of the prior art by adopting the above-described configuration.

First, by using a piezoelectric element, which is known for its high energy conversion efficiency, as the driving source for the flying member, it uses low power, generates little heat, and eliminates magnetic interference.

Also, by applying an axial force to a leaf spring and bending it, the leaf spring becomes a reverse spring, and when the flight member attached to the leaf passes through a straight line connecting both ends of the leaf spring, the leaf spring reverses. Operates and latches.

For such a leaf spring, an electrostrictive or piezoelectric element is provided so as to be parallel to the convex side of the leaf spring, and the electrostrictive or piezoelectric element is connected to the support part at a different position from the support part of the leaf spring. An actuating leaf spring is provided which is supported in a curved manner between the head and the leaf spring and which applies force to the flight member with its curved convex surface. Therefore, when a voltage is applied to the electrostrictive or piezoelectric element, the electrostrictive or piezoelectric element causes a small but high-speed displacement operation, and the amount of displacement is transmitted in the axial or longitudinal direction of the actuating leaf spring. On the other hand, when the actuating leaf spring is displaced in the axial direction, it is bent in the plate thickness direction perpendicular to the axial direction, that is, in the convex direction, as per the well-known buckling theory. Then, the flight member on the convex surface of the actuating leaf spring is accelerated by the deflection of the actuating leaf spring, and the actuating plate moves away from the deer and performs a flying motion.

When the flying member passes through a straight line connecting both ends of the leaf spring, the leaf spring is reversed and latched, making it possible to obtain a stroke of the flying member that is much longer than the displacement of the piezoelectric element.

Furthermore, since no coil is used and the reversing spring is also a leaf spring, the structure is simple and compact.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing an embodiment in which the present invention is applied to a relay. In FIG. 1, a movable contact 2 is provided as a flight member near the center of a leaf spring 1, and both ends of the leaf spring 1 are inserted into grooves 3a, j3b, which serve as supporting parts provided in a mounting member 3, and the leaf spring An axial force is applied to 1, and the plate spring 1 is curved. Further, the first piezoelectric element 4 is provided in parallel with the plate IK, and one end 4a of the first piezoelectric element 4 in the expansion/contraction direction (in the direction of the arrow) and the support ' separated by a distance from the groove 3a or 3b. N
A first actuating leaf spring 5 is disposed, which is supported by the first actuating leaf spring 3c and is curved so as to be convex with respect to the leaf spring 1.

Further, the first actuating plate spring 5 is provided with a first contact 5a corresponding to the movable contact 2. On the other hand, a support portion 3 is also provided at one end 6a of the second piezoelectric element 6 in the expansion/contraction direction (arrow B direction).
A curved second actuating leaf spring 7 is connected with c, and the second actuating spring 7 is also provided with a second contact 7a. That is, the first contact 5a and the second contact 7a are arranged to sandwich the movable contact 2.

Further, as shown in FIG. 1(, ), the piezoelectric element 4 is connected so that the movable contact 2 contacts the first contact 5a arranged on the curved convex side of the leaf spring l with a certain preload. Other end 4
b is fixed to the mounting member 3. The second contact point 7a is
The other end 6b of the second piezoelectric element 6 is fixed to the mounting member 3 in a symmetrical position with respect to the first contact point 5a and a straight line connecting both ends of the plate spring 1.

The movable contact 2 as shown in FIG. 1(,) is the first contact 5a.
When a voltage is applied to the first piezoelectric element 4 while in contact with the first piezoelectric element 4, the first piezoelectric element 4 is slightly displaced at a very high speed in the direction of the arrow. Then, the first actuating plate spring 5 supported by the first piezoelectric element 4 is displaced in the axial direction, and as is clear from the buckling theory, the center part of the first actuating plate spring 5 is Flexural deformation occurs in the direction perpendicular to the axial direction so as to be maximum. At this time, the first contact 5a on the first actuating leaf spring 5 moves due to the deflection of the first actuating leaf spring 5, and the movable contact 2 as a flying member in contact with the first contact 5a moves. It is accelerated by the force and flies away from the first contact point 5, passes through the straight line connecting both ends of the leaf spring 1, and the leaf spring 1 performs a reversal operation, and as shown in FIG. 1(b), the movable contact 2 is in contact with the second contact point 7a. Also, Fig. 1(b)
When a voltage is applied to the second piezoelectric element 6 from a state where the movable contact 2 is in contact with the second contact 7a as shown in FIG. is accelerated and leaves the second contact point 7a and flies toward the first contact point 5a, and the plate spring 1 reverses itself again, and the movable contact point 2 moves to the first contact point 5a as shown in FIG. They are in contact with each other. In this way, the movable contact 2 is moved from the first contact 5a to the second contact 7a, or from the second contact 7a to the first contact 5.
It is possible to switch to a.

In the present invention, the movable contact 2 serving as a flying member is accelerated by the force generated by the first or second piezoelectric element 46 when a voltage is applied, and the leaf spring 1 is reversely operated. It is possible to obtain a stroke of the movable contact 2 that is several tens to hundreds of times larger than the amount of displacement of the first or second piezoelectric element 4.6, and also to obtain a large contact force.

Here, the first or second actuating leaf spring 5, 7 has one end 4as6a on the top or second piezoelectric element 4, and a supporting portion 3c.
Although the supporting method may be rotational support, fixed support, or a combination thereof, the leaf spring 1, the piezoelectric element 4.6, and the actuation plate spring 5. Since it can be configured in a parallel state, it has the effect of being able to be used as a hut. Further, by the flight of the movable contact 2, the first or second contact 5aj7
If a is impacted, the first or second actuating leaf spring 5#7
acts as a buffer and has the effect of quickly calming down the latch operation. Further, in the present invention, a piezoelectric element known for its high energy conversion efficiency is used as a drive source for the movable contact 2 as a flying member, so that there is no magnetic interference with low power consumption and low heat generation.

Furthermore, since there is no coil and an axial force is applied to the leaf spring to turn it into a reversal spring and perform the latching action, the structure is simple and compact.

In the above example, voltage was applied alternately to the first piezoelectric element 4 and the second piezoelectric element 6 to switch the movable contact 2; The movable contact 2 can also be switched by simultaneously applying a voltage to the . This type of usage has not been possible with conventional latch-type electromagnetic actuators.

Note that the voltage applied to the piezoelectric element needs to rise quickly in the form of a pulse, but the pulse width may be short. For example, a pulse width of 0.1 m8 is sufficient, and a longer pulse width does not matter. Since a piezoelectric element is electrically the same as a capacitor, it does not consume power and therefore does not generate heat even if a voltage is continuously applied for a long time.

FIG. 2 is a perspective view showing another embodiment in which the present invention is applied to a relay, and the shape of the mounting member 8 is different from that of the previous embodiment. It goes without saying that the effects of the present invention can be similarly exhibited regardless of the shape of the mounting member.

FIG. 3 is a diagram showing an embodiment in which the present invention is applied to an optical path switch. In FIG. 3 (Taki), the flying member 9 is provided at the center of the leaf spring 1, and the mirror 15 is provided between the flying member 9 and the fixed end 3a° of the leaf spring 1. Further, the plate spring 1 is inserted into a groove 3aj3b as a support part provided in the mounting member 3, and is bent by receiving an axial force, and is connected to the mounting member 3 in parallel with the plate spring 1, and is connected to the first member. A piezoelectric element 4 is arranged. Further, a first actuating leaf spring 5 is arranged between the other end of the first piezoelectric element 4 and the support portion 3c and supported in a curved manner, and the first actuating leaf spring 5 and the flight member 9 are connected to each other. are in contact. On the other hand, the second piezoelectric element 6
The second actuating leaf spring 7 is arranged so that the flight member 9 and the second actuating leaf spring 7 are in contact with each other when the leaf spring 1 reverses as shown in FIG. 3(b). In an embodiment of such a configuration, when the flying member 9 is in contact with the first actuating plate 5 as shown in FIG. Since it is curved, incident light from the direction of arrow C is reflected by mirror 15 and exits as reflected light in the direction of arrow C. When a voltage is applied to the first piezoelectric element 4 in this state, the flight member 9 receives force from the first piezoelectric element 4 and the first actuating leaf spring 5 and is accelerated. It flies away, passes through the straight line connecting both ends of the leaf spring 1, and the leaf spring 1 performs a reversal operation, resulting in a state in which the flight member 9 is in contact with the second actuating leaf spring 7, as shown in 3rd = (b). Become. Therefore, the leaf spring 1 curves toward the second piezoelectric element 6, and the angle with respect to the incident light on the mirror 150 changes, so that the arrow C
Incident light from the direction exits as reflected light in the direction of arrow E. Further, when a voltage is applied to the second piezoelectric element 6 from a state where the flight member 9 is in contact with the second operating leaf spring 7 as shown in FIG. Third
The flight member 9 as shown in FIG.
Return to the state where it is in contact with.

° In this way, the optical path can be switched.

It goes without saying that even in such an embodiment of the present invention, the effects of the present invention such as simple structure, small m = low tolerance, low heat generation, and no magnetic interference are similarly exhibited.

FIG. 4 is a diagram showing an embodiment in which the present invention is applied to a pen lifting mechanism such as a pen recorder. In FIG. 4(a), the leaf spring 1 connected to the pen holder 16 is inserted into the groove 3as3bl/C as a support provided in the mounting member 3, and receives the axial force toward the first piezoelectric element 4. It's curved. The flying member 9 provided on the leaf spring 1 is in contact with the first actuating leaf 5 on the first piezoelectric element 4 connected to the mounting member 3.

As shown in FIG. 4(b), the second piezoelectric element 6 is connected to the flight member 9 and the second operating leaf spring 7 when the leaf spring 1 is reversed.
It is connected to the mounting member 3 so that they are in contact with each other. Further, the pen 17 is supported by the pen holder 16.

In an embodiment with such a configuration, when a voltage is applied to the first piezoelectric element 4 while the flight member 9 is in contact with the first actuating leaf spring 5 as shown in the fourth factor (a), the flight is stopped. The member 9 receives a force from the first piezoelectric element 4 and the first actuating plate spring 5, is accelerated, flies away from the first actuating plate spring 5, passes through a straight line connecting both ends of the plate spring 1, and becomes a plate spring. 1 operates in reverse,
The flight member 9 as shown in FIG. 4(b) comes into contact with the second operating leaf spring 7. Therefore, the pen 17 can perform descending printing from top to bottom. Further, when a voltage is applied to the second piezoelectric element 6 with the flight member 9 in contact with the second actuating leaf spring 7 as shown in FIG. (a) The flight member 9 returns to the state in which it is in contact with the first actuating leaf spring 5 as shown in K. In this way, pen 17
can be raised and lowered.

It goes without saying that even in this embodiment of the present invention, the effects of the present invention such as simple structure, small size, low power consumption, low heat generation, and no magnetic interference are similarly exhibited.

Further, in the present invention, in addition to a single-plate piezoelectric element having a vertical effect or a horizontal effect, the same effect can be obtained by using a laminated piezoelectric element or even an electrostrictive element.

It should be noted that the present invention can be applied not only to the embodiments described above but also to various latch-type actuators and achieve similar effects. The effects of the present invention are achieved by applying an axial force to a leaf spring provided with a flying member and causing it to curve, thereby creating a structure in which a piezoelectric element is arranged to fly the flying member.

Furthermore, in the above embodiment, piezoelectric elements were arranged on both the curved convex side and the opposite concave side of the leaf spring, but if the leaf spring return means is used, the curved convex side of the leaf spring Even if the piezoelectric element is arranged only on the side, the effects of the present invention can be similarly exhibited.

(Effects of the Invention) According to the present invention, a latch-type piezoelectric actuator can be obtained that has a simple structure, is compact, has low power consumption, has low heat generation, and is free from magnetic interference.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment in which the present invention is applied to a relay,
FIG. 2 is a diagram showing another embodiment in which the present invention is applied to a relay, FIG. 3 is a diagram showing an embodiment in which the present invention is applied to an optical path switch, and FIG. 4 is a diagram showing another embodiment in which the present invention is applied to a pen recorder etc. It is a figure which shows one Example applied to the elevating mechanism of. Each symbol in the figure indicates the following content. DESCRIPTION OF SYMBOLS 1... Leaf spring, 2... Movable contact, 3t8... Mounting member, 3ay3b... Groove, 3c... Support part, 4...
・First piezoelectric element, 4a t 4b x 6a p 6
b - one end of the piezoelectric element, 5... first actuating leaf spring, 6...
...Second piezoelectric element, 7...Second operating leaf spring, 9.
... Flight member, 5a... First contact, 7a... Menu contact, 15... Mirror, 16... Pen holder, 1
7...pen. E 1 Figure (b) 7I-2 Figure 71-3 Figure (b)

Claims (1)

[Claims] a leaf spring having a flying member; a support portion that supports the leaf spring in a curved manner; an electrostrictive or piezoelectric element arranged in parallel on the convex side of the curved leaf spring; an actuating leaf spring connected to the piezoelectric element, the other end of which is supported so as to be curved convexly relative to the leaf spring, and whose convex surface transmits the force of the electrostrictive or piezoelectric element to the flight member; A latch type actuator characterized by: