JPH0537490Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a mechanism for expanding the displacement of a minute displacement variable body such as a piezoelectric actuator.

2. Description of the Related Art An example of a displacement amplification mechanism for amplifying minute displacements such as a piezoelectric actuator is shown in FIG. In the figure, reference numeral 1 denotes a fixed base, and 2 and 2 denote a pair of arms arranged substantially parallel to each other on both sides of the fixed base 1, and grooves 2a, 2a are formed in opposing inner walls excluding the axially intermediate portion. 3 is a groove 2a of the arms 2, 2 fixed to the fixed base 1,
Rod inserted and fixed in 2a, 4, 4 are grooves 2a,
Through holes 2b, 2 penetrate through the inner wall on one end side near 2a.
a receiving member inserted through b; 5 a piezoelectric actuator held between the receiving members 4; 6 an arm 2;
2 shows a buckling spring fixed between the inner walls on the other end side of FIG.

In this displacement magnification mechanism, a rod 3 is inserted and fixed into a groove 2a of an arm 2, and both ends of the arms 2, 2 are supported so as to be able to approach and separate from each other, and a buckling spring 6 is fixed to the other end of the arms 2, 2. And arm 2, hole 2 of 2
Insert the receiving members 4, 4 into the receiving members 4, 2b, sandwich the piezoelectric actuator 5 between the receiving members 4, 4, and press and hold the receiving members 4, 4 with the jigs 7, 7. 4 to the arms 2, 2 and the piezoelectric actuator 5, and when the fixing is completed, the jigs 7, 7
Remove.

In this displacement magnifying mechanism, when the piezoelectric actuator 5 expands and contracts, the other ends of the arms move toward and away from each other using the grooves 2a, 2a as fulcrums. Therefore, the displacement of the other end of the arm is increased by the ratio of the distance from the fulcrum to both ends, and the buckling spring 6
is displaced in a direction perpendicular to the plane of the drawing, which is perpendicular to the direction of expansion and contraction of the piezoelectric actuator 5.

Problems to be Solved by the Invention By the way, since the piezoelectric actuator 5 has a length variation of about ±5 μm, by interposing the receiving member 4 between the arm 2 and the piezoelectric actuator 5, the above length variation can be absorbed. However, if the adhesive adheres to the jig 7 during adhesive fixation, the bond between the arm 2 and the receiving member 4 may come off when the jig 7 is removed after the adhesive has hardened.

Means for Solving the Problems The present invention was proposed to solve the above-mentioned problems, and is supported using the side wall excluding the central part in the axial direction as a fulcrum, and is close to the fulcrum of a pair of arms arranged opposite to each other. A groove is provided on the opposing surface on the one end side, and a minute displacement variable body is connected between the grooves via a receiving member,
A buckling spring is connected between opposing surfaces on the other end side of the arm.

Function: There is no adhesion between the assembly shaft and the receiving part, and as a result, there is no adhesive failure between the arm and the receiving part, and a sufficiently strong adhesive strength can be obtained.

Embodiment An embodiment of the present invention will be described below with reference to FIG.
In the figure, the same reference numerals as in FIG. 2 indicate the same parts or parts having the same function, and the explanation will be omitted. The difference from the mechanism in FIG. 2 is that a cut groove 2c is provided in place of the hole 2b in the arm 2, and a receiving member 4
The only thing that happened was that they were fitted and glued together.

This assembly involves fitting the arms 2, 2 to both ends of the rod 3 with the fixed base 1 fixed, and fitting the receiving member 4, which holds the piezoelectric actuator 5, into the cut grooves 2c, 2c of the arms. Then, the buckling spring 6 is temporarily fixed to the other ends of the arms 3, 3. Then, the arms 2 and 2 are held in parallel, and the connecting portions of the rod 3 and the arm 2, the receiving member 4 and the arm, and the buckling spring 6 and the arm 2 are bonded.

This allows the receiving member 4 and the arm 2 to be bonded together while pressing the opposite side of the arm 2 to the receiving member 4.
Even if an adhesive is applied to the fitting portion of the arm, the adhesive will hardly adhere between the pressing jig and the arm, and even if it adheres, the adhesion between the receiving member 4 and the arm 2 will not be impaired.

Further, in the mechanism of the present invention, thermal expansion between the buckling spring 6 and the rod 3 can be ignored by using the same material (for example, phosphor bronze) for the buckling spring 6 and the rod 3. If the amount of thermal expansion of the rod 3 and the sum of the amounts of thermal expansion of the piezoelectric actuator 5 and the receiving member 2 are substantially the same, the temperature characteristics of the displacement amplifying mechanism as a whole can be set to zero. That is, once the materials of the rod 3 and the piezoelectric actuator 5 are determined, an appropriate coefficient of thermal expansion of the receiving member 2 is determined.

Here, let the coefficient of thermal expansion of the rod 3 be α ₁ , the coefficient of thermal expansion of the piezoelectric actuator 5 be α ₂ , the coefficient of thermal expansion of the receiving member 4 be α ₃ , and the respective lengths be l ₁ , l ₂ , l ₃ . , the relationship is expressed as follows.

α ₁ ×l ₁ = α ₂ ×l ₂ + α ₃ ×l ₃ , and the thermal expansion coefficient α ₃ of the receiving member 4 is set as α ₃ = (α ₁ ×l ₁ − α ₂ ×l ₂ )/l ₃ . By doing so, the temperature characteristics of displacement can be canceled out.

Effects As described above, according to the present invention, poor adhesion during assembly can be prevented, and by appropriately selecting the materials of the buckling spring, rod, and receiving member, thermal expansion of materials other than the piezoelectric actuator can be reduced. can cancel out the temperature characteristics of displacement.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of the present invention, and FIG. 2 is a plan view showing an example of a displacement magnification mechanism. DESCRIPTION OF SYMBOLS 1...Fixed base, 2...Arm, 3...Rod, 4...Receiving member, 5...Small displacement variable body (piezoelectric actuator), 6...Buckling spring.

Claims (1)

[Scope of utility model registration request] A groove is provided on the opposing surface of one end of a pair of arms, which are supported using the side wall excluding the central part in the axial direction as a fulcrum, and which is close to the fulcrum of the pair of arms, and a minute displacement variable body is inserted between the grooves via a receiving member. and a buckling spring is connected between opposing surfaces on the other end side of the arm.