JPH02137937A - Kinetic converter for piezoelectric element - Google Patents

Abstract

PURPOSE:To prevent a tilting arm and its stopper from wearing each other in a kinetic converter for a piezoelectric element employed for a printing head with the arm by providing a contact having a wear resistant contact face in plane contact with the face of the stopper when the arm is retreated and tilted. CONSTITUTION:A contact member 33 is formed of a member having excellent wear resistance such as zirconia ceramics of the same material as that of a stopper member 31, and a coupling groove 33a to be fitted with a tilting arm 10 is formed at the lateral center on its upper face. The member 33 is integrally secured to the arm 10 with adhesive in a state that the arm 10 is inserted into the groove 33a. Further, a flat contact face 34 in plane contact with the stopping face 32 of the stopper member 31 when the arm 10 is retreated and tilted is formed on the lower face of the member 33. The stopping face 32 of the stopper 31 is brought into plane contact with the contact face 34 of the member 33 in such a manner that both are formed flatly, thereby reducing mutual wear.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a motion converting device for Lt. and a movable element disposed at the other end in the direction of expansion and contraction of the piezoelectric element, the tilting arm being coupled between the piezoelectric element and a movable element arranged at the other end in the expansion and contraction direction of the piezoelectric element, is tilted based on the displacement of the movable element due to expansion and contraction of the piezoelectric element. b. Concerning the conversion device.

(Prior art) As a motion converting device for this type of a-electronic element, for example, there is already a patent application developed by the same applicant in 1986-
There are examples disclosed in Japanese Patent Application No. 268496, Japanese Patent Application No. 62-277169, etc.

Further, as shown in FIG. 11, such a piezoelectric element motion converting device displaces the movable element 5 based on the expansion and contraction of the piezoelectric element F1, so that the base ends of the frame 2 and the movable element 5 are mutually disposed. By bending the pair of fixed leaf springs 6.7, the tilting arm 10 connected to the tips of both leaf springs 6.7 is tilted.

In the motion conversion device configured as described above, when a voltage is applied to the piezoelectric element f1 and the piezoelectric element 1 is contracted to its original state, the tilting arm 10 tilts backward.

At this time, the tilting arm 10 tends to move back further than the original resting position due to inertia, so the time required for the tilting arm 10 to come to rest at the original position increases, and the high-speed tilting movement of the tilting arm, for example, when printing It becomes difficult to deal with the problem at high speed. In order to quickly stop the tilting arm 10 at its original position, a stopper member 31' is provided at the end of the connecting member 41 fixed to the frame 2 to limit the backward tilting of the tilting arm 10.
is installed.

(Problems to be Solved by the Invention) In the above-mentioned system, the tilting arm is formed of a flat plate member oriented substantially perpendicularly to the stopper surface 32' of the stopper member 31', and when the tilting arm 10 tilts backward, , the tilting arm 10 comes into contact with the stopper surface 32- of the stopper member 31' in line contact at that plate thickness. Therefore, when the stopper member 31 is made of rubber or synthetic resin, the stopper surface 32' of the stopper member 31' that comes into contact with the inclination 11J7-mu 10 has a straight groove as shown in FIG. As a result, the stopper's function as a stopper deteriorates at an early stage.

Further, if the stopper member 31' is made of a material having a higher hardness than the tilting arm 10, there is a problem that the tilting arm 10 is worn out at the portion where it comes into contact with the stopper member 31'.

In view of the above-mentioned problems, the purpose of this invention is to provide a motion conversion device for a piezoelectric element r that can prevent mutual wear between a tilting arm and its stopper portion and improve durability. be.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes a frame having a base that supports one end of the piezoelectric NF in the expansion and contraction direction, and a frame that is disposed at the other end of the piezoelectric collector in the expansion and contraction direction. A motion conversion device comprising a movable element and a tilting arm coupled between the frame and the movable element and performing a tilting motion based on displacement of the movable element due to expansion and contraction of the piezoelectric element, A stopper portion having a wear-resistant stopper surface for restricting backward tilting of the tilting arm is provided at a predetermined position, and the tilting arm is provided with a stopper portion that can come into contact with the stopper surface and that allows the tilting arm to The structure includes a contact portion having a wear-resistant contact surface that comes into surface contact with the stopper surface when tilted.

(Function) In the piezoelectric collector motion conversion device configured as described above, when the mover is displaced by the expansion and contraction of the piezoelectric cable f,
The tilting arm is tilted in the front-rear direction based on the displacement of the movable element.

When the tilting arm is tilted in the backward direction by a predetermined stroke,
The abutting surface of the abutting portion provided on the tilting arm comes into surface contact with the stopper surface of the stopper portion on the frame side, and one selection of the more tilting arms is stopped.

In this way, the backward tilting of the tilting arm is limited by the surface contact between the contact surface of the contact section installed on the tilting arm and the stopper surface of the stopper section provided on the frame side. Mutual wear between the surface and the stopper surface is reduced. Furthermore, since both the true contact surface and the stopper surface are wear resistant, wear between the electric contact surface and the stopper surface is reduced as much as possible.

(Example) Examples of the present invention will be described below with reference to FIGS. 1 to 10.

In this embodiment, the piezoelectric element 1 which expands and contracts in response to the application of a voltage is constructed of a laminated piezoelectric ceramic.

The main frame 2 for supporting the piezoelectric element 1 is
The piezoelectric element F1 is made of a vertically rectangular metal plate having a predetermined thickness and extending substantially parallel to the direction of expansion and contraction of the piezoelectric element F1. A base 3 is provided at one end of the main frame 2 to protrude in the lateral direction for supporting one end ( ) end of the piezoelectric collector 1 in the expansion/contraction direction via a temperature compensating material 12 , which will be described later.

A mover 5 is disposed at the other end (upper end) of the piezoelectric cable F<b>1 in the expansion/contraction direction in a state facing the upper end of the rising portion of the main frame 2 . A pair of leaf springs 6.7 is fixed at one end to the facing surfaces of the movable element 5 and the main room 2 by brazing. Both leaf springs 6.7 face each other with a predetermined distance apart, and
Piezoelectric cable 1 from the upper end surface of main frame 2 and mover 5
It extends a predetermined length C in the direction of expansion and contraction. So τ,
A tilting body 8 is formed at the other ends (extending ends) of both leaf springs 6, 7 and is integrally connected to both leaf springs 6.7.

The tilting body 8 is provided with an arm mounting groove 8a, into which a tilting arm 10 made of a flat plate material is inserted at its base and fixed by brazing.

The tilting arm 10 extends in a direction substantially perpendicular to the direction of expansion and contraction of the piezoelectric element 1, and a cutout-shaped wire attachment 110a is formed at the tip thereof.
08, the base end of the printing wire 11 is inserted and fixed by brazing.

A sub-frame 4 is integrally formed with the base 3 of the main frame 2 at its ends.

The subframe 4 extends along the other side of the piezoelectric element 1 (the side opposite to the main frame 2) to a position facing the movable element 5.

Between the extending end of the frame 4 and the movable element 5, there is a four-bar parallel link mechanism 16 for guiding the movable element 5 in parallel to the expansion and contraction direction of the piezoelectric cable 1 based on the expansion and contraction of the piezoelectric cable 1. is installed. This parallel link mechanism 16 is shown in FIGS.
As shown in the figure, it is formed by punching and bending a sheet of elastically deformable leaf spring material.
A pair of link plates 17 and both link plates 1
The main body is a connecting portion 26 that connects the 7 parts together.

The pair of link plates 17 includes vertical link portions 18.19 parallel to the direction of expansion and contraction of the piezoelectric element 1, and elastically deformable hinges 1% 22.23 between these linear link portions 18.19.
．． Horizontal link part 20.21 constructed by 6 24.25
and form four parallel links. The vertical link portions 18 on each side of both link plates 17 are fixed to both side surfaces of the subframe 4 by spot welding or the like, and the vertical link portions 19 on the other side are respectively attached to both side surfaces of the mover 5. It is fixed by spot welding etc.

Further, in this embodiment, a connecting plate 30 is formed at the bottom of each of the vertical link portions 18 at the ends thereof. Each of the connection plates 30
extends to the side of the main frame 2. Furthermore, both ends of each connecting plate 3° are attached to the main frame 2.
and the side surfaces of the subframe 4, respectively, by spot welding or the like. This allows mainframe 2
The sub-frame 4 is kept parallel to this, and the rigidity of each frame 2.4 is increased.

A temperature compensating material 12 is interposed between the base 3 of the main frame 2 and the end of the armature wire 1 in a state where a predetermined compressive load is applied negatively to the piezoelectric cable f1. The temperature compensator 12 is made of a material having a positive thermal expansion coefficient characteristic opposite to the negative thermal expansion coefficient characteristic of the piezoelectric cable 1, such as a zinc material or an aluminum material. The expansion and contraction of the piezoelectric cable 1 due to changes in ambient temperature is corrected by the expansion and contraction of the temperature compensating material 12 in the upper F direction, and the height of the L plane of the piezoelectric element f1 is always kept constant. There is.

Note that the mutual contact surface between the lower surface of the slider 5 and the other end surface in the expansion and contraction direction of the piezoelectric cable F1, and the mutual contact surface between the temperature compensation @12 surface and the upper surface of the upper plate 13a of the pressure member 13 may be adjusted as necessary. It is attached with adhesive.

The tilting arm 1 is provided on the extending end surface of the subframe 4.
A stopper member 31 is fixed with an adhesive or the like at a position facing substantially the center of the back surface of 0. This stopper member 31 is made of a material with excellent wear resistance, such as zirconia ceramics, and its stopper surface 32 is approximately parallel to the back surface of the tilting arm 10 and several times the thickness of the tilting arm 10 ( It is formed into a wide flat surface with a width of about 3 to 6 times.

The stopper member 31 is provided on the back side of the tilting arm 10.
At a position facing the stopper surface 32 and the contact/separation function,
B several times (3 to 6 times) thicker than the plate thickness of the tilting arm 10,
A wide abutment member 33 is fixed. The abutting member 33 is made of the same material as the stopper member 31 and has excellent wear resistance, and the tilting arm 10 is fitted in the center of the L surface in the width direction, as shown in FIG. A coupling groove 33a to be inserted is recessed. And the contact member 33
is integrally fixed to the tilting arm 10 with an adhesive in a state where the tilting arm 10 is fitted into the coupling groove 33a. Further, the bottom surface of the abutting member 33 is provided with the stopper member 3 when the tilting member 10 is tilted backward.
A flat abutment surface 34 is formed which comes into surface contact with the stopper surface 32 of the first stopper surface 32 .

Further, in a state where the tilting arm 10 is stationary at a predetermined position with no voltage applied to the piezoelectric element 1,
The stopper surface 32 of the stopper member 31 and the abutment member 33
A slight gap (for example, about 10 μm) is set between the contact surface 34 and the abutment surface 34 .

By providing this gap, it is ensured that a compressive load is applied to the piezoelectric element 1 as described above.

In this embodiment configured as described above,! When a voltage is applied between both electrodes of the piezoelectric element 1, the piezoelectric element 1 extends by a predetermined length in the stacking direction, that is, in the direction of the arrow X in FIG. Displaced. Then, the leaf spring 7 on the movable element 5 side is pushed up along the leaf spring 6 on the main frame 2 side by the displacement force of the mover 5, and both leaf springs 6 and 7 are bent into a curved shape. Movable′
As the root spring 7 on the F5 side is largely bent toward the leaf spring 6 on the main frame 2 side, a rotation moment is generated in the direction of the arrow [) at the base end of the tilting arm 10, and as a result, the tilting arm 10 is tilted forward.

Then, with the printing wire 11 at the tip of the tilting arm 10 being guided by a predetermined number of guide members 15, the tip is advanced to the printing position.

When the voltage application to the piezoelectric element f1 is cut off, the piezoelectric cable T
1 contracts to its original state, and the movement f5 is displaced in the opposite direction by the elastic force based on the deflection of both leaf springs 6.7. As a result, a rotational t-ment occurs at the base end of the tilting arm 10 in the opposite direction to that described above, and the tilting arm 10
is tilted back toward its original position.

When the tilting arm 10 tilts backward, the tilting arm 1
0 tends to tilt backward more tangentially than its original position due to its inertia and the mediating force of both leaf springs 6.7. Then, the contact surface 34 of the contact member 33 of the tilting arm 10 comes into surface contact with the stopper surface 32 of the stopper member 31, and further tilting of the tilting arm 10 is stopped. In this way, by restricting the backward tilting of the tilting arm 10, the time required for the tilting arm 10 to return to the original position #1 can be shortened, and printing can be speeded up. . In FIG. 6, the waveform indicated by a solid line indicates the operating waveform at the tip of the printing wire of the apparatus of the above embodiment. In addition, the waveform indicated by a broken line in the same figure shows the operating waveform of the preceding device (the stopper member in FIG. 10 made of synthetic resin). As is clear from each operation waveform, according to this example device, both the vibration time and the amplitude are reduced.

Furthermore, since the stopper surface 32 of the stopper member 31 and the contact surface 34 of the contact member 33 are both formed into flat surfaces and come into surface contact, the wear of the phase n between the stopper surface 32 and the contact surface 34 is reduced. Reduced. Moreover, since both the stopper member 31 and the abutment member 32 are made of a material with excellent wear resistance such as zirconia ceramics, the stopper surface 3
Wear between the contact surface 34 and the contact surface 34 is reduced by -.

In the embodiment described above, the stopper member 31 and the contact member 33 are made of a material having excellent wear resistance such as zirconia ceramics, but the present invention is not limited thereto. For example, as shown in FIGS. 7 and 8, a wear-resistant metal plate, such as a spring steel plate, is bent to form a triangular contact portion with a flat contact surface 34 on the lower surface, and A contact member is formed by a pair of leg pieces 33b, which are opposite to each other with a gap in which the tilting arm 10 can be inserted from the end face of the contact part, and are fixed to both sides of the tilting arm 10 by welding, brazing, etc. 33 may be configured.

Further, as shown in FIGS. 9 and 10, the stopper member 3
Guide walls 31a for guiding the movement of the abutting member 33 only in the tilting direction of the tilting arm 10 may be provided on both sides of the stopper surface 32 of the tilting arm 10.

In this case, the tilting arm 10 is
It is possible to actively prevent bending of the tilting arm 10 and breakage of the printing wire 11 caused by the lateral vibration of the tilting arm 10.

Furthermore, in the above embodiment,! 11 moving arm 10 and abutting member 33, subframe 4 and stopper member 31
Although these are formed separately, the contact part is formed integrally with the tilting arm 10, and the stopper part is integrally formed with the subframe 4, so that the contact surface of the front contact part and the stopper part are formed integrally with each other. A wear-resistant sheet layer such as a ceramic layer may be provided on the stopper surface.

(Effects of the Invention) As described above, according to the present invention, the tilting arm is tilted backward due to surface contact between the contact surface of the contact portion provided on the tilting arm and the stopper surface of the stopper portion provided on the frame side. Since the contact surface and the stopper surface are both wear resistant, mutual wear between the contact surface and the stopper surface can be reduced. This has the effect that wear with the stopper surface can be reduced as much as possible, and durability can be improved.

[Brief explanation of the drawing]

Figures 1 to 10 of the drawings show an embodiment of the present invention, in which Figure 1 is a perspective view showing a motion converting device for piezoelectric water applied to a print head, and Figure 2 is a side view. Figure, 3rd
The figure is a sectional view taken along the ■-m line in Fig. 2, and Fig. 4 is the IV-m line sectional view in Fig. 2.
IV line opening view Figure 5 is a perspective view showing the four-section flat b link 8I structure, Figure 6 is an explanatory diagram showing the operation waveform of the tip of the printing wire, and Figure 7 is a side view showing an example of a modification of the contact member. 8 is a side view taken along the line IIi in FIG. 7, FIG. 9 is a side view showing a modification of the stopper member, and FIG. 10 is a sectional view taken along the line X--X in FIG. 9. FIG. 11 is a side view showing the prior art, and FIG. 12 is a sectional view taken along the line X11-XII in FIG. 11. 1...Piezoelectric element 2...Main frame 3...Base 4...Sub frame 5...Movable end 6.7...Plate spring 10...Tilt arm 31...Stopper Member 32... Stopper surface 33... Contact member 34... Contact surface Applicant Brother Industries, Ltd. Agent Patent attorney Hidehiko Okada (3 others) 1... Pressure i
1 element 2...main frame 3...base 4...subframe 5...movable element 67...plate spring 10...II moving arm 31...stopper member 32... Stopper surface 33...Abutment member 34...Abutment surface

Claims (1)

[Scope of Claims] A frame having a base supporting one end of the piezoelectric element in the expansion and contraction direction, a movable element disposed at the other end of the piezoelectric element in the expansion and contraction direction, coupled between the frame and the movable element, A motion conversion device comprising: a tilting arm that performs a tilting motion based on displacement of a movable element due to expansion and contraction of the piezoelectric element, the motion converting device comprising: a tilting arm that performs a tilting motion based on displacement of a movable element due to expansion and contraction of the piezoelectric element; A stopper portion having a wear-resistant stopper surface is provided on the tilting arm, and the tilting arm has a wear-resistant stopper portion that can come into contact with and separate from the stopper surface and comes into contact with the stopper surface when the tilting arm tilts backward. A motion conversion device for a piezoelectric element, characterized in that a contact portion having a contact surface is provided.