JPH0453183B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is configured such that a printing element, in particular a piezoelectric element is welded to a base member with a preload applied to the piezoelectric element, so that the characteristics of the printing element are made uniform. The present invention relates to a method of manufacturing a printing element.

Prior Art A conventional printing element is constructed as shown in FIG. In FIG. 4, a piezoelectric body (piezoelectric member) 2 whose length increases due to a piezoelectric effect when a driving voltage is applied is held between opposing parts 1a and 1b of a base member 1. Also, the facing part 1 of the base member 1
one end of the first displacement transmitting member 3 is connected to the end of the base member 1;
One end of the second displacement transmission member 4 is connected to.
The other ends of the first and second displacement transmitting members 3 and 4 are connected to the end 5a of the movable member 5 at a distance,
One end of a printing wire 6 is fixed to the other end 5b of the movable member 5. Moreover, 10 and 11 are the first and second hinge parts provided in the facing part 1b, respectively.

In the conventional printing element configured in this way, when a voltage is applied to the piezoelectric body 2, the extension portion 1c rotates clockwise around the first hinge portion 10 due to the expansion of the piezoelectric body 2, and this rotation The second
The displacement transmitting member 4 is rotated clockwise and pulled downward, and at the same time, the first displacement transmitting member 3
The top of follows to the right. Therefore, the movable member 5
rotates clockwise around the first displacement transmitting member 3. As a result, the printing wire 6 fixed to the other end 5b of the movable member 5 is enlarged and moved upward as shown by the arrow, and the tip of the printing wire 6 can perform a dot printing operation. In addition, the first
The second displacement transmitting members 3 and 4, the movable member 5, the extension portion 1c, the first and second hinge portions 10 and 11, etc. constitute a displacement transmitting mechanism.

Problems to be Solved by the Invention However, in this printing element, in order to sandwich the piezoelectric body 2 between the facing parts 1a and 1b of the base member 1, the size of the piezoelectric body 2 is set between the facing parts 1a and 1b. It is difficult to match the length, and if the length of the piezoelectric body 2 is manufactured without matching the dimension between the opposing parts 1a and 1b, the first and second displacement transmitting members 3 and 4 may be damaged during printing operation. There were drawbacks such as breakage due to abnormal stress, and uneven density in printing when a plurality of printing elements were combined to print a plurality of dots at the same time.

On the other hand, when the length of the piezoelectric body 2 is 2 cm, for example, and a voltage of 200 V is applied as the drive voltage, the elongation that occurs in the piezoelectric body 2 during driving is approximately
It is about 10 μm. Therefore, in order to eliminate the dimensional difference between the opposing parts 1a and 1b of the piezoelectric body 2 and the base member 1, it is necessary to perform a process such as selecting combinations of dimensions or rubbing for dimension matching. The drawback was that it required a lot of man-hours.

Means for Solving the Problems In order to solve the above problems, the present invention provides a piezoelectric member 2 that generates dimensional distortion due to the piezoelectric effect, and a base member 1 that has opposing parts 1a and 1b that support the piezoelectric member. and displacement transmission mechanisms 1c, 3, 4, 5, 1 that transmit the dimensional distortion and generate displacement in a predetermined direction.
0, 11, and a printing wire 6 fixed to the other end of the movable member 5 of the displacement transmission mechanism, the piezoelectric member is attached to the U-shaped member 8 that clamps the one opposing portion of the base member. Abut one end of the U-shaped member and the side end 1a ₁ of the opposing part.
A gap 12 is provided between the piezoelectric member and the piezoelectric member, and the U-shaped member is fixed to one opposing portion of the base member with a predetermined preload applied in the axial direction of the piezoelectric body through the U-shaped member. do.

According to the present invention, the other end of the piezoelectric body is supported by the other opposing part of the base member, and the U-shaped member that clamps the one opposing part of the base member is brought into contact with one end of the piezoelectric body, and the base member The U-shaped member is welded to the opposing portion of the base member with a preload applied to the piezoelectric body by pressing the U-shaped member so as not to contact one opposing portion of the base member and the movable member of the displacement transmission mechanism.

Embodiment FIGS. 1a, b, and c are front, side, and top views of a printing element according to an embodiment of the present invention, and FIG. 2 is a partially enlarged view of FIG. 1. In the figure, a base member 1, opposing parts 1a and 1b, and an extension part 1
c, the piezoelectric body 2, the first displacement transmitting member 3, the second displacement transmitting member 4, the movable member 5, the printing wire 6, and the first and second hinge parts 10 and 11 are the same as the conventional example shown in FIG. Although the explanation will be omitted since they are the same, in this embodiment, the piezoelectric body 2 is attached to the second hinge part 11 of the facing part 1b.
A support member 7 supporting the other end of the support member 7 is brazed. Further, the opposing portion 1a is held between both ends 8a of the U-shaped member 8,
The piezoelectric body 2 is brought into contact between the bottom surface 8b of this U-shaped member 8 and the support member 7, and both ends of the piezoelectric body 2 are fixed. Therefore, the inner surface 8c of the U-shaped member 8 and the opposing portion 1
A gap 12 is provided between the side edge 1a1 of the side edge _1a1 of Then, as shown in FIG. 3 (explanatory view of the method for manufacturing a printing element), a predetermined pressure (for example, 2Kg
However, this value is an abbreviation of the maximum allowable pressure of the piezoelectric body 2.
Press the both sides 8a of the U-shaped member 8 while measuring with the pressure measuring device 9a so that the expansion and contraction effect of the piezoelectric body due to compression is not a problem, but the dimensional change of the piezoelectric body is about 5 to 6 μm). In this state, when spot welding (for example, laser beam welding) is performed from the side surface of the U-shaped member 8 as shown by arrows A and B, the opposing portions 1a of the U-shaped member 8 and the base member 1 are welded. Then, after removing the positioning preload jig 9, main welding is performed. Therefore, according to this embodiment, even if there is a variation in the dimensions of the piezoelectric body 2 (difference between the upper limit value and the lower limit value with respect to the design value) or a dimensional change due to pressurization, it can be tolerated by the above-mentioned gap 12, so that printing is not possible. The density is even and the accuracy is good. Furthermore, as is well known, when a driving voltage is applied to the piezoelectric body 2, it suddenly expands due to the mass inertia of the piezoelectric element 2, and the piezoelectric element is mechanically broken and damaged.

To this end, in this embodiment, both side surfaces 8a of the U-shaped member 8 and the facing portion 1a of the base member 1 are welded together by applying pressure and keeping the piezoelectric element 2 in a compressed state while measuring with the pressure measuring device 9a. Therefore, even if a driving voltage is applied, the elongation of the piezoelectric element 2 cancels out the compressive stress during pressurization, so it is possible to manufacture a printing element in which damage to the piezoelectric element 2 is prevented.

Effects of the Invention As is clear from the above description, the present invention provides an arrangement in which one end of the piezoelectric member is brought into contact with a U-shaped member that clamps the one opposing portion of the base member, and the U-shaped member and one opposing portion are brought into contact with each other. Provide a gap between the side edges of
The U-shaped member is fixed to one of the opposing parts of the base member while applying a predetermined preload in the axial direction of the piezoelectric body by pressing the U-shaped member so as not to contact one of the opposing parts of the base member and the movable member. By doing so, it is possible to tolerate dimensional variations and dimensional changes of the piezoelectric body, and there is an advantage that it is possible to manufacture a printing element with high precision and in which damage to the piezoelectric body is prevented.

[Brief explanation of the drawing]

1a, b, and c are front, side, and top views of a printing element according to an embodiment of the present invention; FIG. 2 is an enlarged perspective view of a portion of FIG. 1; FIG. 3 is a partial enlarged perspective view of FIG. FIG. 4, which is a diagram for explaining a method of manufacturing a printing element, is a front view of a conventional printing element. 1...Base member, 1a, 1b...Opposing part, 2
...Piezoelectric body, 3...First displacement transmission member, 4...
Second displacement transmission member, 5... Movable member, 6... Printing wire, 7... Support member, 8... U-shaped member, 8a... Both sides, 8b... Bottom surface, 8c... Inner surface, 9 ...Positioning preload jig, 9a...Pressure measuring instrument.

Claims (1)

[Claims] 1 Piezoelectric member that generates dimensional distortion due to piezoelectric effect 2
, a base member 1 having opposing parts 1a and 1b that supports the piezoelectric member, and displacement transmission mechanisms 1c and 3 that transmit the dimensional strain and generate displacement in a predetermined direction.
4, 5, 10, 11, and a printing wire 6 fixed to the other end of the movable member 5 of the displacement transmission mechanism, a U-shaped member 8 that clamps the one opposing portion of the base member. One end of the piezoelectric member is brought into contact with the piezoelectric member, a gap 12 is provided between the U-shaped member and the side end _1a1 of one opposing portion, and a predetermined preload is applied in the axial direction of the piezoelectric member through the U-shaped member. A method for manufacturing a printing element, characterized in that the U-shaped member is fixed to one opposing portion of the base member in a suspended state.