JPS6079969A - Printing element - Google Patents

Abstract

PURPOSE:To prevent breakdown of a transfer piece of a printer element of piezo-electricity driven dot printer by fixing each end of the first and second transfer pieces to a movable piece and by fixing a wire at a specific location. CONSTITUTION:Each end of the first transfer piece 6 and the second transfer piece 7 are fixed respectively to the movable piece 8 so that the main shaft K of the moment of inertia of the movable piece 8 passes the center R of rotation caused by displacement transferred from the movable pieces 4 and 5. Further, the place of installation of a wire 9 is to be so determined as the center of impact against the working point H of reaction force on the main shaft K agrees with the point R.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing element, particularly a printing element for performing dot printing using a piezoelectric material as a driving force. FIG. 1 is a perspective view illustrating the structure of a printing element according to the present invention. It is. A piezoelectric body 2 whose lower end is fixed to a metal mounting member 1 is a driving source for printing operation. The upper end of the piezoelectric body 2 is fixed to a metal joint @'3K. The metal movable members 4 and 5 are provided in order to operate as a lever when receiving the displacement given by the piezoelectric body 2 and to magnify and transmit the displacement. The lower end portions of the movable members 4 and 5 are respectively connected to the mounting member 1 and the coupling member 3 via plate-shaped connecting portions. Further, one end of transmission members 6 and 7 made of metal plates is fixed to the upper end portions of each of the movable members 4 and 5, and the other ends of the transmission members 6 and 7 are fixed to a predetermined location of a movable member 80, respectively. At the tip of the movable member 8 is a metal rod wire 9 for dot printing.
However, the installation is fixed.

A lead of 10 t is connected between a pair of electrodes provided on both sides of the piezoelectric body 2.
- When a driving voltage is applied through the piezoelectric member 2, the piezoelectric body 2 expands due to the electrostrictive effect, causing dimensional distortion, pushing up the coupling member 3 and displacing the movable members 4 and 5. In response to this displacement, movable members 4 and 5 each act as a lever, causing displacement in the directions indicated by dashed arrows A and B at their respective upper ends. When these two displacements in opposite directions are transmitted through the transmission members 6 and 7t, the movable member 8 causes a rotational movement, and the wire accordingly moves in the direction of the dashed arrow C (/J) to a dot. Perform printing operation.

In such conventional printing elements, the dimensions and angles of the troughs of the displacement transmission paths are carefully adjusted so that the plate surfaces of the transmission members 6 and 7 do not bend roughly during the printing operation, resulting in excessive bending stress. The plate surfaces of the transmission members 6 and 7 are designed to bend in a simple arc shape when viewed from the side when the transmission members 6 and 7 are set to a certain value. As a result, the transmission members 6 and 7
The aim is to prevent breakage from occurring due to excessive bending stress acting on the steel. However, the wire 9 does not overlap on the printing surface.

The transmission members 6 and 7 bend in the simple shape as described above until just before impact, but when the wire 9
The reaction force from the transmission members 6 and 7 is bent into a complicated shape, and excessive bending stress is applied to the transmission members 6 and 7, often causing breakage.

That is, the conventional printing element has a drawback in that the reaction force that the wire 9 receives from the printing surface at the time of impact causes the transmission members 6 and 7 to be roughly bent and excessive bending stress is applied, resulting in easy breakage. be.

SUMMARY OF THE INVENTION An object of the present invention is to provide a printing element which eliminates the above-mentioned drawbacks and prevents the plate surface of the transmission member from being bent or broken even upon impact.

The element of the present invention includes a piezoelectric body that generates dimensional distortion in response to a printing voltage, a mounting member that fixes one end of the piezoelectric body, and a plate-like member that is connected to the other end of the piezoelectric body and the mounting member. first and second movable members that are connected to each other and generate first and second angular displacements in opposite directions, respectively, in response to the dimensional strain applied from the piezoelectric body through the plate member; , plate-shaped first and second transmission member systems having one end of each fixed to the first and second 5J shift members, and the other ends of the first and second transmission members fixed to each other; A third movable member that generates a rotational motion in response to the first and second angular displacements that are transmitted through the two valves, and one end thereof is identified to the third movable member, and the third movable member generates a rotational motion in response to the rotational movement. and a printing member arranged such that the center of the rotational movement and the center of impact against the reaction force transmitted from the printing surface via the wire at the time of impact substantially coincide with each other. There is.

Next, the details will be explained in detail with reference to the drawings. FIG. 2 is a partial side view for explaining the principle of the present invention.

As previously mentioned, the transmission members 6 and 7 are designed to undergo simple flexing during operation. In this case, in the transmission members 6 and 7, the length of the line segment connecting points E and F, which are intermediate between the boundary points where they are attached to the town wJ members 4 and 5 and the boundary point where they are fixed to the movable member 8, is Among them, the length remains unchanged. f, that is, movable members 4 and 5
When the displacement is transmitted to the transmission members 6 and 7, respectively, the line segments passing through the points E and F move correspondingly while keeping their lengths constant. The motion Ff of this line segment is equal to the total composition of the two components of translation and rotation.The translation component is equal to the total composition of the two components of translation and rotation.Since the transmission members 6 and 7 are not bent over the entire length, the translation component is only the rotation component. All you have to do is pay attention to
The rotation center points of this rotational component are 1 normal point E and Fi
It is near the connecting line segment. One end of each of the transmission members 6 and 7 is fixed to each predetermined location of the movable member 8, and when the line segment connecting points E↓ and Fi rotates around point R while maintaining a constant length, , the transmission members 6 and 7 bend in a simple circular arc shape while displacing the movable member 8 and transmitting the wire 9.
perform printing operation.

When a reaction force is transmitted from the wire 9 in the direction of the dashed arrow at the time of impact, the movable member 8 rotates around point Jt, which is the center of impact against point H, and point 0, which is the center of gravity of the movable member 8. If the principal axis of the moment of inertia passing through is shown by the broken line, and all the points H where the reaction force acts on the broken line are shown, then
Point J is on the dashed line, and the product of the length between points G and 8 and the length between points G and 5 is equal to the square of the radius of inertia of the center of gravity. As shown in this figure, the wire 9 is attached near the lower end of the movable member 8, and therefore, when the point H is near the lower end of the movable member 8, the point J is close to the point G and is inside the movable member 8. . In this way, point R is the center of rotation caused by the displacement transmitted from movable members 4 and 5, and point J is the center of rotation caused by the reaction force at the time of impact.
If they are spaced apart from each other, two rotations with different centers will be added, resulting in complex bending in the transmission members 6 and 7. In the element of the present invention, point R and point J substantially coincide. By configuring the transmitting members 6 and 7 to
Avoiding complex bends throughout the entire structure to prevent breakage and breakage.

FIG. 3 is a partial side view showing the first embodiment of the invention. In non-embodiments, the main axis of the moment of inertia of the movable member 8 (
The transmission members 6 and 7 are connected so that the point Ri (indicated by the broken line) passes through the point Ri.
One end of each is fixed to the movable member 8.

The wire 9 should be attached at a location so that the center of the impact on point H coincides with point R.

Note that point R is the same as in Figure 2 <, I'Kodo s4 and ↓
It is the center of rotation caused by the displacement transmitted from Compared to the case shown in FIG. 2, the wire 9 is attached closer to the center of gravity, point 0, and the center of impact on point H (i.e., point J) is accordingly moved farther away from point 0. It is located outside the V movable member 8. By making point R and point J completely coincident in this way, the rotation caused by the displacement transmitted from the movable parts 4 and 5 and the rotation caused by the reaction force at the time of impact are both at the same point R (i.e. J
) Since it occurs at the t-center, even when these two rotations are added, only a simple bend occurs in the transmission members 6 and 7, and there is no excessive bending stress as in the conventional case. Destruction can be prevented.

FIG. 4 is a partial side view showing a second embodiment of the present invention. This embodiment differs from the first embodiment shown in FIG.
A mass adding member 11 is additionally provided at the lower end of the movable member 8. By adding the mass adding member 11,
The center of gravity of the movable member 80 to which this is added, that is, point G, is shifted downward compared to the case of the previous embodiment, and the radius of inertia around the center of gravity is increased compared to the case of the previous embodiment. Therefore, if point H is selected so as to coincide with the center of impact (that is, point Ji and point R), point H-f can also be shifted downward in the case of the previous embodiment. There is an advantage that the stroke transmitted during the printing operation can be made longer than that of the previous embodiment by increasing the total displacement transmitted to the print element.
A comparative example of the magnitude of the stress acting on the transmission members 6 and 7 for both the mass adding member 11L and the provided printing element of this embodiment is shown below. 6 plate width is 1.7mm, plate length is 15++
11n.

The plate thickness is 026 mm and the plate width of the % transmission part 7 is 2.2 m.
m.

The plate length is 7 mm and the plate thickness is 9.2 mm. 'Also, the plate surfaces of transmission parts 6 and 7 form an angle of 10°.

There is. When printing with a maximum printing force of 6 Newtons, the maximum stress acting on the transmission members 6 and 7 due to the reaction force received from the wire 9 (0, 25φ) is, respectively.

In the conventional example, it is 27 kg/mm2 and B1 kg/mm", and in the non-implemented example, it is 18 kg/mm2 and 35 kg/mm".
It is mm2. Therefore, the month of mismatched members 6 and 7...
1, when using a preparation with a fatigue limit of about 4Qkg/mm2, in the conventional example, the stress acting on the transmission member 7VC greatly exceeds the bulge, causing breakage during repeated operation. In contrast, in this embodiment, the stresses acting on the transmission members 6 and 7 are both below the fatigue limit of the material, so no breakage occurs.

As is clear from the above description, the present invention has the effect of being able to realize a printed double-sided pattern that can prevent the transmission member from breaking and breaking by preventing complicated bending of the plate surface of the transmission member at the time of impact.

[Brief explanation of the drawing]

Figure i1 is a perspective view illustrating the structure of a printing element according to the present invention, Figure 2 is a partial side view for explaining the present invention in detail, and Figures 3 and 4 each illustrate an embodiment of the present invention. This is a partial side view shown. 1...Mounting member, 2...Piezoelectric body, 3.
...Connecting member, 4,5.8...Movable member, 6.7...Transmission member, 9...Wire, 10... Lead, ll... quality tht
Additional parts. h l second country and ＼－に／／－

Claims (2)

[Claims] (1) A piezoelectric body that generates dimensional distortion in response to an applied voltage, a mounting member to which one end of the piezoelectric body is fixed, and each connected to the other end of the piezoelectric body and the mounting member via a plate-like member. first and second movable members that respectively produce first and second angular displacements in opposite directions in response to the dimensional strain applied to the plate-like metal piece from the piezoelectric body; and one end of each movable member. through plate-shaped first and second transmission members fixed to the first and second movable parts, and the other ends of the first and second transmission members fixed to each other; a third movable member that generates rotational motion in response to the transmitted first and second angular displacements; and one end of which is fixed to the third movable member, and prints in response to the rotational motion. and a printing member arranged so that the center of the rotational movement coincides with the center of impact against the reaction force transmitted from the printing surface through the entire wire at the time of impact. A printing element featuring (2) The third movable member has a negative view adding member provided at an end opposite to the side to which each end piece of the first and second transmission members is fixed when viewed from the attachment point of the wire. The printing element according to claim 11.