JPH02200450A - Printing element - Google Patents

Abstract

PURPOSE:To achieve prevention of a joint member and a piezoelectric element from rupturing by a method wherein the piezoelectric element is jointed to be kept to the joint member with a bonding layer via an elastic buffer member. CONSTITUTION:When drive voltage is applied to a lead wire 11 and voltage is applied to a piezoelectric element 1, the piezoelectric element 1 is deformed in the A, B direction. A printing frame 6 has pivot fulcrums at points 6c, 6d, and displacement in the A, B direction becomes respectively displacement in the C, D direction at ends 6a, 6b of the printing frame. Said displacement is transmitted to an armature 9 and a wire 10 via spring 7, 8, and the wire 10 is displaced in the E direction to perform printing. When dimensional strain is generated by applying drive voltage to the piezoelectric element 1, force acts on the piezoelectric element 1. That is, though it is the force in the A (and B) direction and force A' in a direction contrary thereto acts on a side of the piezoelectric element 1, a buffer member receives this force and is deformed. Then, crack and peeling are neither generated in a bonding layer 12, and a joint member 3 is nor ruptured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printing element, and more particularly to a printing element that performs printing by transmitting the displacement of its drive to a wire member.

C. Prior Art] Conventionally, in such a printing element, the piezoelectric element is formed into a columnar shape, and both ends of the piezoelectric element in the longitudinal direction are joined to a connecting member using an adhesive.The connecting member is supported on a support frame to connect the piezoelectric element. The displacement of the support frame that occurs according to the dimensional distortion of is transmitted to the wire member to perform printing.

In such a structure, the piezoelectric element undergoes violent expansion and contraction movements during the printing operation, which causes the problem that the adhesive easily peels off during the operation. In the printing element described in the publication, FIG. 4(A).

The structure shown in (B) is adopted.

That is, in FIG. 4(A), the inactive part 20a of the piezoelectric element at the end of the piezoelectric element 20 is connected to the connecting member 2 through the adhesive layer 24.
3, and in order to prevent the adhesive from peeling off at this joint, the protective belt 22 is looped around this joint, and preferably, the protective belt is further held and adhered to the joint with an adhesive. There is.

Further, in the structure shown in FIG. 4(B), a fitting groove 23a is formed in the connecting member 23, and the inactive portion 20a of the piezoelectric element 20 is bonded by being embedded in this fitting groove via the adhesive 24. keeping. In FIG. 4(B), two piezoelectric elements 20 are provided and connected via an intermediate connecting member 23, and the entire structure is supported by a support frame.

[Problems to be Solved by the Invention] In such a conventional structure, when the piezoelectric element expands and contracts by applying a driving voltage from the normal state shown in FIG. 5(A), it changes to the state shown in FIG. 5(B). A large deforming force is generated in the connecting member 23 because a downward force acts on both sides and an upward force acts on the central part. In addition, since bending stress and shear stress act on the piezoelectric element, various stresses act on the connecting member, the protective belt, or the adhesive layer. In all of the structures shown in Figure 4, the protective belt and connecting members have rigidity, so various forces are generated due to the complicated expansion and contraction of the piezoelectric element, bending stress, and shear stress that occur many times. This cannot be absorbed, leading to problems such as cracks in the adhesive layer, or destruction of the sides of the fitting groove of the connecting member, the connecting member, or the piezoelectric element itself.

Therefore, the present invention was made to solve these problems, and it absorbs the various stresses generated in the piezoelectric element,
It is an object of the present invention to provide a printing element that does not cause peeling of an adhesive layer or other damage to a support member that supports a piezoelectric element.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention displaces a support frame that supports a piezoelectric element in accordance with the dimensional distortion of the piezoelectric element that occurs in response to a drive voltage, and corrects the displacement. A printing element that performs printing by transmitting information to a wire member includes a connection member that adheres and holds both ends of the piezoelectric element in the longitudinal direction with an adhesive layer via a buffer member, a support frame that supports the connection member, and a piezoelectric element. A displacement transmission mechanism is provided to transmit the displacement of the support frame that occurs in accordance with the longitudinal strain of the element to the wire member, and a configuration is adopted in which the force acting on the adhesive layer when the piezoelectric element is dimensionally distorted is absorbed by the M-plane member. .

[Function] In such a configuration, the piezoelectric element has elasticity1! Since the connecting member is bonded and held by the adhesive layer through the shock absorbing member, even when the piezoelectric element expands and contracts, or when bending stress or shear stress is applied, the shock absorbing member absorbs these forces. This prevents the adhesive layer from peeling off or the connecting member or piezoelectric element from breaking.

[Example] Hereinafter, the present invention will be described in detail based on the example shown in the drawings.

FIG. 1 shows a printing element according to an embodiment of the present invention. In the figure, what is designated by the reference numeral 1 is a piezoelectric element, both ends 1a of which are inactive parts, and a buffer member 5. It is bonded to the connecting member 3 via an adhesive. The connecting member 3 is supported by a printing frame 6, and springs 7.8 are attached to the ends of the printing frame 6a, 6b. One end 98 of the armature 9 is joined to the other end of the spring 7.8 by soldering, and a printing wire 10 is similarly secured to the other end 9b of the armature 9 by brazing. has been done. A driving voltage is applied to both sides of the piezoelectric element 1 via lead wires 11, and when the driving voltage is applied, the piezoelectric element expands and contracts in its longitudinal direction, causing dimensional distortion.

The connecting member 3 and the printing frame 6 are made of a material with a small coefficient of thermal expansion, such as invar, and the buffer member 5 is made of an elastic material such as rubber.

The connection member 3 of the piezoelectric element 1 is attached as shown in FIGS.
It is carried out as illustrated in C). First, as shown in FIG. 2(A), an adhesive layer 12 is formed by applying an araldite adhesive to the end of the piezoelectric element 1 and the end of the connecting member 3. Next, as shown in FIG. 2(B), the buffer member 5 is
The piezoelectric element 1 is joined to the connecting member 3 with the piezoelectric element 1 sandwiched therebetween. Since the piezoelectric element is very weak against the force X in the tensile direction, when joining the piezoelectric element 1 to the connecting member 3, pressurization is applied in the tensile direction X as shown in FIG. 2(C), that is, prestress is applied. and glue. At this time, the buffer member 5 is deformed due to its elasticity, and its end portion 5a protrudes from the side surface of the piezoelectric element 1, and is bonded and joined in a manner that surrounds the end portion of the piezoelectric element 1.

Next, the operation of the printing element configured as described above will be explained.

First, when a driving voltage is applied to the lead wire 11 and a voltage is applied to the piezoelectric element 1, the piezoelectric element 1 is deformed in directions A and B. Since the printing frame 6 is pivoted at points 6c and 6d, displacement in the A and B directions becomes displacement in the C1D direction at the ends of the printing frames 6a and 6b, respectively, and this spring 7.
8 to the armature 9 and wire 10, the wire 10 is displaced in the E direction, and printing is performed.

When a driving voltage is applied to the piezoelectric element 1 to generate dimensional distortion, a force of type 4 acts on the piezoelectric element 1. A typical example is A (and B) generated when the piezoelectric element 1 expands and contracts.
), and as shown in FIG. 3(D), a force A' in the opposite direction acts on the side surface of the piezoelectric element 1, but the buffer member 5 deforms in response to this force. Therefore, the connecting member 3 is not shaped as much as compared to the normal state shown in FIG.
There is no deformation as shown in B), and therefore, the adhesive layer 12 does not crack or peel, and the connecting member 3 does not break.

Furthermore, when bending stress F is generated in the piezoelectric element 1, as shown in Fig. 3 (
As shown in B), the lower part of the buffer member 5 is pressed and deforms accordingly to absorb this bending stress, and when shear stress G%G° occurs, the lower part of the buffer member 5 ), the buffer member 5 absorbs the displacement, and likewise the adhesive layer, the connecting member, or the piezoelectric element is prevented from being damaged by the force.

In this way, the piezoelectric element 1 is connected to the connecting member 3 via the mi member 5.
By adhesively bonding the piezoelectric element to the connecting member 3, transmission of deformation strain of the piezoelectric element to the connecting member 3 can be absorbed. As the material of the &I impact member, rubber or the like having a predetermined elasticity can be considered as described above.

[Effects of the Invention] As is clear from the above description, according to the present invention, the piezoelectric element is adhesively held to the connecting member by the adhesive layer via the elastic buffer member, so that when the piezoelectric element expands and contracts, Also, when bending stress or shear stress is applied, the buffer member absorbs these forces, so
This prevents the adhesive layer from peeling off or breaking the connecting member or piezoelectric element.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the configuration of a printing element according to an embodiment of the present invention, FIGS. 2(A) to (C) are explanatory views showing a state in which a piezoelectric element is attached to a connecting member, and FIG. 3 (
A) to (D) are explanatory diagrams illustrating the state in which various forces generated in the piezoelectric element are absorbed through the buffer member, and FIG. 4 (A)
, (B) are explanatory diagrams showing the conventional structure, and Fig. 5 (A), (B)
) is an explanatory diagram illustrating the distortion that occurs when a piezoelectric element expands and contracts in a conventional structure. DESCRIPTION OF SYMBOLS 1... Piezoelectric element 3... Connection member 5... Buffer member 6... Printing frame 7.8... Spring 10... Wire 12... Adhesive layer (A) (B) (C ) (D) Explanation of gIp price 1 Bon θ Eruru Figure 3 (B) Record of Juto no Yuzu Figure 4? Mu (A) (Japanese) Shocking & Demise of Jutogure 1 C Figure 5

Claims (1)

[Claims] 1) In a printing element that performs printing by displacing a support frame that supports a piezoelectric element according to dimensional distortion of the piezoelectric element that occurs in response to a driving voltage, and transmitting the displacement to a wire member, A connecting member that adheres and holds both ends of the piezoelectric element in the longitudinal direction with an adhesive layer via a buffer member; a support frame that supports the connecting member; 1. A printing element comprising: a displacement transmission mechanism for transmitting to a wire member; and the buffer member absorbs force acting on the adhesive layer when dimensional distortion of the piezoelectric element occurs. 2) The printing element according to claim 1, wherein the piezoelectric element is pressurized in the longitudinal direction to be adhesively held to a connecting member. 3) The printing element according to claim 1 or 2, wherein a portion of the buffer member protrudes to opposing sides of the piezoelectric element due to the pressurization.