JPH10264386A - Structure of ink-jet recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To judge sureness of bonding through visual inspection by providing a step at an outer periphery of a face where a chamber and a diaphragm of a frame are bonded, forming the diaphragm to be smaller than an outline of the chamber and frame, and setting a glove area in a structure after an ink-jet recording head is integrated that can absorb a bulge of an adhesive. SOLUTION: A diaphragm 2 and a frame 3 are sequentially bonded to a chamber 1, and a glove area 5 is formed at an outer peripheral face of the bonded part. In the thus-constituted recording head, a piezoelectric element 4 is bonded to a projecting part of the diaphragm 2, so that the diaphragm 2 is deformed by a shift of the piezoelectric element 4, thereby pressuring an ink in a pressure chamber 1a and jetting ink drops from a nozzle. In this case, a step is provided at the whole outer peripheral face of the chamber 1 and frame 3 where the diaphragm 2 is bonded, thereby forming the glove area 5. The diaphragm 2 is formed to be smaller by approximately 0.2 mm at one side than outlines of the chamber 1 and the frame 3. A swell 6a of an adhesive 6 used when the recording head is manufactured is accepted by the glove area 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an ink jet recording head for selectively depositing ink droplets on an image recording medium.

[0002]

2. Description of the Related Art FIG. 3 is a schematic sectional view of a conventional structure, and FIG. 4 is an enlarged view of a main part of the present invention. Chamber 1
The frame 3 and the diaphragm 2 have the same outer dimensions as the diaphragm 2. However, it is impossible to reduce the variation in component precision to 0 in terms of cost, and in many cases, the diaphragm 2 projects to the outer periphery as shown in FIG. This is illustrated as a protrusion 2a.

FIG. 5 shows an assembling method in the first step of bonding and fixing the vibration plate 2 to the chamber 1 with high positional accuracy.
In order to achieve the purpose of increasing the position accuracy, a well-known assembly jig is used. The high-precision alignment between the chamber 1 and the diaphragm 2 is performed by inserting an assembly reference hole provided on the chamber 1 and the diaphragm 2 into an assembly reference pin 12 provided on an assembly jig 11 to thereby adjust the position with high precision. Further, the positioning of the chamber 1 with respect to the jig 11 is easy and effective because the outer shape of the chamber 1 is easily used.

In order to stabilize the ink droplet ejection performance of the ink jet recording head and to improve the performance, the bonding between the chamber 1 and the vibration plate 2 requires a seal bonding in which a plurality of pressure chambers 1a are completely separated. It is important that the excess adhesive does not penetrate into the pressure chamber. The intruded adhesive is present in the ink flow path, and is affected by the low hydrophilicity of the adhesive, thereby inhibiting ink flow. For this purpose, the adhesive is applied thinly, and seal bonding is performed by pushing the adhesive with a sufficient pressing force using an assembly jig. As a result, the structure is such that the adhesive protrudes also in the outer peripheral portion of the chamber 1.

In a structure in which the adhesive does not protrude to the outer peripheral portion of the chamber 1, the diaphragm 2 is provided on the outer peripheral portion of the chamber 1.
A narrow gap is formed on the mating surface with the cleaning liquid, and the cleaning liquid infiltrates in the cleaning step during the manufacturing process, and it takes time to dry the cleaning liquid, which is not preferable in terms of manufacturing cost.
Further, it is impossible to check whether the adhesive around the pressure chamber is sufficiently adhered and the quality of the seal around the important pressure chamber is sufficient, and to perform quality inspection. If the structure is such that the adhesive protrudes, the quality of the bonding can be controlled based on the degree of protruding of the adhesive in the appearance inspection without performing a destructive inspection.

[0006] The second step of bonding the frame 3 to a component to which the chamber 1 and the vibration plate 2 are bonded is also performed in the chamber 1.
There is a demand for a method and quality according to the adhesion between the diaphragm and the diaphragm 2.

It has been mentioned earlier that the diaphragm 2 often protrudes from the outer dimensions of the chamber 1 due to the dimensional accuracy of parts. In the second step in which the projection 2a of the diaphragm 2 is inserted into the assembling jig and the frame 3 is adhered in the state where the projection 2a of the diaphragm 2 is present, a component insertion trouble occurs or the projection 2
Deformation due to contact with an object during handling of the head during manufacture of the head a, and problems such as peeling occur. In addition, since the diaphragm 2 has a thickness of 0.1 mm or less, the protruding portion 2a has a knife effect.

If there is a large amount of adhesive 6a protruding from the outer periphery of the chamber 1 and the frame 3, the adhesive 6 comes into contact with the wall surface of the assembling jig 11 and is adhered and fixed to each other. . In this case, it goes without saying that repair of the assembly jig 11 is accompanied.

Although it is possible to change the shape of a part of the assembly jig 11 to prevent the work and the assembly jig 11 from being bonded to each other, the assembly jig 11 becomes complicated and the manufacturing cost increases. Simply providing the relief groove in the assembly jig cannot remove the chamber 1, the diaphragm 2, and the frame 3 from the assembly jig 11 after they are bonded. Adhesive protrusion 6
The portion a becomes convex and interferes with the upper part of the assembling jig, so that the work cannot be taken out.

[0010]

DISCLOSURE OF THE INVENTION The present invention has been made in view of such a problem.
The reliability of bonding can be determined by visual inspection, there is no interference with the assembly jig, the defect rate is small, and assembly is possible safely and easily, and high-performance reliability that ejects ink droplets An object of the present invention is to provide an ink jet recording head.

[0011]

In order to achieve the above object, in the structure of the ink jet recording head of the present invention, a step is provided on the outer peripheral surface of the chamber 1 and the frame 3 where the diaphragm 2 is fitted. Chamber 1 and frame 2
And a glove area that can absorb the protrusion of the adhesive is provided as a structure after assembly.

(Operation) By making the diaphragm 2 smaller than the outer shapes of the chamber 1 and the frame 3, there is naturally no protrusion of the diaphragm 2 and no interference with the assembly jig 11. Therefore, the structure of the assembly jig 11 for bonding the frame 3 in the second step may be simple, and the insertion into the assembly jig 11 can be easily performed. The fact that components can be easily inserted into the assembly jig 11 is also an important condition in the case of automatic assembly. Further, it can be easily understood that since there is no protruding portion, the work can be performed safely even in handling. Further, defects such as diaphragm deformation and peeling caused by hooking the diaphragm 2 are eliminated.

As shown in FIG. 2, a chamber 1 and a diaphragm 2
Since the glove region 5 is provided on the work in relation to the jig at the time of bonding, the protruding portion of the adhesive at the outer peripheral portion by the bonding method in which the adhesive is pushed out fits in the glove region 5 and the assembly jig 11 Therefore, there is no problem that the workpiece and the assembly jig 11 adhere to each other. A structure that allows the adhesive to protrude is established, and it is possible to judge whether the adhesive strength of the seal is good or bad by managing the amount of the protruding adhesive.

[0014]

FIG. 1 shows a part of the structure of an ink jet recording head according to the present invention. Vibration plate 2 in chamber 1
Are bonded, and the frame 3 is further bonded. A glove region 5 is formed on the outer peripheral surface of the bonding portion.
FIG. 1 schematically shows a microstructure actually.
The piezoelectric element 4 is adhered to the convex portion of the vibration plate 2, and the displacement of the piezoelectric element 4 deforms the vibration plate 2, pressurizes the ink in the pressure chamber 1 a, and is shown in the upper part of FIG. 1. Ink droplets are ejected from nozzles that do not exist.

The outer circumference of each of the chamber 1 and the frame 3 has a width of 0.7 m on the mating surface with the diaphragm 2 over the entire circumference.
m and a depth of 0.3 mm. Further, the diaphragm 2
Is 0.2 on one side from the outer shape of the chamber 2 and the frame 3
mm.

An ink jet recording head was manufactured using each part of the present invention. In the first step, the diaphragm 2 was bonded to the chamber 1. The adhesive 6 employs a screen printing method,
As shown in FIG. 2, the assembly jig 11 roughly positions the outer shape of the chamber 1 with the assembly jig 11, and performs high-precision positioning with the diaphragm 2 on the chamber 1 and the diaphragm 2. The fitting reference hole provided was fitted to the assembly reference pin 12 of the assembly jig 11. A method of applying a pressing force by applying a compression spring and a screw to the pressing plate 13 of the assembling jig was used to push and spread the adhesive for seal bonding.
The illustration is omitted. In addition, a transfer method or the like is another effective means for uniformly applying the adhesive.

The adhesive 6 was pressed uniformly over the entire surface, and almost the same amount of the adhesive protruded over the entire outer periphery. The outer periphery of the adhesive does not protrude outside the outer shape of the chamber 1 and the assembly jig 11 does not.
No traces of contact with and no occurrence of adhesion occurred. For quality confirmation, a destructive inspection was performed on the extracted sample. It was confirmed that the adhesive 6 between the chamber 1 and the vibration plate 2 was pressed firmly, spread evenly, and was sealed. This proves that the bonding quality can be guaranteed by controlling the amount of adhesive protruding on the outer periphery without breaking.

Next, the frame 3 in the second step was bonded. Adhesion was performed using an assembly jig having the same concept as in the first step, and assembly with good sealing properties was completed. As in the first step, the adhesive was within the glove region 5, and no trouble occurred. Further, the diaphragm 2 was in a state of being recessed from the chamber 1 and the frame 3, and there was no occurrence of a defect that the diaphragm 2 was deformed by handling or the like and the bonded portion was peeled off.

The outer dimensions of the diaphragm 2 are smaller than the outer dimensions of the chamber 1 and the frame 3 and larger than the inner dimensions of the outer peripheral step of the chamber 1 and the frame 3, which is an extra part due to the wettability of the adhesive and the surface tension. The adhesive sticks out,
Alternatively, it prevents outflow.

[0020]

The structure according to the present invention does not require a special or complicated assembling jig, and can reduce the defective rate and can contribute to cost reduction. Further, since the bonding quality can be determined by an appearance inspection, a highly reliable bonding quality can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic partial sectional view of the structure of an ink jet recording head showing an embodiment of the present invention.

FIG. 2 is a schematic partial sectional view showing an embodiment of the present invention at the time of assembly.

FIG. 3 is a schematic structural view of a conventional inkjet recording head.

FIG. 4 is a schematic partial cross-sectional view of a main part of a conventional ink jet recording head.

FIG. 5 is a schematic partial cross-sectional view of a main part when assembling a conventional inkjet recording head.

[Explanation of symbols]

 Reference Signs List 1 chamber 2 diaphragm 3 frame 4 piezoelectric element 5 glove area 6 adhesive 11 assembly jig 12 assembly reference pin 13 push plate 1a pressure chamber 2a diaphragm protrusion 6a adhesive protrusion

Claims (1)

[Claims] 1. A method according to claim 1, wherein a vibration plate forming one pressure wall of the pressure chamber is deformed by using a displacement of the piezoelectric element to pressurize ink filled in the pressure chamber and eject ink droplets from a nozzle communicating with the pressure chamber. In the ink jet recording head, the diaphragm bonded and bonded between the chamber and the frame has a smaller outer dimension than the chamber and the frame, and the chamber and the frame have a step on the outer periphery of the mating surface of the diaphragm, and the step is A structure of an ink jet recording head, wherein a glove area for absorbing the protrusion of an adhesive can be formed.