JPS61283553A - Vibration unit of ink jet head and its manufacturing - Google Patents

Abstract

PURPOSE:To reduce mutual interference caused by mechanical vibration, by constituting a vibration unit in which plural number of rectangular elec tromechanical conversion elements are provided to a pectinated elastic body. CONSTITUTION:A rectangular electromechanical conversion element 2a and a rectangular elastic plate 3a are bonded together, and then, the conversion element 2a and the elastic plate 3a are simultaneously processed for making flutes by rotation cutting etc. and a pectinated vibration unit is shaped. The length of channeling for the above process l is so set as l>=L in which L is the cutting length of the electromechanical conversion element 2a, that the conversion element is completely separated into pectinated vibration units 21, 22 and it becomes to have the construction of a pectinated elastic plate 3a and many rectangular electromechanical conversion elements 21, 22.... Therefore, each electromechanical conversion element is separated, resulting in reduction in transmission of vibrations between the vibration units, and reduction in the mutual interference.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vibration unit suitable for use in a multi-nozzle inkjet recording apparatus and a method for manufacturing the same.

FIG. 9 is a cross-sectional configuration diagram showing an example of a conventional on-demand multi-nozzle inkjet head, and FIG. 10 is a perspective view thereof. In the figure, 1 is a nozzle, 2 is an electromechanical transducer, and 3 1 is an elastic plate, 4 is a connecting portion, 5 is an ink flow path substrate, 6 is an ink droplet, 7 is an ink pressurized liquid chamber, 8 is an ink supply side flow path, 9 is an ink supply pipe, 10 is a vibration substrate, 11 is an A diaphragm, 12 a support body, 13 a vibration unit, and the vibration unit 13 is constructed by bonding an electromechanical transducer 2 and an elastic plate 3. The channel substrate 5 is made of resin or the like, and the nozzle 1, the ink supply channel 8, the ink pressurized liquid chamber 7, etc. are integrally molded. The vibration substrate IO is also made of resin or the like, and includes a diaphragm 11, a connecting portion 4, and a support body 12.
is integrally molded. As is well known, in the inkjet head, the vibration unit 13 displaces the diaphragm 11 to pressurize the ink in the ink pressurized liquid chamber 7 and eject ink droplets 6 from the nozzles 1 to record on recording paper (not shown). As shown in FIG. 1O, the vibration unit has a comb-teeth shape and has a multi-nozzle structure.

Therefore, in the multi-nozzle inkjet head as described above, it is more advantageous to have an integrated vibrating unit than a single unit in terms of parts cost, and it is easier to install the vibrating unit when adhering the unit and when assembling it to the head. The integrated type is also superior in terms of ease of handling, position accuracy control, etc.

However, when an integrated type is used, the degree of mutual interference between the vibration units, in which the vibration of the vibration unit driven by pulse application is mechanically propagated to other vibration units, makes it difficult to install multiple single vibration units. There is a problem that the size is larger than in the case of the comb teeth, but this is because the electromechanical transducer and the elastic plate are both integrated in the original part of the comb teeth.

FIG. 11 is a diagram showing an example of a method for manufacturing the comb-shaped vibration unit 13 as described above. First, as shown in FIG. At the same time, a rectangular elastic plate is formed into a comb-shaped elastic plate 3 by pressing, etching, etc., and these separately formed comb-shaped electromechanical transducers are The mechanical transducer element 2 and the elastic plate 3 were bonded together to form a vibration unit 13 as shown in Figure (b).

However, according to the above-mentioned conventional manufacturing method, the comb-shaped electromechanical transducer 2 may lose some of the comb teeth during processing, and must be handled with great care after processing until it is bonded. Furthermore, cracks are likely to occur during the bonding process.
Yield was poor.

Furthermore, when bonding, care must be taken to align the comb-shaped electromechanical transducer 2 and the elastic plate 3 and to prevent the adhesive from flowing out between the comb teeth.

The present invention was made in view of the above-mentioned circumstances.
In particular, in an integrated comb-shaped vibration unit, it is necessary to eliminate mutual interference due to mechanical vibration propagation, to enable easy and high-yield processing, and to make it easier to assemble the vibration unit to the head. This was done for the purpose of enabling accurate positioning.

1. In order to achieve the above object, the present invention includes a large number of nozzles, a large number of ink pressurizing liquid chambers corresponding to each nozzle, and a vibration unit that changes the volume of the ink pressurizing liquid chamber. At least a part of the wall of the ink pressurizing liquid chamber is formed of an elastic body, and the elastic body is displaced by the vibration unit to change the volume of the ink pressurizing liquid chamber, thereby,
In the inkjet head configured to eject ink droplets from the nozzle, the vibration unit includes a comb-shaped elastic plate and a strip-shaped electromechanical transducer arranged at each comb-shaped part of the comb-shaped elastic plate. and the length l of the comb-tooth grooves of the comb-shaped elastic plate is l ≧ with respect to the length in the longitudinal direction of the electromechanical transducer element, or the electromechanical transducer plate and This device is characterized by bonding elastic plates and cutting grooves after bonding to form a comb-shaped vibrating unit. Hereinafter, the present invention will be explained based on examples.

FIG. 1 is a diagram for explaining the vibration unit and its manufacturing method according to the present invention. First, as shown in FIG.
The rectangular electromechanical transducer 2a and the rectangular elastic plate 3a are bonded together, and then, as shown in FIG. This is a tooth-shaped vibration unit.

At this time, if the length l of the groove cutting is set so that E≧L with respect to the length L of the electromechanical transducer 2a in the cutting direction, the transducer will be connected to the comb-shaped vibration unit 21, 22 (in the figure, 2
2 and subsequent parts (not yet cut) are completely divided, resulting in a configuration including a comb-like elastic plate 3a and a large number of rectangular electromechanical transducers 2+, 2z, . . . Therefore, since each electromechanical transducer element is separated, vibration propagation between the vibration units is reduced and mutual interference is reduced compared to the conventional vibration unit shown in FIG. In addition, compared to bonding rectangular electromechanical transducers one by one on the comb-shaped elastic plate 3a, processing is easier, there is less variation between each unit, and positional accuracy and tolerance during bonding are improved. The range can be widened. In addition, as is well known, the tooth tips of the vibration unit have grooves 3' (10th
In the figure, a round hole 3') is machined, but in figure (c), when bonding, the comb-shaped electromechanical transducer 2a and the elastic plate 3a are bonded with their tips shifted in position, and only the elastic plate 3a is bonded. An example is shown in which a 3° groove is formed for joining the connecting portion.

In the embodiment shown in FIG. 1, the electromechanical transducer plate 2a and the elastic plate 3a are cut at the same time.
Normally, the electromechanical transducer 2a is made of ceramic and the elastic plate 3a is made of metal, so the setting of cutting conditions becomes strict due to the difference in the properties of the different materials.

FIG. 2 is a diagram for explaining an embodiment that eliminates the above-mentioned disadvantages. First, as shown in FIG. death,
Glue these together as shown in figure (b).
Thereafter, the electromechanical transducer 2a is cut along the kerfs of the comb-like elastic body 3. In this way, the grooving process only needs to be performed on the electromechanical transducer 2a. No such inconvenience will occur. Furthermore, at this time,
The length of the electromechanical transducer 2a in the cutting direction with respect to the comb tooth groove length l of the elastic plate 3 satisfies L≦β. Also, (d)
The figure is a cross-sectional view taken along the line dd in FIG. It becomes. In other words, by using a cutting tool whose teeth are thinner than the comb tooth groove width of the elastic plate, only the electromechanical transducer is cut to form the comb tooth vibration unit. This makes it possible to cut and process easily with a diamond cutter, etc. Further, the comb-shaped elastic body 3 may have a connecting portion 3'' in the comb-teeth groove portion, as shown in Fig. <c>. Oh (at the time,
When handling the electromechanical transducer before gluing it, there is less risk of the comb teeth being cut.
” is cut at the same time as the electromechanical transducer is cut into grooves.

FIG. 3 is a plan view showing another example of the elastic plate 3 suitable for manufacturing the vibration unit according to the present invention.
A hole 3b for positioning is provided in the elastic plate 3. In this way, the machining accuracy during groove cutting can be controlled. For example, as shown in FIG. It is possible to overlap and cut grooves at the same time.

In order to control the positional accuracy when attaching the vibrating unit manufactured as described above to the vibrating board, conventionally, the connection hole between the connecting part 4 and the elastic plate formed at the tip of the vibrating unit is set at a 3° angle. However, according to this prior art, in order to achieve the necessary accuracy, the dimensional difference between the connection hole 3'' and the connection part 4 is small, and it is necessary to smoothly set the plurality of connection parts in the connection hole. This has been an obstacle to automating assembly.

FIG. 5 is a sectional view showing an embodiment of an inkjet head that eliminates the drawbacks of the prior art as described above, and FIG.
In the perspective view, the same reference numerals as in FIGS. 9 and 10 are given to parts that have the same functions as in FIGS. 9 and 10.

In this embodiment, a positioning pin 14 is integrally formed on the vibrating substrate 10, and the positioning accuracy is managed by this positioning pin 14 and the positioning hole 3b shown in FIG. I have to. Therefore, according to this embodiment, the connection hole 3' can have a sufficient dimensional difference with respect to the connection part 4, and the vibration unit can be easily attached to the vibration board even in an automated line.

FIG. 7 is a perspective view showing an embodiment in which a flexible board 15 is attached for the purpose of extracting electricity from the vibration unit. By providing a positioning hole corresponding to 3b, positioning becomes possible.

FIG. 8 is a perspective view of an inkjet head constructed using the above-mentioned vibration unit. For example, the two vibration units (2) and (2) may be arranged in series as shown in (a), or in parallel as shown in (b).

As is clear from the above description, according to the present invention, (a) an integrated comb-like vibration having a configuration in which a plurality of rectangular electromechanical transducers are arranged on an If tooth-like elastic body; The unit makes it possible to reduce mutual interference due to mechanical vibrations.

(b) An integrated comb-shaped vibration unit having the above-described configuration can be easily fabricated.

(c) It is possible to easily process the vibration unit and increase mass productivity.

(d) It becomes easy to assemble the vibration unit to the vibration board.

There is an advantage of 3rd class.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the vibration unit and its manufacturing method according to the present invention, FIG. 2 is a diagram for explaining another embodiment of the present invention, and FIG. 3 is a diagram for explaining the implementation of the present invention. FIG. 4 is a plan view showing an example of a comb-like elastic plate used, FIG. 4 is a diagram for explaining an example of a vibration unit manufacturing method, and FIG. 5 is a cross-sectional view showing another embodiment of an inkjet head according to the present invention. 6 is a perspective view, FIGS. 7 and 8 are perspective views showing other embodiments of the present invention, and FIG. 9 is a sectional view showing an example of a conventional inkjet head. The 1θ diagram is a perspective view thereof, and FIG. 11 is a diagram showing an example of a conventional vibration unit and its manufacturing method. 2a... Electromechanical transducer element t3a... comb-like elastic plate. 3b...Positioning hole, 13...Vibration unit 1
4...Positioning bin.

Claims (5)

[Claims] (1) It has a large number of nozzles, a large number of ink pressurizing liquid chambers corresponding to each nozzle, and a vibration unit that changes the volume of the ink pressurizing liquid chamber, and the ink pressurizing liquid chamber is At least a part of the wall is formed of an elastic body, and the elastic body is displaced by the vibration unit to change the volume of the ink pressurized liquid chamber, thereby ejecting ink droplets from the nozzle. In the head, the vibration unit includes a comb-shaped elastic plate and a rectangular electromechanical transducer element disposed on each comb-shaped part of the comb-shaped elastic plate. A vibration unit for an inkjet head, wherein a length l of the comb tooth groove is l≧L with respect to a longitudinal length L of the electromechanical transducer. (2) The width W_1 of each comb-shaped portion of the elastic plate satisfies W_1≦W_2 with respect to the width W_2 of each comb-shaped portion of the electromechanical transducer. The vibration unit of the inkjet head according to item 1). (3) The comb-like elastic plate has pin holes for positioning.
The vibration unit of the inkjet head according to item 2). (4) A method for manufacturing a vibration unit for an inkjet head, which comprises bonding an electromechanical transducer plate and an elastic plate, and cutting grooves after bonding to form a comb-shaped vibration unit. (5) The inkjet head according to claim (4), wherein either the electromechanical transducer plate or the elastic body is grooved in a comb-like shape before bonding. Vibration unit manufacturing method.