JP2002254655A - Ink jet recording device and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conduct a resonance frequency adjustment for an oscillation body more easily compared with a conventional one. SOLUTION: An ink jet recording device conducts a recording by forcing ink particles to reach a predetermined place on a recording medium by providing oscillation to jetted ink, generating the ink particles, and charging and deflecting the ink particles. The oscillation body which maintains a piezoelectric element providing oscillation to the ink is a langevin type which pinches the piezoelectric element by a bolt/nut, and the two nuts are screwed in one common bolt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus for continuously ejecting ink particles and a method for manufacturing the same.

[0002]

2. Description of the Related Art An ink jet recording apparatus comprises a nozzle body for generating ink particles by applying vibration to ink ejected from a nozzle, a charging electrode for charging the ink particles, and a deflecting electrode for deflecting the charged ink particles. With
The nozzle body includes a vibrating body, and an ink flow path forming member provided with an ink vibrating chamber for applying vibration of the vibrating body to the supplied ink, wherein the vibrating body includes a vibrating unit and a vibrating unit. The vibrating portion includes a piezoelectric element as a vibration element.

Conventionally, this piezoelectric element has been generally sandwiched and held by a bolt and a nut, of which the vibrating part is a part.

The prior art relating to this type of ink jet recording apparatus is disclosed in, for example, JP-A-50-34.
No. 038.

[0005]

The vibration portion has an electrode terminal portion coated with an insulating coating. An adhesive is poured into the nut portion to prevent loosening.

However, these coating agents and adhesives function to prevent vibration of the vibrating body after curing.

Therefore, even if the nut is tightened to obtain a desired resonance frequency as the vibrator, the resonance point is changed by subsequent coating or bonding. In addition, the amount of change depends on the amount of coating agent or adhesive applied.

Japanese Patent Laid-Open Publication No. Sho 50-34038 discloses that a first nut having a substantially Y-shaped cross section is screwed to a nozzle holder tube of an ink jet recording apparatus, and the outer periphery of a central cylindrical portion having a substantially Y-shaped cross section. The second nut is screwed to the screw portion provided in the above, so that a so-called two nuts are tied together, and various kinds of masses are prepared as the second nut, and this second nut is appropriately replaced. Accordingly, a technique for adjusting the resonance frequency of the vibrating body has been disclosed.

However, according to this configuration, when the threading direction of the first nut and the second nut is the same, when the second nut is tightened, the first nut is rotated in the direction of further tightening. It is conceivable that the resonance frequency adjustment of the vibrating body may be disturbed, while the first nut and the second
When the threading direction of the nut is reversed, it is considered that when the second nut is tightened, the first nut is rotated in a loosening direction to make the resonance frequency adjustment of the vibrating body out of order. Is desired.

The present invention has been made on the basis of the above background, and an object of the present invention is to provide an ink jet recording apparatus and a recording apparatus which can adjust the resonance frequency of a vibrator more easily than before. It is to provide a manufacturing method thereof.

[0011]

According to the present invention, a vibrating body for holding a piezoelectric element for applying vibration to ink in an ink jet recording apparatus is of a Langevin type in which the piezoelectric element is sandwiched between bolts and nuts, and the nut is used in common. 1
Two bolts are screwed to the bolt, and a vibrating body having a desired resonance frequency can be easily obtained by changing the tightening torque of one nut or changing the mass.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

First, an outline of an ink jet recording apparatus will be described with reference to FIG.

In front of the nozzle body 1, there are provided a charging electrode 2 for charging the ink particles ejected from the nozzle, and a deflection electrode 3 for deflecting the flight of the charged ink particles. Further, a gutter 4 for collecting ink particles not used for printing is provided ahead of the gutter 4. These occupy the main part of the nozzle head.

A filter 5 is provided on the ink supply side of the nozzle body 1. The excitation source 6 supplies a high-frequency current having an excitation frequency to a vibration element (described later) of the nozzle body 1 via a lead wire. The recording signal source 7 applies a charging video signal to the charging electrode 2 via a lead wire. The high voltage power supply 8 applies a high voltage to the deflection electrode 3 via a lead wire.

Ink container 10 in which ink 9 is stored
Communicates with the nozzle body 1 via a pipe.

The ink container 10 also communicates with the gutter 4 via a pipe. The nozzle body 1 is connected to an ink pump 11, a pressure regulating valve 12 for adjusting ink pressure, and an electromagnetic valve 13 for opening and closing a flow path. The gutter 4 is communicated via a recovery pump 14, a filter 15, and a solenoid valve 16.

The ink 9 is supplied from the ink container 7 to the nozzle body 1.
Is referred to as an ink supply path 17. A path for collecting the ink 9 from the gutter 4 to the ink container 7 is referred to as an ink recovery path 18. In addition, there is an ink circulation path 20 connected between the filter 15 and the electromagnetic valve 16 via the electromagnetic valve 19 from the middle of the nozzle body 1.

In the printing operation, since the solenoid valve 19 is closed and the operation is performed, no ink flows through the ink circulation path 20.
The time when the solenoid valve 19 is opened is when the inside of the nozzle body 1 is washed.

When ink is supplied from the ink container 7 to the nozzle body 1, ink particles are ejected from the nozzles of the nozzle body 1, and the ink particles are charged by the charging electrode 2, deflected by the deflecting electrode 8, and applied to the printing object. Fly towards.

Since the ink particles are deflected in accordance with the amount of charge charged by the charging electrode 2, if the amount of charge is controlled, dots can be arbitrarily formed on the printing object in the direction of deflection. Then, characters can be drawn by moving the printing object in the vertical direction of the deflection direction. The ink particles that have not been used for printing are not charged by the charging electrode 2 and are therefore
The ink collecting path 1 from the gutter 4 without being deflected by
The ink returns to the ink container 7 via 8, and is used again for print formation.

Next, the nozzle body which is a main part of the present invention will be described with reference to FIG.

The nozzle body 1 is provided with a nozzle body base 40, an ink flow path forming member 41, a nozzle plate member 42, and a vibrating body 43. These are made of stainless steel. The nozzle body base 40 has a hollow vibrating body storage chamber 50 inside.

The vibrating body 43 has a vibrating part 60 and a vibrating part 61. The vibration part 60 and the vibration part 61 are formed integrally. Two of the piezoelectric elements 63 as the vibration elements are
Are fastened and fixed by the bolt portion 62 and the first nut 65. A terminal 64 is provided between the two piezoelectric elements 63.
a, a terminal 64 between one of the piezoelectric elements 63 and the nut 65
b. The terminals 64a and 64b are electrically connected to the excitation source 6 by lead wires.

The terminal 64b is in electrical communication with the first nut 65, the bolt portion 62 of the vibrating body, and the nozzle body base 40, and is grounded. The outer periphery of the terminal 64a is insulated by the coating agent 66. After tightening the first nut 65, an adhesive for preventing loosening is poured.

A second nut 67 is provided outside the first nut 65. A loosening prevention member 68 such as a spring washer may be provided between the first nut 65 and the second nut 67.

The vibrating section 60 is a thin disk.
The vibrating portion 60 has a thin disk shape because the vibrating portion 60 and the vibrating portion 61 are connected via a constricted portion 69. The constricted portion 69 is a boundary between the vibrating portion 60 and the vibrating portion 61, and is formed by cutting or pressing.
Due to the constricted portion 69, the vibrating portion 60 has a shape like a thin brim spreading around.

The ink flow path forming member 41 includes the ink vibrating chamber 7.
Has zero. The ink vibrating chamber 70 is formed at the center of the ink flow path forming member 41. The bottom of the ink vibrating chamber 70 is formed by the vibrating section 60.

The annular vibrating body sealing member 75 is sandwiched between the vibrating section 60 of the vibrating body 43 and the joining surface of the ink flow path forming member 41 and is located on the outer peripheral side of the vibrating section 60. Although the ink pressure is applied to the ink vibrating chamber 70, the ink pressure is suppressed by the vibrating body seal member 75, so that the ink does not leak from the joint surface.

Further, the ink flow path forming member 41 has an ink supply hole 76 communicating with the ink vibrating chamber 70. An ink supply pipe 77 constituting the ink supply path 17 is connected to the ink supply hole 76. Similarly, the ink vibration chamber 7
0 has an ink circulation hole 78 and communicates with the ink circulation path 20.

The nozzle plate member 42 has an orifice portion 90. The orifice portion 90 has minute holes, and the minute holes communicate with the ink chamber 70. An orifice plate seal member 100 is sandwiched between the joining surfaces of the nozzle plate member 42 and the ink flow path forming member 41. Although the ink pressure is applied to the ink vibrating chamber 70, the ink is suppressed by the seal member 100 for the orifice plate, and the ink does not leak from the joint surface.

The vibrating section 60 is a thin disk as described above, and the outer peripheral side is fastened and fixed, so that the vibrating section 60 vibrates well in the front-rear direction.

Next, the operation will be described.

When ink is fed from the ink supply pipe 77 into the ink chamber 70 of the nozzle body 1 and the vibrator 43 is vibrated by the piezoelectric element 63, ink particles are ejected from the minute holes of the orifice section 90. Since the ink in the ink vibrating chamber 70 is vibrated by the vibrating section 60 of the vibrating body 43, the ink jet flow becomes particles.

The vibrating body 43 has a unique resonance point depending on its shape and mass. If the piezoelectric element 63 is driven at that resonance frequency, the amplitude of the vibrating body 43 becomes the largest, and the efficiency of particle formation of the ink jet flow is high, but the rate of decrease of the amplitude at frequencies near that is large. Therefore, when driven at the unique resonance point of the vibrating body 43, the unique resonance point of the vibrating body 43 changes subtly due to changes in environment such as temperature, and if the driving frequency and the resonance point deviate, the amount of amplitude obtained is reduced. It greatly changes, and impairs the stability of ink particle formation.

In addition, as described above, the terminal 64a
A coating agent 66 is applied to the outer periphery of the substrate. Also,
Adhesive to prevent loosening is applied. Since these coating agents and adhesives have a function of hindering the vibration of the vibrating body 43, individual differences in resonance frequency occur due to variations in the amount of application in assembling the nozzles. When an individual difference occurs in the resonance frequency, since the driving frequency of the piezoelectric element 63 is fixed, a different amplitude is generated in each individual, and individually different ink particles are generated.

After the first nut 65 is assembled and the application of the coating agent 66 is completed, the resonance frequency is measured,
Thereafter, the second nut 67 and the anti-loosening member 68 are assembled and the resonance point is measured again. If the resonance point is not a desired value, the resonance frequency can be adjusted by the tightening torque of the second nut 67. If the mass is changed by minute processing by removing the second nut 67, the resonance point can be adjusted. If the resonance frequency of the vibrating body 43 can be made the same, the amplitude amount is also the same, and the same ink particle can be obtained.

According to this embodiment, even if the amount of coating agent or adhesive applied varies, a vibrator having a desired resonance frequency can be easily obtained, and individual differences can be reduced.

[0039]

According to the present invention, the resonance frequency of the vibrating body can be adjusted more easily than in the prior art.

[Brief description of the drawings]

FIG. 1 is a schematic system diagram of an inkjet recording apparatus according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a nozzle body according to one embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Nozzle main body, 2 ... Charging electrode, 3 ... Deflection electrode, 43 ...
Vibrator, 41: ink flow path forming member, 63 piezoelectric element, 6
5 ... first nut, 67 ... second nut, 66 ... coating agent.

Claims (3)

[Claims] 1. An ink jet recording apparatus that performs recording by applying vibration to ejected ink to generate ink particles, and charging and deflecting the ink particles so that the ink particles reach a predetermined location on a recording medium. The vibrating body that holds the piezoelectric element that applies vibration to the ink is a Langevin type in which the piezoelectric element is sandwiched between bolts and nuts, and two nuts are screwed to one common bolt. Inkjet recording apparatus. 2. A method of manufacturing an ink jet recording apparatus that applies vibration to ink, comprising: a piezoelectric element that applies vibration to ink is screwed to one common bolt with two nuts; After tightening the first nut close to the piezoelectric element, the first nut is fixed with an adhesive, and the other second nut changes its tightening torque to increase the resonance frequency of the vibrating body. A method for manufacturing an ink jet recording apparatus, comprising adjusting. 3. A method of manufacturing an ink jet recording apparatus that applies vibration to ink, comprising: a piezoelectric element that applies vibration to ink is screwed to one common bolt with two nuts; After tightening the first nut close to the piezoelectric element, the first nut is fixed with an adhesive, and the other second nut changes its mass to adjust the resonance frequency of the vibrating body. A method for manufacturing an ink jet recording apparatus.