JP3267209B2 - Ink jet recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a print head, and contributes to improvement of parts exchangeability.

[0002]

2. Description of the Related Art An ink jet recording apparatus (hereinafter, abbreviated as IJP) is an apparatus for deflecting ink droplets, which become a part of characters, and printing on a moving body.

In general, an IJP print head is a nozzle for forming and ejecting ink droplets, a charging electrode for charging the ejected ink droplets, a deflecting electrode for deflecting the charged ink, and collecting ink droplets not used for printing. It is formed from a gutter block containing gutter.

In addition, a tube for supplying ink from the IJP main body and a connection cable section in which an electric wire for transmitting a print control signal is incorporated are fixed to the print head.

[0005] The print head is installed on the production line,
It is printed on the printing object being transported. Since the IJP deflects the charged ink droplets perpendicularly to the moving direction of the print target, the spread of the character in the moving direction is given by the print target moving with respect to the print head.

The width and height of the print of the print head are defined by the print object. Speaking of the printing height, for example, about 5 mm to 10 mm for beverage cans and 2 to 5
mm and cardboard require 15 mm or more.

The printing height is achieved by changing the size of the ink droplets and the deflection electrodes and charging electrodes.

In order to change the size of the ink droplet, the diameter of the ink ejection port (orifice diameter) of the normal nozzle, the ink ejection pressure, and the nozzle excitation frequency are changed.

Here, the excitation frequency of the nozzle is the vibration frequency of the piezoelectric element incorporated in the nozzle.

The reason for changing the discharge pressure and the excitation frequency of the ink is that the ink ejected from the nozzle becomes an ink droplet due to the surface tension and the vibration of the piezoelectric element. This is to make the ratio constant.

Since the amount of deflection is different when the speed and size of the ink droplet are changed, it is necessary to change the flight distance with the deflection electrode in order to obtain a predetermined character height. To increase the flight distance, you usually respond by increasing the length of the gutter block.

Further, when the size of the ink droplet changes, the position (cut point) where the ink changes to the ink droplet and the distance between the ink droplet and the electrode also change, and the charge amount changes. Therefore, it is necessary to change the charging electrode. .

As described above, in the print head, the nozzles, the deflection electrodes, the charging electrodes, and the gutter blocks are arranged in an optimum shape in order to obtain the required character specifications.

Therefore, when a print head is produced, it is made for each print specification, and the productivity is poor.

On the other hand, since the IJP controls minute ink droplets, the flight distance is preferably short, and the distance between the print target and the tip of the print head is located at a position close to ten and several millimeters. The print head may be damaged by contact.

When the print head is replaced in repairing the print head, it is necessary to replace the print head for each connection cable.

Normally, when the print head is replaced, parts that cannot be reused are concentrated mainly in the first half of the print head.

[0018] In addition, although replacement involves disconnecting the connection part with the main body, the place where the main body is placed is not always a place where it is easy to work, so if the work is difficult, the main body needs to be moved. .

In addition, downtime caused by replacement must be minimized. The closest known example of these problems is described in Japanese Patent Application Laid-Open No. 8-104008. The print heads described therein are divided into a print head base and a gutter base, and only a gutter base can be replaced for troubles such as clogging of the gutter.

On the other hand, when the installation space for the print head is limited, it is indispensable to reduce the size of the print head. However, in order to increase the print character height, a certain deflection distance is required. Is difficult to shorten.

Further, since the connection cable includes a large number of tubes and electric wires, it is necessary to provide a curvature, which also limits the installation space.

In response to this, various companies have proposed L-shaped heads in which the rear portion is bent from the nozzles arranged in the print head.

Thus, since the connection cable can be bent by 90 degrees with respect to the production line, it is applied when the installation distance from the production line is severely restricted.

[0024]

As described above, the IJP
Print head has a nozzle, charged electrode,
Since the deflection electrodes are provided, it is necessary to make all the changes even if there is a specification change only at the tip of the print head.

When the line is changed due to a change in the specification of the product, the mounting position of the print head is restricted, and the current head cannot be used. I needed to.

Furthermore, if even a part of the base is broken, it is necessary to replace the entire connection cable.

The connection cable includes a tube for supplying and recovering ink, and a wire for a print control signal, which are detached from the main body. The main body is not always installed in a place where the replacement work can be easily performed, and the downtime at the time of replacement becomes great.

Further, the replacement parts are limited to the damaged parts, and parts which do not need to be replaced, such as connection cables, must be replaced.

On the other hand, when the installation space for the print head is limited, a small L-shaped head is provided. However, since the base of the print head requires a special part different from the standard product, a small head leads to an increase in cost.

An object of the present invention is to provide a print head which can easily cope with a change or breakage of the specifications of the print head by replacing a necessary minimum part.

A further object of the present invention is to provide a print head which can easily cope with an L-shaped head with a minimum required replacement.

[0032]

The above object is achieved by an inkjet apparatus.
In the recording device, the ink,
Tube for sending print control signal and connection cable including electric wire
And a joint that connects the tube and the electric wire
The second half of the base where the connector
Nozzle generated, charging electrode for charging ink droplets, ink droplets
Electrode for deflecting ink, collecting ink drops unnecessary for printing
The first half of the base where the gutter block containing the gutter to be performed is placed
Formed by the second half of the base and the front of the base
Provide a spacer between the half and replace the spacer
By doing so, the mounting angle of the first half of the base can be changed,
The rear half of the base and the front half of the base are connected to the joint and the connector.
This is achieved by allowing them to be separated by a

[0033]

According to the present invention, the specifications of the print head are changed,
Or, in case of breakage, it can be used or repaired immediately by replacing only the first half.

Further, according to the present invention, by changing the spacer from the standard type to the L type one, the distance from the tip of the print head to the bending position of the connection cable can be shortened. Can respond to.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 shows the structure of a print head. A gutter block 2, a deflection electrode 3,
A charging electrode 4 and a nozzle 5 are arranged.

In order to stabilize the charging of the ink droplets, the nozzle 5 needs to adjust the direction in which the ink is ejected. This is usually
It is set at the center of the gutter 12 '.

A connection cable 7 is fixed to the rear half 6 of the base, and an ink tube 8 and an electric wire 9 are guided to the rear half 6 of the base.

The base front half 1 and the base rear half 6 are a joint 10 in the tube 8 and a connector 1 in the electric wire 9.
1 connected.

The joint 10 and the connector 11 are connected to the rear half 6 of the base.
And is covered by a cover 12 so as not to be accidentally removed.

When the gutter 12 'is clogged and cannot be repaired by washing, the gutter block 2 can be immediately recovered by replacing it.

When only the first half of the base changes, that is,
In the case of changing the printing height, if the tube 8 is detached from the joint 10 and the electric wire 9 is detached from the connector 11, only the base front half 1 can be replaced. Can be changed to the desired print head.

Further, if only the base first half 1 whose ink ejection direction has been adjusted is further prepared, if only the joint 10 and the connector 11 are removed and replaced, the downtime can be minimized.

Another embodiment will be described with reference to FIGS. 2, 3, 4, and 5. FIG.

FIG. 2 shows the structure of a standard print head. FIG. 3 shows the structure of a standard spacer.

A standard spacer 13 is inserted between the first half 1 of the base and the second half 6 of the base. The standard spacer 13 can be divided at the center.
Pass through.

The thickness of the standard spacer 13 in the longitudinal direction is
This is to secure a margin for bending the tube 8 and the electric wire 9 at the time of bending.

FIG. 4 shows the structure of an L-shaped print head. FIG. 5 shows the structure of the L-shaped spacer 14.

After removing the standard spacer 13 and attaching the L-shaped spacer 14 while bending the tube 8 and the electric wire 9 of the front half 1 of the base, the front half of the base is bent and the print head space is easily reduced. be able to.

[0051]

According to the present invention, when the first half of the print head needs to be replaced, only the first half of the base can be replaced to obtain the desired print head.

Further, even if the production line is changed and the space in which the print head can be installed is limited, it can be easily coped with by replacing the standard type spacer with the L type spacer.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a print head according to an embodiment of the present invention.

FIG. 2 is a plan view of a print head having a standard spacer according to another embodiment of the present invention.

FIG. 3 is a configuration diagram of a standard spacer.

FIG. 4 is a plan view of a print head to which an L-shaped spacer according to another embodiment of the present invention is attached.

FIG. 5 is a configuration diagram of an L-shaped spacer.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... First half of base, 2 ... Gutter block, 3 ... Deflection electrode, 4 ... Charging electrode, 5 ... Nozzle, 6 ... Second half of base, 7
... Connection cable, 8 ... Tube, 9 ... Wire, 10 ... Fitting, 11 ... Connector, 12 ... Cover, 13 ... Standard spacer, 14 ... L-shaped spacer.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Seiji Fujikura 1-1-1, Higashitaga-cho, Hitachi City, Ibaraki Prefecture Inside the Taga Headquarters, Electric Appliances Division, Hitachi, Ltd. (72) Inventor Satoshi Kurihara, Higashitaga-machi, Hitachi City, Ibaraki Prefecture 1-1-1, Hitachi, Ltd.Electrical Equipment Division, Taga Headquarters (72) Inventor Tetsunori Kaneko 1-1-1, Higashitagacho, Hitachi City, Ibaraki Prefecture Hitachi, Ltd.Electrical Equipment Division Taga Headquarters (56 References JP-A-63-122545 (JP, A) JP-A-64-11733 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41J 2/085 B41J 2/09 B41J 2/175 B41J 29/00

Claims (1)

(57) [Claims] In an ink jet recording apparatus, a tube for sending ink and a print control signal from a main body to a print head, a connection cable including electric wires, a joint for connecting the tubes, and a connector for connecting the electric wires are arranged. The second half of the base, the first half of the base where the nozzles that generate the ink droplets, the charging electrodes that charge the ink droplets, the deflection electrodes that deflect the ink droplets, and the gutter block that includes the gutter that collects the unnecessary ink droplets for printing. It is formed, the base
A spacer is provided between the rear half of the base and the front half of the base.
By replacing the spacer, the first half of the base
An ink jet recording apparatus mounting angle can be changed, the base half portion and the base half portion is characterized in that can be separated by the connector and the joint.