JPS6153236B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved multi-nozzle head for an inkjet printing device.

Conventionally, this type of apparatus has been constructed as shown in FIG. In FIG. 1, 1 is a multi-nozzle unit provided with a plurality of inkjet nozzles 1a, 2 is a diaphragm unit provided with an arc-shaped diaphragm 2a that vibrates in response to an input signal, and 3 is a multi-nozzle unit 1. The packing 4 interposed between the diaphragm unit 2 and the diaphragm unit 2 is two side walls, one of which has an ink supply port 4a. The multi-nozzle unit 1 and the diaphragm unit 2 are fixed together through a packing 3.
Furthermore, the side wall 4 is fixed to each nozzle 1a and the diaphragm 2.
An ink chamber (not shown) is formed between the ink chamber and the ink chamber a, and an ink supply port 4a is provided to communicate with the ink chamber.

In the conventional example configured in this way, the printing ink that is pressurized by an ink reservoir (not shown) and supplied to the ink chamber from the ink supply port 4a is transferred to the diaphragm 2a provided behind each nozzle 1a. By applying an excitation voltage to vibrate the diaphragm 2a, ink droplets are ejected from the nozzle 1a. However, since the ink supply port 4a is provided in the side wall 4, the flow of printing ink ejected from the ink supply port 4a into the ink chamber flows between the nozzle 1a and the diaphragm 2a along the nozzle 1a, and the ink supply In the vicinity of the ink supply port 4a, the ink does not diffuse and forms a strong and fast flow, and in the distance from the ink supply port 4a, it diffuses to form a weak and slow flow. For this reason, in the vicinity of the ink supply port 4a, the flow of printing ink causes disturbance in the printing ink staying near the nozzle 1a, which obstructs the supply of printing ink to the nozzle 1a and prevents the diaphragm 2a.
This causes unevenness in the vibration intensity transmitted to the printing ink near the nozzle 1a.
The size of the ink droplets ejected from the ink droplets is not uniform, resulting in irregular images printed on recording paper (not shown). Furthermore, the printing ink that has strayed from the flow of printing ink stagnates along the diaphragm 2a, and the printing ink that has remained in this stagnation for a long time deteriorates, accelerating the deterioration of the printing ink in the ink chamber.
There is a drawback that solid substances in the printing ink adhere to and accumulate on the diaphragm 2a, changing the vibration characteristics of the diaphragm 2a.

In addition, Fig. 2 shows another conventional example.
Items with the same reference numerals as in the figure indicate the same thing.
Further, 5 is a pressure regulating pipe that communicates with an ink reservoir (not shown) via an ink supply pipe 6, and 7 is an ink chamber (not shown) formed in the multi-nozzle head for inkjet and the pressure regulating pipe 5. These are multiple pipes that communicate with each other.

In the conventional example configured as described above, the pressure of the printing ink is regulated by the pressure regulating tube 5 so that the pressure of the printing ink passing through each communication pipe 7 is uniform, and the printing ink is supplied to the ink chamber. However, nozzle 1a
and the outlet of the communication pipe 7 are close to each other, pressure fluctuations in the ink reservoir are directly applied to the printing ink near each nozzle 1a, and the diaphragm 2
This causes unevenness in the vibration intensity transmitted from a to the printing ink near the nozzle 1a.
There was a drawback that the size of the ink droplets ejected from a was not uniform, resulting in irregular images printed on recording paper (not shown). Furthermore, the printing ink that has strayed from the flow of printing ink stagnates in the upper part of the ink chamber and along the diaphragm 2a, and the printing ink that has remained in this stagnation for a long time deteriorates, causing deterioration of the printing ink in the ink chamber. However, solid substances in the printing ink may adhere to and accumulate on the diaphragm 2a, changing the vibration characteristics of the diaphragm 2a.

In order to eliminate the drawbacks of the conventional example described above, the present invention provides a multi-nozzle comprising a plurality of nozzles, a diaphragm provided facing the nozzles, and an ink chamber provided between the nozzles and the diaphragm. At the head,
1 to 1 or 2 pipes installed in the ink chamber.
Orient the multiple ink outlets provided in the row in a direction that does not intersect the vibration transmission area between the diaphragm and the nozzle,
A filter is attached around the pipe, and this filter is covered with a resistive plate having numerous holes, and the printing ink jetted from the ink outlet is diffused throughout the ink chamber by the filter and the resistive plate. The flow of printing ink inside the ink chamber is weakened and slowed down.
Another object of the present invention is to provide a multi-nozzle head for an inkjet printing device for the purpose of eliminating stagnation of printing ink in an ink chamber. Hereinafter, embodiments will be described in detail with reference to the drawings.

3 and 4 show an embodiment of the present invention, in which 8 is a pipe provided with a plurality of ink outlets 8a in a row, and 9 is a fibrous material attached to the outer periphery of this pipe 8. A filter formed of a substance of 10
11 is a resistor plate with numerous holes 10a, and 11 is a plurality of inkjet nozzles 1 arranged in a row on the front surface.
1a, a cavity for forming an ink chamber 11b provided behind this nozzle 11a, and both side walls provided with a hole 11c through which a pipe 8 is inserted and supported. The two pipes 8 attached to the outer periphery are installed in parallel above and below the ink chamber 11b, and the ink outlet 8a of the upper pipe 8 faces upward, and the ink outlet 8a of the lower pipe 8 faces downward. Further, the resistance plate 10 is fixed to the front wall of the ink chamber 11b so as to cover the periphery of the filter 9 attached to the outer periphery of the pipe 8 (see FIG. 4). 12 is the inserted pipe 8
13 is a diaphragm unit that has a diaphragm 13a on the front and a connector 13b on the back, and a connector 13b is connected to the back of the diaphragm 13a by a lead wire 13c. An electrostrictor 13d connected to is fixed. 14
is the multi-nozzle unit 11 and the diaphragm unit 1.
3, a gasket 15 is an ink supply pipe whose one end is connected to an ink reservoir (not shown), and 16 is a joint that connects the pipe 8 and the ink supply pipe 15 through a hole 16a. , the left joint 16 is connected to one end of the upper pipe 8 and closes one end of the lower pipe 8, and the right joint 16 is connected to the other end of the lower pipe 8 and closes one end of the lower pipe 8. The other end of 8 is closed. 17 is a packing interposed between the multi-nozzle unit 11 and the joint 16.

Next, the operation of this embodiment will be explained. First, the printing ink pressurized by the ink reservoir is press-fitted into the upper and lower pipes 8 through the ink supply pipe 15 and the hole 16a of the joint 16, and is further jetted upward from the ink outlet 8a of the upper pipe 8. The printing ink passes through the filter 9, hits the top wall of the ink chamber 11b, and is diffused, while the printing ink flows from the top wall of the ink chamber 11b to the front wall through the filter 9. The other printing ink flow flows from the upper wall of the ink chamber 11b to the diaphragm 13a through the filter 9, hits the resistance plate 10, is further diffused, and flows into the nozzle 11a through the hole 10a. Similarly, the printing ink ejected downward from the ink outlet 8a of the lower pipe 8 passes through the filter 9, hits the lower wall of the ink chamber 11b, and is diffused. The flow of printing ink flows from the lower wall of the ink chamber 11b to the front wall through the filter 9, and the other flow of printing ink flows from the lower wall of the ink chamber 11b to the diaphragm 13a through the filter 9, and flows through the filter 9 from the lower wall of the ink chamber 11b to the diaphragm 13a. 10, it is further diffused and flows into the nozzle 11a through the hole 10a. That is, the printing ink ejected from the ink outlet 8a of the upper and lower pipes 8 is diffused by flowing through the filter 9, hits the upper and lower walls of the ink chamber 11b, and is further diffused. Ink chamber 1 by plate 10
Since the printing ink is diffused throughout the nozzle 1b, the flow of the printing ink flowing into the nozzle 11a becomes a weak and slow flow, and the printing ink staying near the nozzle 11a is no longer disturbed, and the printing ink flows smoothly into the nozzle 11a. The nozzle 11 is supplied from the diaphragm 13a.
The vibration intensity transmitted to the printing ink near a becomes constant. Further, even if pressure fluctuation occurs in the ink reservoir, the pressure is also diffused, so that the fluctuating pressure applied to the printing ink near the nozzle 11a is reduced. Furthermore, the printing ink ejected from the ink outlet 8a is diffused throughout the ink chamber 11b and reaches the nozzle 1.
Since the printing ink flows into the ink chamber 1a, no stagnation of printing ink is formed in the ink chamber 11b.

As explained above, according to the present invention, printing ink is smoothly replenished into the nozzle, the vibration intensity transmitted to the printing ink near the nozzle is made constant, and pressure fluctuations in the ink reservoir are further reduced. This has the advantage that the size of the ink droplets ejected from the nozzle becomes uniform, and the image printed on the recording paper becomes regular. Also, by eliminating stagnation of printing ink in the ink chamber, deterioration of the printing ink can be prevented, and solid substances in the printing ink can be prevented from adhering to and accumulating on the diaphragm, thereby changing the vibration characteristics of the diaphragm. It has the advantage of being able to prevent Furthermore, there is an advantage that the filter can remove clumped dust of the printing ink contained in the printing ink, thereby preventing clogging of the nozzle due to such dust.

[Brief explanation of the drawing]

1 and 2 are block diagrams of a conventional multi-nozzle head for an inkjet printing device, FIG. 3 is a block diagram of an embodiment of the present invention, and FIG. 4 is a sectional view of FIG. 3. 1, 11...Multi nozzle unit, 1a, 1
1a... nozzle, 2, 13... diaphragm unit,
2a, 13a... Vibration plate, 3, 14, 17... Packing, 4... Side wall, 4a... Ink supply port, 5
...Pressure adjustment pipe, 6,15...Ink supply pipe, 7...Communication pipe, 8...Pipe, 8a...
Ink outlet, 9...filter, 10...resistance plate, 10a...hole, 11b...ink chamber, 11c
... Hole, 12 ... O-ring, 13b ... Connector, 13c ... Lead wire, 13d ... Electrostrictor, 1
6...Joint, 16a...hole.

Claims (1)

[Claims] 1. In a multi-nozzle head consisting of a plurality of nozzles, a diaphragm provided facing the nozzles, and an ink chamber provided between the nozzles and the diaphragm, one or more nozzles installed in the ink chamber A plurality of ink outlets provided in a row on two pipes are oriented in a direction that does not intersect the vibration transmission area between the diaphragm and the nozzle, and a filter is attached around the pipe, and the filter An inkjet characterized in that the printing ink is covered with a resistive plate having numerous holes, and the printing ink jetted from the ink outlet is diffused and flowed throughout the ink chamber by the filter and the resistive plate. Multi-nozzle head for printing equipment.