JPH04141427A - Ink jet head - Google Patents

Abstract

PURPOSE:To exchange a head in a stopped state of injection easily by providing a pressure generating section of an ink jet head detachably from the top of a pressure chamber. CONSTITUTION:An ink jet head 1 comprises a head 1a and pressure generating sections 10A, 10B. An auxiliary vibrating plate 7 is provided covering a pressure chamber 4 for generating pressure for ejecting ink drips. The pressure generating sections 10A and 10B are arranged detachably on the auxiliary vibrating plate 7. The pressure generating section 10A is formed integrally with a carriage 16 and the pressure generating section 10B is supported movably by the carriage 16 through a pin 22. The head 1a is arranged between the pressure generating sections 10A and 10B so as to close the pressure generating section 10B and to be clamped by the pressure generating sections 10A and 10B. A recording by the ink jet head 1 is performed in a state that the head 1a is clamped. When the head is to be exchanged in a stopped state of the injection, the pressure generating section 10B is opened so that the head 1a can be exchanged easily.

Description

[Detailed Description of the Invention] [Summary] Regarding an inkjet head that performs recording by ejecting ink droplets from a nozzle, the present invention aims to facilitate head replacement when ejection is stopped. The pressure generating unit is configured to perform recording by ejecting ink droplets from a nozzle communicating with the pressure chamber using the generated pressure, and a pressure generating unit including a pressure generating source consisting of a diaphragm and a piezo element is provided above the pressure chamber. In the ink cylinder head, the pressure generating section is provided so as to be separable from above the pressure chamber.

[Industrial Application Field] The present invention relates to an inkjet head that performs recording by ejecting ink droplets from a nozzle.

The Infusiera I printer is in the spotlight as a printer for office automation (OA) because it is small, has low noise, and is inexpensive. However, there is strong demand from users as a printer for word processors and personal computers, and it is also easy to record in color. Since it has the advantage of being able to be used in a variety of situations, its development is urgently needed.

(Prior Art) FIG. 10 is a structural explanatory diagram of a conventional inkjet head 101 used in an inkjet printer, in which a nozzle 102 for ejecting ink droplets and a nozzle for applying pressure to the nozzle 102 are shown. Conduction path 10 for transmitting
3, and a pressure chamber having an ink droplet ejection pressure generation 11o6 composed of a piezo element 104 and a diaphragm 105],
07, and a supply path 10 that supplies ink to the pressure chamber 107.
8 and a common ink chamber 109 that supplies ink to each supply path 108. A flexible printed board 11° that sends a drive signal to the piezo element 104 is pressed against the piezo element 104 via a conductive rubber 111, so that the signal is applied.

The structure of the printing mechanism of a conventional inkjet printer is shown in Fig. 11 (Fig. 11(a) is a front view, Fig. 11(b)
) is a side view), a recording paper 113 is conveyed by a platen 112, and ink droplets are ejected from a nozzle 102 by selectively applying a signal to a piezo element of a head 101 mounted on a carriage 114. Recording paper 11
．． 3 Record on top.

Ink is supplied to the head 10 through a tube 116 from an ink tank 115 arranged separately.

[Problem to be solved by the invention]

In the conventional inkjet head shown in FIG. 10, when jetting stops due to air intake or nozzle clogging, the head and ink tank must be replaced, making maintenance extremely difficult.

SUMMARY OF THE INVENTION An object of the present invention is to provide an ink-end printer that allows easy head replacement when ejection is stopped.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention is configured such that recording is performed by ejecting ink droplets from a nozzle communicating with the pressure chamber by the pressure generated in the pressure chamber of the head part, and the ink droplets are ejected onto the pressure chamber. In the inkjet head provided with a pressure generation section including a pressure generation source consisting of a diaphragm and a piezo element, the pressure generation section is provided so as to be separable from above the pressure chamber (first configuration).

Further, in the inkjet head having the first configuration, an auxiliary diaphragm is provided in the pressure chamber -F of the hennod portion, and the pressure from the pressure generation source is transmitted through the auxiliary diaphragm. (Second configuration).

Further, in the inkjet head of the second configuration, the diaphragm is provided with a protrusion for drawing the auxiliary diaphragm toward the pressure chamber (third configuration).

Further, in the Infusiera I printer having the third configuration, an air venting means is provided to prevent air from remaining in the contact portion between the protrusion of the diaphragm and the auxiliary diaphragm (fourth configuration). shall be.

Furthermore, the above 1. Or second. Alternatively, in the inkjet nozzle of the third or fourth configuration, an ink tank is attached to the head section and integrated (
fifth configuration).

[Function] Since the pressure generating part is separable from the throat part (first and second configurations), only the head part can be replaced when injection is stopped, and the cost of the throat part is reduced. is reduced to about 1/3 compared to a conventional head.

In addition, in the case of the third configuration in which the diaphragm on the pressure generation part side has a protrusion for drawing the auxiliary diaphragm toward the pressure chamber side, the auxiliary diaphragm is in a tensioned state, so the pressure transmission efficiency is improved. will improve. In this case, if an air venting means is provided to prevent air from remaining in the contact area between the protruding part of the diaphragm and the auxiliary diaphragm (fourth configuration), no air will remain in the contact area, making it more effective. be.

Furthermore, in the case of the fifth configuration in which the ink tank is attached to the head part and integrated, the head part can be replaced together with the ink tank, and replacement is easy.

[Example] The present invention will be described in detail below with reference to FIGS. 1 to 9.

A first embodiment is shown in FIGS. 1 and 2.

FIG. 1 is a structural explanatory diagram of a head 1 of an inkjet head 1 according to this embodiment. It is composed of OA and IOB. Head part 1
a represents a nozzle 2 for ejecting ink droplets, a conduction path 3 for transmitting pressure to the nozzle 2, a pressure chamber 4 for generating pressure for ejecting ink droplets, and a supply path for supplying ink to the pressure chamber 4. 5 and a common ink chamber 6 that supplies ink to each supply path 5, and an auxiliary diaphragm 7 is provided covering the pressure chamber 4 and the like. Further, an ink tank 9 is integrally connected to the common ink chamber 6 via a passage 8.

Further, on the auxiliary diaphragm 7 is a pressure generating section 10A.

The JOB is provided in a separable manner and is pressed into contact with a clamp or the like. The auxiliary diaphragm 7 is made of plastic or metal material.

In the former case (plastic material), the auxiliary diaphragm 7 is attached to the head part 1a by adhesive, heat fusion, etc., and in the latter case, by brazing, diffusion bonding, etc. The configuration of these pressure generating parts is referred to as pressure generating part 10A.
The following is an explanation using an example.

The pressure generating section 10A includes a pressure generating source 13 consisting of a diaphragm 11 and a piezo element 2. The piezo element 12 is bonded to the diaphragm 11. The flexible printed board 14 that sends a drive signal to the piezo element 12 and the piezo element 12 are in pressure contact with each other with a conductive rubber 15 interposed therebetween.

The mounting structure of these head portion 1a, pressure generating portion 10A, and IOB is shown in Figure 2 (Figure 2 (a) is a front view, Figure 2 (b)
is a side view).

The pressure generating section 10A is integrally formed with the carriage 16, and the pressure generating section 10B is supported by the carriage 16 via a bottle 22 so as to be openable and closable. The carriage 16 is shown in Fig. 2 (
a) A rack 17 movable in the left and right direction and a motor 19
A pinion 18 driven by the rack 17 is provided, and the pinion 18 meshes with the rack 17. A pin 21 is provided protruding from the rack 17, and the pin 21 is engaged with an elongated hole 20a formed in the arm 20 of the pressure generating section 10B. The pressure generating section 10B operates the motor 19 to generate the pinion 18.
When rotated counterclockwise in Fig. 2(a), the second
The rack 17 moving to the right in Figure (a) is driven via the pin 21 to rotate and close in the counterclockwise direction in Figure 2 (a), and when the pinion 18 is rotated clockwise, it is rotated clockwise. It is designed to open by rotating. The head portion 1a is
Pressure generating section 10A.

10B, and by closing the pressure generating section 10B, the pressure generating section 1. Clamped by OA,,IOB.

Recording by the inkjet head 1 is performed with the head section 1a clamped in this manner, but when replacing the head when ejection has stopped, the pressure generating section 1. By opening the OB, the head portion 1a can be easily replaced. Furthermore, since the removed head portion 1a does not have a piezo element or the like attached, the cost I of the head is approximately 17B compared to a conventional head.

A second embodiment is shown in FIGS. 3 to 9.

FIG. 3 shows the pressure generating section 31 of the inkjet head of this example.
In the structural explanatory diagrams of A and 31B, the same symbols are used for the same members as in the previous example. In the figure, 32 is a diaphragm having a protrusion 32a, and the diaphragm 32 and the piezo element 12 are connected to the pressure generation source 3.
3. The piezo element 12 is bonded to the back side of the protrusion 32a. These pressure generating parts are pressure generating part 3
1A, as illustrated in FIG. 4, it is used by being brought into pressure contact with the head portion 1a similar to the previous example. During this press-contact process, the protrusion 32a bends and draws the auxiliary diaphragm 7 on the pressure chamber 4 so as to conform to the protrusion 32a, thereby transmitting pressure through the auxiliary diaphragm 7 that is in a tensioned state. It is supposed to be done. Thereby, the pressure generated in the pressure generating section can be efficiently transmitted.

FIG. 5 is a structural explanatory diagram of another head section of the inkjet head of this example, in which the head section 34 includes the nozzle 2 and the conduction path 3.
, a pressure chamber 4, a supply path 5, and a common ink chamber 6, an auxiliary pressure chamber 35 is mounted on the pressure chamber 4, and an auxiliary diaphragm 7 is provided thereon to cover the entire surface. In this case, as shown in FIG. 6, the auxiliary diaphragm 7 is bent and drawn from above the pressure chamber 4 by the protrusion 32a on the pressure generating part 31A side so as to fit the protrusion 32a, and the auxiliary diaphragm 7 is It is pressed so as to fill the chamber 35, and the pressure is transmitted through the auxiliary diaphragm 7. In this case, in the case of Fig. 4, the pressure chamber 4
can solve the problem of decreasing volume.

When using the pressure generating part of this example, when bending the auxiliary diaphragm 7 on the head part side by the protruding part 32a of the diaphragm on the pressure generating part side, the protruding part 32a and the auxiliary diaphragm 7
will not adhere to the entire surface, leaving a gap in the center. Air remaining in this gap significantly inhibits pressure transmission. Next, we will discuss various solutions to this problem in the third section.
．． The case of the pressure generating section shown in FIG. 4 will be explained as an example.

Air venting means shown in FIG. 7: A plurality of fine holes 41 for venting air are provided in the protrusion 32a of the diaphragm 32. As a result, air in the contact area between the protrusion 32a and the auxiliary diaphragm 7 is released from the hole 41, thereby increasing the adhesion of the contact area.

Air venting means shown in FIG. 8: A plurality of air venting grooves 42 are provided on the side surface of the protrusion 32a. This allows the air in the contact area to escape from the grooves 42 and improves the adhesion.

Air venting means shown in FIG. 9: A slope is provided on the surface of the protrusion 32a. FIG. 9 shows an example in which the left side is tilted to the left and right so that the amount of protrusion on the left side is small. As a result, the air in the contact area moves from right to left as the auxiliary diaphragm 7 deforms and is released.
Adhesion is improved.

(Effects of the Invention) As described above, according to the present invention, only the head part can be replaced when injection stops, and the cost of the head is reduced to about 1/3 compared to the conventional head. In addition, if the ink tank is integrated into the inkjet head and the head part is replaced with the ink tank, replacement will be made easier.In this case, since the head part can be easily replaced, there will be no clogging. The backup device such as the prevention device can be simplified, which is extremely advantageous in reducing the price of the printer device.

Furthermore, if a protruding part is provided on the diaphragm on the pressure generating part side, and the auxiliary diaphragm provided on the pressure chamber on the head part side is drawn to the pressure chamber side by the protruding part, the auxiliary vibration Since the plate is in tension, pressure transmission efficiency is improved. In this case, it is more effective to take measures to bleed air from the protrusion so that no air remains in the contact area between the protrusion and the auxiliary diaphragm.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the structure of an inkjet head according to the first embodiment of the present invention. FIGS. 2(a) and (b) are explanatory diagrams of the mounting structure of the inkjet head according to the first embodiment of the present invention. 4 is an explanatory diagram of the structure of the pressure generating section of the inkjet head of the second embodiment of the present invention, FIG. 4 is an explanatory diagram of the pressure generating section of FIG. 3 in pressure contact with the head section, and FIG. FIG. 6 is an explanatory diagram of the structure of the other head parts of the inkjet head. FIG. 6 is an explanatory diagram of the state in which the pressure generating part of FIG. 5 is in pressure contact with the head part. FIGS. Figure 10 is a structural diagram of a conventional inkjet head. Figures 11 (a) and (b) are structural diagrams of the printing mechanism of a conventional inkjet printer. In the figure, 1 1 is an inkjet head, la, 34 is a head section, 2 is a nozzle, 7 is an auxiliary diaphragm, 10A, IOB, 31A, 31B are pressure generating sections, 11.
32 is a diaphragm, 12 is a piezo element, 13.33 is a pressure generation source, 32a is a protrusion, 41 is an air vent hole (air venting means), and 42 is an air venting groove (air venting means).

Claims (5)

[Claims] (1) Recording is performed by ejecting ink droplets from a nozzle communicating with the pressure chamber using the pressure generated in the pressure chamber of the head, and a pressure chamber formed by a diaphragm and a piezo element is placed above the pressure chamber. What is claimed is: 1. An inkjet head provided with a pressure generation section including a pressure generation source, wherein the pressure generation section is provided so as to be separable from above the pressure chamber. (2) The inkjet head according to claim 1, characterized in that an auxiliary diaphragm is provided on the pressure chamber of the head section, and pressure from the pressure source is transmitted via the auxiliary diaphragm. Inkjet printer. (3) The inkjet head according to claim 2, wherein the diaphragm is provided with a protrusion for drawing the auxiliary diaphragm toward the pressure chamber. (4) The inkjet head according to claim 3, further comprising an air venting means for preventing air from remaining in a contact area between the protrusion of the diaphragm and the auxiliary diaphragm. (5) The inkjet head according to claim 1, 2, 3, or 4, wherein an ink tank is attached to and integrated with the head portion.