JPH0345815Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to an inkjet recording device, and more particularly to an inkjet recording device with an improved ink supply section that replenishes ink supplied from an ink supply source to an ink chamber of a recording head. .

[Prior art]

Conventional inkjet recording devices have been used as recording devices for computer output, word processors, computer printers, etc., and are low noise.
It has features such as high-speed recording and no need for development or fixing.

As an example of an improved high-performance inkjet recording device, for example, the
There is an on-demand type inkjet recording device described in Japanese Patent No. 35936. This on-demand inkjet recording device is a type that ejects ink by changing volume due to pressure or other factors in response to an electrical signal only when necessary, so there is no need for a system to collect unnecessary ink, so the inkjet recording device It has the characteristics that only a small amount is required, and the device itself can be made small, lightweight, and inexpensive.

Furthermore, since it is possible to implement a large number of channels in one recording head, it is possible to obtain high resolution and high-speed printing performance, and furthermore, it has features such as easy color printing, and has recently become a prized product. Ivy.

However, even in such a high-performance inkjet recording device, there are still problems that need to be improved.

The above-mentioned problems will be explained below with reference to FIGS. 6 and 7 using a known on-demand inkjet recording apparatus as an example. 6A and 6B are schematic diagrams of an inkjet recording head and an ink supply system, showing a sectional view and a plan view, respectively. In these figures, 1 indicates a plurality of nozzles, 2 indicates a plurality of pressure chambers communicating with the nozzles, and 3 indicates a common ink chamber that distributes and supplies ink to the pressure chambers 2. A head substrate 4 is closely joined to a head side plate 5, and grooves are formed on the inner surface of the substrate 4 to form the nozzle 1, the pressure chamber 2, and the common ink chamber 3. A piezoelectric transducer 6 is adhesively fixed to the outer surface of the substrate 4 corresponding to the pressure chamber 2, and is connected to the electronic pulse generator E. When this piezoelectric transducer element 6 receives an electric signal from the generator E, it is suddenly bent inward of the pressure chamber 2, momentarily presses the pressure chamber 2, and the nozzle 1 corresponding to the pressed pressure chamber 2 is The ink is ejected in small droplets. Further, a portion of the side plate 5 corresponding to the common ink chamber 3 is opened, and a flexible film 7 made of, for example, polypropylene, polyethylene, polyvinylidene chloride, etc. is adhered to the opening. I'm trying to form a part of it. The flexible film 7 is configured to absorb the return pressure of ink due to deformation of the pressure chamber 2 when ink is ejected by the action of the piezoelectric transducer 6. That is. In such a multi-nozzle type recording head, a pressure wave generated from the pressure chamber 2 of one channel spreads to the pressure chamber of another channel via the common ink chamber 3, and the ink droplets of the other channel are affected. Although so-called channel interaction, which deteriorates the jet flight characteristics, occurs, the flexible film 7, together with the common ink chamber 3, absorbs and relieves the energy of the pressure wave to prevent channel interaction.

However, this flexible film 7 is extremely thin with a thickness of 0.02 to 0.1 mm and easily peels off.
In cases where the flexible membrane 7 is made of ceramic, even if special treatment such as using a silane coupling agent is applied, the adhesion will still be insufficient, resulting in ink leakage and various problems such as the need to replace the flexible membrane 7. It was hot.

Next, a pipe-shaped inlet 8 for introducing ink is fixed to the substrate 4 of the recording head, and this inlet 8 is connected to an ink tank 11 and an ink connector 10.
The ink L supplied through the ink tube 9 is introduced into the common ink chamber 3.

The inlet 8 is a pipe-shaped member made of metal such as stainless steel or brass, or plastic material such as acrylic resin, and is provided on a part of the wall forming the common ink chamber 3 of the substrate 4 of the recording head. It is directly inserted and fixed into the opening. Fixing methods include a press-fitting method, a caulking method, and an adhesive method. In the press-fitting method, the inlet 8 is tightly press-fitted into the opening of the board 4, but it is difficult to maintain a constant press-fitting accuracy. If there is, the inlet 8 may fall off or ink may leak. In the caulking method, after inserting the inlet 8 into the opening of the substrate 4, the end of the inlet 8 is deformed and fixed under pressure, but there is a risk that the substrate 4 may be damaged during pressurization. The adhesive method is
Before or after inserting the inlet 8 into the opening of the substrate 4, an adhesive is applied or flowed onto the contact surface to fix the inlet 8, but the adhesive does not have good ink resistance, and the components of the adhesive may be mixed into the ink. The adhesive may be eluted, or the adhesive may be affected by the ink and lose its adhesive strength. Furthermore, careful bonding work takes time and also requires time for the bond to harden. Furthermore, adhesives having ink-resistant properties have disadvantages such as being time-consuming to process and requiring the development of special processing methods.

Further, when the ink tube 9 is inserted after the inlet 8 is attached and fixed to the substrate 4, an excessive force may be applied to the inlet 8 and the substrate 4 may be damaged. Further, even after the ink tube 9 is attached, if an excessive external force is applied to the inlet or the tube 9, the substrate 4 and the tube 9 will be damaged.

In any of the above fixing methods, if a defect occurs when fixing the inlet 8 to the substrate 4, the expensive recording head that is integrated therewith will be discarded.
Further, a flexible membrane 7 is separately adhesively fixed to the upper surface of the common ink chamber 3 opposite to the inlet 8 installation surface.
The common ink chamber 3 is closed. Therefore, the flexible membrane 7 and the inlet 8 must be fixed to the upper and lower surfaces of the common ink 3, which is a complicated and time-consuming process.

Note that the ink connector 10 is connected to the ink tube 9.
It is provided in the middle of the ink connector 10 to removably connect the ink tube on the recording head side and the ink tube on the ink tank side, and is separated at the ink connector 10 when replacing the recording head or ink tank. .

FIG. 7 is a partial sectional view showing an example in which an ink connector is provided in a recording head. In the figure, 4 is the side plate of the recording head described above, 20 is a female contact portion (receptacle) of an ink connector 40 fixed to the side plate 4 so as to communicate with the pressure chamber 2 of the recording head, and 30 is a female contact portion 20. This is a male contact portion (plug) of the ink connector 40 that is removably fitted and connected to the ink connector 40. The female contact part 20 includes a cylindrical case 21 with both ends open, and a case 2.
1, a filter 22 for passing ink, and a sleeve 23 fitted in the case 21 so as to press the filter 22 toward the one open end. , a septum 24 made of rubber or the like to prevent ink leakage and air infiltration fitted into the stepped portion of the sleeve 23 , a filter 22 disposed inside the case 21 , a sleeve 23 and It is composed of a spacer 25 and the like arranged on the other open end side of the case 21 so as to press the partition wall 24 toward one open end side and integrate the partition wall 24 with the other open end side.

On the other hand, the male contact part 30 has a bottomed cylindrical case 3 that fits into the case 21 of the female contact part 20.
1, a holder 33, etc., which is arranged to penetrate the bottom of the case 31 and is provided at the bottom of the case 31 so as to fix the needle tube 32 for supplying ink to the case 31. ing. The female contact section 20 is fixed to the recording head so that one open end of the case 21 communicates with the ink flow path of the recording head, and the male contact section 3
0 is removably fitted and connected to the female contact portion 20. Male contact part 30 to female contact part 20
When the needle-like tube 32 is connected, the ink can be supplied to the recording head by penetrating the partition wall 24 as shown by the broken line, and when the male contact section 30 is removed from the female contact section 20, the partition wall formed by the needle-like tube 32 is removed. 24
The through-holes can be closed due to their elasticity to prevent ink from leaking and air from entering.

However, when the connector 40 is configured in this way, an excessive force is applied to the female contact portion 20 each time the female contact portion 20 and the male contact portion 30 are attached/detached, and the substrate 4 which is the base portion of the case 21 is This may cause deformation or damage to the fixed part.
Further, the fixing portion between the case 21 and the substrate 4 has various drawbacks as well as the method of fixing the inlet 8 and the substrate 4. Furthermore, in a structure in which the ink connector 40 is directly fixed to the recording head, a large space is required around the head because the connector 40 is large. Particularly in color inkjet recording devices, one recording head has multiple ink chambers and multiple recording heads need to be placed side by side, so separate ink connectors are used as ink supply ports for supplying each color of ink. Since it is necessary to attach the head to the head base, it becomes difficult to secure space near the head base.

[Problem that the invention attempts to solve]

The present invention was proposed in view of the above-mentioned conventional circumstances in inkjet recording devices, and it prevents difficulty in assembling the ink supply unit that replenishes ink to the ink chamber of the recording head and damage to the head substrate, and improves the ink supply. The purpose of this invention is to enable high-speed printing and cost reduction by making the unit small and using a simple structural material, and to ensure easy replacement of ink tanks and recording heads. Particularly in color inkjet recording, the purpose of this invention is to enable the supply of multicolor inks without increasing the size of the recording head.

[Means for solving problems]

The present invention focuses on and improves the above-mentioned problems by creating a circuit, and the inkjet recording device of the present invention that achieves this purpose has an inkjet recording device that connects an ink supply source to an ink supply tube via an ink connector and an ink tube. In an inkjet recording device that supplies ink to an ink chamber in a recording head, the ink supply tube is connected to a flexible elastic member that absorbs pressure in a thin section, and the ink supply tube is further connected to an ink tube. Accordingly, an ink supply path from an ink supply source to an ink chamber is formed.

That is, the flexible elastic member that covers the opening of the ink chamber of the recording head is configured such that: (1) at least one ink supply pipe can be elastically connected to a portion thereof;
(2) It also prevents channel interaction between the ink chambers, and (3) it has a structure in which it is removably tightly fixed to the base of the recording head by a rigid member.

[Effect]

Replenishment ink in the ink tank passes through an ink tube and an ink connector, enters an ink supply pipe connected to a flexible elastic member, and is replenished into an ink chamber in the recording head. When replacing a recording head or an ink tank, the ink connector part located in the middle of the ink tube is separated and attached/detached while preventing air bubbles from entering and ink leakage. The flexible elastic member in contact with the ink in the ink chamber effectively prevents channel interaction during recording. Furthermore, since the flexible elastic member is closely joined to the base of the recording head by a rigid member, there is no possibility of gas getting into the recording head or leakage of ink, and it can be disassembled from the base using bolts or nuts. When a defective part occurs, it can be removed from the base and replaced.

〔Example〕

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

FIG. 1 is a perspective view schematically showing a recording head and an ink supply system for explaining an embodiment of the present invention, and FIG. 2 is a sectional view thereof. FIG. 3 is a plan view of the recording head, and FIG. 4 is an exploded perspective view of the recording head.

In these figures, the base of the recording head 100 has a plurality of nozzles 101 therein, a plurality of pressure chambers 102 communicating with the nozzles 101, and a substrate 104 forming recesses of a common ink chamber 103 that distributes and supplies ink to the pressure chambers 102. and covering each concave portion of the substrate 10.
4 and a side plate 105 closely joined. The pressure chamber 10 is provided on the outer surface of the substrate 104.
The same number of piezoelectric transducers 1 are placed at positions corresponding to 2.
06 is adhered and electrically connected to an electronic pulse generator E that outputs a pulse voltage based on a print signal.

The substrate 104 has an opening in the common ink chamber. 107 is the common ink chamber 1
This is a plate-shaped flexible elastic member that covers the opening of 03, and is made of a material that is chemically safe from ink, which is especially used in elastic members, such as butadiene rubber, isoprene rubber, butyl rubber, silicone rubber, acrylic rubber, etc. The elastic member 107 is a thin portion formed to have a thickness thinner than other areas of the flat plate portion so as to easily deform in order to absorb return pressure waves of ink caused by deformation of the pressure chamber 102 during ink ejection. It is an elastic member having 107C. This thin part 1
07C has elasticity that can appropriately absorb pressure waves corresponding to changes in volume of the pressure chamber 102 in order to fulfill the function of the flexible membrane described above. Further, the outer edge of the flat plate portion of the elastic member 107 having elasticity needs to have sufficient thickness and elasticity to withstand strong tightening and maintain adhesion when the recording head 100 is closely fixed to the substrate 104. . For this reason, it is preferable to make the peripheral edge part thicker than other parts so that it can be easily elastically deformed during tightening. Further, the elastic member 107 is provided with four screw through holes 107a at positions corresponding to the screw through holes 100a in the substrate 104 and the side plate 105 for fixing it to the base of the recording head 100.

Further, a hollow cylindrical portion 107b is integrally formed near the lower end of the elastic member 107 and protrudes from the surface of the flat plate portion.

One end of an ink supply pipe (hereinafter referred to as pipe) 108 is inserted into the inner diameter part of this hollow cylindrical part 107b.
Connected. An ink supply tube 109A is connected to the other end of the pipe 108, and an ink connector 111 is connected to the other end of the tube 109A. Ink connector 111 is female connector 1
11A and a male connector 111B, which can be freely connected and separated, and the recording head 100 side and the ink tank 112 side can be disassembled by this connector 111. Ink connector 11
1 has a structure as shown in FIG. 8, for example. A male connector 111B of the ink connector 111 is connected to an ink tank 112 via an ink supply tube 109B. Note that it is essential that the pipe 108 be made of a material such as stainless steel and not subject to chemical changes due to ink.

Reference numeral 110 denotes a pressure bonding member for tightly fixing the flexible member 107 to the base (substrate 104 and side plate 105) of the recording head 100 with uniform pressure, and the thin wall portion 1 of the elastic member 107 for absorbing ink pressure waves.
It has an opening 110C at a position corresponding to 07C.

Further, near the lower end of the crimp member 110, a hollow cylindrical portion 10 protruding from the lower end of the flexible member 107 is provided.
7b is provided with an opening 110b that fits into the opening 110b,
During assembly, the hollow cylindrical portion 107b is inserted into this opening 110.
Projects outward from b. Further, the screw through holes 100a and 107a are provided near the outer shape of the crimp plate 110.
It has a screw through hole 110a at a position corresponding to .
Since the pressure bonding plate 110 does not come into direct contact with the recording head 100 and the ink in the ink supply path, there is no need to use expensive materials such as stainless steel that are not chemically changed by the ink. That is, commonly used metal plates or hard resins can be used.

113 is the pressure bonding member 110 and the elastic member 10
7. Each through hole 110 in the base of the recording head 100
These members are crimped and fixed using four bolts passing through a, 107a, and 100a and tightened with nuts 114. Note that instead of the nut 114, a single metal plate having substantially the same shape as the crimp plate 110 and having four screw holes may be used.

FIG. 5 is a sectional view of a recording head showing another embodiment of the present invention. In the figures, structural parts that are the same as those in FIGS. 1 to 4 are designated by the same reference numerals.

Common ink chamber 103 of recording head substrate 104
has an opening shape, and 207 is a flat flexible elastic member that covers and seals the opening. The elastic member 207 is made of the same elastic material as the elastic member 107, and serves as a damper for absorbing pressure waves when ink is ejected and as a packing for preventing ink leakage.

Reference numeral 210 denotes a pressure bonding member for tightly fixing the elastic member 207 to the substrate 104 of the recording head with uniform pressure, and has a flat plate shape substantially similar to the pressure bonding plate 110. A protruding hollow cylindrical portion 210b is integrally formed at one end of the crimp member 210, and an ink supply pipe (hereinafter referred to as a pipe) 20 is provided at the inner diameter portion of the protruding hollow cylindrical portion 210b.
8 is inserted and connected on one side. Note that the pipe 208 passes through a hole provided at one end of the elastic member 207 and reaches the common ink chamber 103. The other end of the pipe 208 is connected to the ink tube 109.

The crimp member 210 is made of a rigid material,
For example, it is made of a metal material or hard plastic material, but since it does not come into contact with the ink used, it does not require special ink-resistant chemical properties, and generally any material that is inexpensive and has good workability may be used.

Further, the pressure bonding member 210 has an opening 210c at a position corresponding to the thin portion 207c of the elastic member 207 for absorbing ink pressure waves.

The crimp member 210 and the elastic member 207 are each provided with four screw holes,
This coincides with the through hole in the base (substrate 104, side plate 105) of the recording head. Four bolts 113 are inserted into each of the four screw holes of these members,
It is tightened with four nuts 114, and each member is crimped and fixed.

Note that the pressure bonding member 2 into which the pipe 208 is fitted is
The recording head 10 may be formed of an elastic member, and a rigid plate may be laminated on the outer layer thereof, and the recording head may be tightly fixed to the base of the recording head.

[Effect of idea]

As described in the above embodiments, the ink supply unit that communicates replenishment ink from the ink tank to the common ink chamber in the recording head, the flexible member for absorbing ink pressure waves in the common ink chamber, and the common ink Since the crimp member for closing and fixing the opening of the chamber is arranged in one place, assembly and maintenance are easy and reliable, and the space can be minimized. It is particularly suitable for supplying inks of multiple colors to the same recording head or to a plurality of recording heads, such as in a color inkjet recording apparatus.

Furthermore, since the pressure bonding member does not come into contact with ink, chemical resistance to ink is not required, and a material that is inexpensive and has good processability can be selected.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an ink supply system of an ink jet recording apparatus according to the present invention, FIG. 2 is a schematic sectional view thereof, FIG. 3 is a plan view of the recording head, and FIG. 4 is an exploded perspective view of the recording head. be. FIG. 5 is a sectional view of a recording head according to another embodiment of the present invention. FIG. 6 is a sectional view and a plan view of a conventional inkjet recording device, and FIG. 7 is a sectional view of another conventional ink supply section. 3,103... Common ink chamber, 4,104...
Board, 8... Inlet, 9,109... Ink tube, 10,111... Ink connector, 1
1,112...Ink tank (ink supply source),
107, 207...Flexible elastic member, 107b,
210b...Hollow cylindrical part, 107c, 207c...
...Thin wall portion, 108, 208... Ink supply pipe (pipe), 110, 210... Crimping member, 113...
…bolt.

Claims (1)

[Claims for Utility Model Registration] (1) In an inkjet recording device that supplies ink from an ink supply source to an ink chamber in a recording head from an ink supply tube via an ink connector and an ink tube, the ink supply tube is thin-walled. The ink supply tube is connected to a flexible elastic member that absorbs pressure at the ink tube, and the ink supply tube is connected to the ink tube to form an ink supply path from the ink supply source to the ink chamber. Inkjet recording device. (2) Utility model registration claim 1, characterized in that the ink supply tube is connected and fixed by fitting into the hole of the flexible elastic member.
The inkjet recording device described in 2. (3) The inkjet recording device according to claim 1, wherein the ink supply pipe is connected to and fixed to a pressure bonding member that presses the flexible elastic member. (4) The utility model according to claim 1 or 2, characterized in that the flexible elastic member is closely fixed by a rigid crimping member made of metal and/or resin. Inkjet recording device. (5) The inkjet recording device according to claim 1 or 3, wherein the pressure bonding member is closely fixed by a rigid member made of metal and/or resin.