JPH05138892A - Cap device for ink head - Google Patents

Abstract

PURPOSE:To provide a cap device for an ink head which can positively prevent ink from leaking due to pressure difference by a method wherein pressure inside an ink cartridge and a cap body can be kept constant even when variation in pressure of the open air is generated. CONSTITUTION:A cap body 14 is freely separatably arranged onto a front side of an ink head 2 which jets ink 8 supplied from an ink cartridge 9 via an ink passage 4 from a nozzle 3, and a pressure tube 22 which supplies pressure air to the ink cartridge 9 is connected to the cap body 14. Further, an open air releasing tube 18 which releases the inside to the open air and an ink discharge tube 17 which discharges ink in the cap body 14 to the outside by attracting it are connected to the cap body 14. An electromagnetic three-way valve 39 which interconnects the cartridge 9 to the open air releasing tube 18, under a state wherein the cap body 14 is connected to the ink head 2 in non-printing, is disposed in the way of the pressure tube 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink head cap device, and more particularly, to an ink for jetting ink for printing, such as an ink jet printer, for covering a nozzle portion of an ink head when not printing. The present invention relates to a head cap device.

[0002]

2. Description of the Related Art Conventionally, in a printer such as an ink jet printer for ejecting ink for printing, the nozzle portion of the ink head is covered to prevent the ink from drying during non-printing, and the ink flow path of the ink head is not covered. An ink head cap device is provided to perform a head recovery operation for removing foreign matters such as clogging due to ink inside and bubbles.

FIG. 3 shows an ink head and a cap device applied to such a conventional ink jet printer. In a head main body 1 mounted on a carriage of a printer, an ink head 2 has a front end surface thereof. It is arranged so as to be substantially flush with the end surface of the head main body 1, and inside the ink head 2, a plurality of nozzles 3, 3 ... Are formed in parallel in the vertical direction. Further, piezoelectric elements 5, 5 ... Connected to electrodes (not shown) are interposed in the middle of each ink flow path 4, and each piezoelectric element 5 is selectively energized according to print information. By doing so, the ink in the specific ink flow path 4 is ejected from the nozzle 3.

On the base end side of the ink head 2,
The tank member 6 is connected in a sealed state, and inside the tank member 6, a buffer tank 7 communicating with each of the ink flow paths 4 is formed.

An ink cartridge 9 for storing ink 8 of a predetermined color is arranged near the tank member 6, and inside the ink cartridge 9 is arranged upward from the lower surface of the ink cartridge 9. An air supply pipe 10 is provided that extends and communicates with an upper air storage portion in the ink cartridge 9. Further, an ink tube 11 having one end connected to the rear end of the tank member 6 and supplying the ink 8 in the ink cartridge 9 to the buffer tank 7 is connected to the lower surface of the ink cartridge 9.

A pressure hole 12 is formed in the head body 1 and opens through the head body 1 and penetrates through the head body 1. The pressure hole 12 has an end portion on the rear surface side of the head body 1. A pressure pipe 13 connected to the lower end of the air supply pipe 10 of the ink cartridge 9 is connected.

On the other hand, the front surface of the head body 1 is covered with each nozzle 3 of the ink head 2 when not in use.
The cap body 14 for preventing the ink 8 inside from drying
Are arranged so that they can be moved toward and away from the head main body 1, and an ink receiving concave portion 15 is formed at a position corresponding to each nozzle 3 portion of the ink head 2 of the cap main body 14. Ink receiving recess 1 of this cap member
When the cap body 14 is joined to the head body 1, a peripheral edge portion of the inner surface of the element 5 comes into close contact with the front surface of the head body 1 around the ink head 2 to seal the ink receiving concave portion 15 and the ink head 2 portion. A cap rubber 16 is attached to the cap body 14, and an ink discharge pipe 17 and an atmosphere release pipe 18 that communicate with the ink receiving recess 15 are formed in the cap body 14. The ink discharge pipe 1
A suction pump 19 is connected to 7, and an atmosphere release valve 20 is connected to the atmosphere release pipe 18.

At a position of the cap body 14 corresponding to the pressure hole 12 of the head body 1, an end portion of the pressure hole 12 is airtight when the cap body 14 is joined to the head body 1. A joining protrusion 21 to be joined is formed, and a pressure pipe 22 penetrating the cap body 14 is formed at the joining protrusion 21 portion of the cap body 14. Further, a pressurizing pump 23 is connected to the pressurizing pipe 22.

In the conventional ink head 2, the piezoelectric element 5 of the ink flow path 4 corresponding to the desired nozzle 3 is energized based on a desired print signal, so that the ink cartridge 9 to the ink tube 11 and the ink tube 11 are ejected. Desired printing is performed by ejecting the ink 8 supplied to the ink flow path 4 via the buffer tank 7 from the nozzle 3 onto a predetermined paper (not shown).

When performing a head recovery operation, the cap body 14 is joined to the front surface of the head body 1,
In this state, by operating the pressure pump 23,
Pressurized air supplied from the pressurizing pipe 22 passes through the pressurizing hole 12 and the pressurizing pipe 13 of the head body 1 and the air supply pipe 10
Is supplied to the air reservoir of the ink cartridge 9.
As a result, the pressure inside the ink cartridge 9 becomes high, the ink 8 inside the ink cartridge 9 is sent to the buffer tank 7 through the ink tube 11, and passes through the ink flow path 4 to cause foreign matters and bubbles in the ink flow path 4. And the like are ejected from the nozzle 3. Then, the ejected ink 8 flows down into the ink receiving concave portion 15 of the cap main body 14 and collects in the lower portion, and the ink 8 is driven by a suction pump 19 to pass a waste liquid (not shown) via an ink discharge pipe 17. After being sent to the tank, the recovery operation of the head is completed by the above operation.

[0011]

However, in the above-described conventional cap device for the ink head 2, when the printing is not performed, such as during transportation, the cap main body 14 is joined to the ink head 2 and the ink in the nozzle 3 portion is joined. However, when an inkjet printer using such a cap device is transported by aircraft, for example, when the altitude reaches about 10,000 m, the pressure in the luggage compartment is 0.7 Since the pressure is reduced to about atmospheric pressure, when a slight leak occurs between the cap rubber 16 of the cap body 14 and the end surface of the ink head 2, the internal pressure PI of the ink cartridge 9 is reduced.
Even if the normal pressure is 1 atm, the internal pressure PC of the ink receiving recessed portion 15 of the cap body 14 becomes as low as 0.7 atm, which is the same as in the luggage compartment due to the leakage, so that PC <PI and the ink cartridge 9 There is a problem that the pressure balance between the ink receiving concave portion 15 and the ink receiving concave portion 15 cannot be maintained.

Therefore, due to the pressure difference between the ink cartridge 9 and the ink receiving concave portion 15, the ink 8 of the ink cartridge 9 flows out from the nozzle 3 to the ink receiving concave portion 15 until PC = PI, and the ink receiving concave portion 1
There is a problem that the ink 8 overflows from 5 to the outside of the cap body 14.

The present invention has been made in view of the above points, and even when the atmospheric pressure changes, the internal pressure of the ink cartridge and the cap body can be kept constant, and the ink leaks due to the pressure difference. It is an object of the present invention to provide an ink head cap device capable of reliably preventing the above problem.

[0014]

In order to achieve the above object, an ink head cap device according to the present invention is provided with an ink channel having a nozzle at its tip and an ink cartridge communicating with this ink channel. A cap body that covers the nozzle portion is disposed on the front side of the ink head so that the nozzle body can be freely contacted and separated, and a pressure pipe that supplies pressurized air to the ink cartridge is connected to the cap body, and the cap body is also provided. In the cap device of the ink head, an air release pipe for releasing the inside of the cap body to the atmosphere and an ink discharge pipe for sucking the ink flowing out into the cap body and discharging the ink to the outside are connected to the pressurizing pipe. In the state where the cap body is joined to the ink head at the time of non-printing, the ink cartridge and the atmosphere are released. Is characterized in that interposed a valve device which communicates and.

[0015]

According to the present invention having the above-described structure, during non-printing such as when the printer is transported, the valve device is switched to the atmosphere release pipe side with the cap body joined to the head body. By communicating the ink cartridge and the atmosphere release pipe through the pressurizing pipe, the internal pressure of the ink cartridge and the internal pressure of the cap main body can be held evenly. When the external air pressure changes and there is a leak between the cap body and the end face of the ink head, a pressure difference between the internal pressure of the ink cartridge and the internal pressure of the cap body may occur. This prevents the ink in the ink cartridge from leaking from the nozzle due to this pressure difference, and the ink from the cap body to the outside can be prevented. In which it is possible to reliably prevent the click of leakage.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. 1 and FIG.

1 and 2 show an embodiment of an ink head to which an ink head cap device according to the present invention is applied. An ink head 2 is mounted on a head body 1 mounted on a carriage of a printer. The ink jet head 2 is arranged so that its tip end surface is substantially flush with the end face of the head body 1. Inside the ink head 2, the tip end portion is provided with a nozzle 3.
A plurality of ink flow paths 4, 4 ... In which a piezoelectric element 5 is interposed are formed in parallel in the longitudinal direction. In the present embodiment, the ink head 2 is formed with four color ink channels 4 of black (B), yellow (Y), magenta (M), and cyan (C) in parallel and independently. Has been done.

On the base end side of the ink head 2,
The tank member 6 is connected in a sealed state, and inside the tank member 6, a buffer tank 7 that communicates with the ink flow paths 4 of the respective colors via a filter 24 is formed. Further, in the present embodiment, the bypass pipe 25 exposed from the buffer tank 7 of the tank member 6 to the front end face of the ink head 2 is formed, and an opening / closing valve 26 is provided in the middle of the bypass pipe 25. It is installed.

Ink cartridges 9, 9 ... Retaining inks 8 of black, yellow, magenta, and cyan, respectively, are arranged near the tank member 6, and the inside of each ink cartridge 9 is arranged. Has
Remaining amount sensors 27 that detect the remaining amount of the ink 8 are provided. Further, inside the ink cartridge 9, an air supply pipe 10 is provided which extends upward from the lower surface of the ink cartridge 9 and communicates with an upper air storage portion in the ink cartridge 9. An ink tube 11 whose one end is connected to the rear end of the tank member 6 and which supplies the ink 8 in the ink cartridge 9 to the buffer tank 7 is connected to the lower surface of the.

A pressure hole 12 is formed in the head body 1 and opens through the head body 1 and penetrates the head body 1. The pressure hole 12 has an end portion on the rear surface side of the head body 1. Pressurizing pipes 13 connected to the lower ends of the air supply pipes 10 of the ink cartridges 9 via filters 28 are connected.

On the other hand, on the front surface of the head main body 1, a cap main body 14 is disposed so as to be capable of being brought into contact with and separated from the head main body 1. An ink receiving recess 15 having a cap rubber 16 mounted on the inner surface is formed at a corresponding position. An ink discharge pipe 17 and an atmosphere release pipe 18 communicating with the ink receiving recess 15 are formed in the cap body 14, and a bypass discharge pipe 29 is formed at a position corresponding to the bypass pipe 25 of the ink head 2. Has been done. Further, the ink discharge pipe 17 has a relay portion 30 for preventing color mixture of the inks 8 of different colors.
The suction side of the suction pump 19 is connected via a check valve 31 and the bypass discharge pipe 29 is connected to the relay section 30 via an electromagnetic opening / closing valve 32. The suction pump 19 has a built-in piston 34 that is reciprocally moved by a drive motor 33, and a waste liquid tank 37 is provided on the discharge side of the suction pump 19 via a check valve 35 and a discharge electromagnetic valve 36, respectively. It is connected.

Further, an atmosphere release valve 20 which is normally closed is connected to the atmosphere release pipe 18.

A pressurizing tube 22 penetrating the cap body 14 is formed at a joint projection 21 portion formed at a position corresponding to the pressurizing hole 12 of the head body 1 of the cap body 14. An electromagnetic three-way valve 39 is connected to the pressurizing pipe 22 via a filter 38. At the non-energized connection side of the electromagnetic three-way valve 39, the atmosphere release pipe 18
Is connected, and the discharge side of the pressurizing pump 23 is connected to the connection side of the electromagnetic three-way valve 39 when energized via the check valve 40. The pressurizing pump 23 includes a drive motor 41
The piston 42 that is reciprocated by
The suction side of the pressurizing pump 23 is open to the outside via a check valve 43. Further, a relief valve 44 and a pressure gauge 45 are connected in parallel between the electromagnetic three-way valve 39 and the pressurizing pump 23.

Next, the operation of this embodiment will be described.

First, in the normal state, the ink 8 of each color stored in the ink cartridge 9 is supplied to the ink flow path 4 of each color via the ink tube 11 and the buffer tank 7, respectively. Then, based on the desired print signal, the ink flow path 4 corresponding to the desired nozzle 3 is formed.
When the piezoelectric element 5 is energized, the ink 8 is ejected from the nozzle 3 onto a predetermined paper, whereby desired printing is performed.

When foreign matters, bubbles or the like enter the ink flow path 4 to perform the head recovery operation, the cap body 14 is joined to the front surface of the head body 1, and in this state, the electromagnetic three-way valve 39 is connected. By connecting the pressurizing pipe 22 and the pressurizing pump 23 to each other by energizing, and driving the drive motor 41 to drive the piston 42 of the pressurizing pump 23,
Pressurized air passes through the pressurizing pipe 22, and the pressurizing hole 1 of the head body 1
2 is supplied to the air reservoir of the ink cartridge 9 from the air supply pipe 10 via the pressure pipe 13 and the pressure pipe 13. As a result, the pressure inside the ink cartridge 9 becomes high, and the ink 8 inside the ink cartridge 9 is transferred to the ink tube 1.
1 to the buffer tank 7, and passes through the ink flow path 4 together with foreign matter, bubbles, etc. in the ink flow path 4 and the nozzle 3
Erupted from.

On the other hand, by driving the drive motor 33 to drive the piston 34 of the suction pump 19 and opening the discharge electromagnetic valve 36, the ink 8 ejected from the nozzles 3 is discharged from the cap body 14. After flowing down to the ink receiving concave portion 15 and collecting in the lower portion, it is sent to the waste liquid tank 37 via the ink discharge pipe 17. Thereafter, the drive motors 33 and 41 are stopped, the electromagnetic three-way valve 39 and the discharge electromagnetic valve 36 are de-energized, and the atmosphere release valve 20 is opened to pressurize the ink receiving recess 15 of the cap body 14. The air is released to the atmosphere through the atmosphere release pipe 18, and the recovery operation of the head is completed by the above operation.

Further, the cap body 14 is attached to the head body 1 during non-printing such as when the printer is transported.
Let it join to. At this time, since the electromagnetic three-way valve 39 is de-energized, the electromagnetic three-way valve 39 is switched to the atmosphere release pipe 18 side, and the pressurizing pipe 22 and the atmosphere release pipe 18 are connected. There is. This allows
Pressurized piping 13 and air supply piping 1 of the head body 1
The air storage portion of the ink cartridge 9 and the atmosphere release pipe 18 are communicated with each other through 0, and the internal pressure PI of the ink cartridge 9 and the internal pressure PC of the ink receiving concave portion 15 of the cap body 14 become PC = It becomes PI, and both pressures can be held uniformly. Therefore, even when the external atmospheric pressure changes, for example, when the air is transported by an aircraft, the internal pressure PI of the ink cartridge 9 and the internal pressure PC of the ink receiving recess 15 can be held in the same state, and each pressure PI can be maintained. , PC pressure difference does not occur.

Therefore, in this embodiment, even when the external atmospheric pressure changes, the internal pressure PI of the ink cartridge 9 and the internal pressure PC of the ink receiving recess 15 are changed.
Can be held uniformly, and even if there is a leak between the cap rubber 16 of the cap body 14 and the end surface of the ink head 2, there is no pressure difference between the pressures PI and PC. The ink in the ink cartridge 9 does not leak from the nozzle 3 due to this pressure difference, and the leakage of the ink 8 from the ink receiving recess 15 to the outside can be reliably prevented.

The present invention is not limited to the above-described embodiments, but various modifications can be made as necessary.

[0031]

As described above, in the ink head cap device according to the present invention, by switching the valve device,
Even if the external atmospheric pressure changes, the internal pressure of the ink cartridge and the internal pressure of the cap body can be held uniformly, and even if there is a leak between the cap body and the end surface of the ink head, Since no pressure difference occurs, the ink in the ink cartridge does not leak from the nozzle due to this pressure difference.
It is possible to reliably prevent the leakage of ink from the cap body to the outside.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an ink head cap device according to the present invention.

FIG. 2 is a vertical cross-sectional view showing a cap device for an ink head according to the present invention.

FIG. 3 is a vertical cross-sectional view showing a conventional ink head cap device.

[Explanation of symbols]

 1 Head Main Body 2 Ink Head 3 Nozzle 4 Ink Flow Path 5 Piezoelectric Element 7 Buffer Tank 8 Ink 9 Ink Cartridge 13 Pressurized Piping 14 Cap Main Body 15 Ink Receiving Recess 16 Cap Rubber 17 Ink Discharge Pipe 18 Atmosphere Release Pipe 19 Suction Pump 20 Atmosphere Release valve 22 Pressurizing pipe 23 Pressurizing pump 37 Waste liquid tank 39 Electromagnetic three-way valve

Claims (1)

[Claims] 1. A cap main body that covers the nozzle portion can be freely attached to and detached from the front side of an ink head in which an ink channel having a nozzle at the tip and an ink cartridge communicating with the ink channel are formed inside. And a pressure pipe for supplying pressurized air to the ink cartridge is connected to the cap main body, and the cap main body is connected to the atmosphere release pipe for releasing the inside of the cap main body to the atmosphere and the inside of the cap main body. In a cap device for an ink head, which is connected to an ink discharge pipe that sucks out the discharged ink and discharges it to the outside, in the state where the cap main body is joined to the ink head at the time of non-printing, the ink A cap device for an ink head, characterized in that a valve device for connecting the cartridge and the atmosphere release pipe is provided.