JP2790742B2 - Ink head cap device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cap device for an ink head, and more particularly to an ink used for a printer such as an ink jet printer which performs printing by ejecting ink, and which covers a nozzle portion of the ink head when printing is not performed. 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 which performs printing by ejecting ink, a nozzle portion of an ink head is covered at the time of non-printing to prevent drying of the ink, and an ink flow path of the ink head. An ink head cap device is provided to perform a head recovery operation for removing foreign matter such as clogging due to ink in the ink and air bubbles.

FIG. 3 shows an ink head and a cap device applied to such a conventional ink jet printer. A head body 1 mounted on a carriage of the printer has an ink head 2 having a tip end surface as described above. The ink head 2 is disposed so as to be substantially flush with the end face of the head main body 1. 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 of the ink flow paths 4, and selectively energize each of the piezoelectric elements 5 in accordance with print information. By doing so, the ink in the specific ink flow path 4 is ejected from the nozzle 3.

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

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

A pressure hole 12 is formed in the head body 1 and is opened at the front surface and penetrates the head body 1. A pressure pipe 13 is connected to a lower end of the air supply pipe 10 of the ink cartridge 9.

On the other hand, the front surface of the head body 1 is covered with the nozzles 3 of the ink head 2 when not in use.
Body 14 for preventing drying of ink 8 inside
Are arranged so as to be freely movable toward and away from the head main body 1, and an ink receiving recess 15 is formed at a position of the cap main body 14 corresponding to each nozzle 3 portion of the ink head 2. Ink receiving recess 1 of this cap member
On the inner surface of the ink jet head 5, a peripheral edge of the cap main body 14 is tightly attached to the front surface of the head main body 1 around the ink head 2 when the cap main body 14 is joined to the head main body 1, thereby sealing the ink receiving recess 15 and the ink head 2. The cap body 14 is provided with an ink discharge pipe 17 and an air release pipe 18 communicating with the ink receiving recess 15. 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.

The cap body 14 is located at a position corresponding to the pressurizing hole 12 of the head body 1 in an airtight state at the end of the pressurizing hole 12 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 pressure pump 23 is connected to the pressure pipe 22.

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

When performing a head recovery operation, the cap main body 14 is joined to the front surface of the head main body 1,
By operating the pressure pump 23 in this state,
The pressurized air supplied from the pressurizing pipe 22 is supplied to the air supply pipe 10 through the pressurizing hole 12 and the pressurizing pipe 13 of the head body 1.
Is supplied to the air reservoir of the ink cartridge 9.
As a result, the pressure inside the ink cartridge 9 becomes high, and the ink 8 in the ink cartridge 9 is sent to the buffer tank 7 via the ink tube 11, passes through the ink flow path 4, and contains foreign matter and bubbles in the ink flow path 4. Are ejected from the nozzle 3 together with the above. The ejected ink 8 flows down into the ink receiving recess 15 of the cap body 14 and accumulates in the lower portion. The ink 8 is driven by a suction pump 19 to discharge waste ink (not shown) through an ink discharge pipe 17. It is sent to the tank and the above operation completes the head recovery operation.

[0011]

However, in the above-described conventional ink head 2 cap device, when printing is not performed, such as during transportation, the cap main body 14 is joined to the ink head 2 so that the ink in the nozzle 3 portion is removed. 8 is prevented, but when an inkjet printer using such a cap device is transported by air, for example, when the altitude becomes about 10,000 m, the air pressure in the luggage room becomes 0.7. Since the pressure is reduced to about the atmospheric pressure, if a slight leak occurs between the cap rubber 16 of the cap body 14 and the end face of the ink head 2, the internal pressure PI of the ink cartridge 9 is reduced.
Is lower than the normal pressure of 1 atm, the internal pressure PC of the ink receiving recess 15 of the cap body 14 is reduced to 0.7 atm similar to that of the luggage compartment due to the leakage. There is a problem that the pressure balance between the ink and the ink receiving recess 15 cannot be maintained.

Due to the pressure difference between the ink cartridge 9 and the ink receiving recess 15, the ink 8 of the ink cartridge 9 flows out of the nozzle 3 into the ink receiving recess 15 until PC = PI.
5 has a problem that the ink 8 overflows to the outside of the cap body 14.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and can maintain a constant internal pressure between an ink cartridge and a cap main body even when a change in atmospheric pressure of outside air occurs, thereby causing ink leakage due to a pressure difference. It is an object of the present invention to provide an ink head cap device that can surely prevent the ink head capping.

[0014]

According to a first aspect of the present invention, there is provided a cap device for an ink head, comprising: an ink channel having a nozzle at an end thereof; and an ink cartridge communicating with the ink channel. A cap body for covering the nozzle portion is provided on the front side of the ink head so as to be able to contact and separate therefrom, and a pressure pipe for supplying pressurized air to the ink cartridge is connected to the cap body, and the cap body is An ink release pipe for releasing the inside of the cap body to the atmosphere and an ink discharge pipe for sucking ink flowing into the cap body and discharging the ink to the outside; In the state where the cap body is joined to the ink head when printing is not performed in the middle of the ink cartridge, 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, at the time of non-printing such as when transporting a printer, the valve device is switched to the atmosphere release pipe side with the cap main body joined to the head main body, By communicating the ink cartridge with the atmosphere release pipe via the pressurized pipe, the internal pressure of the ink cartridge and the internal pressure of the cap body can be uniformly maintained. The pressure difference between the internal pressure of the ink cartridge and the internal pressure of the cap body, even if the outside air pressure changes and leakage occurs between the cap body and the end face of the ink head. This prevents the ink in the ink cartridge from leaking from the nozzles due to this pressure difference. In which it is possible to reliably prevent the click of leakage.

[0016]

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

FIGS. 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 main body 1 mounted on a carriage of a printer. The ink head 2 is provided with a front end portion having a nozzle 3 which is substantially flush with an end surface of the head main body 1.
A plurality of ink flow paths 4, 4... In which a piezoelectric element 5 is interposed in the middle part are formed in parallel in the vertical direction. In the present embodiment, ink channels 4 of four colors of black (B), yellow (Y), magenta (M), and cyan (C) are formed in the ink head 2 in parallel and independently. Have been.

Further, on the base end side of the ink head 2,
The tank member 6 is connected in a sealed state, and a buffer tank 7 is formed inside the tank member 6 so as to communicate with the ink flow path 4 of each color via a filter 24. In the present embodiment, a bypass pipe 25 is formed to be exposed from the buffer tank 7 of the tank member 6 to the front end face of the ink head 2. It is interposed.

In the vicinity of the tank member 6, there are arranged ink cartridges 9, 9... For storing inks 8 of black, yellow, magenta, and cyan, respectively. In
A remaining amount sensor 27 for detecting the remaining amount of the ink 8 is provided. Further, inside the ink cartridge 9, an air supply pipe 10 extending upward from the lower surface of the ink cartridge 9 and communicating with an upper air storage portion in the ink cartridge 9 is provided. 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 a lower surface of the ink cartridge 9.

The head body 1 is formed with a pressurizing hole 12 which is opened at the front surface and penetrates the head body 1. A pressurizing pipe 13 is connected to a lower end of the air supply pipe 10 of the ink cartridge 9 via a filter 28.

On the other hand, a cap body 14 is provided on the front surface of the head body 1 so as to be freely movable toward and away from the head body 1. The cap body 14 is provided at each nozzle 3 of the ink head 2. At the corresponding position, an ink receiving recess 15 having a cap rubber 16 mounted on the inner surface is formed. An ink discharge pipe 17 and an air release pipe 18 communicating with the ink receiving recess 15 are respectively 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. Have been. The ink discharge pipe 17 has a relay section 30 for preventing color mixture of the inks 8 of each color.
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 on the way. The suction pump 19 has a built-in piston 34 that is reciprocated by a drive motor 33. 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 through the cap body 14 is formed at a joint projection 21 formed at a position of the cap body 14 corresponding to the pressurizing hole 12 of the head body 1. An electromagnetic three-way valve 39 is connected to the pressurizing pipe 22 via a filter 38. An air release pipe 18 is connected to the non-energized connection side of the electromagnetic three-way valve 39.
The discharge side of the pressurizing pump 23 is connected via a check valve 40 to the energized connection side of the electromagnetic three-way valve 39. The pressurizing pump 23 has a drive motor 41
The piston 42 reciprocated by is built in,
The suction side of the pressure pump 23 is opened 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 pressure 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 a desired print signal, an ink flow path 4 corresponding to a desired nozzle 3 is provided.
When the piezoelectric element 5 is energized, the ink 8 is ejected from the nozzle 3 onto a predetermined sheet to perform desired printing.

When a head recovery operation is performed by foreign matter or air bubbles mixed in the ink flow path 4, 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. To connect the pressurizing pipe 22 and the pressurizing pump 23 and drive the drive motor 41 to drive the piston 42 of the pressurizing pump 23.
The pressurized air passes through the pressurizing tube 22 and pressurized holes 1
The ink is supplied from the air supply pipe 10 to the air storage section of the ink cartridge 9 via the pressure pipe 2 and the pressure pipe 13. As a result, the pressure in the ink cartridge 9 becomes high, and the ink 8 in the ink cartridge 9
1 to the buffer tank 7, through the ink flow path 4, along with foreign matter, air bubbles, and the like in the ink flow path 4.
Squirted 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 solenoid valve 36, the ink 8 ejected from the nozzle 3 After flowing down into the ink receiving concave portion 15 and accumulating 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 energization of the electromagnetic three-way valve 39 and the discharge electromagnetic valve 36 is released, and the atmospheric release valve 20 is opened to pressurize the ink in 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 head recovery operation is completed by the above operation.

Further, during non-printing such as when the printer is transported, the cap main body 14 is connected to the head main body 1.
To be joined. At this time, since the energization to the electromagnetic three-way valve 39 is released, 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. I have. This allows
Pressurizing pipe 13 and air supply pipe 1 of the head body 1
Thus, the internal pressure PI of the ink cartridge 9 and the internal pressure PC of the ink receiving recess 15 of the cap body 14 are expressed as PC = PI, and both pressures can be kept uniform. Therefore, even when the external air pressure changes, for example, when transported by air, the internal pressure PI of the ink cartridge 9 and the internal pressure PC of the ink receiving recess 15 can be maintained in the same state, and each pressure PI , PC does not occur.

Therefore, in this embodiment, even when the external air pressure changes, the internal pressure PI of the ink cartridge 9 and the internal pressure PC of the ink receiving concave portion 15 are changed.
Can be maintained uniformly, and even if there is a leak between the cap rubber 16 of the cap body 14 and the end face of the ink head 2, there is no pressure difference between the pressures PI and PC. The pressure difference does not cause the ink in the ink cartridge 9 to leak from the nozzles 3, 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 embodiment, but can be variously modified as required.

[0031]

As described above, the cap device of the ink head according to the present invention can be realized by switching the valve device.
Even when the external air pressure changes, the internal pressure of the ink cartridge and the internal pressure of the cap main body can be maintained uniformly, and even if there is a leak between the cap main body and the end face of the ink head, each of them can be maintained. Since there is no pressure difference between the pressures, the pressure difference does not cause the ink in the ink cartridge to leak from the nozzles.
It is possible to prevent the leakage of the ink from the cap body to the outside.

[Brief description of the drawings]

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

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

FIG. 3 is a longitudinal sectional view showing a conventional ink head cap device.

[Explanation of symbols]

 DESCRIPTION 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 Pressure piping 14 Cap main body 15 Ink receiving concave part 16 Cap rubber 17 Ink discharge pipe 18 Air 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)

(57) [Claims] 1. A cap body for covering a nozzle portion is detachably provided on a front surface side of an ink head having an ink flow path having a nozzle having a tip end formed therein and an ink cartridge communicating with the ink flow path. The cap body is connected to a pressurizing pipe for supplying pressurized air to the ink cartridge, and the cap body is connected to an atmosphere release pipe for releasing the inside of the cap body to the atmosphere and the inside of the cap body. In a cap device for an ink head, which is connected to an ink discharge tube that sucks out the discharged ink and discharges the ink to the outside, in a state where the cap main body is joined to the ink head when printing is not performed in the middle of the pressure tube, the ink is removed. A cap device for an ink head, wherein a valve device for communicating a cartridge with the atmosphere release pipe is provided.