JPH0740538A - Head cap of ink jet recording device - Google Patents

Abstract

PURPOSE:To avoid a state in which a drained ink is resident around an ink drainage orifice and improve drained water recovery performance by providing a second gradient surface which tilts steeply from an area near the ink drainage orifice of a first gradient surface to an ink drainage orifice. CONSTITUTION:An ink drainage orifice 1d opened at a bottom is connected to a negative pressure suction recovery means 3, and a front opening part 1c is positioned against the ink drainage orifice 1d in such a manner that the opening part 1c covers the nozzle 2a face of an ink jet head 2 on ink jet recording device. In a head cap which recovers a drained ink 4 from the ink jet head 2 by suction to a negative pressure suction recovery means 3 side, a first gradient surface 1a which tilts mildly toward the ink drainage orifice 1d and a second gradient surface 1b which tilts steeply toward the ink drainage orifice 1d from an area near the ink drainage orifice 1d of the first gradient surface 1a are provided on the inner surface of the bottom of the head cap 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink ejection performance recovery device used for maintaining ink ejection performance of an ink jet recording apparatus, and more particularly to improvement of a head cap covering an ink jet head.

[0002]

2. Description of the Related Art Generally, an ink ejection performance recovery device is provided to maintain the ink ejection performance of an ink jet recording apparatus. This is used to initially fill the ink jet head with ink and to remove dust and bubbles on the ink jet head side during maintenance. The head cap that covers the nozzle surface of the ink jet head and the ink of this head cap are used. The negative pressure suction pump is connected to the discharge port, and the waste ink tank is connected to the negative pressure suction pump to collect the sucked waste ink. As a conventional head cap of this type, as shown in FIGS. 5 to 7, a rectangular front opening 1 is formed.
Ink discharge port 10 at the bottom of the cap 101 having
3 is provided, and the ink discharge port 1 is provided on the inner surface of the bottom of the cap 101.
Inclined surface 1 that inclines toward 03 with a constant gentle slope
No. 02 is formed (for example, JP-A-3-2931).
No. 50). In such a head cap,
In order to facilitate the discharge of the ink, the slope of the inclined surface 102 may be made steep and the diameter of the ink discharge port 103 may be increased. However, in this case, the volume and outer shape of the head cap 101 increase. As a result, the suction capacity, the outer shape, and the suction time of the negative pressure suction pump increase, and it becomes impossible to satisfy the demands for downsizing, weight reduction, and cost reduction of the ink ejection performance recovery device. Therefore, in the head cap, there is a constraint that the slope of the inclined surface 102 and the diameter of the ink discharge port 103 cannot be increased.

[0003]

By the way, in the head cap having such a shape, the slope of the inclined surface 102 is gentle and the ink discharge port 103 is small. A technical problem has been found that the material stays in the cap 101 and gradually accumulates. That is, as shown in FIG. 8, the gently inclined surface 102 and the nozzle 104 of the ink discharge port 103.
A corner portion 106 that is close to a right angle is formed at the joint with the surface. At this time, the discharged ink 108 discharged from the inkjet head (not shown) flows along the inclined surface 102 at the bottom of the cap 101, and the corner portion 106 of the ink discharge port 103.
9A, the small droplets of the discharged ink 108 are not sucked into the ink discharge port 103 even by negative pressure suction from the ink discharge port 103 due to the surface tension thereof, as shown in FIG. A situation occurs in which the vehicle stays in the surrounding corner portion 106. The waste ink 10 remaining in this way
As indicated by reference numeral 109 in FIG. 10, 8 solidifies with time, accumulates gradually, and eventually the ink discharge port 1
It could lead to the worst situation of blocking 03.

The present invention has been made in order to solve the above technical problems, and avoids a situation where the waste ink in the ink jet head stays around the ink discharge port, and improves the waste ink recovery performance. The present invention provides a head cap that is

[0005]

That is, according to the present invention, as shown in FIG. 1, an ink discharge port 1d formed at the bottom is connected to a negative pressure suction recovery unit 3, and a front opening 1c is used for ink jet recording. In a head cap that is disposed so as to cover the surface of the nozzle 2a of the inkjet head 2 of the apparatus and sucks and recovers the waste ink 4 in the inkjet head 2 toward the negative pressure suction and recovery means 3 side, on the inner surface of the bottom of the head cap 1, the ink A first inclined surface 1a that inclines at a gentle slope toward the outlet 1d, and the first inclined surface 1
From the vicinity of the ink discharge port 1d of a, the ink discharge port 1
It is characterized in that a second inclined surface 1b which inclines at a steep gradient toward d is provided.

In such a technical means, the size and shape of the ink discharge port 1d may be appropriately selected within a range in which the discharged ink 4 can be discharged, and the arrangement position of the ink discharge port 1d may be selected. Although it may be located anywhere on the bottom of the head cap 1, it is desirable to provide the ink discharge port 1d at approximately the center of the bottom in consideration of uniform recovery of ink. Further, the second inclined surface 1b may be a curved surface extending from the portion of the first gently inclined surface in the vicinity of the ink discharge port 1d to the inside of the discharge port. The slope of the second inclined surface 1b can be appropriately selected as long as it can smoothly guide the discharged ink 4 moving along the first inclined surface 1a to the discharge port 1d side. 30 ° -60 °
Something is selected. The front surface shape of the head cap 1 is not limited to a rectangular shape, and any shape (for example, an elliptical shape) can be selected as long as it can cover the surface of the nozzle 2a of the inkjet head 2.

[0007]

In the above technical means, the head cap 1
When the negative pressure suction / collection means 3 connected to the ink discharge port 1d at the bottom of the head is operated, the discharged ink 4 discharged from the inkjet head drops onto the gentle first inclined surface 1a of the head cap 1, The first inclined surface 1a is slid toward the ink discharge port 1d. When the discharged ink 4 approaches the ink discharge port 1d, it slides on the second inclined surface 1b and drops into the ink discharge port 1d to be sucked. At this time, since the second inclined surface 1b has a steeper slope than the first inclined surface 1a, when the discharged ink 4 approaches the second inclined surface 1b, the ink is quickly retained without staying there. Outlet 1d
To fall. By forming the second inclined surface 1b in this way, the fluidity of the ink to the discharge port 1d is improved.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the embodiments shown in the accompanying drawings. FIG. 2 is an explanatory diagram showing an embodiment of an ink ejection performance recovery device having a head cap to which the present invention is applied. In the figure, the ink ejection performance recovery device is connected to a head cap 20 that selectively covers the surface of the nozzle 11 of the inkjet head 10 by an unillustrated advancing / retreating drive mechanism and the head cap 20 via a tube 30. The negative pressure suction pump 40 and a waste ink tank 50 that is connected to the negative pressure suction pump 40 and collects the waste ink sucked into the negative pressure suction pump 40 are provided. In the figure, 12 is an inkjet head 10.
An ink tank for supplying the ink to 41, a one-way valve 41 which is opened only during suction operation of the negative pressure suction pump 40 (pushing operation of the piston 43), and 42 is opened only during discharge operation of the negative pressure suction pump 40 (pushing operation of the piston 43). It is a one-way valve.

In this embodiment, the head cap 20
2 to 4, the front opening 21 is made of, for example, butyl rubber and has a substantially rectangular shape and extends in the arrangement direction (length direction) of the nozzles 11 of the inkjet head 10. An abutting portion 21a that elastically contacts the surface of the nozzle 11 of the inkjet head 10 is formed on the peripheral edge of the ink jet head 10. On the bottom portion 22 of the abutting portion 21a, an ink discharge port 23 that penetrates the abutment part 21a and an ink discharge nozzle communicating with the ink discharge port 23 are formed. 24 are formed. Further, in particular, as shown in FIG.
Also, as shown in FIG.
A first inclined surface 31 having a gentle slope α (13 ° in this embodiment) is formed toward. Furthermore, the second inclined surface 32 having a steeper slope β (45 ° in this embodiment) than the first inclined surface 31 from the portion of the first inclined surface 31 near the ink outlet 23 toward the ink outlet 23. Is formed. On the other hand, the inner surface in the width direction (direction orthogonal to the length direction) of the bottom portion 22 of the head cap 20 is particularly shown in FIG.
As shown in (c), a steep gradient γ (6 in this embodiment)
2 °) is formed as an inclined surface 33. In FIGS. 2 and 3 (a), reference numeral 25 is an engaging piece to be engaged and held by a cap holder (not shown).

The head cap 20 formed in this way
According to the method, after the head cap 20 covers the surface of the nozzle 11 of the inkjet head 10, the negative pressure suction pump 40 is operated to generate a negative pressure in the head cap 20,
Of the waste ink discharged from the inkjet head 10, the waste ink flowing along the first slope 31 having a gentle slope slides on the second slope 32 and is quickly sucked into the ink discharge port 23, and , Steep slope 33
The discharged ink flowing along the sliding surface slides on the inclined surface 33 and is quickly sucked into the ink discharge port 23, and no phenomenon in which the discharged ink stays around the ink discharge port 23 was observed.

[0011]

As is apparent from the above description, according to the present invention, the corner portion around the ink discharge port facing the first sloped surface of the bottom of the head cap having a gentle slope is removed, and the discharged ink is discharged. Since the second inclined surface having a steep slope that is smoothly guided to the ink discharge port side is provided, when the negative pressure suction / collection means connected to the head cap is operated to suck and collect the discharged ink, the bottom portion of the head cap is removed. The ink moving on the first inclined surface with a gradual slope does not stay around the ink discharge port, and the moving speed is increased on the second inclined surface with a steep slope to facilitate the ink discharge port. It is dropped or aspirated. Therefore, the ink does not stay in the vicinity of the ink discharge port, and it is possible to effectively prevent the accumulated ink from solidifying and accumulating to block the ink discharge port.

Further, if the ink discharging performance in the head cap is improved, the discharged ink does not remain in the head cap. Therefore, even if dust is attached to the flowing discharged ink, it is discharged together with the discharged ink. And then
The inkjet head is always kept clean, and thus the print quality and reliability can be kept high. Furthermore, since the second steep slope is formed relatively small near the ink discharge port, there is no concern that the head cap becomes unnecessarily large as in the case where only the first gentle slope is formed. Absent.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of a head cap of an inkjet recording apparatus according to the present invention.

FIG. 2 is a cross-sectional view showing an embodiment of an ink ejection performance recovery device having a head cap to which the present invention is applied.

3A is a cross-sectional explanatory view of a head cap according to an embodiment, FIG. 3B is a view seen from a direction B of FIG.
(C) is a sectional view corresponding to the line CC in (a).

FIG. 4 is a cross-sectional view of a main part (corresponding to an IV part in FIG. 3A) around the ink discharge port of the head cap according to the embodiment.

FIG. 5 is a perspective view showing an example of a conventional head cap.

FIG. 6 is a cross-sectional explanatory view thereof.

FIG. 7 is a cross-sectional view of an essential part around the ink discharge port.

8 is a cross-sectional view of relevant parts showing a state of discharged ink reaching an ink discharge port in the conventional head cap of FIG.

9 is a cross-sectional view of relevant parts showing a state in which the discharged ink has accumulated around the ink discharge port in the conventional head cap of FIG.

FIG. 10 is a cross-sectional view of relevant parts showing a state in which the ink that has accumulated around the ink discharge port is solidified in the conventional head cap of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Head cap, 1a ... 1st inclined surface, 1b ... 2nd inclined surface, 1c ... Front opening part, 1d ... Ink discharge port, 2
... Inkjet head, 2a ... Nozzle, 3 ... Negative pressure suction and recovery means, 4 ... Waste ink

Claims (1)

[Claims] 1. An ink discharge port (1d) opened at the bottom.
Are connected in communication with the negative pressure suction and recovery means (3), and the front opening (1c) is disposed so as to face the nozzle (2a) surface of the inkjet head (2) of the inkjet recording device, and the inkjet head (2) side In the head cap of the ink jet recording apparatus for sucking and collecting the waste ink of the same to the negative pressure suction collecting means (3) side, the head cap (1)
On the inner surface of the bottom portion, a first inclined surface (1a) that inclines at a gentle slope toward the ink discharge port (1d), and a portion near the ink discharge port (1d) of the first inclined surface (1a) A head cap for an ink jet recording apparatus, comprising: a second inclined surface (1b) that inclines at a steep slope toward the ink discharge port (1d).