JP3214727B2 - Air brush for drawing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an air brush used for an automatic drawing apparatus and the like.

[0002]

2. Description of the Related Art In an automatic drawing apparatus developed as a full-color image printing system for printing an ultra-large screen with a large number of fine pixels, an ink jet type pen is used as an ink jet type pen. An air brush that draws ink from the ink and ejects the ink is used.

As an air brush for the automatic drawing apparatus,
An air brush shown in FIG. 6 has been proposed. This air
The brush has a double-pipe structure with an outer air jetting pipe member 1 and an inner ink jetting pipe member 2, and a needle member 3 for controlling an ink jetting amount is placed in the ink jetting pipe member 2. At the rear end, a solenoid type driving mechanism 4 for reciprocating the needle member is connected, and in the operation of drawing out ink from the ejection port of the ink ejection tube member 2 and ejecting the ink by the negative pressure generated by air ejection, the needle member causes It has a structure that controls the injection port. In the figure, 5 is a compressed air inlet, and 6 is an ink inlet.

In the air brush for an automatic drawing apparatus having the above-described structure, the control of the ink ejection amount for forming pixels is more accurate than that of the air brush of the type in which the supplied air pressure is adjusted to control the ink ejection amount. There are advantages to do.

[0005]

However, on the other hand, since the needle member is reciprocated at a speed of several thousand times per second, the friction at the time of reciprocating movement at the contact portion with the ink jetting tube member is large. The mouth is severely worn and the jet is turned up, so the life is very short. Further, the energy required for the reciprocating motion of the needle member is large, and the speed of the reciprocating motion cannot be increased. That is, the on / off frequency of the needle member is reduced, and high-speed drawing cannot be performed.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a drawing airbrush which can make the ink jetting amount accurate without using a needle member. It is another object of the present invention to provide a drawing air brush which can jet ink uniformly without being affected by jet air.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an ink jet tube member which uses a negative pressure generated when air is jetted from an annular jet port surrounding the jet port of the ink jet tube member. as for jetting pull out the ink from
Configured to, on the rear of the ink injection pipe member, provided with a valve mechanism for controlling the supply of ink to the ink jet pipe member drawing
In the air brush for painting, the ejection port of the ink ejection tube member
Into an oblique injection port with a tube cut diagonally from both sides.
The gist is that it has been completed.

[0008]

According to the above configuration, the supply air pressure is kept constant, and the amount of ink jetted to the ink jet tube member can be controlled by operating the valve mechanism without using a needle member. In addition , the shape of the ink ejection port is
Therefore , the air in front of the ink jet port becomes a laminar flow along the inclined port face of the jet port, so that the vortex does not occur, and the ink flow position in the ink jet port is kept constant without fluctuation. It is.

[0009]

1 to 3 show an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an air ejection pipe member, reference numeral 2 denotes an ink ejection pipe member, and reference numeral 7 denotes a support member which supports both pipe members at their rear ends.

In this case, the ink jet tube member 2
7 may have an ejection port 2c as shown in FIG. 7, but if the ejection port 2a has a shape in which a pipe is cut obliquely from one side as described later, the ink ejection unevenness can be further reduced. Can be reduced. The cutting inclination angle of the injection port 2a is set in a range of 30 to 35 degrees.

The ink jet tube member 2 is provided in the support 7.
An ink valve chamber 8 is provided on the operating shaft 10 for opening and closing the communication port by contacting a conical valve seat 8a formed in the communication port.
The shaft end that penetrates through and protrudes to the outside is connected to the solenoid type driving mechanism 11. Reference numeral 12 denotes a gantry.

According to the above configuration, the operating shaft 10 is controlled by the solenoid type driving mechanism 11 while the supply air pressure is kept constant.
By controlling the opening degree of the valve body 9 through the, the ink ejection amount can be adjusted without using a needle member.

In the case where the ink ejection port is formed as shown in FIG. 7B, especially when the ink ejection amount is controlled to be small, the ink ejection becomes uneven, and the density level corresponding to the ink ejection amount is accurately determined. The tone may not be obtained.

The cause of the unevenness in the ink ejection is that the vortex R generated on the front surface of the ink ejection port 2b by the air ejection is generated.
It is thought to be due to the influence of That is, when the ink ejection amount is small, the ink is easily affected by the eddy current, and the ink ejection becomes uneven as shown in FIG. Further, since the ink flow position in the ink ejection port also fluctuates beyond the fixed portion shown in FIG. 8, the ink ejection direction is not constant.

However, as described above, if the ink jet port is formed as the inclined jet port 2a obliquely cut from one side, the jet air can be inclined as shown by the arrow in FIG. The flow becomes laminar along the mouth surface, and eddies are less likely to occur. In addition, the location of ink flow at the ink ejection port is kept constant without fluctuation. For example, as shown
When the ejection port is inclined downward, the ink flows toward the sharp end of the ejection port, and the ejection direction is determined by the flow position.

As an experimental example, the inner diameter of the ink jet tube member 2 was 0.2 mm, the outer diameter was 0.4 mm, the inner diameter of the air jet tube member 1 was 0.9 mm, and the ink jet port was inclined at 30 degrees from one side. An air brush made by cutting at a corner is manufactured, the air pressure is kept constant, and the operating shaft 1 is driven by a solenoid type driving mechanism 11.
When the ink ejection was performed while controlling the opening of the valve element 9 to a low ink amount via 0, it was possible to create a screen with a density gradation adapted to the ink ejection amount.

FIGS. 4 and 5 show another embodiment of the present invention. In this embodiment, the ejection port of the ink ejection tube member 2 is formed as an ejection port 2b cut obliquely from both sides. According to this configuration, the injection air has a laminar flow along the inclined surfaces on both sides of the injection port 2b, as indicated by arrows in FIG.
As in the above-described embodiment, eddy current is less likely to occur. In addition, it was confirmed by drawing experiments that the laminar flow effect was superior to the structure of the above-described embodiment.

[0018]

As described above, according to the present invention, since the valve mechanism is provided at the rear of the ink jetting tube member, the ink is supplied while the supply air pressure is kept constant, similarly to the air brush using the needle member. The injection amount can be controlled accurately. In addition, since the needle member is not used, the ink jet tube member does not wear out, and can be used for a long time. In addition, if the ejection port of the ink ejection tube member is an inclined ejection port,
The generation of eddy currents at the front of the ejection port can be eliminated, and the ink can be ejected without unevenness. This is particularly remarkable at the time of drawing a small density with a small amount of ink.

[Brief description of the drawings]

FIG. 1 is a side view of a drawing air brush showing an embodiment of the present invention.

FIG. 2 is a sectional view of an air brush.

FIG. 3 is a perspective view of an ink jet tube member.

FIG. 4 is a cross-sectional view of a drawing air brush showing another embodiment of the present invention.

FIG. 5 is a perspective view of an ink jet tube member.

FIG. 6 is a cross-sectional view of a conventional drawing air brush.

FIG. 7 is a cross-sectional view of an ink ejection tube member having different ejection ports in the embodiment.

FIG. 8 is a cross-sectional view illustrating a state of ink flow in the ink ejection tube member of FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air injection pipe member 2 Ink injection pipe member 2a One-side cut inclined injection port 2b Both-side cut inclined injection port 3 Needle member 4 Solenoid type drive mechanism 5 Compressed air inlet 6 Ink inlet 7 Support 8 Ink valve chamber 8a Valve seat 9 Valve body 10 Operating shaft 11 Solenoid type drive mechanism 12 Mount

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41J 2/175

Claims (1)

(57) [Claims] A negative pressure generated when air is ejected from an annular ejection port surrounding an ejection port of an ink ejection tube member,
I will pull out the ink from the ink jet tube member and jet it .
The drawing air brush provided with a valve mechanism for controlling the supply of ink to the ink jetting tube member at the rear of the ink jetting tube member.
The injection port of the pipe member has a shape obtained by cutting the pipe diagonally from both sides.
An airbrush for drawing characterized by being formed in an inclined jet opening .