JPH0553629B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a negative pressure suction structure of a printing table in a screen printing machine that prints by fixing a printing material to a printing table using negative suction force.

Conventionally, in screen printing machines that print circuit patterns on printed circuit boards, the printed circuit board, which is the object to be printed, is positioned and fixed on a printing table for the printing process. Fixation on the table is usually done by negative pressure suction means.

However, the effect of this negative pressure suction means varies greatly depending on the arrangement structure of the negative pressure suction holes formed in the printing table. This tendency is noticeable in the processing of industrial substrates. In other words, the negative pressure suction holes in the printing table must always be positioned to avoid perforations in the substrate, which is the object to be printed, and if such consideration is not taken, the effect of suctioning and fixing the substrate to the printing table will be high. This is because it will not be possible.

Various ideas have been proposed to make negative pressure suction holes on the surface of the printing table effective by adapting to the size and difference of the substrate, and the presence or absence of perforations.
Although some methods have shown some effectiveness, the invention disclosed here is extremely easy to process and handle, and in response to changes in board specifications, the suction hole can be adjusted appropriately within a 360 degree range. It can be said that it is superior to the conventional method in that it can be set at a desired position.

Hereinafter, the structure of the present invention will be explained in detail based on examples thereof.

A circular recess 2 is provided on the surface of a printing table 1 on which a printed circuit board, which is a printing medium M, is placed. This circular concave portion 2 communicates with a negative pressure suction device (not shown) via a ventilation hole 3 formed in its bottom surface. Each of the circular concave portions 2 is formed in the same shape as the concave portion 2 and has a diameter slightly smaller than that of the concave portion 2, and has a negative hole at an eccentric position communicating with the ventilation hole 3 of the concave portion 2. A lid 4 having a pressure suction hole 5 is rotatably fitted. Making the concave part 2 circular and specifying the same shape for the lid body 4 ensures forward rotation of the lid body 4, and also ensures that rotation while maintaining airtightness between the concave part 2 and the concave part 2 as much as possible. This is to enable smoother movement.

A plurality of circular recesses 2 are provided on the surface of the printing table 1.
The installation position is preferably selected so as to cover the four corners and the center of the printing table 1.

Further, it is important that the negative pressure suction holes 5 formed in the lid body 4 are formed at eccentric positions in each lid body 4 so as to communicate with the ventilation holes 3 of the concave portion 2. The suction hole 5 does not necessarily have to be located at a fixed distance from the center of the lid body 4; rather, the negative pressure suction hole 5 may be located at a different eccentric position in order to meet various demands. It is preferable to do so.

P shown in the figure is a ring-shaped packing member installed between the lid body 4 and the recessed part 2 of the printing table 1. If this packing member P is interposed, the above-mentioned circular recess can be removed. There is an advantage that dimensional control for maintaining airtightness between the inner wall of the portion 2 and the outer wall of the lid body 4 becomes easier.

Further, 6 is a packing member P formed on the lid body 4.
It shows the notch that accommodates the. Note that the means for rotating the lid 4 may be any suitable means. For example, a plurality of engaging portions may be formed on the surface of the lid 4, and a hook may be engaged with the engaging portions. They may be performed together.

Furthermore, C in the figure shows the printing material M on the printing table 1.
It is a belt conveyor for carrying things upwards, and
Reference numeral 7 denotes a weight member that opens and closes the vent hole 3 communicating with the negative pressure suction device, and the contact surface 7a, which has a diameter larger than the diameter of the vent hole 3, is brought into contact with and separated from the surface of the vent hole 3. Open and close. Since the weight member 7 is always positioned so as to face the ventilation hole 3 during the rotation process of the lid 4, and is loosely fitted into the accommodating portion 8 of the lid 4,
The weight member 7 that has come above the ventilation hole 3 uses its own weight to ensure that the contact surface 7a closes the ventilation hole 3. Therefore, if such a structure is adopted, it becomes easier to eliminate the need for the negative pressure suction holes 5 in a certain part of the printing table 1 compared to other means. Become.

In addition, in the example shown in FIG. 4, the accommodating portion 8 of the lid body that loosely accommodates the weight member 7 is penetrated to the surface of the printing table 1, and the contact surface 7a of the weight member 7 is provided with a ventilation hole 3 from the diameter. A falling portion 7b having a small diameter is formed. When using such a structure, the weight member 7
When the contact surface 7a of the contact surface 7a comes into contact with the ventilation hole 3, the weight member 7 is lower than the surface of the printing table 1 by the length of the falling part 7a'. There is an advantage that it can be visually observed from the surface of the table 1.

Now, as for the negative pressure suction structure on the surface of the printing table 1, in addition to the structure described above, structures as shown in FIGS. 5 to 7 can be considered. It forms a second recess 10 in the rotating lid 9, and this second
A second lid 9a having a negative pressure suction hole 5' formed at an eccentric position in the concave portion 10 is rotatably fitted, but according to this structure, one lid 9
The negative pressure suction hole 5' drilled at the eccentric position of a can significantly expand the range of displacement of the negative pressure suction hole 5' by rotating the two lids 9 and 9a. This is particularly effective when dealing with printing materials having perforations, such as industrial substrates.

The invention related to this structure will be explained in more detail below.

A plurality of circular recesses 2 are provided on the surface of the printing table 1 and communicate with a negative pressure suction device (not shown) through ventilation holes 3.
A lid body 9, which is formed in the same shape as the recessed part 2 and has a diameter slightly smaller than that of the recessed part 2, is rotatably fitted. Further, this lid body 9 is provided with a second circular recess 10 that communicates with the ventilation hole 3 at an appropriate position.
0 has a second recess 10 formed in the same shape as the second recess 10, a diameter slightly smaller than that of the second recess 10, and a negative pressure suction hole 5' bored at an eccentric position. A lid body 9a is rotatably fitted.

Pa and Pb in the figure are ring-shaped packing members housed in the notches 6a and 6b of the two lids 9 and 9a, and their functions and effects are explained in Figs.
There is no difference from the structure shown in FIG.

In addition, 7' in the figure is a weight member that is loosely fitted into the housing part 8' of the lid body 9a, and the contact surface 7a', which has a diameter larger than the diameter of the vent hole 3, comes into contact with and separates from the surface of the vent hole 3. Air vent 3
In addition, it is possible to open and close the housing part 8' by penetrating the surface of the printing table 1 and further forming a falling part with a smaller diameter than the diameter of the ventilation hole 3 on the contact surface 7a' of the weight member 7'. As mentioned above, there is an advantage that the opening and closing of the pores 3 can be visually observed from the surface of the printing table 1.

As for the means for rotating the lids 9, 9a in this example, it goes without saying that any suitable means may be used. For example, a plurality of engaging portions may be provided on the surfaces of the lids 9, 9a. Similarly to the structure described above, the hook may be formed and rotated by engaging the hook with the engaging portion.

The present invention is constructed as described above, and the position of the negative pressure suction holes on the surface of the printing table is such that each negative pressure suction hole is positioned within a 360 degree range and as far as possible into the recessed part of the printing table. This allows for easy displacement to the desired position while maintaining airtightness between the print material and the material, making it possible to handle print materials of different sizes or materials with perforations in the same way. Processing on the print table is now easier and more reliable.

[Brief explanation of the drawing]

Fig. 1 is a partially omitted top view of a printing table embodying the present invention, Fig. 2 is a partially omitted side sectional view of the printing table relating to the main parts of the present invention, and Figs. 3 and 4 are ventilation holes. 4 is an explanatory diagram of an improved example of FIG. 3, FIG. 5 is an enlarged explanatory diagram of main parts of another example of the present invention, and FIG. 6 is a top view of FIG. 5, and FIG. 7 is a partially omitted side sectional view illustrating the structure of the example of FIG. 5 having a vent opening/closing member. 1...Printing table, 2,10...Circular recess, 3...Vent hole, 4,9,9a...Lid, 7,
7'... plumb member, 7a, 7a'... contact surface, 7b
... Falling part, 8, 8'... Plumb member housing part.

Claims (1)

[Scope of Claims] 1. In a printing table of a screen printing machine that fixes a printing material to the surface thereof through a negative pressure suction hole, the surface of the printing table 1 communicates with a negative pressure suction device through a ventilation hole 3. A plurality of circular concave portions 2 are provided, and each of the concave portions 2 is formed in the same shape as the concave portion 2 and has a diameter slightly smaller than the diameter of the concave portion 2, and the concave portion 2 is provided at an eccentric position.
A negative pressure suction structure for a printing table in a screen printing machine, characterized in that a lid body 4 having a negative pressure suction hole 5 communicating with a ventilation hole 3 is rotatably fitted. 2. In a printing table of a screen printing machine that fixes a printing material to the surface thereof through a negative pressure suction hole, a circular recess 2 is provided on the surface of the printing table 1 and communicates with a negative pressure suction device through a ventilation hole 3. A plurality of lid bodies 9 are provided, each of which is formed in the same shape as the concave part 2 and has a diameter slightly smaller than the diameter of the concave part 2. A second circular recess 10 communicating with the ventilation hole 3 is formed in the second recess 1 .
0, a negative pressure suction hole 5 is bored at an eccentric position, and a second
A printing table for a screen printing machine, characterized in that a second lid body 9a is formed in the same shape as the concave part 10 and has a diameter slightly smaller than the diameter of the concave part 2, and is rotatably fitted therein. Negative pressure suction structure. 3. In a printing table of a screen printing machine that fixes a printing material to the surface thereof through a negative pressure suction hole, a circular recess 2 is provided on the surface of the printing table 1 and communicates with a negative pressure suction device through a ventilation hole 3. A plurality of lids are provided, and each of the recesses 2 is formed in the same shape as the recess 2 and has a slightly smaller diameter than the diameter of the recess 2, and a negative pressure suction hole 5 is bored at an eccentric position. The body 4 is rotatably fitted, and further,
A vertical plumb member 7 having a contact surface 7a having a diameter larger than the diameter of the ventilation hole 3 is placed in the accommodation portion 8 of the lid 4 so that the contact surface 7a faces the ventilation hole 3 during the rotation process of the lid 4. A negative pressure suction structure for a printing table in a screen printing machine, which is equipped with a vent opening/closing member that is fitted. 4 The vertical plumb member accommodating portion 8 of the lid body 4 is formed in a penetrating shape, and the ventilation hole 3 is formed in the contact surface 7a of the vertical plumb member 7.
4. A negative pressure suction structure for a printing table according to claim 3, further comprising a falling portion 7b having a diameter smaller than that of the falling portion 7b.