WO2013175639A1

WO2013175639A1 - Screen printer

Info

Publication number: WO2013175639A1
Application number: PCT/JP2012/063555
Authority: WO
Inventors: 前田　篤志; 小島　一夫
Original assignee: マイクロ・テック株式会社
Priority date: 2012-05-25
Filing date: 2012-05-25
Publication date: 2013-11-28
Also published as: CN103687728B; TWI566951B; CN103687728A; TW201348003A; KR101591612B1; KR20140041900A

Abstract

A compact screen printer, which enables a squeegee to follow a printing surface, is provided. The screen printer (100), which uses a squeegee (203) and a screen mask (201) to print, is provided with: an elongated frame (231) that moves the direction of printing; an elongated squeegee holder (203) that holds the squeegee; a pair of guide bushes (213), said guide bushes being fixed at either end of the frame (231) and vertically guiding the movement of the squeegee holder (204); and a pair of air cylinders (211), said air cylinders being fixed to the frame (231) at positions further to the inside than the pair of guide bushes (213), and vertically moving the squeegee holder (204).

Description

Screen printing machine

This invention relates to a screen printing machine. In particular, the present invention relates to a squeegee mechanism that can apply pressure evenly from a squeegee to a screen.

In the case of screen printing, it is desirable that the squeegee flexibly follows the printing surface of the screen and applies an even pressure to the screen.
For example, in a conventional screen printing machine, one air cylinder is provided at the center of the squeegee. A central portion of the squeegee is connected to one air cylinder so as to be relatively rotatable with a pin, and the squeegee is pressed against the screen. For this reason, the squeegee can be rotated during printing and can follow the printing surface of the screen.
Further, for example, in Patent Document 1 below, a technique is proposed in which pressure is applied to the left and right ends of a squeegee by two air cylinders so that the squeegee follows the printing surface.

Japanese Patent Laid-Open No. 5-193105

In the conventional screen printer, there is a problem that it is difficult to obtain an appropriate printing pressure of the squeegee. When the central portion of the squeegee is connected to one air cylinder so as to be relatively rotatable with a pin and the squeegee is pressed against the screen, it is difficult to obtain an appropriate printing pressure at both ends.
In the embodiment of the present invention, it is desired to provide a screen printer that obtains an appropriate printing pressure in the entire range including both ends of the squeegee.
Moreover, the screen printing machine by patent document 1 has the air cylinder and the guide cylinder arrange | positioned in the vertical direction, and the height of an apparatus becomes high.
In the embodiment of the present invention, it is desired to provide a small screen printing machine in which the squeegee can follow the printing surface.

The screen printer of the present invention is a screen printer that performs printing using a squeegee and a screen mask.
A longitudinal frame moving in the printing direction;
A longitudinal squeegee holder that holds the squeegee;
A pair of guide bushes fixed to both ends of the frame for guiding the vertical movement of the squeegee holder;
A pair of air cylinders that are fixed to the frame at positions inside the pair of guide bushes and that move the squeegee holder in the vertical direction are provided.

For the length WS in the longitudinal direction of the squeegee holder,
The distance WG between the pair of guide bushes is 80% or more and 95% or less of the length WS,
The distance WA between the pair of air cylinders is 50% to 75% of the length WS.

Each guide bush of the pair of guide bushes has a guide rod that slides up and down,
The squeegee holder has a receiver for attaching the lower end of the guide rod with a bolt,
The guide rod has a through hole at the lower end that penetrates in the printing direction.
The receiver is characterized in that the squeegee holder is rotatably attached around the bolt by inserting the bolt into the through hole.

Each air cylinder of the pair of air cylinders has a pressure rod that transmits pressure,
The screen printing machine further includes a joint that is fixed to the lower end of the pressure rod and the squeegee holder and provides a predetermined allowable eccentric amount and a predetermined swing angle with respect to the axial center of the pressure rod.

The through hole has a diameter D2 that is larger than the bolt diameter D1,
The difference in diameter S1 between the bolt diameter D1 and the through hole diameter D2 is that the squeegee holder rotates to the horizontal distance L1 between the center of the pair of bolts when the squeegee holder is arranged in the horizontal direction and the inclination angle α. In this case, the distance difference S2 is equal to or less than the distance L2 in the horizontal direction at the center of the pair of bolts.

The guide rod has a rod hole penetrating in the printing direction and an annular bush inserted into the rod hole,
Bush outer diameter = Rod hole inner diameter Bush inner diameter = Through hole diameter D2> Bolt diameter D1
It is characterized by being.

The screen printing machine has a pair of pins fixed to a pair of guide rods,
The squeegee holder has a pair of stoppers that come into contact with the pins when the squeegee holder rotates.

Each pin of the pair of pins is characterized in that the position of the tip of the pin can be adjusted so that the tip of the pin comes into contact with the stopper when the squeegee holder rotates by a restraining angle β with respect to the horizontal direction.

According to the present invention, since the air cylinder and the guide bush are arranged separately, a small screen printing machine in which the squeegee can follow the printing surface can be provided.

It is a figure of the position before the table movement of the screen printer 100 of this Embodiment 1. FIG. It is a figure of the table vertical movement completion position of the screen printer 100 of this Embodiment 1. FIG. FIG. 2 is a front view of the printing unit 200 in the left-right direction (Y direction) (AA cross-sectional view in FIG. 1). The top view which looked at the printing part 200 of FIG. 3 from the top. BB sectional drawing of the printing part 200 of FIG. FIG. 4 is an enlarged view of a tilt mechanism (K part) of the printing unit 200 of FIG. 3. CC sectional drawing of the inclination mechanism (K part) enlarged view of FIG. DD sectional drawing of the inclination mechanism (K section) enlarged view of FIG. The model explanatory drawing of an inclination mechanism. The figure which shows another example. The figure which shows another example. The figure which shows another example. The figure which shows another example. The figure which shows another example.

Embodiment 1 FIG.
1 and 2 are diagrams showing a screen printing machine 100 according to the first embodiment.
FIG. 1 is a diagram of a position before moving the table.
FIG. 2 is a diagram of the table vertical movement completion position.
In the figure, it is assumed that the left-right direction (X direction, horizontal direction), the up-down direction (Z direction, vertical direction), and the depth direction (Y direction, horizontal direction) orthogonal to the drawing are orthogonal.
The screen printing machine 100 includes a gantry 10 and a moving table 20.
Inside the gantry 10 is a drive mechanism 80 and a control unit 11. The control unit 11 controls the drive mechanism 80.
A vertical guide 12 stands upright on the top of the gantry 10. There is a vertical surface 13 on the moving table 20 side of the longitudinal guide 12.

The moving table 20 has a table lower part 30 and a table upper part 40.
A connection portion 31 is provided at the lower portion of the table lower portion 30, and the connection portion 31 is fixed to the driving timing belt 82.
Due to the rotation of the drive servo motor 81, the drive timing belt 82 moves to the left and right, and the table lower portion 30 slides in the lateral (left and right) direction via the connecting portion 31.

FIG. 1 shows a case where the movement table 20 is at the pre-movement position P1.
By the forward / reverse rotation of the drive servo motor 81, the moving table 20 can move in the lateral direction (forward / reverse direction) between the pre-movement position P1 and the lateral movement completion position P2.
On the upper portion of the table lower portion 30, there are a saw blade-shaped front saw blade portion 35 and a rear saw blade portion 36. Both the front saw blade part 35 and the rear saw blade part 36 have inclined surfaces (sliding surfaces) of a predetermined angle inclined forward.

The table upper part 40 has a jig plate 41, an alignment part 42, and a table skew part 43.
The jig plate 41 is a flat plate on which a workpiece 210 such as a printed board is placed.
The alignment unit 42 is an XYθ positioning mechanism that adjusts the XYθ direction of the jig plate 41.
The table skew section 43 is attached to the table lower portion 30 so as to be slidable in the tilt direction.
The table skew portion 43 has a roller 44 at a height position facing the vertical surface 13.
The roller 44 protrudes forward from the lower front surface 38 of the table lower portion 30.
The table skew part 43 has a front leg 45 and a rear leg 46.

The tilt slide mechanism 50 has a tilt linear motion slider 51 and a tilt rail 52 below the front leg 45 on the right side of the moving table 20. The tilt slide mechanism 50 includes a tilt linear motion slider 53 and a tilt rail 54 below the rear leg 46 on the left side of the moving table 20.

The tilting linear motion slider 51 and the tilting linear motion slider 53 are linear guides that are tilted and attached to the front leg 45 and the rear leg 46 below the table skew portion 43.
The inclined rail 52 and the inclined rail 54 are guide rails that are attached to the inclined surfaces of the front saw blade part 35 and the rear saw blade part 36 at the upper part of the table lower part 30.

The tilt positioning unit 60 has an upper stopper 61 and a lower stopper 62.
The upper stopper 61 is a stopper attached to the lower portion of the table skew portion 43 so as to be inclined obliquely downward to the right.
The lower stopper 62 is a stopper attached to the upper portion of the table lower portion 30 so as to be inclined obliquely upward to the left. The lower stopper 62 is fixed to the lower positioning surface 37 between the front saw blade part 35 and the rear saw blade part 36 of the table lower part 30.

The upper stopper 61 and the lower stopper 62 face each other, and are attached to the position where the table upper part 40 is to be positioned with respect to the table lower part 30 with high accuracy. The upper stopper 61 and the lower stopper 62 are made of steel that does not deform, so that distortion and positional deviation do not occur. Therefore, the table lower part 30 is accurately positioned with respect to the table upper part 40 by the stopper.

Either the upper stopper 61 or the lower stopper 62 has a screw mechanism, and the distance in the tilt direction between the table lower portion 30 and the table upper portion 40 can be accurately adjusted by adjusting the screwing amount of the screw. .

The lateral slide mechanism 70 includes a lateral movement linear motion slider 71 and a lateral rail 72.
The lateral movement linear slider 71 is a linear guide attached horizontally to the lower portion of the table lower portion 30.
The horizontal rail 72 is a guide rail attached horizontally to the upper part of the gantry 10.

The drive mechanism 80 includes a drive servo motor 81 and a drive timing belt 82.
The drive servo motor 81 is a digital servo motor that rotates by a predetermined angle in accordance with a pulse signal from the control unit 11.
The driving timing belt 82 fixes the connecting portion 31 at a predetermined position.

The pressure unit 90 includes a tension coil spring 91.
The tension coil spring 91 is a spring that spans the side surfaces of the table lower portion 30 and the table upper portion 40 and attracts the table lower portion 30 and the table upper portion 40 in an inclined direction.
The table lower portion 30 and the table upper portion 40 attracted by the tension coil spring 91 are positioned at a predetermined distance by the tilt positioning portion 60.

In addition, since the table upper part 40 slides in the tilting direction due to the weight of the table upper part 40, if the weight of the table upper part 40 is sufficiently large, the pressure unit 90 may not be provided.

The table skew section 43 has front legs 45 at both left and right ends. The rear legs 46 are also at the left and right ends. That is, the table upper part 40 is a table supported by four legs.

Also, the roller 44, the inclined slide mechanism 50, the lateral slide mechanism 70, and the pressurizing unit 90 are provided at the left and right ends.

Thus, since each part exists on the left and right, the horizontality of the jig plate 41 is reliably maintained.

The connecting portion 31 and the driving timing belt 82 may be one in the center, or may be on the left and right.

The vertical guide 12 is on the left and right. The interval between the two rollers 44 and the interval between the two vertical surfaces 13 are the same.

When the moving table 20 is positioned at the pre-movement position P1, the print space (work 210) such as a substrate is placed on the jig plate 41 using the space above the work space.

The printing unit 200 and the screen mask 201 are arranged above the horizontal movement completion position P2. The printing unit 200 has a housing 202. A squeegee 203 is attached to the inside of the housing 202 so as to be movable in the X direction and the Z direction.

As shown in FIG. 2, the screen mask 201 is disposed immediately above the vertical movement completion height Q2 of the jig plate 41. That is, the screen mask 201 is disposed at a position where printing can be performed with the jig plate 41 positioned at the vertical movement completion height Q2.

The general operation of the positioning control of the control unit 11 is as follows.
1. At the pre-movement position P1, the entire table is positioned and stopped by the motor.
2. By driving the motor, the entire table moves to the right, and the entire table is positioned and stopped at the lateral movement completion position P2 immediately before the roller 44 hits the vertical surface 13 (roller guide).
3. Further, when the table lower part 30 is moved from the lateral movement completion position P2 to the right by the motor drive to the vertical movement completion position P3, the roller 44 is restrained from lateral movement by the vertical surface 13 (roller guide). The portion 43 moves upward from the height Q1 before the vertical movement to the height Q2 of the vertical movement completion.
4). When the motor drive is stopped, the table skew section 43 stops positioning at the designated vertical movement completion height Q2.
5. The return stroke operates in the reverse order.

When the jig plate 41 of the moving table 20 is positioned at the horizontal movement completion position P2 and the vertical movement completion height Q2, screen printing can be performed by the squeegee 203 on the workpiece 210 via the screen mask 201. it can.

<<< Structure of Printing Unit 200 >>>
The structure of the printing unit 200 of the screen printer 100 will be described with reference to FIGS.
FIG. 3 is a front view of the printing unit 200 in the left-right direction (Y direction).
3 is a view as seen from the direction AA in FIG. 1, and a portion J in FIG. 3 is a cross-sectional view.
FIG. 4 is a plan view of the printing unit 200 of FIG. 3 as viewed from above.
FIG. 5 is a BB cross-sectional view of FIG.

As shown in FIG. 4, the printing unit 200 includes a squeegee mechanism 230 and a scraper mechanism 240.
Both the squeegee mechanism 230 and the scraper mechanism 240 are fixed to a pair of sliders 205 on the left and right.
The pair of sliders 205 are attached to the casing 202 of the printing unit 200 so as to be movable in the front-rear direction (X direction).

As shown in FIG. 4, the squeegee mechanism 230 has a pair of air cylinders 211. The scraper mechanism 240 has one air cylinder 291.
The squeegee mechanism 230 has a pair of guide bushes 213.
The scraper mechanism 240 has a pair of guide bushes 293.

Hereinafter, the squeegee mechanism 230 will be described.
The squeegee mechanism 230 has the following parts.
1. Frame 231
2. Squeegee holder 204
3. Squeegee 203
4.1 Pair of air cylinders 211
5.1 A pair of guide bushings 213
6). Tilting mechanism K part (connection structure in FIG. 3)

The squeegee mechanism 230 has a long plate-like frame 231 on the left and right.
A pair of air cylinders 211 are fixed on the left and right sides of the frame 231.
A pair of guide bushes 213 are fixed to the left and right ends of the frame 231.
The pair of air cylinders 211 is inside the pair of guide bushes 213.
In the Y direction, each air cylinder 211 is fixed next to each guide bush 213.
Each air cylinder 211 and each guide bush 213 are connected to the squeegee holder 204. For this reason, each air cylinder 211 and each guide bush 213 exist within the range of the longitudinal length WS of the squeegee holder 204 (hereinafter also referred to as the squeegee length WS).

The air cylinder 211 has a pressure rod 212 penetrating in the vertical direction (Z direction).
The lower end of the pressure rod 212 is fixed to the joint 226.
The joint 226 is fixed to the squeegee holder 204.
The pressure rod 212 is actively moved up and down by the air pressure supplied to the air cylinder 211.
As the pressure rod 212 moves up and down, the squeegee holder 204 and the squeegee 203 move up and down.
By adjusting the air pressure, the squeegee holder 204 can be moved up and down and the printing pressure during printing can be adjusted.

The guide bush 213 has a guide rod 214 that penetrates in the vertical direction (Z direction).
A squeegee holder 204 is attached to the lower end of the guide rod 214.
The guide rod 214 moves up and down passively as the squeegee holder 204 moves up and down.
The guide bush 213 guides the movement of the squeegee holder 204 only in the vertical direction (Z direction).
The guide bush 213 prohibits the squeegee holder 204 from shifting forward, backward, left and right (X direction, Y direction) and allows the squeegee holder 204 to move only in the vertical direction (Z direction).
Note that the squeegee holder 204 is allowed to slightly rotate in the YZ plane by the tilt mechanism provided at the lower end of the guide rod 214. The tilt mechanism will be described later.

A squeegee 203 is fixed under the squeegee holder 204.
The squeegee holder 204 and the squeegee 203 are firmly fixed at both ends in the Y direction.
A screen mask 201 is disposed below the squeegee 203.
A work 210 placed on the moving table 20 is arranged under the screen mask 201.

The air cylinder 211 lowers the squeegee 203 and applies pressure to the screen mask 201 by the squeegee 203. When the slider 205 slides in the front-rear direction, ink (not shown) on the screen mask 201 is pushed out from the screen mask 201 to the work 210, and the pattern of the screen mask 201 is printed on the work 210.

<<< Position of Air Cylinder 211 and Guide Bush 213 >>>
The center of the pair of air cylinders 211 and the center of the pair of guide bushes 213 coincide with the center of the squeegee 203, respectively.
That is, the pair of air cylinders 211 and the pair of guide bushes 213 are symmetrically positioned around the center of the squeegee holder 204 in the Y direction. The parts at the symmetrical positions described below are the same on the left and right, and constitute a pair of parts on the left and right.
The length in the longitudinal direction of the squeegee 203 (squeegee holder 204) is defined as a length WS.
In FIG. 3, the distance WG between the center lines of the pair of guide bushes 213 is 81% of the length WS. The distance WA between the center lines of the pair of air cylinders 211 is 63% of the length WS.
In order to guide the squeegee at both ends as much as possible, the distance WG between the guide bushes 213 is preferably 80% or more and 95% or less of the length WS.
In order to transmit the printing pressure uniformly over the entire length WS, the interval WA between the air cylinders 211 is preferably 50% or more and 75% or less of the length WS.

<<< Connecting structure of frame 231 and squeegee holder 204 >>>
Even when the screen mask 201 and the workpiece 210 do not present a complete horizontal plane, the squeegee 203 needs to follow the surface of the screen mask 201 and apply a uniform printing pressure to the surface of the screen mask 201.
For this purpose, a structure is required in which the squeegee 203 can tilt to the left and right as the slider 205 slides in the front-rear direction.
Hereinafter, a connection structure that allows the squeegee 203, that is, the squeegee holder 204, to tilt at a predetermined angle with respect to the horizontal direction during printing will be described.

A connection structure of the air cylinder 211, the guide bushing 213, and the squeegee holder 204 will be described with reference to FIGS.
Since the connection structure is bilaterally symmetric, the left side connection structure (inclination mechanism K in FIG. 3) will be described below.
K section is a connecting mechanism and an inclination mechanism.

FIG. 6 is an enlarged view of a portion K in FIG.
FIG. 7 is a CC cross-sectional view of the tilt mechanism of FIG.
FIG. 8 is a DD cross-sectional view of the tilt mechanism of FIG.
FIG. 9 is an explanatory diagram of the tilting principle of the tilting mechanism.

<<< Tilt allowable structure 1 >>>
The frame 231 fixes the guide bush 213.
A cylindrical guide rod 214 passes through the center of the guide bush 213.

As shown in FIG. 8, a prismatic inserter 221 is integrally formed at the lower end of the guide rod 214 by machining. The inserter 221 is a portion in which at least two parallel planes are formed by processing the lower end of the cylindrical guide rod 214.
A cylindrical rod hole 229 is formed in the front-rear direction of two parallel planes of the inserter 221.
The rod hole 229 is orthogonal to two parallel planes and penetrates the inserter 221 horizontally.
A pair of bushes 225 are fitted into the rod hole 229 from both sides.
The bush 225 has an earthen pipe shape, and has an annular flange 281 and a cylindrical body 282. The outer diameter of the body portion 282 is equal to the inner diameter of the rod hole 229.
A through hole 222 is formed by the pair of bushes 225.
The through hole 222 penetrates the inserter 221 horizontally in the front-rear direction.

A receiver 218 is fixed to the upper part of the squeegee holder 204 with screws 223. The receiver 218 has a front wall 251 and a rear wall 252.
Between the front wall 251 and the rear wall 252, there is a concave groove 224 into which the inserter 221 is inserted.
The distance between the front wall 251 and the rear wall 252 (the width of the concave groove 224 in the front-rear direction) is larger than the thickness of the inserter 221 in the front-rear direction.
There is a space in the left-right direction of the inserter 221 attached to the concave groove 224.
There is a gap 299 between the bottom surface of the inserter 221 and the top surface of the squeegee holder 204.

A hole 219 is formed in each of the front wall 251 and the rear wall 252 in the front-rear direction.
The hole 219 penetrates the front wall 251 and the rear wall 252 horizontally.

The inserter 221 is inserted into the concave groove 224 after the pair of bushes 225 are fitted into the rod hole 229 and attached to the receiver 218 with the bolt 220.
The bolt 220 is inserted into the hole 219 and the through hole 222 from the front to the rear.
Thus, the squeegee holder 204 can rotate on the YZ plane with the bolt 220 (the center of the bolt 220) as an axis.
That is, the squeegee holder 204 can be tilted with respect to the horizontal direction.
Further, a space is provided in the left and right direction and the lower part of the inserter 221 so as not to prevent the inclination of the squeegee holder 204.

The flange portion 281 of the bush 225 is fitted between the rear surface of the front wall 251 (the front surface of the concave groove 224) and the front surface of the inserter 221.
The flange 281 of the bush 225 is fitted between the front surface of the rear wall 252 (the rear surface of the recessed groove 224) and the rear surface of the inserter 221.
Since the flange portion 281 is provided between the front wall 251 and the inserter 221 and between the rear wall 252 and the inserter 221, the inserter 221 is easily rotated with respect to the receiver 218.
Note that there are no gaps in the front-rear direction among the inserter 221, the recessed groove 224, and the flange 181.
Therefore, the squeegee holder 204 does not tilt in the X direction.

As shown in FIG. 9, the horizontal interval WG of the center line of the pair of bolts 220 is L1.
When the squeegee holder 204 is horizontal, the distance between the guide rods 214 and the distance between the bolts 220 are both equal to the distance L1.
When the squeegee holder 204 is inclined by the inclination angle α degrees, the horizontal interval L2 of the bolts 220 becomes smaller than the interval L1. That is, the connection point J between the squeegee holder 204 and the pressure rod 212 is shifted in the center direction.
Here, an interval difference between the horizontal interval L1 and the inclined interval L2 is S1.
Interval L1−Interval L2 = Interval difference S1
The tilt mechanism needs to absorb this gap difference S1.
Here, if it is assumed that the inclination angle α is very small and is an inclination close to 0 degrees, the inclination mechanism only needs to have a structure that absorbs the interval difference S1 in the horizontal direction.

Therefore, the diameter (inner diameter) D1 of the through hole 222 is made larger than the diameter (outer diameter) D2 of the bolt 220.
The diameter difference between the diameter D1 of the through hole 222 and the diameter D2 of the bolt 220 is S2, and the radius difference is T2.
Diameter D1-Diameter D2 = Diameter difference S2
Radius R1-Radius R2 = Radius difference T2 = Diameter difference S2 / 2
When the squeegee holder 204 is horizontal, it is assumed that the bolt 220 is located at the center of the through hole 222.
The bolt 220 can move in the through hole 222 in the horizontal direction by a half of the diameter difference S2 (by the radius difference T2).
Since the gap difference S1 is absorbed by half on one side, if the diameter difference S2 is made equal to the gap difference S1, the gap difference S1 can be absorbed on both right and left sides.
Diameter difference S2 = Distance difference S1 = Radial difference T2 × 2
In other words, the distance difference S1 cannot increase beyond the diameter difference S2, and the maximum value of the inclination angle α can be set by the diameter difference S2.

The diameter difference S2 (radius difference T2) can be changed by the thickness of the body 282 of the bush 225. That is, by exchanging the bush 225, the maximum value of the inclination angle α can be set.

The above relationship is summarized as follows.
Outer diameter of body portion 282 = Inner diameter of rod hole 229 Inner diameter of body portion 282 = Diameter of through hole 222> Outer diameter of bolt 220 Diameter of through hole 222-Outer diameter of bolt 220 = Diameter difference S2

<<< Tilt tolerance structure 2 >>>
A joint 226 is used to connect the pressure rod 212 and the squeegee holder 204.
The joint 226 is disposed at substantially the same height as the bolt 220 in the horizontal direction.
The lower end of the pressure rod 212 is fixed to the socket 227 at the top of the joint 226.
The stud 228 at the lower part of the joint 226 is fixed by being screwed into the squeegee holder 204.
The joint 226 has a built-in mechanism for absorbing axial misalignment between the socket 227 and the stud 228.
The joint 226 incorporates a mechanism that absorbs insufficient accuracy of parallelism between the socket 227 and the stud 228.
The joint 226 has an allowable eccentricity of Umm with respect to the axial center of the pressure rod 212, and has a swing angle of V degrees (Rotating angle).
For example, it is preferable to use a floating joint JA20-8-125 manufactured by SMC Corporation (SMC Corporation Akibahara UDX15F, 4-14-1, Sotokanda, Chiyoda-ku, Tokyo 101-0021, JAPAN).
The floating joint JA20-8-125 has an allowable eccentricity of 0.5 mm, and a swing angle of + -5 degrees (Rotating angle).

As shown in FIG. 9, the position of the connecting point J between the squeegee holder 204 and the pressure rod 212 is shifted toward the center due to the inclination of the squeegee holder 204 in the YZ plane.
However, if the displacement in the horizontal direction is within the allowable eccentricity of the two joints 226, the displacement of the connecting point J in the left-right direction can be absorbed.
That is, the following relationship is established.
Allowable eccentricity Umm × 2 <Spacing difference S1
Allowable eccentricity Umm <Spacing difference S1 / 2
As a result, the pressure rod 212 can accurately transmit the printing pressure to the squeegee holder 204 even when a deviation in the Y direction occurs between the axis of the stud of the joint 226 and the axis of the pressure rod 212.

Further, as shown in FIG. 9, the pressure rod 212 and the stud 228 do not become straight due to the inclination of the squeegee holder 204 in the YZ plane. That is, the pressure rod 212 and the stud 228 are not parallel.
The inclination of the stud 228 with respect to the pressure rod 212 can be absorbed by a swinging angle (rotating angle) of V degrees.
When the squeegee holder 204 is inclined by the inclination angle α, the inclination of the stud 228 with respect to the pressure rod 212 is also the inclination angle α, and therefore the inclination angle α may be within the swinging angle (Rotating angle).
That is, the following relationship is established.
Inclination angle α <Rotating angle V degree

As a result, even when the axis of the stud of the joint 226 and the axis of the pressure rod 212 are not parallel, the pressure rod 212 can accurately transmit the printing pressure to the squeegee holder 204.

<<< Inclination suppression structure >>>
Although the squeegee holder 204 can be rotated by the

tilt allowance structures

1 and 2 described above, if it is allowed without limitation, breakage and distortion are not preferable.
Hereinafter, the inclination suppression structure of the squeegee holder 204 will be described.

As shown in FIG. 6, an arm 215 protruding in the horizontal direction is fixed to the lower portion of the guide rod 214.
The arm 215 protrudes toward the center of the squeegee mechanism 230.
As shown in FIG. 7, the arm 215 is bent in an L shape, and a pin 216 protrudes downward from the end of the arm 215.
The pin 216 is disposed between the pressure rod 212 and the guide rod 214.
Since the pin 216 is on the center side of the guide rod 214, the guide rod 214 can be fixed close to both the left and right ends.
The length of the pin 216 protruding downward can be adjusted by a screw structure.

A squeegee holder 204 is provided with a stopper 217 corresponding to the pin 216.
The pin 216 and the stopper 217 are disposed at substantially the same height as the joint 226 and the bolt 220 in the horizontal direction.
When the squeegee holder 204 is horizontal, a minute gap I is provided between the pin 216 and the stopper 217.
The interval of the gap I can be adjusted by the screwing amount of the pin 216.
When the squeegee holder 204 is tilted by a predetermined restraining angle β, the stopper 217 hits the pin 216 and prohibits the squeegee holder 204 from tilting further.
For example, the left stopper 217 prohibits the right side of the squeegee holder 204 from being raised by a predetermined suppression angle β or more. The right stopper 217 prohibits the left side of the squeegee holder 204 from moving up by a predetermined suppression angle β or more.
This suppression angle β is less than the tilt angle α allowed by the tilt allowance structure No. 1 and less than the swing angle (V degrees) allowed by the tilt allowance structure No. 2.
Suppression angle β <Inclination angle α
Suppression angle β <oscillation angle V degrees

As described above, the maximum value of the inclination angle α can be set by the diameter difference S2, but the regulation of the inclination angle by the gap I between the pin 216 and the stopper 217 is more accurate than the regulation of the inclination angle α by the diameter difference S2. Regulation becomes possible.
The longer the arm 215 extends in parallel with the squeegee holder 204, the more accurate the tilt angle is regulated. Therefore, the position of the pin 216 is preferably closer to the joint 226 than the bolt 220. That is, the position of the pin 216 is preferably closer to the pressure rod 212 than the guide rod 214.

Since the size of the gap I between the pin 216 and the stopper 217 can be arbitrarily changed by the screw structure of the pin 216, the maximum value of the inclination angle can be changed according to the state of the screen mask 201 and the workpiece 210.

<<< Description of Printing Method (Printing Operation) >>>
The screen printer 100 operates as follows during printing.
The longitudinal frame 231 moves in the printing direction (X direction).
A longitudinal squeegee holder 204 holds the squeegee 203.
The pair of guide bushes 213 are fixed to both ends of the frame 231 and guide the movement of the squeegee holder 204 in the vertical direction (Z direction).
The pair of air cylinders 211 is fixed to the frame 231 at a position inside the pair of guide bushes 213, and moves the squeegee holder 204 in the vertical direction.

During printing, when a force is applied to the squeegee 203 in a vertical direction from other than the pair of air cylinders 211, the squeegee 203 tilts.
At that time, the receiver 218 of the squeegee holder 204 rotates by an inclination angle α with respect to the Y direction with the bolt 220 as the central axis.

At the same time, the joint 226 absorbs the amount of eccentricity depending on the inclination angle α with respect to the axial center of the pressure rod 212.
At the same time, the joint 226 absorbs the inclination (inclination angle α) of the joint 226 in the Y direction with respect to the axis of the pressure rod 212.
The joint 226 accurately transmits the printing pressure of the pair of guide bushes 213 while absorbing the amount of eccentricity and absorbing the inclination during printing.
The inclination angle α changes in real time during printing.
The tilt mechanism permits the rotation of the squeegee holder 204 following the change in the tilt angle α in real time.

When the inclination angle α becomes the suppression angle β, one of the pair of pins and one of the pair of stoppers come into contact with each other, and the inclination beyond the suppression angle β is prohibited.

<<<< Various Modifications >>>>
Hereinafter, various modifications will be described with respect to differences from the above-described portions.
You may combine multiple examples below.

Example 1.
The screen printing machine may have a structure other than that shown in FIGS.
For example, the screen printer may have separate drive mechanisms for left and right movement and vertical movement.

Example 2.
The number of air cylinders 211 and guide bushes 213 is not limited to two, and may be three or more.
For example, when the squeegee 203 is very long in the Y direction, it is preferable to arrange three air cylinders 211 and guide bushes 213 at the center and the left and right. Or it is good to arrange the air cylinder 211 and the guide bushing 213 at four and equidistantly.
The number of air cylinders 211 and guide bushes 213 may be plural, and the number may be different.

Example 3
It is preferable to arrange the pair of air cylinders 211 inside the pair of guide bushes 213. However, the arrangement of the air cylinder 211 and the guide bushing 213 is reversed and the pair of air cylinders 211 is replaced with the pair of guide bushes 213. You may arrange | position outside.
That is, the air cylinder 211 and the guide bush 213 may be disposed side by side, and the pressure rod 212 and the guide rod 214 may be disposed in parallel.

Example 4
Although the arm 215 is attached to the center side of the guide rod 214, the arm 215 may be attached to the end side of the guide rod 214 as shown in FIG. That is, the pair of arms 215 may be attached to the outside of the pair of guide rods 214.
In addition, as shown in FIG. 11, arms 215 may be attached to both sides of only one guide rod 214 of a pair of guide rods 214.

Example 5.
As shown in FIG. 12, the pin 216 and the stopper 217 may be arranged in the opposite directions, the pin 216 may be provided on the squeegee holder 204, and the stopper 217 may be provided on the arm 215.

Example 6
As shown in FIG. 13, instead of attaching the arm 215 to the guide rod 214, the arm 215 may be fixed to the frame 231 and the pin 21 may be fixed to the frame 231.

Example 7.
As shown in FIG. 14, the bush 225 may not be provided. When there is no bush 225, the rod hole 229 becomes the through hole 222.
When the bush 225 is not provided, the width in the front-rear direction of the inserter 221 and the interval between the concave grooves 224 are made equal.
The rear surface of the front wall 251 (the front surface of the groove 224) and the front surface of the inserter 221 are in contact with each other on a plane.
The front surface of the rear wall 252 (the rear surface of the recessed groove 224) and the rear surface of the inserter 221 are in contact with each other on a plane.
There is no gap in the front-rear direction between the inserter 221 and the recessed groove 224.
Therefore, the squeegee holder 204 does not tilt in the X direction.

Example 8
The scraper mechanism 240 may be provided with a tilt mechanism similar to the squeegee mechanism 230.

10 frame, 11 control unit, 12 vertical guide, 13 vertical surface, 20 moving table, 30 table lower part, 31 connecting unit, 35 front saw blade part, 36 rear saw blade part, 37 lower positioning surface, 38 lower front surface, 40 Table top, 41 jig plate, 42 alignment section, 43 table skew section, 44 rollers, 45 front legs, 46 rear legs, 50 tilt slide mechanism, 51 tilt linear slider, 52 tilt rail, 53 tilt linear motion Slider, 54 tilt rail, 60 tilt positioning part, 61 upper stopper, 62 lower stopper, 70 lateral slide mechanism, 71 lateral movement linear slider, 72 lateral rail, 80 drive mechanism, 81 drive servo motor, 82 drive timing Belt, 90 pressurizing part, 91 tension coil spring, 100 Screen printer, 200 printing unit, 201 screen mask, 202 housing, 203 squeegee, 204 squeegee holder, 205 slider, 210 work, 211 air cylinder, 212 pressure rod, 213 guide bush, 214 guide rod, 215 arm, 216 pin, 217 stopper, 218 receiver, 219 hole, 220 bolt, 221 inserter, 222 through hole, 223 screw, 224 groove, 225 bush, 226 joint, 227 socket, 228 stud, 229 rod hole, 230 squeegee mechanism, 231 frame, 240 Scraper mechanism, 251 front wall, 252 rear wall, 281 buttocks, 282 trunk, 291 air cylinder, 293 guy Bush, 299 gap, L horizontal moving distance, H vertical movement distance, P1 pre-movement position, P2 lateral movement completion position, P3 vertical movement completion position, Q1 longitudinal movement before height, Q2 vertical movement completion height.

Claims

In a screen printing machine that prints using a squeegee and a screen mask,
A longitudinal frame moving in the printing direction;
A longitudinal squeegee holder that holds the squeegee;
A pair of guide bushes fixed to both ends of the frame for guiding the vertical movement of the squeegee holder;
A screen printing machine, comprising: a pair of air cylinders fixed to the frame at a position inside the pair of guide bushes and moving the squeegee holder in the vertical direction.
For the length WS in the longitudinal direction of the squeegee holder,
The distance WG between the pair of guide bushes is 80% or more and 95% or less of the length WS,
The screen printing machine according to claim 1, wherein the distance WA between the pair of air cylinders is 50% or more and 75% or less of the length WS.
Each guide bush of the pair of guide bushes has a guide rod that slides up and down,
The squeegee holder has a receiver for attaching the lower end of the guide rod with a bolt,
The guide rod has a through hole at the lower end that penetrates in the printing direction.
3. The screen printing machine according to claim 2, wherein the receiver has a squeegee holder rotatably mounted around the bolt by inserting the bolt into the through hole.
Each air cylinder of the pair of air cylinders has a pressure rod that transmits pressure,
The screen printing machine further includes a joint that is fixed to the lower end of the pressure rod and the squeegee holder and provides a predetermined allowable eccentric amount and a predetermined swing angle with respect to the axial center of the pressure rod. Item 4. A screen printer according to item 3.
The through hole has a diameter D2 that is larger than the bolt diameter D1,
The difference in diameter S1 between the bolt diameter D1 and the through hole diameter D2 is that the squeegee holder rotates to the horizontal distance L1 between the center of the pair of bolts when the squeegee holder is arranged in the horizontal direction and the inclination angle α. 5. The screen printing machine according to claim 4, wherein the distance between the center of the pair of bolts and the distance L2 in the horizontal direction is not more than S2.
The guide rod has a rod hole penetrating in the printing direction and an annular bush inserted into the rod hole,
Bush outer diameter = Rod hole inner diameter Bush inner diameter = Through hole diameter D2> Bolt diameter D1
The screen printing machine according to claim 5, wherein:
The screen printing machine has a pair of pins fixed to a pair of guide rods,
7. The screen printing machine according to claim 1, wherein the squeegee holder has a pair of stoppers that come into contact with the pins when the squeegee holder rotates.
Each pin of the pair of pins is adjustable in position so that the tip of the pin comes into contact with the stopper when the squeegee holder is rotated by a restraining angle β with respect to the horizontal direction. 8. A screen printing machine according to item 7.