WO2020162469A1

WO2020162469A1 - Curved surface screen printing device and curved surface screen printing method

Info

Publication number: WO2020162469A1
Application number: PCT/JP2020/004194
Authority: WO
Inventors: 啓佑松田; 優貴立山
Original assignee: Ａｇｃ株式会社
Priority date: 2019-02-07
Filing date: 2020-02-04
Publication date: 2020-08-13
Also published as: JP7456390B2; JPWO2020162469A1; CN113557141B; CN113557141A

Abstract

This curved surface screen printing device (1) is provided with a pedestal (2), a screen plate (3), a squeegee (4), and a printing control unit configured so as to perform printing on a base material (G) by having the pedestal (2) rotate about a rotating shaft (24) and having the pedestal (2), the screen plate (3), and the squeegee (4) move in a relative manner with respect to an orthogonal direction of the rotating shaft (24). The printing control unit is provided with a rotational angle control unit (63) configured so as to apply a force for causing the pedestal (2) to rotate to one side of the orthogonal direction that is horizontal to the rotating shaft (24) of the pedestal (2), and a load control unit (64) configured so as to apply a force for causing the pedestal (2) to rotate to the other side of the orthogonal direction that is horizontal to the rotating shaft (24). The rotational angle control unit (63) is provided with a rotational force application mechanism where a backlash is present between intermeshed constituent elements. The load control unit (64) is configured so as to have loaded, about the rotating shaft (24), a moment that is greater than the moment about the rotating shaft (24) that is produced by a printing pressure of the squeegee (4).

Description

Curved screen printing device and curved screen printing method

The present invention relates to a curved screen printing device and a curved screen printing method.

Conventionally, there is known a curved surface screen printing apparatus that prints on a base material having a curved surface (see, for example, Patent Document 1).
The curved screen printing apparatus of Patent Document 1 moves the pedestal holding the base material, the screen plate, and the squeegee relatively in the printing direction, and rotates the pedestal around a rotation axis orthogonal to the printing direction. Print the material.

The curved screen printing apparatus of Patent Document 1 includes a substrate moving mechanism that rotates a pedestal while moving it horizontally.
The base material moving mechanism of the first embodiment includes a ball screw mechanism driven by a horizontal drive motor, and a horizontal moving base that moves in the horizontal direction by driving the ball screw mechanism. The horizontal moving table is provided with a vertical moving table that moves in the vertical direction by driving a vertical drive motor. The vertical moving table is provided with a rocking table that is driven by a rocking drive motor to rotate about a rotation axis orthogonal to the printing direction. The rocking table is formed in an L shape. A pedestal is attached to the protruding portion protruding from the upper portion of the rocking base.
Then, at the time of printing, the pedestal is moved in the horizontal and vertical directions by the drive of the horizontal drive motor and the vertical drive motor, and is rotated by the drive of the swing drive motor.

The base material moving mechanism of the second embodiment includes a substrate that moves in the horizontal direction by driving an actuator. A pair of linear guides extending in the vertical direction are fixed to the substrate. A drive member is fixed to the lower ends of the shafts fitted into the pair of linear guides. A pedestal holder having cam grooves of the same shape formed on the front and rear surfaces is fixed to the lower portion of the drive member. The cam groove is bent into a shape substantially the same as the printed surface of the base material. A pair of cam followers, which are fixed to a movable base that moves up and down by the drive of an up-and-down drive mechanism and horizontally arranged on the left and right sides, are fitted in the respective cam grooves from the front and rear surfaces.
The drive member and the pedestal holder are connected by two chains that cross and bridge between them. The first chain connects one end of the drive member in the movement direction and the other end of the pedestal holder in the movement direction, and the second chain connects the other end of the drive member in the movement direction to the pedestal holder. One end of the moving direction is connected to the other end.
The pedestal is attached to the pedestal holder with a pair of arms extending forward.
Then, at the time of printing, when the driving member moves in accordance with the driving of the actuator, the pedestal is pulled by the chain and moves in the horizontal direction while rotating along the shape of the cam groove.

International Publication No. 2017/086197

However, in the configuration of the first embodiment of Patent Document 1, although not described in Patent Document 1, if the pedestal is directly fixed to the swing drive motor, there is a risk that the torque for rotating the pedestal will be insufficient. It is considered that the pedestal is attached to the swing drive motor via the reduction gear. In a speed reducer composed of a plurality of gears, a gap called backlash is provided at a meshing portion of a gear tooth of one gear and a gear tooth of another gear.

In such a configuration, for example, when the base material is rotated to the right when viewed from one end side of the rotation axis of the pedestal, the printing pressure of the squeegee is applied when printing is performed on the right side of the rotation axis of the base material. Because the force to rotate the base material to the right acts on the surface of the driven gear that is directly fixed to the pedestal in the rotation direction front surface of the driven gear tooth and the rotation direction of the drive gear tooth of the drive gear that rotates the driven gear. Contact with the rear surface. After that, when printing is performed on the left side of the rotation axis of the base material, a force that rotates the base material to the left by the printing pressure of the squeegee acts, so that the surface on the front side in the rotation direction of the driven gear tooth and the drive gear tooth are The surface on the rear side in the rotational direction is separated, and this time, the surface on the rear side in the rotational direction of the driven gear tooth and the surface on the front side in the rotational direction of the drive gear tooth come into contact with each other.
When the contact surface between the driven gear tooth and the drive gear tooth changes in this way, backlash exists in the meshing portion of these gear teeth, so that a period in which the two do not contact occurs. In the period in which the two do not contact with each other, the pedestal does not rotate due to the meshing of the gear teeth, so there is a possibility that the pedestal rotates at a speed different from the set speed. As a result, printing may be displaced in the rotation direction of the base.

In the configuration of the second embodiment of Patent Document 1, since the pedestal holder is pulled by the chain connected to the drive member, if the chain becomes loose due to long-term use, the drive member moves to start moving the pedestal. However, there is a possibility that a period during which the pedestal holder does not move may occur. As a result, printing may be displaced in the rotation direction of the base.

An object of the present invention is to provide a curved surface screen printing apparatus and a curved surface screen printing method capable of suppressing the displacement of the printing base in the rotation direction.

A curved screen printing apparatus according to an aspect of the present invention is a curved screen printing apparatus that prints a predetermined pattern on a plate-shaped base material having a curved surface, the base having a holding surface that holds the base material, and a screen plate. A squeegee configured to apply ink to the base material held on the pedestal through the screen plate, and the pedestal around a rotation shaft located on the opposite side of the holding surface of the pedestal And a print control unit configured to print the base material by relatively moving the pedestal, the screen plate, and the squeegee in a direction orthogonal to the rotation axis. The unit includes a rotation angle control unit configured to apply a force for rotating the pedestal to one side of the rotation axis in a horizontal orthogonal direction, or a rotation angle control unit configured to apply a force to rotate the pedestal in a horizontal orthogonal direction. On the other side, a load control unit configured to apply a force for rotating the pedestal is provided, and the rotation angle control unit is provided with a rotational force application mechanism in which a backlash exists between components that mesh with each other. The load control unit is configured to load a moment about the rotation axis that is larger than a moment about the rotation axis generated by the printing pressure of the squeegee.

According to this aspect, when performing printing on the base material while rotating the pedestal, the rotational force imparting mechanism imparts a force for rotating the pedestal to one side of the pedestal in a direction orthogonal to the rotational axis or the rotational axis, A moment larger than the moment about the rotation axis generated by the printing pressure of the squeegee is applied to the other side in the direction orthogonal to the rotation axis about the rotation axis. With such a configuration, the contact state of the intermeshing components of the rotational force imparting mechanism remains constant and does not change. In addition, since the rotational force applying mechanism is composed of a plurality of constituent elements that are engaged with each other, slack unlike a chain does not occur. As a result, the pedestal rotates at the same speed as the set speed, and deviation of the printing pedestal in the rotation direction is suppressed.

In the curved screen printing apparatus, it is preferable that the rotational force applying mechanism is a ball screw that applies a force to the one side of the opposite surface by the relative movement of the screw shaft, the nut, and the ball.
In this aspect, it is possible to suppress the deviation of the printing base in the rotation direction by a simple method using only an easily available ball screw. The feed or rotation accuracy can be controlled more precisely than the gear mechanism or the rack and pinion mechanism.

In the curved screen printing apparatus, it is preferable that the load control unit includes a pneumatic cylinder, a hydraulic cylinder, or a weight.
In this aspect, it is possible to suppress the displacement of the printing base in the rotation direction by a simple method using only pneumatic or hydraulic cylinders or weights that are easily available.

In the curved screen printing apparatus, it is preferable that the print control unit includes a rotary shaft holding unit configured to hold both end sides of the rotary shaft.
In this aspect, the pedestal can be prevented from tilting during printing, and the printing accuracy is improved.

A curved screen printing method according to one aspect of the present invention is a curved screen printing method for printing a predetermined pattern on a plate-shaped base material having a curved surface, and a pedestal having a holding surface for holding the base material, and a screen plate. And, using a squeegee, while rotating the pedestal around a rotation axis located on the side opposite to the holding surface of the pedestal, the pedestal, the screen plate and the squeegee in a direction orthogonal to the rotation axis. When the base material is printed by moving the base material relative to each other, there is a backlash between the components that mesh with each other, a rotating force imparting mechanism, one side in the horizontal orthogonal direction of the rotating shaft, or the rotating shaft. A force to rotate the pedestal, and a moment larger than the moment about the rotation axis generated by the printing pressure of the squeegee is applied to the other side of the rotation axis on the other side in the horizontal orthogonal direction. While rotating the pedestal.

FIG. 1 is a schematic diagram of a curved screen printing apparatus according to the first embodiment of the present invention. FIG. 2 is a side view of a pedestal moving mechanism that constitutes the curved screen printing apparatus. FIG. 3 is a front view of the pedestal moving mechanism. FIG. 4 is a sectional view showing a part of a ball screw which constitutes the pedestal moving mechanism. FIG. 5A is an operation explanatory diagram of a curved screen printing method using the curved screen printing apparatus. FIG. 5B is an operation explanatory diagram of a curved screen printing method using the curved screen printing apparatus. FIG. 5C is an operation explanatory diagram of a curved screen printing method using the curved screen printing apparatus. FIG. 6 is a side view showing an operating state of the pedestal moving mechanism in the curved screen printing method. FIG. 7 is a side view showing an operating state of the ball screw in the curved screen printing method. FIG. 8 is a side view of a pedestal moving mechanism that constitutes the curved screen printing apparatus according to the second embodiment of the present invention. FIG. 9 is a front view of the pedestal moving mechanism.

[First Embodiment]
Hereinafter, the first embodiment of the present invention will be described. When describing the arrangement position of each component, the directions are defined with reference to the XYZ axes in FIG. 1, and the +X direction is the right, the −X direction is the left, the +Y direction is the front, the −Y direction is the rear, and the +Z direction. Is expressed as up and the −Z direction is expressed as down.

[Structure of curved screen printing device]
As shown in FIG. 1, the curved screen printing apparatus 1 prints a predetermined pattern on a plate-shaped substrate G having a curved surface.
Examples of the base material G include glass, plates of ceramics, resin, wood, metal and the like. Examples of glass include colorless and transparent amorphous glass, as well as crystallized glass and colored glass. The planar shape of the base material G is not particularly limited, and may be polygonal, circular, elliptical, or any other shape.
The curved surface means a surface having a radius of curvature of 5000 mm or less. The curved surface provided on the base material G is composed of only convex surfaces whose one main surface side projects to the other main surface side. The curved surface may have a portion having a different curvature as long as it has a convex shape. Further, both a flat portion and a bent portion may be present, or a bent portion accompanied by a twist may be present.
The base material G of the present embodiment is formed in a rectangular shape in a plan view, and is bent in one direction around the center of the long side direction thereof, but is not limited to this configuration and has another shape. Good.
The curved surface screen printing apparatus 1 includes a base 2, a screen plate 3, a squeegee 4, and a print control unit 5. The print control unit 5 includes a base moving mechanism 6 that moves the base 2, a screen plate moving mechanism 8 that moves the screen plate 3, and a squeegee moving mechanism 7 that moves the squeegee 4.

The base material G is placed on the pedestal 2. As shown in FIGS. 2 and 3, the surface 21 of the pedestal 2 is formed to be larger than the planar shape of the base material G. A part of the surface 21 constitutes a holding surface 21A having the same shape as the target bending shape of the base material G. In this embodiment, the holding surface 21A is formed in a convex shape.
The back surface 22 as the opposite surface of the pedestal 2 is formed in a flat shape. A rotary shaft 24 is fixed to the back surface 22 via a shaft fixing member 23. The rotary shaft 24 is fixed at the center of the back surface 22 in the left-right direction so as to extend in parallel to and in the front-rear direction with respect to the back surface 22.
The pedestal 2 is provided with a suction unit (not shown) that suctions the base material G on the holding surface 21A.

The pedestal moving mechanism 6 includes a base 61, a rotary shaft holding unit 62, a rotation angle control unit 63, a load control unit 64, and a base moving mechanism 65.

The rotary shaft holding unit 62 holds the pedestal 2 rotatably around the rotary shaft 24. The rotary shaft holding unit 62 includes a pair of columns 621 that extend upward from the upper surface 611 of the base 61. Bearings 622 that support the end portions of the rotary shaft 24 are provided at the upper ends of the pair of columns 621. The bearing 622 supports the rotary shaft 24 so that the center of the rotary shaft 24 overlaps with a virtual center line C passing through the center of the base 2 when the curved screen printing apparatus 1 is viewed from the front. The bearing 622 may support the rotating shaft 24 so that the center of the rotating shaft 24 does not overlap the virtual center line C.

The rotation angle control unit 63 applies a force for rotating the pedestal 2 to a portion of the back surface 22 of the pedestal 2 on the right side of the rotation shaft 24. The rotation angle control unit 63 includes a ball screw 631 as a rotational force imparting mechanism, a ball screw drive unit 632, a first vertical guide 633, and a first movement direction conversion unit 634.

The ball screw 631 is supported by the ball screw drive unit 632 on the upper surface 611 of the base 61 on the right side of the rotary shaft holding unit 62. As shown in FIG. 4, the ball screw 631 includes a screw shaft 631A, a nut 631B, and a plurality of balls 631C.
A spiral shaft groove 631D is formed on the outer peripheral surface of the screw shaft 631A.
A spiral nut groove 631E is formed on a part of the inner peripheral surface of the nut 631B. The space formed by the nut groove 631E and the shaft groove 631D constitutes a rolling path 631F along which the balls 631C roll. In order to reduce the torque for rotating the screw shaft 631A as much as possible, a gap is provided between the ball groove 631C and the shaft groove 631D and the nut groove 631E forming the rolling path 631F. That is, the ball screw 631 has a backlash between the components that mesh with each other. The nut 631B is provided with a circulation path 631G that circulates the balls 631C by connecting the upper end and the lower end of the rolling path 631F.

The ball screw drive unit 632 includes a motor 632A fixed to the upper surface of the base 61, and a coupling 632B connecting the upper end of the motor shaft 632C of the motor 632A and the lower end of the screw shaft 631A.

The first vertical guide 633 is provided on the upper surface 611 of the base 61 on the right side of the rotary shaft holding unit 62 and on the left side of the ball screw 631. The first vertical guide 633 includes a support member 633A, a first vertical rail 633B fixed to an upper end of the support member 633A so as to extend upward, and a first lift up and down along the first vertical rail 633B. And a slider 633C.
The side surface of the nut 631B is fixed to the side surface of the first elevating slider 633C such that the moving direction of the first elevating slider 633C is parallel to the axial direction of the nut 631B.

The first motion direction conversion unit 634 includes a first horizontal guide 634A and a first conversion bearing 634B.
The first horizontal guide 634A includes a first horizontal rail 634C fixed to the rear surface 22 of the pedestal 2 so as to extend left and right, and a first horizontal slider 634D that moves left and right along the first horizontal rail 634C. Equipped with. The first horizontal rail 634C is fixed such that the center in the width direction thereof overlaps with the virtual center line C when the curved screen printing apparatus 1 is viewed from the right. A rotary shaft 634E extending in the front-rear direction is fixed to the lower end side of the first horizontal slider 634D.
The first conversion bearing 634B is fixed to the upper surface of the nut 631B. The first conversion bearings 634B respectively support both ends of a rotary shaft 634E fixed to the lower end side of the first horizontal slider 634D.

The load control unit 64 applies a force for rotating the pedestal 2 to a portion of the back surface 22 of the pedestal 2 on the left side of the rotation shaft 24. The load control unit 64 includes an air cylinder 641, a second vertical guide 642, a lifting member 643, a second movement direction changing unit 644, and a cylinder drive unit 645 that drives the air cylinder 641.

The air cylinder 641 is fixed on the upper surface 611 of the base 61 on the left side of the rotary shaft holding unit 62 so that the output shaft 641A moves vertically.

The second vertical guide 642 has the same structure as the support member 633A, the first vertical rail 633B, and the first elevating slider 633C of the first vertical guide 633, respectively. The support member 642A, the second vertical rail 642B, and A second lifting slider 642C is provided.

The elevating member 643 is fixed to the second elevating slider 642C, and includes a base portion 643A extending upward, and an extending portion 643B extending from the upper end of the base portion 643A above the air cylinder 641. The extending portion 643B is formed in a plate shape. The lower surface of the extending portion 643B is fixed to the upper end of the output shaft 641A of the air cylinder 641 via a connecting member 643C.

The second movement direction conversion unit 644 has a second horizontal guide 644A and a second horizontal guide 644A having the same configurations as the first horizontal guide 634A and the first conversion bearing 634B of the first movement direction conversion unit 634, respectively. And a conversion bearing 644B.
The second horizontal rail 644C of the second horizontal guide 644A is fixed to the back surface 22 of the pedestal 2 so as to extend in the left-right direction. The second horizontal rail 644C is fixed such that the center in the width direction thereof overlaps with the virtual center line C when the curved screen printing apparatus 1 is viewed from the left. The second horizontal rail 644C is fixed at a position that is line-symmetrical to the first horizontal rail 634C with respect to the virtual center line C when viewed from the front. A rotary shaft 644E extending in the front-rear direction is fixed to the lower end side of the second horizontal slider 644D.
The second conversion bearing 644B is fixed to the upper surface of the extending portion 643B of the elevating member 643. The second conversion bearings 644B respectively support both ends of the rotating shaft 644E.

The base moving mechanism 65 includes a pair of base supporting members 651 that support the base 61 from below, and a support member moving unit (not shown) that moves the pair of base supporting members 651 vertically and horizontally. The pair of base support members 651 are provided at positions that are line-symmetric with respect to the virtual center line C when the curved screen printing apparatus 1 is viewed from the left.

[Printing method using curved screen printing device]
Next, a printing method using the curved screen printing apparatus 1 will be described. The movement direction and operation sequence of the pedestal 2, the screen plate 3, and the squeegee 4 are not limited to the following contents, and any movement direction and operation sequence that can be printed on the base material G may be applied.

First, an operator or a transport unit (not shown) places the base material G on the base 2. Next, after a positioning unit (not shown) positions the base material G at a predetermined holding position on the pedestal 2, a suction unit (not shown) sucks the base material G on the holding surface 21A.
Then, as shown in FIG. 5A, the base moving mechanism 65 of the pedestal moving mechanism 6 moves the pedestal 2 to the right and positions it just below the screen plate 3.
When the pedestal 2 is moved, the motor 632A of the rotation angle control unit 63 is driven to rotate the screw shaft 631A so that the nut 631B rises, and the cylinder drive unit 645 of the load control unit 64 drives the air cylinder 641. The output shaft 641A is driven to descend.

As shown in FIG. 6, when the nut 631B rises, the first elevating slider 633C fixed to the nut 631B is guided by the first vertical rail 633B, so that the nut 631B is kept straight. Ascends vertically. When the first conversion bearing 634B moves up together with the nut 631B, the first horizontal slider 634D rotates counterclockwise about the rotation shaft 634E supported by the first conversion bearing 634B, and rotates the first horizontal slider 634D. Guided by the horizontal rail 634C, it moves to the left.
When the elevating member 643 descends together with the output shaft 641A, the second elevating slider 642C fixed to the elevating member 643 is guided by the second vertical rail 642B, so that the elevating member 643 keeps straightness. It descends vertically. When the second conversion bearing 644B descends together with the elevating member 643, the second horizontal slider 644D rotates counterclockwise about the rotation shaft 644E supported by the second conversion bearing 644B, It is guided by the horizontal rail 644C of and moves to the left.
As described above, the respective configurations of the rotation angle control unit 63 and the load control unit 64 are driven to rotate the pedestal 2 counterclockwise so that the right end of the base material G comes closest to the screen plate 3.

Next, by driving the pedestal moving mechanism 6 or the screen plate moving mechanism 8 to bring the screen plate 3 and the base material G close to each other, the squeegee moving mechanism 7 lowers the squeegee 4 to set the lower surface of the screen plate 3 to the base. Press on the upper surface of material G. Thereafter, with the screen plate 3 fixed, as shown in FIGS. 5B and 5C, the squeegee moving mechanism 7 moves the squeegee 4 to the left, and the pedestal moving mechanism 6 synchronizes with the movement of the squeegee 4. The pedestal 2 is rotated clockwise while moving to the left and up and down. The movement of the squeegee 4 and the pedestal 2 causes the squeegee 4 to push the ink out of the screen plate 3 and apply it to the entire printing area of the base material G.
After that, the print control unit 5 returns the base 2, the screen plate 3 and the squeegee 4 to the initial positions shown in FIG.

In the printing operation shown in FIGS. 5A to 5C, the nut 631B of the rotation angle control unit 63 is lowered and the output shaft 641A of the load control unit 64 is raised to rotate the pedestal 2 clockwise. When rotating the base 2 clockwise, the load control unit 64 always presses the left side of the center of the base 2 with a pressing force F _T larger than the printing pressure F _{S of the} squeegee 4.

During the transition from the state of FIG. 5A to the state of FIG. 5B, both the printing pressure F _S and the pressing force F _T act to lower the right side of the pedestal 2. This force pushes the nut 631B downward. As described above, the gap is provided between the ball groove 631C and the shaft groove 631D and the nut groove 631E that form the rolling path 631F. Therefore, as shown in FIG. 7, the upper side of the center of the ball 631C contacts the nut groove 631E but does not contact the shaft groove 631D, and the lower side contacts the shaft groove 631D but does not contact the nut groove 631E. Become.

In the state of FIG. 5B, the printing pressure F _S presses the position where it overlaps the virtual center line C of the pedestal 2, so only the pressing force F _T acts to lower the right side of the pedestal 2. As a result, the contact state between the ball 631C and the shaft groove 631D and the nut groove 631E remains the state shown in FIG.

During the transition from the state of FIG. 5B to the state of FIG. 5C, the printing pressure F _S acts to lower the left side of the pedestal 2, while the pressing force F _T acts to lower the right side of the pedestal 2. However, since the pressing force F _T is larger than the printing pressure F _{S, a} force for lowering the right side acts on the pedestal 2. As a result, the contact state between the ball 631C and the shaft groove 631D and the nut groove 631E remains the state shown in FIG.

As described above, during the printing operation, presses the base 2 with a large pressing force F _T than the load control unit 64 is always the printing pressure F _S of the squeegee, than the moment around the rotation shaft 24 caused by the printing pressure F _S of the squeegee By applying a large moment around the rotary shaft 24, the contact state between the ball 631C and the shaft groove 631D and the nut groove 631E remains unchanged as shown in FIG. As a result, the pedestal 2 rotates at the same speed as the set speed, and the deviation of the printing of the pedestal 2 in the rotation direction is suppressed.

Also, since both ends of the rotary shaft 24 are held by the rotary shaft holding unit 62, the pedestal 2 can be prevented from tilting, and printing accuracy is improved.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.

[Structure of curved screen printing device]
As shown in FIGS. 8 and 9, the difference between the curved screen printing apparatus 1 of the first embodiment and the curved screen printing apparatus 1A of the second embodiment is that the rotation angle control unit 63 of the pedestal moving mechanism 6 is replaced by the rotation angle control unit 63. That is, the rotation angle control unit 66A is provided.
The rotation angle control unit 66A applies a force for rotating the pedestal 2 to the rotation shaft 24. As such a rotation angle control unit 66A, a gear 661A fixed to, for example, the front end of the rotary shaft 24, a meshing member 662A meshing with the gear 661A, and a meshing member driving unit 663A driving the meshing member 662A are provided. The structure can be illustrated. The gear 661A and the meshing member 662A form a rotational force applying mechanism. Examples of the meshing member include gears and racks. The meshing member may be composed of one piece or plural pieces. When the meshing member is composed of a plurality of members, it may be composed of the same kind of member or different kinds of members.
A gap called backlash exists between the gear 661A and the meshing member 662A. When the engagement member 662A is composed of a plurality of members, a gap also exists between the plurality of members.

[Printing method using curved screen printing device]
Next, a printing method using the curved screen printing apparatus 1A will be described. The description of the same operation as that of the first embodiment will be omitted or simplified.

First, as shown in FIG. 5A, in a state in which the left end of the pedestal 2 is lower than the right end, the screen plate 3 and the base material G are brought close to each other, and then the squeegee 4 is lowered to bring down the lower surface of the screen plate 3. It is pressed against the upper surface of the base material G. After that, with the screen plate 3 fixed, as shown in FIGS. 5B and 5C, the squeegee 4 is moved to the left and the pedestal 2 is moved to the left and up and down, and is rotated in the clockwise direction to set the ink The material G is applied to the entire printing range.

In the printing operation shown in FIGS. 5A to 5C, the meshing member drive unit 663A of the rotation angle control unit 66A is driven to rotate the gear 661A clockwise. At this time, the load control unit 64 always presses the left side of the center of the base 2 with the pressing force F _T larger than the printing pressure F _{S of the} squeegee 4.

During the transition from the state of FIG. 5A to the state of FIG. 5B, both the printing pressure F _S and the pressing force F _T act to lower the right side of the pedestal 2. This force biases the gear 661A clockwise. A gap is provided between the gear 661A and the meshing member 662A. Therefore, the tooth front surface of the gear 661A in the rotational direction and the meshing member 662A come into contact with each other, but the tooth rear surface of the gear 661A in the rotational direction does not come into contact with the meshing member 662A.

In the state of FIG. 5B, only the pressing force F _T acts to lower the right side of the pedestal 2. As a result, the contact state between the teeth of the gear 661A and the meshing member 662A becomes the same state as during the transition from the state of FIG. 5A to the state of FIG. 5B.

Since the pressing force F _T is larger than the printing pressure F _S during the transition from the state of FIG. 5B to the state of FIG. 5C, a force for lowering the right side acts on the pedestal 2. As a result, the contact state between the teeth of the gear 661A and the meshing member 662A becomes the same state as during the transition from the state of FIG. 5A to the state of FIG. 5B.

As described above, during the printing operation, the load control unit 64 loads a moment around the rotary shaft 24, which is larger than the moment around the rotary shaft 24 generated by the printing pressure F _S of the squeegee, so that the teeth of the gear 661A and the meshing member are engaged. The contact state with 662A remains the same and does not change. As a result, the pedestal 2 rotates at the same speed as the set speed, and the deviation of the printing of the pedestal 2 in the rotation direction is suppressed. When the meshing member 662A is composed of a plurality of members, the contact state of the plurality of members remains unchanged during the printing operation.

[Modification]
The present invention is not limited to the above-described embodiment, and various improvements and design changes can be made without departing from the scope of the present invention.

For example, instead of the ball screw 631 of the rotation angle control unit 63, a rotational force applying mechanism in which backlash exists between the elements that mesh with each other may be used. As the rotational force applying mechanism, a gear mechanism in which a plurality of gears mesh , A rack and pinion mechanism, a roller and pinion mechanism, and the like.
Instead of the air cylinder 641 of the load control unit 64, a configuration in which the pedestal 2 can be pressed with a pressing force F _T larger than the printing pressure F _{S of} the squeegee during the printing operation may be applied. A hydraulic cylinder, a spring, a weight, etc. can be illustrated.
Although the pedestal 2 is rotated so as to raise the output shaft 641A of the load control unit 64, the pedestal 2 may be rotated so as to lower the output shaft 641A. Even in this case, the load control unit 64 always applies a moment around the rotary shaft 24, which is larger than the moment around the rotary shaft, which is generated by the squeegee printing pressure F _S , so that the ball 631C, the shaft groove 631D, and the nut groove. The change of the contact state with 631E can be suppressed.
The rotating shaft 24 may be fixed to the pair of support columns 621, and the pedestal 2 may be provided with a bearing that rotatably holds the rotating shaft 24.
A plurality of rotation angle control units 63 and a plurality of load control units 64 may be provided side by side in the front or rear direction or left and right, respectively, or a plurality of one may be provided and only one may be provided in the other.
At least one of the first and second

vertical guides

633 and 642 may not be provided.
In the above-described embodiment, during the printing operation, the load control unit always presses the base with the pressing force F _T larger than the printing pressure F _{s of the} squeegee. However, the load control unit may press the pedestal with a pressing force F _T larger than the printing pressure F _{s of} the squeegee at least during the transition from the state of FIG. 5B to the state of FIG. 5C. In other words, if pressed pedestal between the load control unit in the printing pressure F _s large pressing force F _T than the squeegee at least the printing pressure F _S of the squeegee provides a rotational moment in the direction opposite to the rotation direction of the base Good.

Although the present invention has been described in detail and with reference to particular embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.
This application is based on Japanese Patent Application 2019-020698 filed on Feb. 7, 2019, the content of which is incorporated herein by reference.

1, 1A... Curved screen printing device, 2... Pedestal, 21A... Holding surface, 22... Back surface (opposite surface), 24... Rotation axis, 3... Screen plate, 4... Squeegee, 5... Printing control unit, 62... Rotation axis Holding unit, 63, 66A... Rotation angle control unit, 631... Ball screw (rotational force imparting mechanism), 631A... Screw shaft, 631B... Nut, 64... Load control unit, 641... Air cylinder, G... Substrate.

Claims

A curved screen printing device for printing a predetermined pattern on a plate-shaped substrate having a curved surface,
A pedestal having a holding surface for holding the base material;
Screen version,
A squeegee configured to apply ink to the base material held on the pedestal through the screen plate,
While rotating the pedestal around a rotation axis located on the opposite side of the holding surface in the pedestal, by relatively moving the pedestal, the screen plate and the squeegee in a direction orthogonal to the rotation axis, A print control unit configured to print the substrate,
The print control unit,
A rotation angle control unit configured to apply a force for rotating the pedestal to one side of the rotation axis in the horizontal orthogonal direction, or to the rotation axis,
On the other side in the orthogonal direction like the rotation axis, a load control unit configured to apply a force for rotating the pedestal,
The rotation angle control unit includes a rotation force applying mechanism in which a backlash exists between components that mesh with each other.
The curved screen printing apparatus, wherein the load control unit is configured to apply a moment larger than the moment about the rotation axis generated by the printing pressure of the squeegee about the rotation axis.
The curved screen printing device according to claim 1, wherein the rotational force applying mechanism is a ball screw that applies a force to the one side of the opposite surface by the relative movement of the screw shaft, the nut, and the ball.
The curved screen printing device according to claim 1 or 2, wherein the load control unit includes a pneumatic cylinder, a hydraulic cylinder, or a weight.
The curved screen printing apparatus according to any one of claims 1 to 3, wherein the print control unit includes a rotary shaft holding unit configured to hold both ends of the rotary shaft.
A curved screen printing method for printing a predetermined pattern on a plate-shaped substrate having a curved surface,
Using a pedestal having a holding surface for holding the base material, a screen plate, and a squeegee, while rotating the pedestal around a rotation shaft located on the opposite side of the holding surface in the pedestal, the pedestal By relatively moving the screen plate and the squeegee in a direction orthogonal to the rotation axis, when performing printing of the base material,
A rotating force imparting mechanism in which backlash exists between components that mesh with each other, and a force for rotating the pedestal is imparted to one side of the rotating shaft in a horizontal orthogonal direction or to the rotating shaft, and the rotating shaft. The curved surface screen printing method, wherein the pedestal is rotated while a moment larger than the moment about the rotation axis generated by the printing pressure of the squeegee is applied to the other side in the horizontal orthogonal direction of the above.