JPH031945A - Method and apparatus for clamping and tensioning screen mesh - Google Patents

Abstract

PURPOSE:To prevent excessive partial tension force from acting on a screen mesh by operating a limit switch by the piston moved toward the screen mesh against the air pressure in an air cylinder to stop the driving of a motor operating an interval control mechanism. CONSTITUTION:A screen mesh clamping and tensioning apparatus 1 is fundamentally constituted of the part of a motor stretcher 1a provided with a stretching mechanism 3 grasping a screen mesh 2 to impart tension thereto and the part of a tensile strength control mechanism 4 controlling the tensile strength of the stretching mechanism 3. When tension is applied to the screen mesh 2 by said apparatus 1, the air in an air tank 14 is compressed and a piston 9 is moved toward the screen mesh 2 against the air pressure to operate the limit switch 10 in an air cylinder 8 and the driving of a motor 16 is stopped to stop the widening of the interval (m) between the clamp parts 5 of the stretching mechanism 3. This state is kept to impart constant tension to the screen mesh 2.

Description

[Detailed Description of the Invention] [Background of the Invention] [Field of Industrial Application] The present invention provides a method for tightening a screen mesh for manufacturing a screen for screen printing by stretching the screen mesh onto a screen frame. and regarding equipment.

<Prior art> Conventionally, in order to manufacture a screen for screen printing by tightening a screen mesh onto a screen frame, it is usual to arrange several air stretchers facing each other or to use a spacing adjustment mechanism. A screen mesh tensioning device equipped with a flexible motor stretcher was used.

That is, in the screen mesh tightening device 1 equipped with the air stretcher 24, as shown in FIG. The ends of the screen mesh 2 are connected to the piston 9 of the air stretcher 24.
After clamping with the clamp part 5 attached to the tip of the
By supplying compressed air 25 into the air tank 14 of the air cylinder 8 formed on the base end side of the piston 9 that supports the clamp part 5 and contracting the piston 9, the screen mesh 2 Pull it from both sides,
After applying appropriate tension to the screen mesh 2, fix it to the screen frame 11 and stretch the screen mesh 2 to the screen frame 11, or use a clamp section to clamp the ends of the screen mesh 2. 5.5
A screen mesh tensioning device 1 is provided with a motor stretcher 3 equipped with a distance 1 adjustment mechanism 7 for adjusting the distance m between both clamp portions 5□5 by driving a motor 6.
After applying appropriate tension to the screen mesh 2 by pulling the screen mesh 2 from both sides, it was fixed to the screen frame 11 and the screen mesh 2 was stretched on the screen frame 11.

<Problem to be Solved by the Invention> However, if there are variations in the operating speed of the piston of the air stretcher or variations in the pinched portion of the screen mesh of the motor stretcher, it will directly affect the tension of the screen mesh. Since it gives
This may affect the way the screen mesh is stretched over the screen frame. Therefore, if the operation status of the piston of the air stretcher is not always in a normal state, or if the screen mesh of the interval adjustment mechanism of the motor stretcher is not controlled evenly, There are variations in the tension in the center, periphery, and four corners of the screen mesh, which tends to cause distortion in printed matter during printing after plate making.

In particular, air stretchers and motor stretchers have 4 to 8 clamps for small screen frames, and 40 to 50 clamps for large screens. It is not easy to control whether the motor stretcher is tensioned evenly. Therefore, it is virtually impossible to manage them.

In addition, even with the screen mesh stretched with an appropriate tension in this manner, as time passes, the screen mesh begins to stretch again due to the elongation due to the properties of the material of the screen mesh itself, so the tension changes. Therefore, again
It may be necessary to re-tighten the material several times.

Therefore, this type of tension adjustment must be repeated as many times as necessary until the material of the screen mesh itself has almost completely stretched, and the tension must be measured and re-stretched each time. , it was a difficult task.

[Summary of the invention]

Summary> As a result of extensive research in view of the above problems, the present inventors have provided an air cylinder equipped with a limit switch disposed on the proximal end side of the clamp part of the motor stretcher. When the gap adjustment mechanism provided between the clamp parts is activated to widen the gap between both clamp parts and apply tension to the screen mesh, the screen mesh moves against the air pressure in the air cylinder. The pushed piston activates the limit switch,
The present invention was completed based on the knowledge that by stopping the drive of the motor that operates the interval adjustment mechanism, it is possible to prevent excessive partial tension from being applied to the screen mesh. This is what we have come to.

That is, the screen mesh tightening method of the present invention is as follows:
After the end of the screen mesh is clamped between the clamp parts of a motor stretcher equipped with two sets of stretching mechanisms arranged perpendicularly to the screen frame, the above-mentioned In a screen mesh tightening method in which a screen mesh is fixed to a screen frame under tension to produce a screen for screen printing, the motor stretcher is driven to widen the interval between the clamp parts and tighten the screen mesh. When tension is applied to the screen mesh, the piston moves toward the screen mesh against the air pressure in the air cylinder equipped with a limit switch located at the proximal end of the clamp section of the motor stretcher. The limit switch is actuated to stop driving the motor of the motor stretcher and prevent unnecessary partial tension from being applied to the screen mesh, and then when the screen mesh is stretched again. The piston is pushed back by air pressure to release the limit switch, and the motor of the motor stretcher is driven again to widen the interval between the clamp parts and apply tension to the screen mesh. It is.

Further, the screen mesh tensioning device of the present invention includes a clamp section for clamping the end of the screen mesh, a drive motor, and a spacing: A adjusting mechanism for widening the spacing between the clamp sections. , two sets of motor stretchers arranged perpendicular to the screen frame, a piston supporting the clamp part arranged on the proximal end side of the clamp part, and the piston sliding by storing compressed air. and a tensile strength adjustment mechanism equipped with a limit switch for stopping the driving motor of the motor stretcher, which is disposed on the clamping portion side of the air cylinder. It is something.

Effect> The screen mesh tensioning method and device of the present invention include an air cylinder equipped with a limit switch on the proximal end side of the clamp part of the motor stretcher, and the air in the air cylinder is By activating a limit switch by the piston moved against the pressure and stopping the drive of the motor for activating the distance adjustment mechanism, variations in tension are prevented. .

By eliminating such variations in tension, it is possible to prevent tension from being applied to the screen mesh more than necessary locally, so that the screen mesh can be tensioned uniformly.

Therefore, a screen with constant tension can be manufactured without constantly controlling the operating status of the interval adjustment mechanism of the motor stretcher.

In addition, the person who operates the screen mesh tightening device of the present invention simply sets the air pressure and tightening time, clamps the end of the screen mesh between the clamps, and turns on the power. Since it automatically adjusts and tightens the tightening tension of the screen mesh, it has the advantage that it is easy to operate and can be easily operated even by a person who does not require skill.

In addition, even if the material of the screen mesh side body stretches over time and begins to stretch again, the tension will be automatically adjusted, so there will be no need to re-tension it due to changes in tension. Never.

Therefore, it is an extremely effective method because it saves labor.

[Detailed description of the invention]

<Example> The screen mesh tightening method and apparatus of the present invention will be specifically described below by giving an example thereof.

Screen mesh tensioning device FIG. 1 is a side view of the screen mesh tensioning device of the present invention, and FIG. 2 is a plan view of the screen mesh tensioning device of FIG. 1.

As shown in FIG. 1, the screen mesh tensioning device 1 of the present invention includes a motor stretcher la provided with stretching machines 11 to 13 that can clamp and tension the screen mesh 2; It basically consists of a tensile strength adjustment mechanism 4 part that adjusts the tensile strength of the stretch mechanism 3.

The stretching mechanism 3 is operated by a drive motor 6, a clamp part 5 for clamping the end of the screen mesh 2, and the motor 6 to widen the distance m between the two clamp parts 5.5. The space adjustment mechanism 7 is constructed from a space adjustment mechanism 7 that can be adjusted.

Further, the tensile strength adjustment mechanism 4 portion includes an air cylinder 8 provided on the proximal end side of the clamp portion 5, and an air cylinder 8 provided on the base end side of the clamp portion 5.
When the piston 9 slides inside the air cylinder 8 due to the tensile force of and a limit switch 10 for stopping the drive of the motor.

In FIG. 1, 11 is a screen frame placed on a support plate 12, and around the screen frame 11, a second
As shown in the figure, two sets of stretching mechanisms 3 are arranged in a direction perpendicular to the screen frame 11. A base 1'3 is fixed to the stretching machine +IX>3, and on the base 13 there are a number of holes parallel to the screen frame 11 for clamping the ends of the screen mesh 2. A clamp portion 5 is provided. A piston 9 that supports the clamp portion 5 and slides within the air cylinder 8 is disposed on the proximal end side of the clamp portion 5.
An air tank 14 formed by the piston 9 and the air cylinder 8 is formed at the base end side of the air tank 14 . A limit switch 10 such as a proximity switch is disposed on the screen mesh 2 side of the piston 9 to stop the driving of the motor 6 of the stretch mechanism 3.

Furthermore, a pressure tube 15 for supplying compressed air to the air tank 14 is connected to the air cylinder 8, and at the end of the pressure tube 15 is a compressor 16 and a pressure 1. Sugoki 1
7 are connected.

The stretch mechanism 3 also includes a sprocket or pulley 18 that can adjust the distance between the opposing clamp parts 5 by driving a motor 6;
A spacing adjustment mechanism 7 consisting of a chain or belt 19, a sprocket or pulley 20, a rod-shaped rotating shaft 21, and a bearing portion 22 is provided.

How to Tighten Screen Mesh Accordingly, in order to use such a screen mesh tensioning device 1 and stretch the screen mesh 2 on the screen frame 11, it is necessary to tighten the screen mesh 2 on the screen frame 11''.
The ends of the screen mesh 2 were placed at the ends of a plurality of stretching machines 1143, and compressed air at a pressure determined by the pressure EffiW 17 was supplied into the air tank 14. After the end of the screen mesh 2 is clamped by the clamp part 5, the motor 6 is driven to rotate the rotation shaft 2 of the motor 6.
Sprocket or pulley 18 attached to the end of 3
This chain or belt 19 rotates a sprocket or pulley 20 fixed to the rod-shaped rotating shaft 21, and the rod-shaped rotating shaft 21 rotates. Since threaded portions 21a and 21b are formed in opposite directions at both ends of the rod-shaped rotating shaft 21, the bearing portion 22 screwed into the threaded portions 21a and 21b can be rotated without rotating. By moving the rod-like rotating shaft 21 in the length direction, the interval m between the clamp parts 5 of the stretching machine j, '173 is widened, and tension is applied to the screen mesh 2.

As a result, when tension is applied to the screen mesh 2, the air in the air tank 14 is compressed, resisting the air pressure, and the piston 9 moves toward the screen mesh 2, causing the limit switch 10 in the air cylinder 8 to move.
is activated, the drive of the motor 16 is stopped, and widening of the interval m between the clamp parts 5 of the stretching mechanism 3 is stopped.

Then, maintain this state and apply constant tension to the screen mesh 2.

However, after a while, the screen mesh 2 stretches and the tension loosens, and is pushed back by the pressure inside the air tank 14. When the force of the piston 9 that was pushing the limit switch 10 is released, the drive of the motor 16 is stopped. It will be restarted. As a result, the limit switch 10 is turned off again.
The motor 6 is driven again to widen the interval m between the clamp parts 5 of the stretch mechanism 3 and apply tension to the screen mesh 2.

[Brief explanation of drawings]

FIG. 1 is a side view of a tightening device according to an embodiment of the present invention, and FIG.
1 is a plan view of the screen mesh tensioning device shown in FIG. 1, and FIG. 3 is a side view of the conventional screen mesh tensioning device. 1 Ni-screen mesh tensioning device 1a: Motor stretcher 2 Ni-screen mesh 3-Stretching mechanism 4: Tensile strength adjustment mechanism 5: Clamp section 6: Drive motor 7: Interval 5', J straightening machine (11IS8: Air Cylinder 9: Piston 10: Limit switch 1-1 = Screen 12: Support slope 13
: Discussion 14: Air tank 15: Pressure tube] 6: Compressor
17; Pressure controller 18: Sprocket or pulley 19: Chain or belt 20: Sprocket or pulley 21 = Rod-shaped rotating shafts 21a, 21b = Threaded portion 22: Bearing portion 23: Rotating shaft m: Spacing.

Claims (1)

[Claims] 1. After the ends of the screen mesh are clamped between the clamp parts of a motor stretcher provided with two sets of stretching mechanisms arranged perpendicularly to the screen frame, the opposing clamp parts In the screen mesh tightening method, which manufactures a screen for screen printing by fixing the screen mesh to a screen frame while applying tension by widening the interval between the clamp parts, the motor stretcher is driven to increase the interval between the clamp parts. When tension is applied to the screen mesh by expanding it, the screen mesh is moved toward the screen mesh against the air pressure in the air cylinder equipped with a limit switch located at the proximal end of the clamp section of the motor stretcher. activating the limit switch by the piston, stopping the drive of the motor of the motor stretcher;
This prevents excessive partial tension from being applied to the screen mesh, and then, when the screen mesh expands again, the piston is pushed back by air pressure, the limit switch is released, and the motor starts again. A screen mesh tightening method characterized by driving a letcher motor to widen the interval between clamp parts and applying tension to the screen mesh. 2. Two sets of clamps arranged perpendicular to the screen frame, each equipped with a clamp section for clamping the ends of the screen mesh, a drive motor, and a spacing adjustment mechanism for widening the spacing between the clamp sections. A motor stretcher provided with a stretching mechanism, a piston disposed on the proximal end side of the clamp part that supports the clamp part, an air cylinder that stores compressed air and on which the piston slides, and the air cylinder. A screen mesh tensioning device comprising: a tensile strength adjustment mechanism disposed on a clamp portion side and equipped with a limit switch for stopping a driving motor of the motor stretcher.