DE102004033565A1 - Scraper guide for scraper in screen printing machine whereby scraper head is operatable in slide rail using slide block, arranged on base frame, and it is movable along slide rail using drive belt - Google Patents

Abstract

The scraper guide has a scraper head (8) which is operatable in a slide rail (2) using a slide block (3). The slide rail is arranged on the frame (1). The scraper head is movable along the slide rail using a drive belt (4).

Description

State of technology

The The invention relates to a device for guiding a doctor blade according to the preamble of claim 1.

The For example, in a screen printing machine, a squeegee is passed over a Screen stencil drawn and strokes a mostly pasty medium (color) through to an object to be printed. The squeegee is using a doctor blade guided along a frame. This guide is done in a known manner by means of pneumatic and / or hydraulic Cylinder. Since these above the medium, or to be printed Object are arranged, the medium can be contaminated by dripping oil or become dirty. The pneumatic cylinders require compressed air, their production is expensive. For the production of compressed air is a compressor unit with a refrigeration dryer in a separate Room and a separate maintenance necessary. The longitudinal movement through the pneumatic squeegee guide is not uniform, but rather restless.

moreover can tilt the squeegee at the known guides. There are too Devices for guiding known by doctoring, in which in a cylinder a piston is pneumatic or hydraulically movable, wherein the piston with the doctor by means of a Holder is connected, which passes through the cylinder and To seal the cylinder duct opening sealing strips needed. These sealing tapes shut down not completely tight, so that leaks occur with pressure losses. To some extent these losses need to keep low the sealing tapes often be replaced. The cylinders generate a high during operation noise and are during of the travel in their speed almost not controllable.

task The invention is to provide a generic device, their manufacture and use is simplified.

The invention and their benefits

The inventive device with the characterizing features of claim 1 has the other hand Advantage that the at least one sliding block in the slide rail and the timing belt quiet are movable.

To an advantageous embodiment of the invention, the toothed belt via a precise controllable electric motor controllable.

To a further advantageous embodiment of the invention is the Electric motor, which is a three-phase motor, regulated by the frequency.

To an additional one advantageous embodiment of the invention is the electric motor while the starting and / or deceleration of the doctor blade over a Frequency ramp controlled to a mechanical load on the frame and the squeegee head.

To an additional one advantageous embodiment of the invention is the braking of the Squeegee head triggered by a light barrier on the frame.

To an additional one advantageous embodiment of the invention are plastic parts on the sliding block arranged to reduce friction, so that is the breakout force very low and the squeegee is uniformly controllable.

To an additional one advantageous embodiment of the invention, the doctor blade with at least two sliding blocks guided in the slide to to reduce the rotation of the squeegee.

To an additional one advantageous embodiment of the invention is as a slide rail a flat guide used to significantly reduce the tilting of the squeegee head. The leadership can record more moments in all directions without being influenced by disturbances to be. The quieter leadership allowed by the slide also a more uniform one Contact pressure for the squeegee. The leadership has a low height, is resistant to dust, corrosion resistant, has low wear at low Friction value and low weight due to the material combination of aluminum-plastic.

To an additional one advantageous embodiment of the invention, the wear parts of at least a sliding block interchangeable to the cost in continuous operation too reduce.

To an additional one advantageous embodiment of the invention can be inventively guided doctor the Hinlauf to flood and another inventively guided squeegee on the return to Serve blank printing the template.

Further Advantages and advantageous embodiments of the invention are the following description, the drawings and the claims.

drawings

An embodiment of the subject invention is shown in the drawings and described in more detail below.

It demonstrate:

1 a side view of the device for guiding a doctor blade;

2 a plan view of the device for guiding a doctor blade;

3 a plan view from below of the slide rail and

4 a view on the section AA the 3 ,

description of the embodiment

In 1 is a frame 1 represented, on which a slide rail 2 is attached, in this are the sliding blocks 3 by means of a toothed belt 4 guided. The timing belt 4 is about a gear 5 driven, which by another toothed belt 6 from a three-phase electric motor 7 is driven. On the sliding blocks 3 is a squeegee head 8th mounted and on this by means of a squeegee holder 9 a first squeegee 10 , To the mechanical load for the frame 1 and the squeegee head 8th and to keep the parts attached to these parts as small as possible, the three-phase electric motor 7 when approaching the squeegee head 8th from a first end position 81 accelerated over a frequency ramp, doing so with a second squeegee 101 a printing table 13 flooded. After passing through a light barrier, the squeegee head becomes 8th decelerated via a frequency ramp and comes to a stop in a second end position. Then the squeegee head 8th via the frequency ramp from the end position 82 accelerated and with the squeegee 10 will be printed. After passing through a light barrier, the squeegee head becomes 8th braked over the frequency ramp and comes in the final position 81 to stand. This frequency ramp has a minimum frequency of 5 Hz and a maximum of 80 Hz. If the control for the squeegee head fails, there is a buffer rubber at each end of the slide rail 11 . 12 arranged.

In the plan view of 2 It is shown that the slide rail is designed as a flat guide in the width of the frame and thus prevents tilting of the doctor blade head. By acting for the guidance of the squeegee head 8th two sliding blocks 3 used, also a rotation of the squeegee head is prevented.

In 3 is the slide rail 2 shown in plan view from below with the sliding block 3 , In order to improve the sliding properties and to reduce the breakaway torque, easily replaceable lower plastic elements are on the sliding block 14 arranged. The middle rail 15 leads to additional leadership stability. The encasements 16 . 17 hold the sliding block 3 also in the unloaded state in its slide rail 2

4 shows the view on the section AA the 3 with the slide rail 2 , which is designed as a C-profile, with the encirclements 16 . 17 and the middle rail 15 , In this slides the sliding block 3 in the unloaded condition, especially on the exchangeable lower plastic parts 14 and in loaded condition, especially with the exchangeable upper plastic parts 18 that also surround the sliding block on the side.

All in the description, the following claims and the drawing Features can both individually and in any combination with each other invention essential be.

1

frame

2

slide

3

sliding blocks

4

toothed belt

5

gear

6

toothed belt drive

7

Three-phase electric motor

8th

squeegee head

9

blade holder

10

first doctor

11

Puffergummi

12

Puffergummi

13

printing table

14

Lower Plastic elements

15

middle rail

16

encasement

17

encasement

18

upper Plastic parts

81

squeegee head in a 1st end position

82

squeegee head in a second end position

101

second doctor

Claims (12)

Device for guiding at least one doctor blade ( 10 . 101 ) in particular for a screen printing machine which can be lowered by means of a squeegee holder ( 9 ) on a squeegee head ( 8th ), along a frame ( 1 ) is arranged, characterized in that - the squeegee head ( 8th ) by means of at least one sliding block ( 3 ) in a slide rail ( 2 ) attached to the frame ( 1 ), is feasible and - that the squeegee head ( 8th ) by means of a toothed belt ( 4 ) along the slide rail ( 2 ) is movable. Apparatus according to claim 1, characterized in that the drive of the toothed belt ( 4 ) by means of an electric motor ( 7 ) he follows. Device according to claim 2, characterized in that the electric motor ( 7 ) is a three-phase motor, which is adjustable over the frequency. Device according to claim 3, characterized in that the electric motor ( 7 ) during startup and / or deceleration of the squeegee head ( 8th ) is controllable via a frequency ramp. Device according to claim 4, characterized in that that the beginning of the braking is controlled by means of a light barrier becomes. Device according to claim 4, characterized in that that the frequency ramp has a minimum of 5 Hz and a maximum of 80 Hz. Apparatus according to claim 1, characterized in that the squeegee head ( 8th ) a first doctor blade ( 10 ) for printing and a second squeegee ( 101 ) is present to the previous flooding. Device according to claim 1, characterized in that the toothed belt ( 4 ) the slide rail ( 2 ) in its longitudinal direction and at the doctor blade ( 8th ) is attached. Apparatus according to claim 1, characterized in that in the longitudinal direction of the slide rail ( 2 ) near each end of the slide rail ( 2 ) one buffer rubber each ( 11 . 12 ) is available. Device according to claim 1, characterized in that the squeegee head ( 8th ) with at least two sliding blocks ( 3 ) in the slide rail ( 2 ) to be led. Apparatus according to claim 1, characterized in that the wear parts of the at least one sliding block ( 3 ) are interchangeable. Apparatus according to claim 1, characterized in that the slide rail ( 2 ) is designed as a flat guide rail.