DE1652061A1 - Process and machine for grinding large workpieces - Google Patents

Description

Karl Heesemann, Bad Oeynha'usen -Rehme

"Process and machine for grinding large workpieces"

The invention relates to a method and a machine for automatic fine grinding and subsequent fine grinding large workpieces.

The painstaking and fine grinding of large-area veneered, lacquered or otherwise coated or even more massive Workpieces are now made in a known and advantageous manner using the cross grinding process on two different automatic machines Belt grinders.

The cross-shaped grinding results in terms of surface formation,

The surface and roughness depth are the best sanding quality. Here ; 109811/0355

the pre-cut is used as a cross-cut (across the grain direction) and the regrinding is carried out as a longitudinal sanding (parallel to the grain direction).

Because the workpieces are cut lengthways with cross-cut and cross-cut with lengthwise sanding using conventional machines must be guided, it is necessary to adjust the workpiece direction to change from the pui? s cut to the longitudinal cut by 90 °. Separate machines must be used for transverse and longitudinal sanding, which are controlled by a so-called angle transfer device are to be connected to each other in such a way that the direction of travel of the workpieces is from the first to the second machine undergoes the required change. Such systems require high investments and, because of the changes in direction during the passage of the workpieces, greater space requirements. Also will because of the inertial forces that occur when the direction changes the throughput speed is limited.

As far as previously known wide band sanding machines for cross sanding are considered as a second machine, these machines are not able to produce a precision sanding of sufficient quality, since the feed direction of the workpiece and the direction of the sanding belt run parallel. Since the sanding marks cannot overlap and the sanding errors or sanding marks add up instead of being balanced out, the sanded surface remains rough.

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Next, the sanding belt is only ever in the one to be sanded Workpiece width claimed. Glue joints, which normally recur in the same places on the workpieces, put a strain on this Sanding belt also always on the same section. As a result, the tape settles on this section, leaving behind Sanding marks and becomes unusable prematurely.

The object of the invention is to provide a method and a machine

to create through which the workpieces in the longitudinal direction ™

and can be guided in a straight line and in which the cross grinding process is still fully applied.

According to the invention is a method for tormenting in particular Fine grinding of a large, plate-shaped workpiece, that are successively subjected to several grinding processes is, characterized in that with constant feed direction under surface pressure initially only transversely to Direction of advance and then then essentially parallel to the direction of advance is ground, at the same time a .the grinding transverse movement that distracts the grinding marks is carried out.

BeJ. a preferred machine according to the invention for implementation such a procedure are about a trati

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direction two or more cross grinding devices one after the other arranged, which a wide belt longitudinal sander nit one between the sanding belt and continuous workpiece

en
made / reversing movement is connected downstream.

It is preferred that _s traverse grinding devices with an elastic pressure beam and a switched between the grinding belt and print bar to provide endlessly circulating Druckbalamellenband.

The wide belt longitudinal grinding machine is preferably equipped with a reversing, provided with an endless, circumferential sanding belt, which is acted upon by an elastic on the inside The pressure bar is pressed onto the workpiece to be ground; the sanding belt can regulate its center run with one Be provided device.

In a particularly preferred embodiment of the broadband grinding device are belt drive and guide devices and possibly also the pressure beam with its holding device on a guide body transversely to the direction of travel of the workpiece movably mounted. For this purpose, a displacement device such as a spindle or the like can be used. be provided. Furthermore, it is preferred to use the effective pressure surface of the grinding belt according to the respective workpiece width,

" ⁵ " 108811/03 56

Zugswelse can be changed continuously. " a loop through to avoid the edges.

In another embodiment of the invention it is preferred, not the entire wide belt unit, but only the wide sanding belt through special control units to move back and forth across the workpiece feed direction.

A machine according to the invention is characterized by a excellent sanding quality, as the sanding marks In i are advantageously overlapped, while the workpiece <k the machine runs through in the same direction.

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109811/0355

In the drawings, an exemplary embodiment of the invention is shown. Show it :

Fig. 1 is a side view of a Kreuzschlelfmaschine in a schematic representation,

Pig. 2 shows a section through the same grinding machine according to line I-I in Pig. I,

Pig. 3 shows a section through the guide body of the same

with
Machine / surrounding crossbeam and sanding belt,

Fig. 4 is a front view of the pressure beam of the same Grinding machine, partially cut,

FIG. 5 shows a cross section of the pressure beam according to the section line II-II in FIG. 4,

FIG. 6 shows a cross section of the same pressure beam according to the section line III-III in FIG. 1.

On the body of a cross-grinding Io with two uprights and 12 and lower connecting rails 13 and 14 passes around a reversing roller 15a and drive roller 15b, a conveyor belt 15 for the workpiece feed endlessly. The conveyor belt 15 is driven by a feed motor (not shown)

via an infinitely variable · gear.

1098H / 035B

On the body between the uprights 11 and 12, an upper connecting rail 16 is attached, on which two cross _{grinding devices 17 s} 18 are arranged at a distance from one another. Which are provided with height-adjustable pressure beams. Each of the two pressure bars of the two cross grinding devices 17 and 17 are assigned pressure rollers 19 and 20 or 21 and 22 in front of and behind them, as seen in the feed direction. With the pressure rollers or rollers 19 and 21 respectively, there is a contact roller which is actuated by the workpiece passing through and which controls the downward and upward movements of the associated pressure bars. These pressure bars are provided with devices, not shown, with which the working width can be adjusted according to the width of the workpieces passing through.

In the direction of advance of the memorized pieces behind the two cross grinding devices 17, 18 with pressure beams, a longitudinal grinding device 23 with pressure beams 23a is arranged. This formed as High-grinding longitudinal grinding apparatus 23 has a fixed guide body 2 ^l \ on the one hand attached to a support arm 25 on the stand 11 and on the other hand is supported by a pivotal support 26 on the stand 12th The connection between the pivotable support 26 and the stand 12 can, for example, be released by changing the belt by means of a locking lever 26a.

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On the box-shaped guide body 24, which is provided, for example, with four guide tracks 27 bevelled on the longitudinal edges, two bearing plates 28 and 29 including one fastened between them, partially enclose the guide body, rolling over the traverse 3o by means of cam roller bearings 31 transversely to the workpiece feed direction. Lateral cuffs 3oa cover the part of the guide body that has remained free from the cross member 3o. In the upper ends of the end shields 28 and 29, a drive roller 32 driven by a motor 32 for a grinding belt 3 ¹ J is rotatably mounted on an axle 37. This wide, endless sanding belt 34 runs over this drive roller 32 and over lower rollers 35 and 36 arranged in front of and behind the pressure beam 23a For the centering regulation of the grinding belt 34, for example, an electropneumatic control device with compressed air cylinder 4o is provided, with which the axis 37 of the drive roller 32 around a universal joint 41 or the like. is moved when one of the edges of a sanding belt 34 is in its immediate vicinity arranged, not shown lateral limit switches touches.

The cross member 3o with end shields 28 and 29 and the other parts of the wide belt grinding machine 23 connected therewith are driven by a motor 42 via a spindle 43 and one in the end shield 29 built-in spindle nut 44 on the guide body 24 emotional. The back and forth movement (reversion) of the aforementioned parts of the broadband, generated by the reversible motor 42

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Grinding machine 23 are in the two end positions by limit switches 45 and 46 limited, which in turn cause the reversal of the motor 42 when these moving parts each one Have reached the end position. The area of to-and-fro movement is arranged to be movable on a rail 47 by moving the Limit switch 45 adjustable.

The pressure bar 23a is arranged with a parallel linkage 48 on the end shields 28 and 29 so that it can move in height. In front of and behind the deflection rollers 35 and 36 for the grinding belt 34 a pressure rollers or pressure rollers 49 and 50 are provided for guiding the workpiece on the conveyor belt 15. In one plane with the pressure roller or the pressure rollers 5o lies a construction roller, not shown, which is actuated by the workpiece 52a passing through and thus automatically controls the downward and upward movements of the pressure bar 23a caused by a compressed air cylinder 51 with piston rod 51a via a shaft 51b. For this purpose, clamps 51g are fastened to the shaft 51b, which is supported in bearings 51c, and these clamps support the pressure beam 23a at two external points via levers 51d and 51e with holding feet 51f. By rotating the shaft 51b , the pressure beam 23a is lowered or raised.

Vm the rectilinearly traversing workpiece 52a on the surface full to grind, but not to grind through the workpiece edge, If the pressure surface of the Oruckbalkene 23a moved back and forth with the movable part of the wide belt grinding machine by a Einfelleinriohtung controlled. This setting device uses a device to pre-set the width of the traversing

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Workpiece 52a as well as an automatic and dependent device operating from contact roller control and reversing movement for adapting the pressure surface of the pressure bar 23a to the workpiece 52a running along a stop ruler 52.

The guide body 24 is closed at its free end by a bearing plate 53, at the upper end of which the motor 42 and the spindle 43 are mounted. At the lower end of this end shield 53 there is a vertical guide 54 for the end of a guide rail 55 which is immovably mounted therein in the axial direction and whose other end rests in an identical vertical guide 56 located on the support arm. The vertical guides 54 and 56 allow the guided beams 23a in the pressure guide rail 55, the downward and upward movements of the pressure bar participate 23a.

Due to its indirect connection to the end shields 28 and, the pressure beam 23a can be moved back and forth transversely to the workpiece feed direction. The guide rail in the pressure beam 23a is guided in a suitable manner, for example by means of ball bearings 55a, the arrangement of which is adapted to the particular shape of the guide rail 55. Running rails 57 and 58 are guided in the guide rail 55 in an adjustable and lockable manner, which are provided with bevels 57a, 58a at the ends facing one another. These run-on bevels 57a, 58a run through a steel plate 65 in accordance with the required gradual lifting of the lower one

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formed pressure surface of the pressure beam 23a next to both longitudinal edges of the workpiece 52a passing through. The running rail 58 is provided with bores 59 for pre-setting and locking, in which, corresponding to the width of the workpiece passing through, a locking pin 6o engages, which is mounted on both sides of the running rail 58 in a fork piece 6l located on the guide rail 55.

The lower steel plate 65 of the pressure beam 23a is fastened by tie rods at its two longitudinal edges at intervals 66 and 67 carried, which are screwed with their upper ends to pivot levers 68 and 69, which like a pivot lever 7 o, on a

in bearing blocks 71 and 72 mounted common shaft 7 ^ are attached. The pivot lever 7o carries at its free end a ball bearing 7 ¹ I, which rolls on the running rails 57 and 58 during the reversing movement of the pressure bar 23a.

With the setting of the running rail 58 according to the workpiece width the corresponding distance between the free ends of the running rails 57 and 58 is fixed. This pushes it out of the steel plate 65 formed pressure surface of the pressure beam 23a only ever there on the sanding belt 34, where the workpiece 58a is under the Pressure bar 23a is located - without prejudice to the reversing movement de3 pressure bar 23a.

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10881 ^ / 0355

The machine Io or machine group according to the invention works as follows :

For grinding similar workpieces of a certain width, the corresponding working width on the two pressure beams of the cross grinding device 17 and 18 and on the running rail 58 of the pressure beam 23a, as well as the range of the reversing movement, are set by means of limit switches ^l \ 5 . In the exemplary embodiment of the invention described here, the full reversion range is effective when the workpiece width is not greater than the difference between the maximum grinding belt width and the maximum reversion range.

The workpieces 52a run on the conveyor belt 15 under the pressure beam of the Qurschleifvorrichtungen 17, l £ and the pressure beam 23a through which, in a known manner, one after the other in and out of attack by the contact rollers arranged in front of them to be brought.

In order to achieve the best possible sanding quality by overlapping the sanding tracks on the workpiece, the pressure bar 23a and the associated machine parts of the wide belt sanding machine are constantly moved back and forth across the feed direction in the set area. This reversing movement is transmitted from the hot or ¹ 12 via the spindle 45 to the reversing part of the wide belt grinding machine. ^ At the end of the reversing range, end shield 28 actuates limit switch k5 or end shield 29 actuates limit switch HS , which reverses motor * i2 and reverses the direction of rotation of spindle. $ 3

wide sanding belt follows the revision movement. The lateral shear forces generated during the grinding process reduce the lateral running of the grinding belt 34, the has the consequence that the device described for the center run regulation needs to be less effective and a better one Causes grinding pattern.

The pressure bar 23a also takes part in this reversing movement. Since the passing workpiece is moved in a straight line on the one hand and does not take part in the reversing movement taking place transversely to the feed direction, but on the other hand must be constantly touched over the full width of the grinding belt 3 ^ pressed by the pressure beam 23a while passing under the pressure beam 23a, it is preferred that The effective pressure surface of the pressure beam 23a formed by the steel plate 65 is permanently displaced. For this purpose, the ball bearings 7 ** roll alternately depending on the set areas for reversing movement and workpiece width on the locked running rails 57 or 58 or are located at the distance between the free ends of the running rails 57 ₃ 58 above the workpiece and do not practice there Puncture out. Where at a certain point in time of the reversing movement the ball bearings Jk do not roll on the rails 57 and 58, the tie rods 66 and 67 are in the lowest position and the corresponding section of the pressure surface of the pressure bar 23 a presses the grinding belt 34 during the grinding process the workpiece 52a passing through. Since the guide rail 55 is only axially movable in the pressure beam, it makes the down and up

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movements of the pressure bar 23a with: it is guided with the running rails 57 and 58 accordingly in the vertical guides 5 ^ and 56 in the vertical direction.

The pressure bar 23a is preferably box-shaped and provided with a U-rail 55b inserted from above, on which the ball bearings 55a are rotatably mounted and which run along the guide rail W 55 extending in the interior of the U-rail 55b.

There is an air gap between the pressure beam 23a and the steel plate 65 65a, foam rubber pillow or the like. turned on to the pressure bar to train elastically resilient.

The reversing movement can also be carried out by other devices, for example by mechanical adjustment of the axes of a reversing roller be brought about in the horizontal or vertical direction or by a fe idler pulley.

With the machine according to the invention, workpieces 52 a, which are transported in a straight line, are ground transversely according to the exemplary embodiment described with two narrow grinding belts running in opposite directions of the transverse grinding devices 17, 18 and a wide grinding belt 34 is longitudinally re- ground in the feed direction, with the reverse movement of the broadband grinding unit 23 in cooperation with the two transverse grinding devices 17, 18 an excellent surface quality of workpieces is achieved.

" ¹⁵ " 109811 / 03-55

It is within the scope of the invention to select another embodiment 2U in which, under a fixed (not infrequently displaceable) broadband grinding device, the workpieces are pushed against the original feed direction while maintaining their longitudinal axis at a certain angle (ie obliquely) and after the grinding process is finished, they are returned to the original feed path in the opposite (ie mirror-inverted) direction, with effective pressure bar attack surface such as the steel plate 65 described above moving so that it is always located above the workpiece passing through.

According to a fourth embodiment of the invention, the Reversing movement of the wide belt grinding machine in such a Rhythm can be interrupted, like the machine with workpieces are fed at a distance from each other. This is done on the individual Workpiece the bevel movement is only effective in one direction, because they depend on the feed rate and Work piece length is a contact roller arranged in front of the machine is switched automatically.

Instead of a print bar there was also a contact roller be.

1 0? 3 1 1 / ö 2 3

Claims (10)

1G52ÜS1-16 patent claims 1. Method for painstaking, in particular, a very fine grinding large, plate-shaped workpiece, one after the other is subjected to several grinding operations, thereby characterized in that with the same feed direction initially only transversely to the feed direction and then is then sanded essentially parallel to the feed direction. 2. The method according to claim 1, characterized in that it is sanded with surface pressure. 3. The method according to claim 1 or 2, characterized in that when grinding a parallel to the feed direction Grinding marks deflecting grinding transverse movement is made. 4. Machine for Pein- especially fine grinding of large, plate-shaped workpieces that are successively subjected to several grinding processes, characterized in that one or more cross grinding devices are arranged one after the other over a transport device preferably moving in the same direction, which a broadband longitudinal grinding machine with a reversing movement is connected downstream between the sanding belt and the continuous workpiece. -17- 10981 1/0355 5. Machine according to claim 4, characterized in that grinding machines (17, 18) each serve as cross-grinding devices with an elastic pressure beam and an intermediate sanding belt and pressure bar switched on, endlessly rotating pressure lamella belt are provided. 6. Machine according to claim 4 and 5 _3, characterized in that the broadband - longitudinal _{sanding machine with a reversing, preferential Λ} meadow endlessly revolving sanding belt (34) is provided, which is by an elastic pressure beam (23a) acting on the inside efc grinding workpiece (52a) is pressed. 7. Machine according to claims 4 to -6, characterized in that the grinding belt (34) by means of a regulating its center run η device adjustable mounted 1st. 8. Machine according to claims 4 to 7, characterized in that the pressure bar (23a) with the sanding belt drive device reverse " Can be stored in the machine frame. 9. Machine according to claims 4 to 8, characterized in that the pressure bar (23a) with sanding belt drive device in since union mounts such as end shields (28, 29) or the like. is held , which are mounted displaceably by a displacement device such as a spindle (43) or the like. " ^l8 " 109811/0355 -ίδιο. Machine according to claims 4 to 9, characterized in that the lateral supports (28,29) of the pressure bar (23a) and the grinding belt (34) on one in the machine frame transversely to the direction of the ¥ ork-piece _s arranged guide body (cross member) (24) are stored. 11. Machine according to claims 4 to Io, characterized in that the guide body (24) is pivotably mounted in the machine frame. 12. Machine according to claims 4 to 11, characterized in that the guide body (24) is rectangular or round in cross section with guide surfaces (27) arranged on the edges or opposite sides, on which the end shields (28,29) are bearing Run along the rollers (31). 13. Machine according to claims 4 to 12, characterized in that the effective pressure surface (65) of the pressure bar ( 23a ) can be changed by means of an adjusting device. -19- 109811/0355 I ^. Machine according to claims 4 to 13 » characterized in that a steel plate (65) is provided as the pressure surface of an elastically flexible pressure beam (23a) ₃ which is lifted by tie rods (67) and pivot levers (69) in the outer areas and in the grinding area as an effective pressure surface is kept lowered. 15. Machine according to claims 4 to 14, characterized in that the free ends of the pivot lever (69) or the like by means of rollers. (7U) are guided on two parallel to the pressure beam (23a), an intermediate space between running rails (57, 58). 16. Machine according to claims 4 to 15, characterized gekennzecj ^ hnet that the space corresponding to the desired effective pressure surface between the rails (57 _S 58) can be adjusted by their length-adjustable storage. 17. Machine according to claims H to 16, characterized in that the running rails (57 _a 58) are displaceably mounted on a guide rail (55) extending over the width of the machine. 18. Machine according to claims 4 to 17, characterized in that that the pressure beam (23a) by means of rollers, ball bearings (55a) or the like, is guided on the guide rail (55). -2o- 10981170355 -2ο- 19 · Machine according to claims 4 to 18, characterized by that the box-shaped pressure beam (23a) by means of rollers (55a) or the like arranged in its interior. at the is guided through its interior extending Pührungsschiene (55). 2o. Machine according to Claims 4 to 19, characterized in that that the pressure beam (23a) is connected via articulated levers (51e) to a shaft (51b) which is driven by a pressure-controlled verse sub-device is rotatable. 10 9 8 11/0356 Blank page