EP0018023B1 - Separating device for vibratory finishing machines - Google Patents

Abstract

1. A separating device for low-pressure vibratory grinding machines comprising an annular working container (2), consisting of a movable run-up ramp, which is disposed in the working container (2), and an elevated sieving zone, which run-up ramp (3/13) when in mch> position of rest mch< is disposed below the revolving contents of the container and when in mch> operative position mch< extends as far as to the leading edge of the sieving zone disposed above the revolving contents of the container and when it has assumed the mch> operative position mch< temporarily forms an overflow edge (4, 14), which protrudes above the surface of the revolving contents of the container and extends substantially transversely to the direction of travel, characterized in that the sieve (5, 15) of the sieving zone is also movably arranged and its leading edge is adapted to be moved to the exposed overflow edge (4, 14).

Description

The invention relates to a separating device for vibratory vibratory grinding machines with an annular work container according to the preamble of claim 1 (US-A-3 633 321; DE-A-2 606 510).

Vibratory vibratory grinding machines are used for surface treatment - such as deburring, edge rounding, grinding, polishing, etc. - of workpieces, whereby a spring-loaded work container is set in motion by a vibration drive and the bed of workpieces and processing equipment contained therein is circulated and conveyed. The treatment effect is based on the relative movement between workpieces and processing means, which essentially consist of lumpy or granular abrasive grains or the like and to which liquid agents are often added to improve the removal of the abrasion and, if appropriate, to supplement the chemical treatment of the workpiece surface.

In the case of annular work containers, a plurality of revolutions are generally required in order to finish the workpieces. The workpieces are then separated from the processing means and led out of the machine, while the processing means remain in the working container for the treatment of further batches.

For the separation and removal of the workpieces, separating devices are used, by means of which the circulating container contents are conveyed to an elevated sieve section, the mesh size of which is dimensioned such that the processing means can fall back through the sieve into the work container, while the workpieces pass over the sieve to a discharge chute or the like.

Two basic types of separators can be distinguished. In the case of ring-shaped working containers with a container bottom that rises helically in the conveying direction, the conveying to the level of the sieve section takes place already during the processing phase, but the surrounding container contents are dropped over a fall or slide distance from the upper container part to the lower container part until the surface treatment of the Workpieces is finished. For separation, the falling back is interrupted and the container contents are conveyed to the sieve section arranged in the extension of the highest container bottom part. For this purpose, either a passage opening located between the highest container bottom part and the permanently installed discharge section is bridged by a sieve part (cf. DE-A-1502565, Fig. 7/8; DE-B-1 288 947; US-A-3 422 577) or else a movable sieve stretch led to the overflow edge of the highest part of the container bottom (cf. DE-A-2 047 406; DE-A-2 315 449, Fig. 3).

In the case of ring-shaped work containers with a non-rising container bottom, the conveying is carried out to the level of the usually permanently installed sieve section by inserting vertical baffle walls into the circulation path of the container contents, via which the container contents then rise to the sieve section as a result of the oscillation impulses (cf. DE-A-2 002 646, Figs. 1 and 3, item 32; DE-A-2 606 510, Fig. 2, item 34) or by inserting or swiveling inclined ramps or flaps into the circulation path for separation (see DE- B1-2721943, Fig. 4).

In addition, other forms of separating devices have become known, in particular those in which the required lifting-up takes place partly via a corresponding design of the container bottom and partly via movable flaps or the like (cf. DE-A-2 425 095, Fig. 2; US-A- 3 633 321, Fig. 3).

All of these separating devices have a fundamental disadvantage. The parts that are moved for separation (flap, ramp or sieve) must be pushed or swiveled against a fixed stop, whereby there is always the risk that workpieces or processing equipment can become trapped and the intended movement cannot be completed. As a result, the openings to be bridged are not completely closed, so that workpieces do not reach the screen section, but fall through and are then further processed with the new batch, and as a rule they become unusable due to the dimensional tolerances being undershot. In particular, the clamped workpieces are not removed and / or damaged.

In order to be able to recognize workpieces that are not properly separated and therefore double or triple machined or damaged in these cases, all pieces of a batch must be checked in order to be able to sort out the parts with undersize and errors. As a result of the incomplete separation, not only are individual pieces unusable, but a separate operation must be switched on for checking.

These disadvantages of the separating devices with moving parts, which are guided against a fixed stop, can be demonstrated in all known embodiments.

A certain exception are only those work containers with a rising bottom, in which a sufficiently high steep step is provided between the top and bottom bottom part, so that the pouring cone forming in the lower part of the container does not reach the upper edge of the steep step, in this case one of workpieces and editing free edge is available. However, such embodiments can only be used if the workpieces are insensitive and are not damaged when falling over the high steep step. However, since very high demands are generally placed on the surface quality of the workpieces, the high steep steps mentioned can only be used in exceptional cases, or there is only a very limited area of use for vibratory vibratory grinding machines with such steep steps.

The registration is based on the task of avoiding the aforementioned disadvantages, i. That is, to create a separating device with which 100% separation can be guaranteed, the function of which is not impaired by the clamping of workpieces or processing means, and with which vibratory vibratory grinding machines are not subject to any restrictions in their area of application, in particular also for workpieces that are sensitive to impact and shock can be used.

This object is achieved according to the invention by a separating device, which is characterized in that the sieve of the sieve section is also arranged to be movable and its front edge can be brought up to the free-standing overflow edge.

The invention is based on the knowledge that the complex problem described can only be solved in that, at least temporarily, a free-standing overflow edge has to be created by means of a movable ramp and that, in addition, a movable screen has to be provided which has its leading edge on the free-standing overflow edge in the working position can be brought in without workpieces being trapped between the overflow edge and the front edge of the sieve. In this way it is avoided that moving parts of the separating device have to be moved against a fixed stop, the "pinching problem" always being present. The ramp according to the invention moves from the bottom through the revolving container contents upwards until a free-standing overflow edge is formed above the free surface of the revolving container contents, to which the movable sieve section can then in turn be easily brought up or which acts directly as a stop for the movable one Strainer can serve. In this way, perfect separation is possible without having to resort to the high steep step known in the prior art with the risk of damage to the workpieces.

The run-up ramp is expediently designed as a flap which is pivotably mounted in the base region of the working container. It can also be advantageous if the ramp is designed as a slide plate, which is sunk below the bottom of the container in the rest position. In a further development of the inventive concept, it is provided that the run-up ramp in the working position can be adjusted to rise in the flow direction of the container contents at an angle of 0 to 90 ° to the horizontal. The overflow edge is preferably straight and extends in the working position substantially parallel to the free surface of the rotating container contents. When the ramp is designed as a slide plate, on the other hand, it can be expedient to design the overflow edge in such a way that it corresponds to the contour of the container bottom and essentially closes the bottom slot in the rest position. According to the invention, the screen should then have a cross-sectional shape adapted to the overflow edge.

According to a further embodiment of the inventive concept, it is provided that the swivel axis is arranged above the lowest-lying bottom area and that the container bottom is designed to rise in the flow direction up to the swivel axis. Furthermore, it is possible to provide a dam which is approximately triangular in cross section in the container bottom and to arrange the pivot axis in the region of its horizontally running upper edge. If the ramp is designed as a slide plate, a dam with an approximately triangular cross-section can also be provided in the bottom of the container, a slot opening being formed in the upper edge of the dam for the slide plate, which opening is essentially closed when the slide plate is in the rest position.

The movable sieve can be arranged pivotably about a horizontal axis or can be displaced essentially transversely.

Furthermore, it is expedient to form the run-up ramp from two parts which partially overlap one another, the length of the run-up ramp being variable by changing the overlap area. In this way, different angles of attack of the ramp can be set in a simple manner without any other changes to the machine being necessary.

• Fig. 1 zeigt einen vertikalen Schnitt durch eine Separiereinrichtung sowie einen Teilschnitt durch eine Vibrationsgleitschleifmaschine mit in Förderrichtung ansteigendem Behälterboden; Separiereinrichtung in Ruhestellung;
• Fig. 2 zeigt die Separiereinrichtung gemäß Fig. 1 in Arbeitsstellung;
• Fig. 3 zeigt eine Vibrationsgleitschleifmaschine ähnlich Fig. 1 und 2 mit einer alternativen Gestaltung des beweglichen Siebes;
• Fig.4 zeigt einen Teilschnitt durch eine Vibrationsgleitschleifmaschine mit nicht ansteigendem Boden und einer als Schieberplatte ausgebildeten Auflauframpe.

Exemplary embodiments of the invention are explained in more detail below with reference to the figures:

• 1 shows a vertical section through a separating device and a partial section through a vibratory vibratory grinding machine with a container bottom rising in the conveying direction; Separating device in the rest position;
• FIG. 2 shows the separating device according to FIG. 1 in the working position;
• Fig. 3 shows a vibratory vibratory grinding machine similar to Figures 1 and 2 with an alternative design of the movable screen.
• 4 shows a partial section through a vibratory vibratory grinding machine with a non-rising bottom and a ramp designed as a slide plate.

The vibratory vibratory grinding machine 1 according to FIG. 1 consists of a foundation frame 18 or the like, on which an annular work container 2 is mounted such that it can vibrate via springs 19. The working container 2 is set into three-dimensional vibrations by an oscillation or vibration drive (not shown), as a result of which the container contents consisting of workpieces and processing means are set into a circular circulating movement around the main container axis and into a conveying movement parallel to the main container axis. The contents of the container behave more or less like a liquid, the free surface of which adjusts itself approximately during the processing phase according to the line shown in broken lines in FIG. 1. The contents of the container "flow" from the upper part 17 of the container via the flap 3 in the rest position into the lower part 22 of the container. The flap is pivotable about the approximately horizontally arranged axis 7 and has an overflow edge 4. During the processing phase, the horizontally displaceable screen 15 is retracted so far that its front edge 16 does not interfere with the flow of the container contents.

In Fig. 1, the flap 3 is also shown in dashed lines in the working position, with its front edge 14 clearly protruding beyond the free surface of the container contents and forming an edge free of workpieces and processing means downstream. Downstream from the flap 3 (ramp), the material fill does not reach the free overflow edge 4 of the flap.

FIG. 2 shows a separating device according to FIG. 1 in the working position, the free surface of the container contents now running according to the line again drawn in broken lines. The container contents "rises" over the flap 3, the overflow edge 4 and the front edge 16 of the sieve onto the sieve 15 which has been shifted into the working position counter to the conveying direction of the container contents, where the workpieces are separated from the processing means and guided out of the vibratory vibratory grinding machine. The processing means fall through the screen 15 into the container part 22 below, where they are available for processing a further batch as soon as the entire container content has once passed over the separating device.

FIG. 3 shows a vibration vibratory grinding machine similar to that in FIGS. 1 and 2, but the transition from the upper container part 17 to the lower container part 22 is comparatively steep. This steep drop is mitigated by the corresponding arrangement of the flap 3 in the rest position (shown in broken lines). In this case, the sieve 5 is arranged to be pivotable about a horizontal axis 23 and, in the working position, forms with its front edge 6 with the overflow edge 4 of the flap 3 an uninterrupted conveying path for the container contents. Following the pivotable sieve 5, a permanently installed sieve section 20 can be provided, which opens into a discharge chute 21. Otherwise, the reference numerals have the same meaning as in FIGS. 1 and 2. The free surface of the container contents which is set in the working position of the separating device is again shown by a broken line.

Fig. 4 shows an embodiment of the working container 2 with a non-rising bottom, wherein the ramp ramp is designed as a slide plate 13 (ramp ramp) with a free-standing overflow edge 14. The slide plate 13 is mounted in a guide 12 and can be moved by a hydraulic drive 23 or the like. In the bottom of the container, an approximately triangular dam 8 is provided, the upper edge of which has a slot 9 for the passage of the slide plate 13. The essentially horizontally displaceable sieve 15 has a front edge 16. All other reference numerals have the same meaning as in FIGS. 1 to 3. The free surface of the container which is obtained is shown in broken lines for the rest position and the working position of the separating device.

If it is ensured that the movable screen section in the working position swings with its front edge in absolute synchronization with the free overflow edge of the ramp, the overflow edge can be used directly as a stop for the front screen edge. If relative movements between the edges are to be expected in this area, the transition will be made "contactless", i. that is, move the screen section only as far to the overflow edge as is necessary to avoid the diarrhea or stuck workpieces in the remaining slot.

Taking these conditions into account, it is even possible to use a separately driven, i.e. H. Sieve section not stored in the working container should be provided if this is necessary or advantageous for the separation process or if the sieve section is still to be used for the further transport of the workpieces.

In addition, by means of the separating device according to the invention it is possible, with the sieve retracted, to set a drop level of a defined height in the circulation path of the container contents by adjusting the run-up ramp designed as a flap between rest and working position, if this is for workpieces that tend to stick together for processing is advantageous.

Claims (12)

1. A separating device for low-pressure vibratory grinding machines comprising an annular working container (2), consisting of a movable run-up ramp, which is disposed in the working container (2), and an elevated sieving zone, which run-up ramp (3/13) when in »position of rest« is disposed below the revolving contents of the container and when in »operative position« extends as far as to the leading edge of the sieving zone disposed above the revolving contents of the container and when it has assumed the »operative position« temporarily forms an overflow edge (4, 14), which protrudes above the surface of the revolving contents of the container and extends substantially transversely to the direction of travel, characterized in that the sieve (5, 15) of the sieving zone is also movably arranged and its leading edge is adapted to be moved to the exposed overflow edge (4,14).

2. A device according to claim 1, characterized in that the run-up edge consists of a plate (3), which is hinged adjacent to the bottom of the working container (2).

3. A device according to claim 1, characterized in that the run-up ramp consists of a slidable plate (13), which in position of rest is disposed below the bottom (17) of the container.

4. A device according to any of claims 1 to 3, characterized in that the overflow edge (4, 14) is straight and in »operative position« is substantially parallel to the free surface of the revolving contents of the container.

5. A device according to claim 3, characterized in that the overflow edge (14) is designed to match the contour of the bottom (17) of the container and to substantially close the slot in the bottom in »position of rest«.

6. A device according to any of claims 1 to 5, characterized in that the sieve (5, 15) has a cross-sectional shape which matches the overflow edge (4,14).

7. A device according to claim 2, characterized in that the hinge axle (7) is disposed above the lowermost portion of the bottom and the bottom (17) of the container rises in the direction of flow as far as to the hinge axle (7).

8. A device according to claim 2, characterized in that a dam (8) which is approximately triangular in cross-section is provided in the bottom (17) of the container and the hinge axle (7) is disposed adjacent to the horizontal top edge of said dam.

9. A device according to claim 3, characterized in that a dam (8) which is approximately triangular in cross-section is provided in the bottom ot the container, a slotlike opening (9) for the slidable plate (13) is formed in the top edge of the dam (8), and the slotlike opening (9) is substantially closed when the slidable plate (13) is in »position of restc.

10. A device according to any of claims 1 to 9, characterized in that the sieve (5) is hinged on a horizontal axis.

11. A device according to any of claims 1 to 9, characterized in that the sieve (15) is designed to be substantially transversely displaceable.

12. A device according to any of claims 1 to 11, characterized in that the run-up ramp consists of two parts which partly overlap each other.

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