EP0173802B1 - Abrasive blasting machine with at least one rotary holding device for workpieces - Google Patents

Description

The invention relates to a centrifugal jet machine with at least one rotating workpiece holding device, as characterized in the preamble of claim 1.

For the blasting treatment of predominantly cubic workpieces such as B. cylinder blocks, cylinder covers, gear housings or similar workpieces, rotatable workpiece holding devices are required, which ensure a secure hold of the workpieces and at the same time enable all-round blasting treatment, the device should be designed so universally that workpieces of different sizes and shapes can be used without time-consuming retooling work can be blasted.

A conveyor device for cylinder blocks or similar workpieces by means of a centrifugal jet machine is known (DE-B-2 510 827), in which the workpiece support has a fixed dimension with respect to the axis of rotation, so that centric rotation of the workpiece is only possible at a certain workpiece height.

With an eccentric rotation of the other workpieces, no uniform blasting treatment is guaranteed, moreover, the eccentric holding of the workpiece has a disadvantageous effect on the clamping device and the rotary drive.

The workpiece support shown in this document is only suitable for cylinder blocks, so that complex conversion is required for other workpiece shapes.

A centrifugal jet machine with a workpiece holder of the type mentioned is known (EP-A-0100 944). In this embodiment, the support plane is adjustable to the axis of rotation, but separate adjustment devices with drives are required for their adjustment and for the tensioning or holding device, which means that the device is very complex and prone to failure.

The object of the present invention is to provide a centrifugal jet machine with at least one workpiece holding device of the type mentioned at the outset, by means of which workpieces of different shapes and sizes are held firmly in a central position with respect to the axis of rotation, the construction effort being considerably less than the known devices and the adjusting devices less prone to failure , especially should also be better protected against centrifugal jets.

In addition, the adjustment of the workpiece holding device to the respective workpiece height should be independently adjustable depending on the workpiece to be blasted, so that fully automatic operation without manual changeover work should be possible even with continuously different workpieces.

According to the invention, this is solved by the characterizing features stated in claim 1.

Further advantageous embodiments of the invention are characterized in the dependent claims.

The features according to the invention ensure that the workpiece holding device can be adjusted to the height of the workpiece to be blasted by means of a swivel drive and can be held firmly with the same swivel drive after the workpiece has been inserted. In this case, a central position of the workpiece with respect to the axis of rotation is always ensured for the purpose of uniform blasting treatment and the least possible imbalance of the rotating device.

The invention is shown in simplified form in exemplary embodiments in the accompanying drawings and described below.

• Figur 1 einen Teilquerschnitt durch eine Schleuderstrahlmaschine mit einer rotierenden Werkstückaufnahmeeinrichtung,
• Figur 2 einen Schnitt entlang der Linie 11-11 von Fig. 1,
• Figur 3 einen Schnitt entlang der Linie III-III von Fig. 1,
• Figur 4 eine Ausführungsvariante von Fig. 1,
• Figur 5 eine Ansicht in Richtung A von Fig. 1 in einer ersten Arbeitsstellung,
• Figur 6 eine Ansicht entsprechend Fig. 5 in einer zweiten Arbeitsstellung,
• Figur 7 einen Schnitt entlang der Linie VII-VII von Fig. 4 in der Arbeitsstellung gemäss Fig. 5,
• Figur 8 einen Schnitt entsprechend Fig. 7 in einer Arbeitsstellung gemäss Fig. 6,
• Figur 9 eine weitere Ausführungsvariante mit Federtrieb entsprechend Fig. 4 in einem Teillängsschnitt,
• Figur 10 ein Schnitt entlang der Linie X-X von Fig. 9,
• Figur 11 eine weitere Ausführungsvariante von Fig. 1 in einem Teillängsschnitt und
• Figur 12 ein Schnitt entlang der Linie XII-XII von Fig. 11.
• Fig. 1 zeigt eine Strahlkammer 1 einer Schleuderstrahlmaschine zwischen deren Seitenwänden 2 mindestens eine Werkstückaufnahmeeinrichtung 3 angeordnet ist.

Show it :

• FIG. 1 shows a partial cross section through a centrifugal jet machine with a rotating workpiece holding device,
• FIG. 2 shows a section along the line 11-11 of FIG. 1,
• 3 shows a section along the line III-III of FIG. 1,
• FIG. 4 shows an embodiment variant of FIG. 1,
• 5 shows a view in the direction A of FIG. 1 in a first working position,
• FIG. 6 shows a view corresponding to FIG. 5 in a second working position,
• FIG. 7 shows a section along the line VII-VII from FIG. 4 in the working position according to FIG. 5,
• 8 shows a section corresponding to FIG. 7 in a working position according to FIG. 6,
• FIG. 9 shows a further embodiment variant with spring drive corresponding to FIG. 4 in a partial longitudinal section,
• FIG. 10 shows a section along the line XX from FIG. 9,
• Figure 11 shows a further embodiment of Fig. 1 in a partial longitudinal section and
• FIG. 12 shows a section along the line XII-XII from FIG. 11.
• 1 shows a blasting chamber 1 of a centrifugal blasting machine between whose side walls 2 at least one workpiece holding device 3 is arranged.

The workpiece holding device 3 consists of a workpiece support device 4, a holding device 5, of bearing parts 6 arranged on both sides, each with a swivel drive 7. Usually, only the arrangement of a swivel drive 7 on one of the two bearing parts is required.

The bearing part 6 has a raw shaft 8, which is rotatably mounted in bearings in the side wall 2 and by means of a rotary drive 9 and z. B. a sprocket 10 attached to the hollow shaft 8 is driven. On the blasting chamber side, the bearing part 6 is designed as a gear housing 11 in which the support device 4 and the holding device 5 is pivotally mounted by means of trunnions 12, the pivot axes 14 being arranged diametrically opposite one another at the same distance from the axis of rotation 13.

To the bearing journal 12 11 tooth segments 15 are fastened in the gear housing, which are operatively connected to a gear 16 arranged centrally to the axis of rotation 13. The gearwheel 16 is fastened to a shaft 17 mounted in the hollow shaft 8, on the free outer end of which a slip-on gear 18 with an electric motor 19 designed as a standstill motor is arranged. A hydraulic or pneumatic motor or an electric brake motor can also be used as swivel drive 7. Instead of the toothed drive 15, 16, a chain, crank or other mechanical swivel gear can also be installed in the gear housing 11.

The co-rotating slip gear 18 is on the bearing part 6 z. B. articulated on the sprocket 10 by means of a bracket 20. The two bearing parts 6 are connected to each other for reinforcement by means of rods 21. (See Fig. 3).

As can be seen from FIG. 3, the support device 4 and the holding device 5 each have a grate 22, which are of identical design in the exemplary embodiment shown.

If the workpiece holding device is to be designed to hold two or more workpieces 23, the holding device 5 should have at least one movably articulated holding claw for each workpiece.

The two gratings 22 have a support level 24 or a holding level 25, which, for. B. runs in the respective pivot axis 14 (see FIG. 3) or at least in each case with the same distance to this or to the axis of rotation 13. However, as shown in FIGS. 5 and 6, an arrangement is particularly advantageous in which the workpiece support device 4 and the holding device 5 are designed to be angled from the support levels 24 or support levels 25 to the pivot axes 14.

When the support and holding device is pivoted simultaneously by means of the swivel drive 7, the distance between the support plane 24 and the holding plane 25 from the axis of rotation 13 is changed uniformly, the two planes always occupying a position parallel to one another. This ensures that the workpiece holding device for workpieces 23 of different heights can each be set so that they are held in the center of the axis of rotation 13. Only one drive is required to adjust the holder and clamp the workpieces.

For an automatic operation of the blasting machine and its loading with different workpieces in each case, the rotary drive 9 and the swivel drive 7 are operatively connected to a program control, by means of which the support device 4 and the holding device 5 are dependent on a programmable or scanned workpiece height 26 to a specific insertion distance 27 are pivoted and the support plane 24 is rotated by the rotary drive 9 such that it corresponds to a preferably horizontal, height-adjustable insertion plane 28. Rotary drive 9 and rotary drive 7 are each provided with a measuring device 29 and 30 for determining the respective position, which are operatively connected to the program control. After the workpiece 23 has been inserted in the center, the swivel drive 7 is actuated, the workpiece 23 being held firmly in the center by simultaneous pivoting of the support device 4 and the holding device 5, and a sufficient clamping force by the standstill motor during the rotation of the workpiece 23 during the blasting treatment is produced.

In a further embodiment variant according to FIG. 4, the workpiece receiving device 3 can be designed to be supported on one side only, so that the workpiece support device 4 and the holding device 5 are overhung on one side in a bearing part 6. For smaller and lighter workpieces, this results in a greatly simplified version. The swivel drive 7 can in this case be designed in accordance with the manner shown in FIGS. 1 and 2, or else in further embodiment variants as described below for FIGS. 4 to 12.

In an embodiment variant according to FIGS. 4 to 8, the bearing part 6 is in the side wall 2 z. B. a blasting chamber 1 by means of a hollow shaft 8 rotatably and by the rotary drive 9 z. B. driven via a sprocket 10.

7 and 8, a gear 31 is arranged in the bearing part 6, centered on the axis of rotation 13, which preferably has only two tooth segments 31e lying opposite one another. The gear wheel 31 is attached to one end of a shaft 32 rotatably supported in the hollow shaft 8, at the other end of which a disk 33 is attached with a cam 34. The gear 33 is operatively connected via intermediate gears 35 to toothed segments 36 arranged on the swivel axes 14, the translation between the gear 33 and the toothed segment 36 being 1: 1. A lever 37 is attached to each pivot axis 14, on the end of which the stored force of a compression spring 39 acts via a pressure piece 38. This spring force holds the workpiece 23 between the support plane 24 and the holding plane 25 (FIG. 6). On the wall 2, a preferably pneumatically or hydraulically displaceable pin 40 is arranged, which forms a stop 41 for the gear 31 in the lowest position with the cam 34.

The removal of a workpiece held between the workpiece support device 4 and the holding device 5 and rotating according to arrow 42 takes place as described below.

During rotation, the bolt 40 (FIG. 4) is in the lower locking position pushed, the co-rotating cam 34 abuts the pin 40 and the gear 31 is stopped in the position shown in Fig. 8. In this position, the support plane 24 is also horizontal according to FIG. 6. Since the bearing part 6 is rotated further in the direction of the arrow 42 by the rotary drive 9, the intermediate wheels 35 roll on the gear wheel 31 and the toothed segments 36 are pivoted in the direction of the arrows 43 and 44, whereby against the pressure of the springs 39 the workpiece support device 4 according to arrow 44 and the holding device 5 according to arrow 43 are pivoted apart. However, since the bearing part 6 continues to rotate according to arrow 42, the support plane 24 and the holding plane 25 remain in a horizontal position until the support plane 24 corresponds to the insertion plane 28 according to FIG. 5. Here, the rotary drive 9 is stopped by a switching device (not shown) and held in the braked position until the workpiece 23 which has already been blasted has been removed and a new workpiece 23a, possibly of a different shape, has been inserted. Then the rotary drive 9 is briefly switched on in the opposite direction of rotation against the arrow 42 until an angle of rotation of approximately 45 ° is reached. During this rotation of the bearing part 6, the workpiece support device 4 and the holding device 5 are simultaneously pivoted by the force of the springs 39 until the workpiece is held firmly. After reaching the set angle of rotation, the bolt 40 is raised again and the direction of rotation of the rotary drive 9 is reversed, as a result of which the bearing part 6 rotates with the held workpiece in the direction of the arrow 42 during the blasting treatment.

9 and 10 also show an embodiment with a spring in the swivel drive. In this case, a tension spring 50 is arranged in the bearing part 6 which can be driven by the rotary drive 9 and which exerts a tensile force on a lever 51 which is fixedly connected to one of the pivot axes 14. This two-armed lever 51 is connected via a linkage 53 to a lever 52 fastened to the second pivot axis 14. A lever 54 is also articulated on the linkage 53 and is pivotally mounted in the bearing part 6. This lever 54 is rotatably connected outside the bearing part 6 with a stop lever 55, which in turn is operatively connected to an unlockable stop 56. When the bearing part 6 is rotated by means of a rotary drive 9 in the direction of the arrow 42, the stop lever 56 is simultaneously pivoted in the opposite direction when the stop 56 is pushed in, as a result of which the workpiece support device 4 and the holding device 5 are pivoted from one another against the tension of the spring 50. The mode of operation of this embodiment variant thus corresponds to the embodiment variant described with reference to FIGS. 4 to 8, the compression springs of the tension spring 50, the pinion gear corresponding to the linkage 53 and the cam 34 corresponding to the stop lever 55.

11 and 12 show a further embodiment variant, each with a motor-driven rotary drive 9 and swivel drive 7. Here, the bearing part 6 with the swivel axes 14 pivotally mounted therein is rotatably mounted in the side wall 2 by means of a first hollow shaft 60. In the first hollow shaft 60, a second hollow shaft 61 is rotatably mounted, at the end of which extends into the bearing part 6, a gear wheel 62 is arranged, which is in engagement with two circumferentially opposite intermediate wheels 64 which are rotatably supported in the bearing part by means of shafts 63. Toothed segments 65 engage in these idler gears and are fixed in a rotationally fixed manner on the pivot axes 14. The transmission ratio between the gear 62 and the toothed segments 65 is 1: 1. A further gear 66 is fastened to one of the shafts 63 and engages with a gear 67 arranged centrally to the axis of rotation 13. This gear 67 is in the bearing part 6 at the end of a in the second hollow shaft 61. rotatably mounted shaft 68, which shaft 68 can be driven by a gear motor 69 which is attached to the end of the second hollow shaft 61 and is provided with a brake 70. The second hollow shaft 61 can be driven via a slip-on gear 71 and a drive motor 72 also provided with a brake 73, this drive being articulated on the wall 2 by means of a torque support 74. By means of the pivot axes 14, the workpiece support device 4, which is either mounted on both sides (FIG. 1) or only supports on one side (FIG. 4), and the holding device 5 can be pivoted simultaneously, as already described.

For the rotation of the workpiece, the gear 67 is rotatably connected to the second hollow shaft 61, which is driven by the drive motor 72, by means of the brake 70. Since the intermediate wheels 64 cannot rotate due to the locking mechanism via the gear wheels 67 and 66, the entire bearing part 6 and with it the centrally held workpiece are rotated about the axis of rotation 13. For loading and unloading the workpiece receiving device 3, the bearing part 6 is stopped by means of switches (not shown) such that the workpiece support plane 24 runs horizontally in the lower position. When the rotary drive 9 is braked, the intermediate motor 63 and the toothed segments 65, the workpiece support device 4 and the holding device 5 are then pivoted to one another or from one another, depending on the direction of rotation of the geared motor 69, by the geared motor 69 via the toothed wheels 67, 66, with the intermediate wheels simultaneously rolling off 63 on the gear 62, the bearing part 6 is rotated so that the support plane 24 is always horizontal. To insert a new workpiece, the two levels 24 and 25 are moved so far apart that the support level 24 is at the same height as a horizontal insertion level 28 (see FIG. 5).

The variant described here as 1 to 8 or 9 and 10 also have the advantage that there is a mechanical coupling of the pivot axes 14 with a rotation of the bearing part 6 such that the support plane always remains horizontal when the device is loaded or unloaded becomes. This has the advantage that when the workpiece is clamped, the workpiece inserted in the center can no longer slip, and when loading or unloading, the insertion level always corresponds to the support level.

The side walls 2 shown in FIGS. 1, 2, 9 and 12 can be part of a drum conveyor of a multi-station blasting machine rotating about a horizontal axis, wherein a plurality of circumferentially described previously described workpiece receiving devices 3 arranged the workpieces from a loading and unloading station through one or more blasting stations and transport a drum station.

The described workpiece receiving device 3 can also be arranged between the support yokes of a overhead conveyor, by means of which the workpieces are transported from a loading station through at least one blasting chamber to an unloading station.

Such conveyors of centrifugal jet machines are described in EP-A-0 100 944.

Claims (16)

1. Abrasive blasting machine with at least one rotary holding device for the workpieces, such as e. g. cylinder blocks or similar workpieces which are to undergo blast treatment in a blasting chamber, the holding device being equipped with a workpiece supporting device positioned on at least one rotary bearing part and whose supporting plane is adjustable with respect to the rotation axis and with a retaining device which can be pressed against the workpiece or workpieces, characterized in that the workpiece supporting device (4) and the retaining device (5) are pivotably mounted in diametrically facing manner on at least one bearing part (6) and are simultaneously pivotable towards or away from one another in such a. way that their supporting plane (24) and retaining plane (25) assume a parallel position to one another in each pivoting position with respect to the rotation axis (13).

2. Abrasive blasting machine according to claim 1, characterized in that the holding device (3) has two facing bearing parts (6), on which are pivotably mounted at either side the workpiece supporting device (4) and the retaining device (5).

3. Abrasive blasting machine according to claims 1 or 2, characterized in that at least one pivot drive (7) has a chain or gear wheel (16) centrally drivable with respect to rotation axis (13) by means of an electric, hydraulic or pneumatic motor and engages with chain or toothed segments (15) located on the two pivot pins (14).

4. Abrasive blasting machine according to one of the claims 1 to 3, characterized in that a rotary drive (9) and the pivot drive or drives (7) are operatively connected to a program control, by means of which as a function of a workpiece height (26) which can be programmed in or scanned the workpiece supporting device (4) and retaining device (5) can be pivoted to a given slide-in distance (27) and the supporting plane (24) is adjustable by rotary drive (9) corresponding to a preferably horizontal slide-in plane (28).

5. Abrasive blasting machine according to one of the claims 1 to 3, characterized in that a pivot drive (7) and a rotary drive (9) are so mechanically operatively interconnected on pivoting the workpiece support device (4) and retaining device (5) that only in the case of simultaneous rotation of bearing part (6) only the distance of the support plane (24) and retaining plane (25) with respect to rotation axis (13) is symmetrically variable and the set angular position, preferably the horizontal position of the planes (24, 25) is constant.

6. Abrasive blasting machine according to one of the claims 1, 2 or 5, characterized in that the pivot drive (7) has at least one spring (39, 50) operatively connected with in each case one lever (37, 51, 52) of the workpiece supporting device (4) and the retaining device (5).

7. Abrasive blasting machine according to claim 6, characterized in that the spring is constructed as a compression spring (39), that rack and pinion drives (36) are arranged on the pivot pins (14) of workpiece support device (4) and retaining device (5) and are operatively connected by means of in each case one idler gear (35) to a gear (31) located centrally with respect to rotation axis (13) and that a cam (34) connected in non- rotary manner to gear (31), together with an unlockable bolt (40) forms a stop (41).

8. Abrasive blasting machine according to claim 6, characterized in that the spring is a tension spring (50), that levers (51, 52) are arranged on the pivot pins (14) of the workpiece support device (4) and the retaining device (5) and which are operatively connected by a linkage (53) and that a stop lever (55) connected to linkage (53) is operatively connected with an unlockable stop (56).

9. Abrasive blasting machine according to one of the claims 1, 2 or 5, characterized in that a first drivable gear (62) arranged centrally with respect to rotation axis (13) is operatively connected by means of two idler gears (63) with rack and pinion drives (65) located on pivot pins (14) and that a second gear (67) positioned centrally with respect to the first is operatively connected to the pivot pins (14) via a further gear (66) connected in non- rotary manner with at least one of the idler gears (65).

10. Abrasive blasting machine according to claim 9, characterized in that the first gear (62) is positioned on a hollow shaft (61), which can be driven by means of a drive motor (72) and that the second centrally arranged gear (66) can be driven by a further motor (69) via a shaft (68) mounted in hollow shaft (61).

11. Abrasive blasting machine according to one of the claims 1 to 10, characterized in that the support plane (24) and retaining plane (25) are in each case equidistant to pivot pin (14).

12. Abrasive blasting machine according to claim 11, characterized in that the workpiece support device (4) and retaining device (5) are constructed in angled manner from support plane (24) or retaining plane (25) to pivot pins (14).

13. Abrasive blasting machine according to one of the claims 1 to 12, characterized in that the workpiece support device (4) and retaining device (5) are identically constructed.

14. Abrasive blasting machine according to one of the claims 1 to 13, characterized in that several workpiece support devices (3) are arranged in a drum conveyor rotating about a horizontal axis and by means of which the workpieces can be brought from a loading and unloading station into at least one blasting station.

15. Abrasive blasting machine according to one of the claims 1 to 13. characterized in that several workpiece support devices (3) are arranged on a suspended conveyor, by means of which they can be conveyed from a loading station, through at least one blasting chamber to an unloading station.

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