DE19736252A1 - Pallet changer - Google Patents

Abstract

The invention relates to a pallet door (44) for a rotating pallet changer (16), in which a partition wall (46) placed between two pallets (19, 20) can swivel with at least one segment of the peripheral wall (49, 50) surrounding one of the pallets. The peripheral walls and the partition walls are supplemented by a compartment surrounding, at least partially, a workpiece holder to form a closed processing chamber.

Description

The invention relates to a pallet changer according to the Preamble of claim 1.

Usually when machining Coolant supplied by workpieces to one hand the stability of the tool through cooling and Increase lubrication and on the other hand by the Zer Machining process in the workpiece and in the tool brought heat from the processing point as quickly as possible dissipate.

In the automotive industry, people have started Engine, chassis or body components made from Leichtme tallen, preferably made of aluminum or magnesium alloy gene to use. The processing of such magnesium hal However, alloys are relatively problematic because the processing chips are easily flammable, so that a relatively high effort to preserve it required production security must be operated. The use of cooling lubricants based water-based bases is only possible to a limited extent because of magnesium reacts with these components, so that oily cooling lubricants must be used. Such oily However, cooling lubricants often adhere to it tendency workpiece so that this after the cutting Be be cleaned with suitable cleaning agents got to. The means used for cooling and cleaning must follow the processing / cleaning cycle to be disposed of or separated, which with a relatively ho hen effort is connected.  

In order to overcome these disadvantages, one is increasing to the extent that the workpieces are dry, d. H. without cooling lubricant to edit. Essential to this bear Processing is that the machining chips during machining transport process away from the workpiece as quickly as possible be animals. To ensure this, they are used for Dry machining used machine tools with ge closed processing chambers in which the workpiece to be machined is located and into which the ar immersed in the machine tool.

In special cases, the machining in the Bear Processing chamber still take place under inert gas, so that the Operational safety is increased.

Such machining centers for drilling and milling work by equipping with pallet changers and Pallet storage expanded to flexible manufacturing cells. Different in the known pallet changing devices are basically a pallet changer with a linear we pallet shifting station and pallet changer are designed as swivel changers. Both systems work with at least two pallets, one of which is in a processing position in which it is on a Workpiece carrier is clamped, and the other in one Transfer position in which a workpiece to be machined is stretched, which is then after editing the one work piece without delay in the processing position is pivotable. Through these measures, the span to chip time compared to machine tools without pallets lower changer.

Fig. 1, to which reference is already made, shows a plan view of a machining center 1 in which a spindle carrier 2 movable in the X and Y directions (perpendicular to the plane of the drawing) is guided over a cross guide on a stand 4 . The spindle carrier 2 carries a horizontal work spindle 6 for receiving a machining tool.

The machining center 1 also has a tool changer, which can be formed, for example, as a laterally arranged drum magazine 8 , in which the tools 10 to be supplied to the machining spindle 6 are accommodated.

A workpiece carrier (table) 12 of the machining center 1 is mounted on a machine bed, not shown, in the feed direction (Z). The workpiece carrier 12 and the work spindle 6 are surrounded by a processing chamber 14 , so that dry machining is possible. To reduce the chip-to-chip times, the workpiece carrier 12 is assigned a pallet changer 16 in which two pallets 18 , 20 are mounted on a swivel device 22 .

In the position shown in FIG. 1, the pallet 18 is in its processing position, in which it is firmly clamped on the workpiece carrier 12 by means of suitable clamping means.

The other pallet 20 is in a loading area in the transfer position in which a previously machined workpiece can be removed and a workpiece to be machined can be clamped.

The pallet changer 16 carries a swing door 26 , hereinafter called partition 26 . This forms together with the side walls 15 and circular arcuate circumferential walls 24 of the processing chamber 14 a Vollkap development of the work area, which allows a wet and dry processing. The pallet changer 16 also has an arcuate sliding door 25 , which completes a loading area for the pallet 20 and which serves as operator protection when changing the pallet.

The partition 26 is sealing against the circumferential extension 24 , so that the space in which the processing area 18 located in the processing area is separated from the workpiece loading area in which the other pallets 20 are arranged.

The closed processing chamber 14 is thus limited by the side walls of the cabin which extend along the guide for the workpiece carrier 12 , the upper half of the peripheral wall 24 and the partition wall 26 in FIG. 1. The latter is Gert gela on the pivoting device 22 so that the partition wall 26 at pivoting of the crisps Pa is also rotated by 180 °.

A disadvantage of the embodiment shown in FIG. 1 is that the volume encompassed by the peripheral wall 24 and the partition wall 26 is comparatively large, and reliable removal of chips from the processing chamber 14 is difficult.

In contrast, the invention is based on the object to create a pallet changer where the machining room is reduced to a minimum.

A pallet changer with the Features of claim 1 solved.

Through the measures according to the invention, the order catch walls and the partition wall pivoted together, so that the geometry of the circumferential walls no longer matches the Swivel radius of the partition must be adjusted, but be designed essentially according to the shape of the pallet can, so that the space encompassed by the peripheral walls is reduced to a minimum. The processing chamber leaves compared to the conventional solution  reduce so that the dead space of the processing chamber is lower and thus the chip removal is facilitated and the risk of ignition is reduced.

In a particularly preferred variant, the Partition and the peripheral wall common an H-shaped body, with the two legs of the H through the um catch walls are formed and one of the two Grasp pallets at a small parallel distance.

In this embodiment, it is preferred if the peripheral walls and the partition are made in one piece are formed so that no tightness problems in the Transitional area between the partition and the circumference wall occur. The side edges of the H-legs are provided with sealing edges and form together with the Workpiece carrier guide surrounding side walls of the Ka bine a closed processing chamber.

In an alternative embodiment, the tenwandungen formed by two U-legs, with reference slidable to the partition along its longitudinal axis are, so that the two U-legs partially one of the at can reach around the pallets. In principle, therefore the longitudinal displaceability of the two U-legs over one Pallet change cycle again formed an H, so that practically the same principle as for the previously described Lö solution is used.

The U or H-shaped pallet door, consisting of partition wall and associated peripheral walls can be by means of egg ner lifting device in the vertical direction from a directional posi tion are raised so that the pivoting without Ab slide the peripheral edges on the cabin floor can.  

The construction is particularly simple when the past written door of the pallet changer with telescopic Is provided sections on which the lifting device engages so that not the entire door but only the telescopic sections can be raised.

To seal the roof area of the processing chamber This area can also be simplified with telescopic baren sections of the door are formed on which a Actuating device for lowering so that the Door can be freely pivoted together with the pallets on the roof or the support surface of the processing chamber to lie on.

Sealing to the immovable part of the machining chamber is also done via seals, the advantageous usually on the side edges of the fixed cabin wall manure parts are arranged.

In the following, advantageous developments of the Invention explained with reference to schematic drawings. Show it:

Figure 1 is a plan view of a machining center with egg nem conventional pallet changer.

Fig. 2 is a three dimensional representation of a modern fiction, tool changer;

Fig. 3 is a plan view of the tool changer of FIG. 2; and

Fig. 4 is a schematic diagram of another game Ausführungsbei a pallet door for a tool changer.

Fig. 2 shows a schematic three-dimensional Dar position of a pallet changer 16 , which can be assigned to a machine tool, for example a machining center 1 according to FIG. 1.

The pallet changer 16 according to the invention is mounted about a pivot axis 28 running parallel to the Y direction ( FIG. 1) via a support frame 30 on a machine bed, not shown, of a machine tool, for example a machining center. On the support frame 30, a vertically extending in the representation of FIG. 2, pivot shaft 32 is supported (coaxially with the pivot axis 28) to which a transverse beam 34 is fixed.

The swivel shaft 32 is driven via a swivel motor 36 arranged in the radial direction with respect to the swivel axis 28 , the rotational movement of which is transmitted via a Winkelge 38 to the swivel shaft so that it can be rotated together with the cross member 34 about the swivel axis 28 .

The pallets 18 , 20 , of which only the pallet 20 pointing to the viewer is shown in solid lines in the illustration according to FIG. 2, are attached to support brackets 40 of the cross member 34 . The interchangeable pallets 18 , 20 have uniform interfaces to the workpiece carrier of the machining center, not shown. In addition to some manufacturer-specific versions, especially pallets with a standardized interface are used, the square or rectangular pallet 18 , 20 shown being provided on the clamping side with raster bores or parallel T-slots.

In order to prevent a collision of the pallets 18 , 20 during the pivoting movement with the workpiece carrier or with other elements of the machine bed, the pallet ten changer 16 is provided with a lifting device 42 , which the pallets 18 , 20 with respect to the workpiece carrier surface or to the base of the machine bed or the cabin floor can be raised in the Y direction.

On the cross member 34 , an H-shaped pallet door 44 is also mounted, the central partition wall 46 extends between the two pallets 18 , 20 along the cross member 34 . Transversely to the partition wall 46 , two H-legs forming circumferential walls 48 , 50 are arranged, which in the case of the pallets 18 , 20 indicated in FIG. 2 extend with a right angular clamping surface in parallel distance to the side surfaces 52 , 54 of the pallets 18 , 20 . In other words, the pallets are gripped by the adjacent sections of the peripheral walls 48 , 50 and by the partition wall 46 , so that the section of the pallet 20 pointing towards the viewer and the section of the pallet 18 pointing towards the work spindle remains open.

Fig. 3 shows a schematic plan view of the Pa changer 16 from Fig. 2. It can be seen that the workpiece carrier side legs 48 a, 50 a of the circumferential walls 48 , 50 and the partition wall 46 with Seitenwandun conditions 56 , 58 and one shown canopy and the base of the workpiece carrier or a Kabinenbo to complete a closed processing booth, de ren peripheral walls in the illustration of FIG. 3 are shown hatched.

On the legs 48 a, 50 a adjacent side edges of the side walls 56 , 58 sealing devices 64 , 66 , for example labyrinth seals are arranged, which can be brought into sealing contact with the side edges 60 , 62 of the legs 48 a, 50 a, so that the processing chamber in the transition area between the side walls 56 , 58 to Pa lettentür 44 is sealed.

As indicated in Fig. 3, corresponding seals 68 can also be arranged on the horizontally extending upper and / or lower edges (parallel to the plane of the drawing in Fig. 3) of the pallet door 44 , so that the gap between the canopy or the booths the / Workpiece carriers can be sealed. The partition 46 is provided in a corresponding manner with seals 68 .

In the case of a rigid pallet door 44 , these seals would be 68 or, where appropriate (in the case of sealless constructions), the corresponding upper / lower edges during the pivoting of the pallet door 44 on the canopy or the booth grind the / workpiece carrier, so that the contact surface is exposed to excessive wear is. In order to avoid this, the pallet door 44 in the case of the pallet changer 16 shown in FIG. 2 is formed with telescopic support surfaces. In the indicated game Ausführungsbei these telescopic areas of the pallet door 44 are formed by telescopic walls 70 , 72 , which are arranged overlapping on the peripheral walls 48 , 50 and the partition wall 46 and protrude beyond the respective upper or lower edge, so that the contact surfaces on the Kabi nentür or on the cabin floor on the telescopic walls 72 and 70 are formed, while the end edges of the side walls 48 , 50 and the partition wall 46 are arranged at a distance from the contact surfaces. This circumferential Teleskopwandungen 70, 72 can be for pivoting the pallet door 44 apart from the respective contact surface (cabin floor / workpiece support, canopy), so that the car door 44 is free to pivot. To actuate the telescopic walls 70 , 72 these can be connected, for example, via suitable coupling / deflection devices with the Hubein device 42 , so that the lifting movement of the plates 18 , 20 can also be used for actuating the telescopic walls 70 , 72 . Of course, other telescopic constructions, such as bellows, etc.

can be used to form the contact surfaces of the pallet door 44 . It is also possible to form only in the lower edges of the pallet door 44 by means of a telescopic wall 70 , while the upper edge remains in contact with the cabin roof during the pivoting movement. To actuate the upper telescopic walls 72 , the lifting device 42 can be provided with a deflection device, by means of which the pallet lifting movement is deflected by 180 ° into a wall lowering movement.

When changing the pallet, the workpiece to be machined is clamped on the pallet 20 located in the transfer position and the clamping of the pallet 18 located in the machining position is released on the workpiece carrier. The lifting device 42 is then activated so that the pallet 18 is lifted off the workpiece carrier. Simultaneously, the lifting movement of the Hubein will direction 42 skopwandungen via a not shown coupling to the telephoto 70 and - if present - transfer 42, so that the Teleskopwandungen 70, moved 72 successive who the and the seals 68 from the cabin floor / workpiece carrier or lifted from the car roof will.

Subsequently, the cross member is pivoted by 180 ° by actuation of the swivel motor 36 , so that the finished workpiece clamped on the pallet 18 is brought into the transfer position and the workpiece 20 that is sensitive to the pallet is brought into the machining position. The relative arrangement of the pallet door 44 with respect to the two pallets 18 , 20 is maintained during this pivoting movement.

After pivoting, the pallet 20 is lowered abge on the workpiece carrier by actuating lifting device 42 and jammed with it. At the same time the Te leskopwandungen 70 , 72 are brought back into their contact position ge, so that the processing chamber is tightly closed again ver. The processing can now take place by suction extraction of the tool chips and / or under an inert gas atmosphere, so that the risk of explosion / ignition is reduced to a minimum.

Since the circumferential walls 48 , 50 were in a relatively small amount from the adjacent side surfaces 52 , 54 of the pallets 18 , 20 are arranged, the volume of the processing chamber is compared to the known solutions with circular arc-shaped circumferential walls on both sides by the dashed line in Fig. 3 indicated Share reduced, so that the chip removal from the processing chamber is significantly simplified due to the minimal volume.

When designing the machine, it is only necessary to ensure that the swivel area indicated in FIG. 3 remains free, so that a collision with peripherals or with the operator is excluded.

The area of the pallet door 44 facing away from the workpiece carrier is freely accessible, so that during the machining of the one workpiece, a new workpiece can be clamped on the pallet 20 without obstructions
In Fig. 4 another embodiment is Darge presents, in which a U-shaped pallet door 80 is used instead of a one-piece, H-shaped Pa lettentür 44 . In this embodiment, the partition 46 is attached to the cross member, but the circumferential walls are formed by legs 80 , 82, which are mounted transversely to the partition 46 on the cross member. The indicated in Fig. 4 shift from the drawn position into the dashed position allows that depending on the position of the legs 82 , 84 one of the pallets is encompassed by the peripheral walls, while the other range is freely accessible. In the position of the legs 82 , 84 shown in FIG. 4, the side edges 86 , 88 running perpendicular to the plane of the drawing bear against the sealing devices 64 , 66 . In order to bring the dashed line to indicated pallet 20 with the workpiece clamped thereon into the machining position, the swivel motor 36 is actuated so that the partition wall 46 and the two legs 82 , 84 are rotated through 180 ° about the swivel axis 28 , so that the is open in Fig. 4 shaded area downward. Then the two legs 82 , 84 are moved by a suitable displacement mechanism on the cross member until they have reached the dashed position and encompass the pallet 20 . When the pallet door 44 is pivoted, the side edges 90 , 92 then rest against the sealing devices 62 , 64 , so that a sealed processing chamber is formed around it.

The variant described in Fig. 4 has the advantage over the above-described embodiment that only one half of the peripheral walls 48 , 50 must be formed with the corresponding sealing devices, so that the weight to be pivoted is reduced and the number of seals to be installed is reduced.

Instead of the examples shown in FIGS . 2 and 4, with flat peripheral walls 48 , 50 and 82 , 84 , pallet doors with curved peripheral walls can also be designed to adapt the geometry of the processing chamber to the geometry of the pallet used.

A pallet door for a pallet is disclosed swivel changer with a partition between Bear processing and loading area (transfer area) for two pallets together with at least one of the pallets Circumferential wall sections is pivotable, the order catch walls and the partitions together with a workpiece carrier at least in sections cabin to a closed processing chamber complete.

Claims (10)

1. Pallet changer with at least two pallets ( 18 , 20 ), each of which can be brought from a transfer position into a processing position by means of a rotary drive ( 36 ), in which a pallet ( 18 , 20 ) can be clamped onto a workpiece carrier, at least which is in the processing position of the pallet ( 18 ) of the pallet changer ( 16 ) surrounded by a peripheral wall ( 48 , 50 ; 82 , 84 ) and between the pallets ( 18 , 20 ) a partition ( 46 ) is arranged, which together with one of the tool carriers surrounding cage (56, 58) complementary to a processing chamber, characterized in that at least adjacent to the partition wall (46) section of the peripheral wall (48, 50; 82, 84) is connected to the partition wall (46) which can pivot bar. 2. Pallet changer according to claim 1, characterized in that the partition ( 46 ) and the two peripheral walls ( 82 , 84 ) together form a U-shaped Pa lettentür ( 44 ). 3. Pallet changer according to claim 2, characterized in that the two circumferential walls forming the U-legs ( 82 , 84 ) are displaceable along their longitudinal axis from one side to the other side of the partition ( 46 ). 4. Pallet changer according to claim 1, characterized in that the peripheral walls ( 48 , 50 ) and the partition ( 46 ) together form an H-shaped pallet door ( 44 ) and each have a pallet ( 18 , 20 ) within one through the partition ( 46 ) and two peripheral wall sections ( 48 a, 50 a) defined Rau mes is arranged. 5. Pallet changer according to claim 4, characterized in that the peripheral walls ( 48 , 50 ) and the partition ( 46 ) are integrally formed. 6. Pallet changer according to one of the preceding claims, characterized by a lifting device ( 42 ) through which the peripheral walls ( 48 , 50 ; 82 , 84 ) and the partition ( 46 ) can be lifted off the cabin floor or from the cabin roof. 7. Pallet changer according to claim 6, characterized in that the walls ( 46 ; 48 , 50 ; 82 , 84 ) have telescopic support sections ( 70 ) which can be lifted from the workpiece carrier by the lifting device ( 52 ). 8. Pallet changer according to claim 7, characterized in that the walls ( 46 ; 48 , 50 ; 82 , 84 ) are provided in the contact area to a canopy with teleskopierba rem sections ( 72 ) which can be actuated by an actuating device ( 42 ) . 9. Pallet changer according to claim 7 or 8, characterized in that along the support edges of the support sections ( 70 ) and / or the sections ( 72 ) you lines ( 68 ), preferably labyrinth seals are angeord net. 10. Pallet changer according to one of the preceding claims, characterized in that the side edges ( 60 , 62 ; 86 , 88 ; 90 , 92 ) of the peripheral wall sections are designed as sealing edges.