DE4315537A1 - Tool changing device for wood processing machine - has grippers on end of electro spindle to hold tools which are taken from seats on tool magazine - Google Patents

Abstract

Tools (5) are arranged along part of the electro spindle (3) grippers from the rotating head (4) of the spindle. A drive (32), also so arranged, slides the grippers in both directions to the vertical (Z). A tool magazine (13) is arranged in a tool changing position and has several tool seats (15) and is served by a first drive. The electro spindle slides between two positions, the first being a work piece (10) processing position and the second to the different seats of the magazine for picking the tools. USE/ADVANTAGE - Partic. for use with milling and boring machines for mass production of wooden items. Provides accommodation for several different tool.

Description

The present invention relates to a tool changing device, attachable to woodworking machines. In particular, the present invention relates to a Device of the type mentioned above, which advantageously on milling and / or drilling machines with vertical Axis can be used, on which the following Description refers, but without referring to general lose, in this name also very extensive Devices are included that are usually associated with "machining centers" be designated.

In the field of woodworking, and especially when there is a need to start milling or drilling Plates or parts to be made for production intended for industry or institutions in large series are (e.g. the classic add-on furniture, furnishings, details related to furniture, etc.) commonly used machine tools where if there is only one tool, use a vertical one Axis is arranged so that it extends along the Z can move for the machining depth and in the Location (this itself or the workpiece holder table),  to move along corresponding guide elements, to perform shifts on a horizontal plane (Axes X and Y).

The tool is usually held and driven by a commercially available electrospindle a body with quick tool change (with hydraulic Drive), the expansive and with dovetail connection or equivalent means one Carriage is associated with the corresponding drive means is moved.

In the machining centers, the "structure" in the sense highlighted that this always along the three axes is movable, several machining tools can be assigned: Usually a double series of Drilling tools arranged along two right angles extending axes (X and Y), and several electrospindles of the above type for use of milling or groups of processing tools different Type (for example, one of these groups may be of the Electrospindle can be controlled a certain number of drills included that are on multiple axes or on opposite sides for special processing are arranged, for example with different center distances between the drilling tools than that of the normally used on the head of the machining center).  

In these latter machines of the more extensive type it is known that the change from the mentioned Tool held electro-spindle completely automatically takes place, the electrospindle itself (the is the name of the head that carries it) towards a station for the tool change that is shifted located to the side of the surface of the entire machine, and on which some heads are arranged, which are the exchange tools wear. These heads are able to under the action of the respective drive means (fluid dynamic Piston) vertically between two extreme Moving positions, an upper one for the tool change and a lower rest position, and point up to the head of the machining center open elastic ring in which the head Tool or from which he uses the replacement tool takes out, and in its place a new tool to be able to order.

The limits of the tool changing devices described above consist of the limited number of heads of the type described in the available Place the relevant woodworking machines as well as in the fact that these Heads, since appropriate drive means are provided need to be very expensive in the whole of the solution  prove. In addition, the execution of the same and their row-by-row arrangement actually not the use of those special groups mentioned above, because practically the necessary available space is missing. It follows that the automatic Tool change in number based on the number of heads is limited, which are geometrically positionable to to form the magazine and that he was on the tools classic type is limited, the above "Special" groups are excluded.

For the purpose of the present invention, this is a device for the automatic tool change, the woodworking machines of the above described Is attachable, and which allows it to be large Number of immediately available for exchange to be able to dispose of standing tools, particularly simple and relatively economical are of various shapes and dimensions.

The invention characterized by the claims is a tool changing device solves the problem to deliver that can be attached to woodworking machines is, the machines mentioned being of the type which contains at least one electrospindle with a vertical axis, in one body with the motor and a turret with quick clamping for a single tool and movable,  through the action of the first drive means, parallel to at least two horizontal axes that run at right angles to one another, the said Rotary head of a workpiece holding surface with horizontal Facing course for laying and processing wooden parts is characterized in that said Electrospindle gripping means for part of that Rotary head of the self-held tool are assigned as well as second drive means to the aforementioned Vertical gripping device in both directions to move, and by making a first Tool magazine contains that in a tool change position is arranged, provided with a number of Seats for the appropriate tools; in which the first drive means mentioned serve the called electrospindle between a position for Processing of the mentioned wooden parts and a position vertically aligning your turret to a seat to postpone the first magazine mentioned and between multiple positions of vertical alignment of her turret to different seats of the first Magazine itself.

The said gripping means preferably contain a holding element, available behind a section of a named Tool, said holding element clamping means  are assigned, and being on said tool there is a sling on which the mentioned clamping devices.

According to a preferred embodiment of the present Invention, said holding element contains an annular Element that coaxial a section of the said Tool surrounds, said section of the called tool an annular circumferential recess is incorporated, and wherein said annular Element in the said circular, revolving Deepening of the mentioned tool insertable clamping means assigned.

The technical characteristics of the invention are according to the above-mentioned purposes clearly recognizable from the content of the claims below, and the advantages thereof are made even clearer by the following detailed description with reference to the accompanying Drawings that are only intended as an example and represent a non-limiting form of realization, and of those

- Fig. 1 shows schematically and in front view a woodworking machine which contains the tool changing device according to the present invention in a simplified embodiment;

- Fig. 2 shows a perspective view of a tool holder element belonging to the tool changing device as in Fig. 1;

- Fig. 3 shows a schematic side view in magnified form and partially in section of a portion of a usable in the machine of Figure 1 the tool, together with a portion of the tool change device according to the present invention. and
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Fig. 4 shows schematically a plan representation of a more complicated version of the tool changing device from the previous figures.

In accordance with the accompanying figures, the relevant tool changing device, designated in its entirety by 1 , can be attached in particular to a woodworking machine 2 (see, for example, milling machines or machining centers), of the type containing a universal head 2 t, which has a double row of drilling tools (with 2 f)) and carries at least one electrospindle 3 with a vertical axis, in a body with a motor and a rotary head 4 ; this rotary head 4 has an element (not shown here) for quick connection (for example the known cone connector) for a single tool 5 , and the electrospindle 3 is carried by a spindle head 6 which is connected to a support and displacement structure 7 of a known type , shown schematically in a block (the universal head 2 t as above), and capable of acting as a drive and in a known manner, the electrospindle 3 itself displacements in a vertical direction and along two horizontal and mutually perpendicular axes (X and Y , see Fig. 4). More specifically, the head 2 t performs vertical working displacements, while the support structure 7 carries out the vertical displacements for driving the tool in question, such as the individual drilling tools. In other words, depending on the machining to be carried out, the operator gives a drive impulse to each tool that is to carry out the work, while the head 2 t also carries out several operations simultaneously with a single vertical displacement.

A base 8 of the machine 2 carries a workpiece holder surface 9 with a horizontal course for supporting and machining the wooden parts 10 , which contain slide means 11 , which extend over the entire length of the base 8 of the machine and in a direction X as above, and which are normally as Support for the interrupted workpiece holder surface serve, as can be seen schematically in Fig. 1.

According to what is shown, the slide means 11 , displaceable in a horizontal direction X, carry a holding head 12 for a magazine or a tool carrier element 13 , which essentially consists of a horizontal plate 14 (see FIG. 2), which has a number of continuous seats or bores 15 is provided with a vertical axis, which are preferably arranged uniformly in two rows running parallel to one another. Each bore 15 has a diameter that is approximately somewhat larger than the diameter of the body of the tool 5 mentioned. The head 12 is connected to a drive element 16 which is able to move it in the two directions according to the said horizontal X, and it is between a first position in which it is complete together with the tool carrier element 13 arranged above it is in a fixed housing body 17 , and a second position in which it is extended from the housing body 17 itself, movable. The housing body 17 is described in part by a movable closing element 18 , which preferably contains a roll-up and roll-off roller shutter 19 which, under the action of reversible drive means 21 , which are carried by the said base 8 and in connection with the extension movement of the housing body 17 stand, runs in holding guides 20 .

After what is shown in Fig. 3, the tool 5 includes an upper shaft 21 ', which is intended to be gripped by the rotary head 4 (or rather, by the clamping means of the spindle), and under which the body of the tool 5 itself is provided with a circumferential, annular recess or a stop element 22 of a toroidal cut, in which a number of clamping means can be accommodated, which consist of balls 23 which belong to a carrier element 24 forming part of the tool changing device mentioned. The balls 23 are supported in a recess 25 which is coaxially machined into an annular element or a carrier element 26 , and they extend in part in the direction of the axis of the annular element 26 itself, through corresponding openings 27 which are coaxial in a wall 28 of the annular element 26 is incorporated and the axis mentioned faces. The openings 27 mentioned have a circular shape and have a smaller diameter than that of the balls 23 , so that they cannot emerge from the annular element itself.

The said balls 23 and the annular element 26 , which holds them in their recess 25 , form in their entirety the part which is hereinafter referred to as "gripping means" of the tool 5 .

The diameter of the bore formed by the wall 28 is slightly larger than the portion of the tool 5 into which the said annular recess 22 is incorporated, and the recess 25 of the annular element 26 is connected to a flow source by a flexible and stretchable conduit 29 , and preferably compressed air, shown schematically in Fig. 1 by a block 30 . The annular element 26 is held laterally by a bracket 31 , which has an upper section which is connected to a drive 32 ( FIG. 1) attached to one side of the electrospindle 3 , capable of holding the bracket 31 itself and thus the annular element 26 to give displacements in the two directions along the vertical Z. Below the recess 22 of the tool 5 is coaxially connected to a peripheral portion with the body which is formed of an annular element 33 which, since it itself has an enlarged diameter relative to the body of the tool 5, even better illustrated as follows , from the support and support element for the tool 5 itself acts when it is inserted into one of the bores 15 in the plate 14 . The annular element 33 could also have a shape other than that described, but must in any case have a larger transverse dimension than the diameter of the bores 15 in order to be able to carry out its task correctly.

The operation of the tool changing device 1 will now be described, with a condition being assumed at the beginning in which a tool 5 held by the head 4 assigned to the electrospindle 3 has just finished machining on a part 10 and is to be replaced (a situation , which corresponds approximately to that shown in Fig. 1). In this state, the head 12 and the overlying tool carrier element 13 are located completely within the housing body 17 , specifically because a considerable amount of dust is formed during processing, which dust must not touch the waiting tool magazine.

When the changing process of the tool 5 assigned to the electrospindle 3 begins, the drive means cause the roller shutter 19 to open along the guides 20 and the resultant opening of a surface ( 17 a in FIG. 1) of the housing body 17 .

The drive element 16 now brings the head 12 into the extended position shown in FIG. 1, while the support and displacement structure 7 of the spindle head 6 leads the tool 5 brought up by the electrospindle 3 into the sphere of influence of an electronic control unit 34 of known type, which is located above a tool-free bore 15 of the plate 14 carried by the head 12 is located. Said quick connector element of the electrospindle 3 now releases the tool 5 , which after this process is therefore only held by the balls 23 which engage in the annular recess 22 . The drive element 32 consequently causes the annular element 26 and the tool 5 held by the latter to be lowered until the tool 5 itself is inserted into the empty bore 15 mentioned (see dashed line in FIG. 1).

It must be noted that while the tool 5 is working on a part 10 (shown in Fig. 1) and during the operating phases of the tool changing device 1 just mentioned, the depression 25 of the annular element 26 is always kept in communication with a compressed air source 30 , and that the balls 23 contained therein are pressed in the direction of the opening 27 and inserted into the annular recess 22 , without contact with the tool 5 , which in this phase, thanks to the dimensioning of the opening 27 and the recess 23 of the tool 5 itself is completely carried by the electrospindle 3 . This forms a safety factor in the event of incorrect operation of the clamping device of the electrospindle for the tool, a very rare case, but basically not impossible. In this case, the tool no longer held by the spindle would not fall out, but would remain in a safe position.

After the tool 5 has been inserted into the empty bore 15 mentioned, the connection between the chamber 25 inside the annular element 26 and the compressed air source 30 is interrupted and the balls 23 , which are no longer pressed in the direction of the axis of the annular element 26 , release the tool 5 itself, which remains inserted by its own weight in a bore 15 , with its own annular element 33 arranged on a corresponding section of the surface of the plate 14 .

Due to the action of the electronic control unit 34 , the drive 32 now causes the annular element 26 to be lifted (the balls 23 , which are no longer subject to the action of the compressed air, give to the interior of the receiving chamber by a radial force caused by the weight of the tool itself after) and the spindle head 6 moves (first in the vertical direction, then horizontally and finally vertically downwards) until the quick connector element of the electrospindle 3 is brought over a new tool 5 to be removed, which is located in a bore 15 in the plate 14 . The ring-shaped element 26 is consequently lowered at the command of the electronic control unit 34 until it is aligned with the balls 23 contained therein horizontally with the ring-shaped recess 22 of the new tool 5 , and the balls 23 themselves become thanks to the reconnection of the internal recess 25 of the annular element 26 with the compressed air source 30 partially inserted into this annular recess 22 . The ring-shaped element 26 is raised back to the originally assumed position by the action of the drive 32 , and the quick connector element of the electrospindle 3 closes around the shaft of the new tool 5 .

At the conclusion of these operations just described, the electronic control unit 34 causes the spindle head 6 and consequently the electrospindle 3 to return to the initially assumed operating position, and the machining of the part 10 can be continued using the new tool 5 after retracting the head 12 and closing the roller shutter 19 for the purpose of keeping the tool magazine including the plate 14 clean. Of course, the tool changing processes just described are repeated in the same way each time it is necessary to replace a tool 5 in use with another one carried by the plate 14 . In the embodiment of the tool changing device 1 as shown in FIG. 4, a magazine, which consists of a platform 35, is arranged on one side of the machine 2 and at an essentially same height as that of the plate 14 mentioned and enclosed in the housing body 17 which carries a number of plates 14 a arranged transversely next to one another and lying in the corresponding bores 15 for the tools 5 , tools which are normally different from one another and also different from the tools 5 which are carried by the plate 14 (they could also be the same, so that a set that is already worn can be sent for grinding). This platform 35 is able to move horizontally in both directions under the action of a drive element 36 carried by the machine 2 and locked by the electronic control unit 34 , namely after steps the length of which essentially corresponds to a transverse dimension of the plates 14 a.

According to what is shown in Fig. 4, a plate 14 a is missing from the platform 35 , which is (designated 14 ) in the previously considered position on the edge of the machine 2 .

A drive element 37 , carried by the base 8 in a manner not shown here, close to one side of the platform 35 and locked by the electronic control unit 34 , holds and moves axially in both directions a transfer means, including an arm 38 , which is at its end a gripping element 39 of a type known per se is capable of individually gripping the plates 14 a carried by the platform 35 and guiding them into the interior of the housing body 17 in a longitudinal movement, as will be better explained below , which in this case is constantly or temporarily shown as being open to the side, and is also able to grip the plate 14 contained in the housing body 17 and to guide it in a longitudinal movement into a position above the platform 35 . Since the head 2 t is of the type with control on all three axes, as an alternative it can also be used as a drive element 37 , whereby of course the entire transmission must be replaced.

The operation of this tool changing device 1 , which is shown in Fig. 4, differs from the device 1 from Figs. 1 to 3 only in the fact that it is possible at any moment when moving the platform 35 by the drive element 36 is to bring the part of the platform 35 itself, on which there is no plate 14 a, in front of the plate 14 arranged at the edge of the machine 2 , to take this plate 14 out of its position by the gripping element 39 and to arrange it on the platform 35 to move the platform 35 in such a way that the side of the housing body 17 faces a new plate 14 a, and to guide this new plate 14 a into the housing body 17 by the gripping element 39 , thus placing the machine 2 in position will work with a new set of tools 5 .

Of course it would be possible, instead of the platform 35, which practically forms a magazine for a number of tool holder plates 14 a to provide a logical manner and according to what has been said before, the use of a magazine for arbitrarily formed plates 14 a.

From what has been said, it is clear that the tool changing device 1 described fully achieves the desired purposes, since it enables the following advantages:

- The machine 2 has a large number of replacement tools 5 available, which are immediately ready for replacement, and this proves to be particularly simple and economical: the exchange of the plate 14 can in fact be carried out by hand in a limited time or automatically in a very short time Time through a plate magazine with automatic change of the type as shown in Fig. 4;

- The economy is thus due to the lack the individually driven drive heads are still highlighted, as in the previous solutions, and at the same time, the space occupied is less;

- The times for changing tools are in proportion to the solutions that are state of the art form, still reducible, because of the Control the movements of the moving head is transferred, as well as through the use of the the above-mentioned gripping means;

- Greater safety for the operator through the Monitoring the position of the operating Tool;

- the possibility of arranging the tool change of special groups, since the plate, if it is designed accordingly, can accommodate groups outside the standard dimensions, as shown with broken lines in Fig. 4 and labeled 5 g, and for example the space of two or can occupy more holes 15 ; in this case the tool change is possible in any case, since the magazine itself is completely passive and the operating movement is completely transferred to the universal head and its relevant additional elements.

The invention thus conceived is subject to numerous changes  and variants, all in the field of inventive Concept fall. You can also see all the details exchanged for technically equivalent elements will.

Claims (9)

1. Tool changing device which can be attached to woodworking machines, said machines ( 2 ) being of the type which contains at least one electrospindle ( 3 ) with a vertical axis, in one body with the motor and a rotary head ( 4 ) with quick-action clamping for a single tool ( 5 ) and displaceable, due to the action of first drive means ( 7 ), parallel to at least two horizontal axes (X, Y), which run at right angles to one another, said rotary head ( 4 ) having a workpiece holding surface ( 9 ) with a horizontal The course for placing and processing wooden parts ( 10 ) faces, characterized in that said electrospindle ( 3 ) gripping means ( 23, 26 ) for part of the tool ( 5 ) itself held by the rotary head ( 4 ) of the electrospindle ( 3 ) are assigned and second drive means ( 32 ) to move said gripping means ( 23, 26 ) to the vertical (Z) in both directions, and in that they contains a first magazine ( 13 ) for the tools ( 5 ), which is arranged in a tool changing position, provided with a number of seats ( 15 ) for receiving the corresponding tools ( 5 ); said first drive means ( 7 ) serve to move said electrospindle ( 3 ) between a position for machining said wooden parts ( 10 ) and a position for vertically aligning its rotary head ( 4 ) to a seat ( 15 ) of said first magazine ( 13 ) as well as between several positions of the vertical alignment of its rotary head ( 4 ) to different seats ( 15 ) of the first magazine ( 13 ) itself. 2. Tool changing device according to claim 1, characterized in that said gripping means include a holding element ( 26 ) which is available at the rear of a portion of said tool ( 5 ), said holding element ( 26 ) being assigned clamping means ( 23 ) and a stop element ( 22 ) is present on the said tool ( 5 ), which the clamping means ( 23 ) meet. 3. Tool changing device according to claim 2, characterized in that said holding element contains an annular element ( 26 ) which axially surrounds a portion of said tool ( 5 ), an annular recess ( 22 ) being incorporated, which said abutment means forms, and wherein said annular element ( 26 ) is assigned clamping means ( 23 ) which can be inserted into said annular recess ( 22 ) of said tool ( 5 ). 4. Tool changing device according to claim 3, characterized in that said annular element ( 26 ) is provided with an internal recess ( 25 ) and with at least one opening ( 27 ) which is in communication with the internal recess ( 25 ) and abutting said annular recess ( 22 ), said tensioning means including at least one ball ( 23 ) mounted in said internal recess ( 25 ) and having larger dimensions in relation to that of said opening ( 27 ) so that it partially exits said opening ( 27 ) to partially fit into said annular recess ( 22 ) and said internal recess ( 25 ) is connectable to a pressurized flow source ( 30 ). 5. Tool changing device according to claim 1, characterized in that said first magazine ( 13 ) contains a horizontally arranged plate ( 14 ) whose seats consist of bores ( 15 ) which are incorporated in said plate ( 14 ), each said tool ( 5 ) being provided with a peripheral portion ( 33 ) for resting on said plate ( 14 ), which has a larger transverse dimension than the diameter of said bores ( 15 ). 6. Tool changing device according to claim 5, characterized in that it includes a partially openable housing body ( 17 ) for receiving said plate ( 14 ), third drive means ( 16 ) being provided to alternate said plate ( 14 ) to move into and out of the inside of said housing body ( 17 ). 7. Tool changing device according to claim 6, characterized in that it includes a movable roller shutter ( 19 ) for partially closing said housing body ( 17 ), fourth drive means ( 21 ) being provided to guide said roller shutter ( 19 ) in each case ( 20 ) roll up and down. 8. Tool changing device according to any one of the claims from 5 to 7, characterized in that it contains a second magazine ( 35 ) for carrying a number of said plates ( 14 a), with transfer means ( 38, 39, 2 t) are provided for the individual plates ( 14, 14 a) between said second magazine ( 35 ) and said tool change position. 9. Tool changing device, attachable to woodworking machines, according to the preceding claims and after what with reference to the pictures in the accompanying drawings and to those mentioned Has been described and shown for purposes.