WO2008062489A1

WO2008062489A1 - Oscillating cutting system for a sawing machine

Info

Publication number: WO2008062489A1
Application number: PCT/IT2007/000726
Authority: WO
Inventors: Ambrogio Magoni
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-11-21
Filing date: 2007-10-18
Publication date: 2008-05-29
Anticipated expiration: 2009-05-21
Also published as: ITTO20060825A1

Abstract

An oscillating cutting bench (1), in particular per sawing machine (10), is described, comprising at least one moving frame (5) equipped with an abutment plane (6) of a workpiece (7) to be cut, such moving frame (5) being pivoted through at least one fixed rotation fulcrum (8) to a possible fixed frame (3) in order to have a cyclic oscillating movement related thereto around a rotation axis (R) orthogonal to a cutting direction (T) of at least one cutting blade (9) of the sawing machine (10) and coplanar with a plane parallel to a first plane (P) defined by the support plane (6), and actuating means (13) adapted to drive the cyclic oscillating movement of the moving frame (5) with respect to the fixed frame (3).

Description

OSCILLATING CUTTING SYSTEM FOR A SAWING MACHINE

The present invention refers to an oscillating cutting system, in particular for a sawing machine.

With reference to the enclosed Figures Ia, Ib and Ic, it is known that, for cutting metals 101, generally band-type sawing machines are used, in which the sawing band can be found in a horizontal position (as schematically shown in FIG. Ia) , a vertical position (as schematically shown in FIG. Ib) or can have a movement controlled by a hinge-type kinematism (as schematically shown in FIG. Ic).

The tool used in the above sawing machines is generally a band-sawing blade with various sizes and usually made with one of the following types of cutting material: Carbon, Bimetal M42/M51, Carbide (Widia) .

It is known that the removal of a band saw blade, expressed in cmVmin (also defined as cutting rate) , has a variable behaviour depending on the diameter of the material to be cut, namely the section affected by cutting.

The graph in the enclosed FIG. 2, in which the abscissas represent diameter values of the metallic material to be cut expressed in millimetres and the ordinates represent the cutting rate, shows the removal behaviour with respect to the increasing diameter of the workpiece to be cut. In particular, from such graph it can be noted how, when the diameter increases, the specific cutting capability expressed in cm²/minute decreases, extending the cutting times on diameters from 500 mm till 2000 mm in a way that is not industrially feasible.

The reason for this prolonged cutting time length and for the low removal in terms of cmVminute next to great diameters, is the major effort that the machine (and more precisely the blade) must exert when it encounters bigger and bigger sections of the material, such effort being due to various reasons such as frictions, high temperatures, presence of chips, incorrect blade toothing at any cutting time, etc.

As can be noted from the graph in FIG. 2, the maximum removal can be obtained next to the cutting of a diameter of about 300 mm. In order to solve the above problem, the prior art has proposed then to use sawing machines equipped with oscillating cutting heads that allow the blade to encounter a smaller section of material (or better the ideal section of material to be cut) so that there are no excessive efforts when cutting: an oscillating cutting head in fact allows the blade teeth catching the material to be always corresponding to the ideal number and that therefore the resistance that a blade encounters at any time is always less than the one it would encounter in the normal case in which the section encountered by the blade were greater. Examples of such known sawing machines are disclosed in patents n. KR8800632, US4546682, US4558614. The realisation of oscillating cutting heads, above all if using band-sawing blades, though theoretically feasible, is anyway from the practical point of view rather complex, since it must unavoidably suit the rotary movement of the band-type saw to the oscillating movement of the support frame, using relatively complex kinematisms and mechanisms.

Therefore, object of the present invention is solving the above prior art problems, by providing an oscillating cutting system, in particular for a sawing machine, that allows a cutting blade having a fixed cutting direction to encounter the ideal section of material to be cut.

Another object of the present invention is being able to directly manufacture a sawing machine equipped with an oscillating cutting system.

The above and other objects and advantages of the invention, as will result from the following description, are obtained with an oscillating cutting bench, in particular for a sawing machine, as described in claim 1. Preferred embodiments and non-trivial variations of the present invention are the subject matter of the dependent claims. The present invention will be better described by some preferred embodiments thereof, provided as a non-limiting example, with reference to the enclosed drawings, in which:

FIG. Ia, Ib and Ic show some types of band-type sawing machines according to the prior art;

FIG. 2 shows a graph representing the behaviour of the cutting rate depending on the diameter of the metallic material to be cut;

FIG. 3 shows a top perspective view of a sawing machine (10) equipped with a preferred embodiment of the oscillating cutting bench according to the present invention;

FIG. 4a show a front view of the sawing machine of FIG. 3 in an operating position of the oscillating cutting bench according to the present invention;

FIG. 4b shows a front view of the sawing machine of FIG. 3 in another operating position of the oscillating cutting bench according to the present invention.

With reference to Figures 3 to 4b, it is possible to note that the oscillating cutting bench 1 according to the present invention is arranged in cooperation with at least one blade 9, for example a substantially known band-sawing blade, of a sawing machine 10 and comprises:

- at least one fixed rotation fulcrum 8: the fixed rotation fulcrum 8 can be cooperating with at least one fixed frame 3 which can be abutted on the ground, possibly by interposing an adequate number of support legs 4 that are suitably placed and mutually spaced to guarantee the necessary working stability and strength, or be directly manufactured on the sawing machine basement;

- at least one moving frame 5, equipped with an abutment plane 6 of a workpiece 7 to be cut, and pivoted to the rotation fulcrum 8 in order to have a cyclic oscillating movement related to this latter one around a rotation axis R passing through the fixed rotation fulcrum 8 and orthogonal to a cutting direction T of the cutting blade 9 and coplanar with a first plane P defined by the support plane 6. Depending on specific cutting needs, the support plane 6 can be made, for example, as table or as roller assembly (like in the preferred embodiment of the oscillating cutting bench 1 shown in the Figures) . The moving frame 5 can also be equipped with fastening means, made for example as at least one pair of jaws 11 of a closing vice, adapted to keep the workpiece 7 to be cut unmoving on the support plane 6 and integral with the moving frame 5;

- actuating means 13 adapted to control the cyclic oscillating movement of the moving frame 5 with respect to the rotation axis R; in particular, the actuating means 13 can be of the pneumatic, hydraulic, oleodynamic, electromagnetic, or mechanical type (such as for example a transmission of the connecting rod-crank type) and are possibly operating on the moving frame 5 by means of a kinematic chain 14 and/or suitable linkages whose realisation is within the reach of any technician in the field. The actuating means 13 can also be placed in cooperation with the sawing machine 10, so that the cyclic oscillating movement of the moving frame 5 is synchronised with the cutting movement of the blade 9; alternatively, the cyclic oscillating movement of the moving frame 5 and the blade 9 movement can be mutually independent.

With reference to FIG. 4a and 4b, it is possible to note the preferred operaring principle of the oscillating cutting bench 1 according to the present invention: in particular, the cyclic oscillating movement of the moving frame 5 with respect to the fixed frame 3 is controlled by the actuating means 13 so that the moving frame 5 itself, and consequently the workpiece 7 to be cut integral therewith, passes when rotating around the rotation axis R, with continuity or in a discrete way, for example from a first extreme position in which the first plane P of the support plane 6 is slanted by a first angle α with respect to a reference plane S parallel to the rotation axis R and to the cutting direction T (FIG. 4a), through a second position in which the first plane P of the support plane 6 is coplanar with the reference plane S, to a third extreme position, opposite to the first extreme position, in which the first plane P of the support plane 6 is slanted by a second angle β with respect to the reference plane S (FIG. 4b) ending a cycle; at that time, the actuating means 13 start another cycle again by taking back the fixed frame 3 towards its first extreme position following, along the contrary direction, the previously described movement. In order to simplify the realisation of the oscillating cutting bench 1 according to the present invention, preferably |α| = |β|, but depending on particular and specific cutting needs, it is possible to provide that |α | ≠ |β|.

The sequence of previously described cycles continues, obviously, till the desired cutting on the workpiece 7 is obtained.

The oscillation cycle period is preferably included between approximately 3 minutes and approximately 15 minutes. In particular, the cycle period is set depending on how big the workpiece to be cut is and on the type of material of which the workpiece 7 to be cut is made: the easier the material to be cut (such as, for example, in case of common steels and special low-alloyed steels) , the shorter the cycle period, and vice versa.

The advantage starts to appear when it is necessary to cut very big sections of workpiece 7 material (starting from approximately 400 mm) : in general, the greater the section of the workpiece 7 to be cut, the more evident the advantage, in terms of cutting time,- deriving from the use of the oscillating cutting bench 1 according to the present invention. Savings in terms of time in fact can change from a minimum of about 20% to a maximum of about 500% with respect to traditional cutting systems, and this is true for any material and shape of the workpiece 7.

Moreover, the use of the oscillating cutting bench 1 according to the present invention allows obtaining other not neglectable advantages, such as saving of used and consumed energy and lower consumption of the cutting blade 9 with the same performed work.

In the Figures, merely as an example, an embodiment of the oscillating cutting bench 1 according to the present invention has been shown in cooperation with a sawing machine 10 equipped with a horizontal cutting blade 9: in this case, the reference plane S is preferably horizontal; it is however clear that the same cutting bench 1 can be used with different sawing machines, such as, for example, sawing machines with vertical or hinged cutting blade, in which the reference plane S, in addition to be horizontal, can also be vertical or slanted, without therefore departing from the scope of the present invention. A relevant advantage of the oscillating cutting bench 1 according to the present invention in fact is that it can be used for equipping already existing sawing machines.

An object of the present invention is also a sawing machine 10 equipped with an oscillating cutting bench 1 as previously described.

Claims

1. Oscillating cutting bench (1), in particular for a sawing machine (10), characterised in that it comprises:

- at least one fixed rotation fulcrum (8);

- at least one moving frame (5) equipped with a support plane (6) of a workpiece (7) to be cut, said moving frame (5) being pivoted to said fixed rotation fulcrum (8) in order to have a cyclic oscillating movement related thereto around a rotation axis (R) that is orthogonal to a cutting direction (T) of at least one cutting blade (9) of said sawing machine (10) and coplanar to a first plane (P) defind by said support plane ( 6) ;

- actuating means (13) adapted to control said cyclic oscillating movement of said moving frame (5) with respect to the fixed rotation fulcrum (8).

2. Oscillating cutting bench (1) according to claim 1, characterised in that said fixed rotation fulcrum (8) is cooperating with a fixed frame (3).

3. Oscillating cutting bench (1) according to claim 1, characterised in that said fixed frame (3) is abutted on the ground by interposing support legs (4).

4. Oscillating cutting bench (1) according to claim 1, characterised in that said support plane (6) is a table.

5. Oscillating cutting bench (1) according to claim 1, characterised in that said support plane (6) is a roller assembly .

6. Oscillating cutting bench (1) according to claim 1, characterised in that said moving frame (5) is equipped with fastening means of said workpiece (7) on said support plane (6) .

7. Oscillating cutting bench (1) according to claim 6, characterised in that said fastening means are at least one pair of jaws (11) of a closing vice.

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8. Oscillating cutting bench (1) according to claim 1, characterised in that said actuating means (13) are of a pneumatic, hydraulic, oleodynamic, electromagnetic, or mechanical type, adapted to generate an oscillating motion.

9. Oscillating cutting bench (1) according to claim 1, characterised in that said actuating means (13) are a transmission of a connecting rod-crank type.

10. Oscillating cutting bench (1) according to claim 1 or 8, characterised in that said actuating means (13) are operating on said moving frame (5) through a kinematic chain (14) and/or linkages.

11. Oscillating cutting bench (1) according to claim 1, characterised in that said actuating means (13) are cooperating with said sawing machine (10) to synchronise said cyclic oscillating movement of said moving frame (5) with an advancing movement of the blade (9) towards the workpiece (7) to be cut .

12. Oscillating cutting bench (1) according to claim 1, characterised in that said cyclic oscillating movement of said moving frame (5) with respect to the fixed rotation fulcrum (8) is controlled by said actuating means (13) so that said moving frame (5) and said workpiece (7) to be cut integral therewith pass, by rotating around said rotation axis (R) , from a first extreme position in which said first plane (P) of said support plane (6) is slanted by a first angle (α) with respect to a reference plane (S) parallel with said rotation axis (R) and with said cutting direction (T) , through a second position in which said first plane (P) is coplanar with said reference plane (S) , to a third extreme position, opposite to said first extreme position, in which said first plane (P) is slanted by a second angle (β) with respect to said reference plane (S) ending an oscillation cycle, and vice versa.

13. Oscillating cutting bench (1) according to claim 12, characterised in that |α| = |β|.

14. Oscillating cutting bench (1) according to claim 12, characterised in that |α | Φ |β|-

15. Oscillating cutting bench (1) according to claim 12, characterised in that a period of said oscillation cycle is included between approximately 3 minutes and approximately 15 minutes .

16. Oscillating cutting bench (1) according to claim 1, characterised in that said reference plane (S) is horizontal.

17. Oscillating cutting bench (1) according to claim 1, characterised in that said reference plane (S) is vertical or slanted.

18. Sawing machine characterised in that it comprises at least one oscillating cutting bench (1) according to claim 1.