Cutting unit, particularly for lines of drilling and milling machines for machining metal structural beams and the like

Abstract

A cutting unit (1), particularly for lines of drilling and milling machines for machining metal structural beams and the like, which comprises a main body (2), integrally associatable with a machining head (3) of a drilling and milling machine or the like (100), and a circular blade (4), rotatably associated with the main body (2) and functionally connectable to rotating means of the machining head (3): blade guiding means (6) are associated with the main body (2) and have an internal channeling which can be connected to a compressed air system and is shaped for the generation of two mutually opposite air flows acting on the side faces (4a, 4b) of the circular blade (4) with the aim of damping vibrations through the formation of a compressed air cushion, as well as cooling the circular blade (4).

Description

[0001] CUTTING UNIT, PARTICULARLY FOR LINES OF DRILLING AND MILLING MACHINES FOR MACHINING METAL STRUCTURAL BEAMS AND THE LIKE

[0002] The present invention relates to a cutting unit, particularly for lines of drilling and milling machines for machining metal structural beams and the like.

[0003] In the sector of heavy metal structural work, the use is known of cutting units of various kinds for the mechanical machining of workpieces.

[0004] Such cutting units are not devoid of drawbacks, including the fact that they exhibit high levels of wear as a consequence of overheating of the cutting blade and of vibrations in the cutting blade owing to the cutting force applied.

[0005] Furthermore, linked to the vibrations in the cutting blade, another drawback of conventional cutting units consists in the loss of precision of machining with the increase in the amplitude of the vibrations described above.

[0006] Another drawback of conventional cutting units is that they are fitted with electrospindles which make it possible to reach high speeds at the cost of cutting torque.

[0007] The aim of the present invention consists in providing a cutting unit, particularly for lines of drilling and milling machines for machining metal structural beams and the like, that is capable of overcoming the above- mentioned drawbacks.

[0008] Within this aim, an object of the present invention consists in providing a cutting unit that is capable of ensuring a lesser level of wear than cutting units of the prior art.

[0009] Another object of the present invention consists in providing a cutting unit with high performance levels, both in terms of cutting parameters and in terms of machining precision.

[0010] This aim and these and other objects which will become better evident hereinafter are achieved by a cutting unit, particularly for lines of drilling and milling machines for machining metal structural beams and the like, which comprises a main body, integrally associatable with a machining head of a drilling and milling machine or the like, and a circular blade, rotatably associated with said main body and functionally connectable to rotating means of said machining head; characterized in that it comprises blade guiding means which are associated with said main body and have an internal channeling which can be connected to a compressed air system and is shaped for the generation of two mutually opposite air flows acting on the lateral faces of said circular blade.

[0011] Further characteristics and advantages of the invention will become more apparent from the detailed description of a preferred, but not exclusive, embodiment of a cutting unit, particularly for lines of drilling and milling machines for machining metal structural beams and the like, which is illustrated by way of non-limiting example with the aid of the accompanying drawings wherein:

[0012] - Figure 1 is a perspective view from the front of the cutting unit according to the invention;

[0013] - Figure 2 is a perspective view from behind of the cutting unit shown in Figure 1;

[0014] - Figure 3 is an exploded perspective view of the cutting unit shown in the previous figures;

[0015] - Figure 4 is a cross-sectional view of the cutting unit shown in the previous figures, taken along an axial cross-sectional plane;

[0016] - Figure 5 is an enlarged- scale detail of the cutting unit shown in Figure 4;

[0017] - Figure 6 is a perspective view of a drilling and milling machine for machining metal structural beams, with a cutting unit according to the invention installed.

[0018] With reference to the figures, the cutting unit, particularly for lines of drilling and milling machines for machining metal structural beams and the like is designated with the reference numeral 1 and comprises a main body 2, integrally associatable with a machining head 3 of a drilling and milling machine or the like 100, and a circular blade 4, rotatably associated with the main body 2 and functionally connectable to rotating means of the machining head 3.

[0019] In more detail, in the embodiment, the circular blade 4 is made of steel and has a large diameter (for example greater than 500 millimeters) with inserts 5 made of weld-brazed hard metal.

[0020] According to the invention, blade guiding means 6 are associated with the main body 2 and have an internal channeling, better described below, which is connectable to a compressed air system and is shaped for the generation of two mutually opposite air flows acting on the side faces 4a and 4b of the circular blade 4.

[0021] In this way, it is possible to damp the vibrations through the formation of a compressed air cushion laterally to the circular blade 4, as well as cooling the latter.

[0022] All this produces less wear of the circular blade 4, better cutting performance, and superior machining precision.

[0023] In more detail, the circular blade 4 is arranged in a cantilevered manner with respect to the main body 2 and the blade guiding means 6 comprise a connecting arm 7, extending from the main body 2 radially with respect to the rotation axis 8 of the circular blade 4 and parallel to the cutting plane defined by that circular blade 4, and a jaw 9, which is integral with the free end of the connecting arm 7 and is shaped so as to wrap around a sector of the circular blade 4.

[0024] Conveniently, the above-mentioned internal channeling extends inside the connecting arm 7 and the jaw 9 with a main duct 10 and ends at two mutually opposite nozzles 11 defined on the mutually opposite faces of the jaw 9 which are directed toward the circular blade 4. More specifically, given the shape of the jaw 9, between the main duct 10 and the mutually opposite nozzles 11 second conduits 12 are provided to channel the air flow from the side hub to the cantilevered side_of the circular blade 4.

[0025] Moreover, the internal channeling described above comprises an initial portion 13 which is defined inside the main body 2 and extends from at least one coupling duct 14, coupled to the compressed air system, to the main duct 10.

[0026] In the illustrated embodiment, the initial portion 13 has a toroidal shape and four coupling ducts 14 are provided so as to offer greater flexibility in mounting the cutting unit 1 on the machining head 3.

[0027] Advantageously, the blade guiding means 9 comprise at least two blade guiding pads 15 placed on the mutually opposite faces of the jaw 9 which are directed toward the circular blade 4, the function of which is to support the circular blade 4 in its transverse direction through the mechanical action of two inserts made of hard metal.

[0028] In more detail, spacers 16 can be inserted between the blade guiding pads 15 and the respective seats of the jaw 9; these spacers are conveniently dimensioned as a function of the wear of the blade guiding pads 15 and of the thickness of the circular blade 4.

[0029] In the illustrated embodiment, the blade guiding pads 15 are fixed in the respective seats of the jaw 9 by means of screws and central holes 17 which define the outlet of the mutually opposite nozzles 11.

[0030] Furthermore, the internal channeling just described is advantageously connectable to a lubrication / cooling system in order to improve the cooling of the circular blade 4 and the reduction in friction of the cutting region of the circular blade 4.

[0031] In a variation, not shown, the blade guiding means 6 can comprise multiple pairs of blade guiding pads 15 placed circumferentially and / or radially at different points of the circular blade 4 according to the specific requirements of the case. Conveniently, in such case, the jaw 9 and the internal channeling will be redesigned in order to be both upgraded to the new configuration with multiple blade guiding pads.

[0032] The transmission of the motion to the circular blade 4 occurs by means of a gear reducer 18, accommodated inside the main body 2, with the circular blade 4 being integral in rotation with the rotating body 22 of the gear reducer 18.

[0033] Advantageously, in the illustrated embodiment, the gear reducer 18 is of the planetary gear type with a rotating housing, making it possible to reduce the speed by a fixed ratio and, as a consequence, to increase the torque by a value equal to the reduction ratio, and comprises a rotary coupling 19 which is functionally engageable with the drive means of the machining head 3.

[0034] This rotary coupling 19 is rotatably supported by the main body 2 by means of a crossed roller bearing 20 which allows the rotation and the consequent transmission of torque to the gear reducer 18, but in parallel it releases only the rotation, thus allowing the transmission of overturning moments and of the axial load generated by the cutting motion on the machining head 3 and through the bearings thereof to the structure of the machine 100.

[0035] Conveniently, the main body 2 comprises at least one rotationpreventing pin 21 (four in the illustrated embodiment) connected to the main body 2 and connectable to the fixed part of the machining head 3.

[0036] The coupling ducts 14 are defined inside the anti-rotation pins 21.

[0037] With reference to Figure 6, the cutting unit 1 can be installed on a drilling and milling machine 100 for machining metal structural beams or any metallic profile of metal structural work, and the machining head 3 can be selected from the group constituted by: fixed vertical-axis spindles, fixed horizontal-axis spindles, rotating-axis spindles, capable of positioning the axis at an angle of 180° on a plane, and multi-axis heads, capable of positioning the blade in space so as to be able to perform complex cuts.

[0038] The operation of the cutting unit 1 according to the invention is easily understood from the foregoing description.

[0039] In particular, it should be noted that the cutting unit 1 according to the invention can be managed as an accessory that is loaded and deposited in a completely automatic manner in the tool magazine in a dedicated station.

[0040] This makes operations for drilling, milling and cutting completely automated.

[0041] In practice it has been found that the cutting unit, according to the present invention, achieves the set aim and objects.

[0042] For example, an advantage of the cutting unit according to the invention consists in being able to reach high cutting speeds without losing cutting torque by virtue of the use of the gear reducer interposed between the blade and the spindle, while maintaining precise cutting by virtue of the blade guiding means and with a tool operating temperature that is always in the optimal range.

[0043] The cutting unit, thus conceived, is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims.

[0044] Moreover, all the details may be substituted by other, technically equivalent elements.

[0045] In practice the materials employed, provided they are compatible with the specific use, and the contingent dimensions and shapes, may be any according to requirements and to the state of the art.

[0046] The disclosures in Italian Patent Application No. 102023000012033 from which this application claims priority are incorporated herein by reference.

[0047] Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

CLAIMS1. A cutting unit (1), particularly for lines of drilling and milling machines for machining metal structural beams and the like, which comprises a main body (2), integrally associatable with a machining head(3) of a drilling and milling machine or the like (100), and a circular blade(4), rotatably associated with said main body (2) and functionally connectable to rotating means of said machining head (3); characterized in that it comprises blade guiding means (6) which are associated with said main body (2) and have an internal channeling which can be connected to a compressed air system and is shaped for the generation of two mutually opposite air flows acting on the lateral faces (4a, 4b) of said circular blade (4).

2. The cutting unit (1) according to claim 1, characterized in that said circular blade (4) is located in a cantilevered manner with respect to said main body (2).

3. The cutting unit (1) according to claim 1 or 2, characterized in that said blade guiding means (6) comprise:- a connecting arm (7), extending from said main body (2) radially with respect to the rotation axis (8) of said circular blade (4) and parallel to the cutting plane defined by said circular blade (4);- a jaw (9), which is integral with the free end of said connecting arm (7) and is shaped so as to wrap around a sector of said circular blade (4); said internal channeling extending inside said connecting arm (7) and said jaw (9) with a main duct (10) and ending at two mutually opposite nozzles (11) defined on the mutually opposite faces of said jaw (9) which are directed toward said circular blade (4).

4. The cutting unit (1) according to claim 3, characterized in that said internal channeling comprises an initial portion (13) which is defined inside said main body (2) and extends from at least one coupling duct (14), coupled to said compressed air system, to said main duct (10).

5. The cutting unit (1) according to one or more of the preceding claims, characterized in that said blade guiding means (6) comprise at least two blade guiding pads (15) placed on said mutually opposite faces of said jaw (9) which are directed toward said circular blade (4).

6. The cutting unit (1) according to one or more of the preceding claims, characterized in that said internal channeling is connectable to a lubrication / cooling system.

7. The cutting unit (1) according to one or more of the preceding claims, characterized in that said main body (2) comprises a gear reducer (18) and in that said circular blade (4) is integral in rotation with the rotating body (22) of said gear reducer (18).

8. The cutting unit (1) according to claim 7, characterized in that said gear reducer (18) is of the planetary gear type with a rotating housing.

9. The cutting unit (1) according to claims 7 and 8, characterized in that said gear reducer (18) comprises a rotary coupling (19) which is functionally engageable with said drive means of said machining head (3) which is rotatably supported by said main body (2) by means of a crossed roller bearing (20).

10. The cutting unit (1) according to one or more of the preceding claims, characterized in that said main body (2) comprises at least one rotation-preventing pin (21) which is connected to said main body (2) and is connectable to the fixed part of said machining head (3); said coupling duct (14) being defined inside said at least one rotation-preventing pin (21).

11. The cutting unit (1) according to one or more of the preceding claims, characterized in that said machining head (3) is selected from the group constituted by: fixed vertical-axis spindles, fixed horizontal-axis spindles, rotating-axis spindles and multi-axis heads for complex cuts.

12. A drilling and milling machine (100) for machining metal structural beams, characterized in that it comprises at least one cutting unit (1) according to one or more of the preceding claims.

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