GRINDING MACHINE

Abstract

A grinding machine for grinding tools comprises a support unit configured to support a tool to be ground and provided with members suitable to incline it by certain angle with respect to a horizontal reference plane; and an operating unit that is mobile along a main axis of development of the grinding machine in order to move with respect to the support unit and comprises an abrasive element intended to abrade at least a portion to be ground of the tool. The grinding machine comprises an adjustment system to adjust the inclination of the support unit with respect to the reference plane. The adjustment means system is mobile parallel to the main axis of development to move to a predetermined distance from the reference plane.

Claims

11. A grinding machine for grinding a tool, the grinding machine comprising: a support unit configured to support said tool to be ground and located on a horizontal reference plane, wherein said support unit comprises members configured to incline said support unit by any angle with respect to said reference plane; an operating unit comprising an abrasive assembly intended to abrade at least a portion to be ground of said tool, wherein said operating unit is mobile along a main axis of development of said grinding machine, perpendicular to said reference plane, in order to move nearer to or farther away with respect to said support unit, an adjustment system to adjust the inclination of said support unit with respect to said reference plane; wherein said adjustment system has at least an adjustment element mobile parallel to said main axis of development to assume at least an adjustment position disposed at a distance from said reference plane that corresponds to said angle.

12. The grinding machine as recited in claim 11, wherein said adjustment element is associated with said operating unit and extends in a direction parallel to said main axis of development.

13. The grinding machine as recited in claim 12, wherein said operating unit comprises a support body that supports at least one between said abrasive assembly and said adjustment element, and a drive system configured to command at least one between the movement of said support body along said main axis of development and the rotation movement of said abrasive assembly around said main axis of development.

14. The grinding machine as recited in claim 13, wherein said adjustment element is mobile with respect to said support body.

15. The grinding machine as recited in claim 13, wherein said operating unit comprises a clamping device configured to alternately clamp or release the position of said adjustment element with respect to said support body.

16. The grinding machine as recited in claim 12, wherein said support unit comprises an abutment element configured to abut on said adjustment element.

17. The grinding machine as recited in claim 16, wherein said adjustment element comprises a lower end portion shaped so as to define a localized contact zone between said adjustment element and said abutment element.

18. The grinding machine as recited in claim 11, wherein said main axis of development extends in a vertical direction that is perpendicular to said reference plane.

19. A method for grinding a tool using a grinding machine as in claim 11, the method comprising the steps of: positioning a tool on the support unit, in which said tool has a cutting portion inclined by a certain angle of inclination with respect to the horizontal; introducing in a user interface associated with said grinding machine the value of an angle, in which said angle is equal to or different from said angle of inclination of the cutting portion; calculating a distance between an adjustment system and a reference plane, in which said distance is a linear distance corresponding univocally to said angle; moving an operating unit that comprises an abrasive assembly toward a support unit that supports said tool by a predetermined quantity which is a function of said distance; taking said adjustment system to said distance from said reference plane; inclining said support unit by said angle with respect to said reference plane until an abutment element comprised in said support unit abut on an adjustment element comprised in said adjustment system; distancing said adjustment system from said reference plane so that they do not obstruct the operation of said abrasive assembly; grinding said tool by using said abrasive means assembly.

20. The method as recited in claim 19, wherein before said taking step, it is provided to act on a clamping device to release the position of said adjustment element with respect to a support body comprised in said operating unit so that said adjustment element can move in a direction parallel to said main axis of development with respect to said support body until an end portion of said adjustment element reaches said distance from said reference plane, and wherein after said taking step, it is provided to act further on said clamping device to clamp the position of said adjustment element with respect to said support body.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0062] These and other characteristics of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein:

[0063] FIG. 1 is a schematic view in front elevation of a grinding machine according to the invention;

[0064] FIGS. 2-4 are views in front elevation of the grinding machine of FIG. 1, in which the machine is shown in different successive positions;

[0065] FIGS. 5 and 6 are perspective views of two tools suitable to be ground by a grinding machine according to the invention.

[0066] To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can conveniently be incorporated into other embodiments without further clarifications.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

[0067] We will now refer in detail to the various embodiments of the present invention, of which one or more examples are shown in the attached drawings. Each example is supplied by way of illustration of the invention and shall not be understood as a limitation thereof. For example, the characteristics shown or described insomuch as they are part of one embodiment can be adopted on, or in association with, other embodiments to produce another embodiment. It is understood that the present invention shall include all such modifications and variants. With reference to FIGS. 1-4, a grinding machine 10 is described for grinding tools 100, 100 provided with at least one cutting portion 101. In particular, the grinding machine 10 is able to grind tools 100, 100 having a cutting portion 101 inclined by a certain angle with respect to the horizontal.

[0068] FIGS. 5 and 6 show two different examples of a tool 100, 100 suitable to be ground by a grinding machine 10 according to the invention. FIG. 5 shows a tool 100 having a single cutting portion 101 inclined by an angle of inclination with respect to the horizontal. FIG. 6 shows instead a tool 100 having two cutting portions 101a and 101b, which are joined in correspondence with a top 102 of the tool 100. Both cutting portions 101a, 101b are inclined by an angle of inclination with respect to the horizontal. In FIG. 4, the tool 100 is shown positioned in position on the grinding machine 10 in order to be ground.

[0069] The grinding machine 10 comprises a support unit 11 configured to support one or more tools 100, 100 to be ground.

[0070] The support unit 11 is located on a substantially horizontal reference plane 12.

[0071] The support unit 11 comprises members, of a known type and not shown, suitable to incline the support unit 11 by a certain angle (visible in FIGS. 3 and 4) with respect to the reference plane 12. These members can be typically enclosed inside the support unit 11 and can comprise mechanical elements such as for example toothed wheels, a screw-female screw connection, etc. It should be noted that the angle by which the support unit 11 is inclined can be equal to or different from the angle of inclination of the cutting portion 101, 101a, 101b of the tool 100.

[0072] The grinding machine 10 also comprises an operating unit 13 comprising abrasive means 14 intended to abrade at least a portion 101 to be ground of the tools.

[0073] The operating unit 13 is mobile along a main axis of development X of the grinding machine 10 so as to move with respect to the support unit 11, in particular to move nearer to or away from it.

[0074] In some embodiments, the main axis of development X extends along a substantially vertical direction which is transverse, in particular perpendicular, to the reference plane 12. In these embodiments, the grinding machine 10 is of a vertical type so that the main axis of development X can be disposed vertical.

[0075] The operating unit 13 comprises a support body 17 which supports the abrasive means 14.

[0076] The operating unit 13 comprises drive means 18 configured to command the displacement of the support body 17 along the main axis of development X.

[0077] In some embodiments, the drive means 18 are configured to also allow a rotary movement of the abrasive means 14 around the main axis of development X.

[0078] In other embodiments, a device can be provided to rotate the abrasive means 14 which is not located on the operating unit 13.

[0079] In some embodiments, the drive means 18 can comprise an electric motor.

[0080] In some embodiments, position transducer means are provided, such as for example an encoder of the known type, which are associated with the drive means 18 to know the position of the operating unit 13 so as to suitably drive the drive means 18.

[0081] The grinding machine 10 comprises adjustment means 15 to adjust the inclination of the support unit 11 with respect to the reference plane 12.

[0082] In some embodiments, the adjustment means 15 can be associated with the operating unit 13.

[0083] In other embodiments, the adjustment means 15 can be associated with a wall 25 of the grinding machine 10 which delimits an operating chamber 26 of the machine in which the operating unit 13 and the support unit 11 are located.

[0084] The adjustment means 15 are mobile parallel to the main axis of development X so as to be able to assume a position distanced by a predetermined distance D from the reference plane 12 (FIG. 2).

[0085] The adjustment means 15 comprise an oblong adjustment element 16, for example an adjustment rod, which extends in a direction parallel to the main axis of development X.

[0086] In some embodiments, the adjustment rod 16 is supported by the support body 17.

[0087] In some embodiments, the adjustment rod 16 is mobile with respect to the support body 17. In particular, the adjustment rod 16 can translate with respect to the support body 17.

[0088] In some embodiments, the operating unit 13 comprises clamping means 19 configured to alternately clamp or unclamp the position of the adjustment rod 16 with respect to the support body 17.

[0089] In some embodiments, the clamping means 19 are known in the state of the art and can for example comprise a screw acting on a stop element. By acting on the screw, the operator can take the stop element into contact with the adjustment rod 16 so as to clamp the position of the latter.

[0090] It should be noted that, in one embodiment, the displacement of the adjustment rod 16 can be operated manually by the operator.

[0091] In other embodiments, not shown, the adjustment means 15 can comprise a drive unit, of a known type, which moves the adjustment rod 16 in an automated manner.

[0092] The support unit 11 comprises abutment means 20 configured to abut on the adjustment rod 16. To this purpose, the adjustment rod 16 comprises a lower end portion 16A shaped in such a way as to define a localized contact zone between the adjustment rod 16 and the abutment means 20.

[0093] In some embodiments, the end portion 16A can have, for example, a hemispherical shape.

[0094] In other embodiments, the end portion 16A can have different shapes from the hemispherical shape, such as for example conical or truncated cone shape, with the top of the cone facing toward the abutment means 20.

[0095] In some embodiments, the adjustment element 16 can comprise at least one sensor, of a known type, configured to detect the contact between the end portion 16A and the abutment means 20. In particular, the sensor can be positioned in correspondence with the end portion 16A. The presence of the sensor allows to motorize the inclination movement of the support unit 11. For this purpose, an additional motor can be provided which drives the support unit 11 to take it into the inclined position and keep it clamped in this position.

[0096] In some embodiments, the abutment means 20 can be configured as a base on which the support unit 11 rests.

[0097] In some embodiments, a clamping device 21 can be associated with the abutment means 20, which is configured to selectively clamp the position of the support unit 11 once it has been inclined by the angle .

[0098] During use, the support unit 11 is rotatable with a rotational motion around the axis of longitudinal development X.

[0099] In some embodiments, the support unit 11 can comprise a rotary table 22 and a tool-bearing mandrel 23, for example of the universal type.

[0100] The tool-bearing mandrel 23 is fixed to the rotary table 22 and the latter is connected to the abutment means 20.

[0101] The grinding machine 10 comprises a user interface 24 through which an operator can control its functioning. The user interface 24 is operatively connected to a control and management unit (not shown) of the grinding machine 10.

[0102] According to the invention, a method is also provided to grind tools 100, 100 using a grinding machine 10, for example like the one described above.

[0103] The method according to the invention comprises the steps of:

[0104] positioning on a support unit 11 a tool 100, 100 comprising a cutting portion 101, 101a, 101b having a certain angle of inclination with respect to the horizontal,

[0105] introducing into a user interface 24 the value of an angle , in which the angle is equal to or different from the angle of inclination of the cutting portion 101, 101a, 101b,

[0106] calculating a distance D between adjustment means 15, configured to adjust the inclination of the support unit 11, and a substantially horizontal reference plane 12; wherein the distance D is a linear distance corresponding univocally to the angle ,

[0107] moving an operating unit 13 comprising abrasive means 14 toward the support unit 11 by a predetermined entity that is a function of the distance D,

[0108] taking the adjustment means 15 to the distance D from the reference plane 12 (FIG. 2),

[0109] inclining the support unit 11 by the angle with respect to the reference plane 12 until the abutment means 20 comprised in the support unit 11 abut on an adjustment element 16, for example shaped like a rod or an oblong element, comprised in the adjustment means 15 (FIG. 3),

[0110] distancing the adjustment means 15, in particular the adjustment element 16, from the reference plane 12 so that they do not obstruct the action of the abrasive means 14 (FIG. 4),

[0111] grinding the tool 100, 100 using the abrasive means 14.

[0112] It should be noted that the distance D, in particular, is the distance between an end portion 16A of the adjustment element 16 and the reference plane 12.

[0113] The step of calculating the distance D provides to calculate the latter according to the angle and the geometry of the support unit 11, in particular the radial distance between the main axis of development X and the point where the end portion 16A abuts on the abutment means 20.

[0114] Once the distance D has been calculated, the method provides the step of moving the operating unit 13 along the main axis of development X. To do this, the method provides to determine the entity of displacement of the operating unit 13 along the main axis of development X. The entity of this displacement is a function of the distance D calculated in the previous step.

[0115] The control and management unit of the grinding machine 10 is able to calculate the entity of displacement of the operating unit 13 based on the geometries and the spatial disposition of the operating unit 13, of the support unit 11 and of the adjustment means 15.

[0116] In some embodiments, once the distance D is known, to determine the displacement of the operating unit 13 it is sufficient to know the length of the adjustment rod 16, its maximum translation travel with respect to the support body 17, and the thickness of the abutment means 20, that is, the distance of the latter from the reference plane 12.

[0117] In some embodiments, in the method according to the invention the step of taking the adjustment means 15 to the distance D from the reference plane 12 comprises the step of acting on clamping means 19 to unclamp the position of the adjustment rod 16 with respect to a support body 17 comprised in the operating unit 13.

[0118] In this way, the adjustment rod 16 can move with respect to the support body 17 in a direction parallel to the main axis of development X, as indicated by the arrow F in FIG. 2. In particular, it is provided that the adjustment rod 16 moves as indicated by the arrow F until an end portion 16A of the adjustment rod 16 reaches said distance D from the reference plane 12.

[0119] It should be noted that, in some embodiments, the adjustment rod 16 can comprise a reference element, for example shaped like an annular ridge, which engages with a relative shoulder made on the support body 17. During use, when the operator unclamps the position of the adjustment rod 16 by acting on the clamping means 19, the adjustment rod 16 translates with respect to the support body 17, moving in the direction indicated by the arrow F, until the annular ridge abuts with the shoulder.

[0120] After the step of acting on the clamping means 19, the step of taking the adjustment means 15 to the distance D from the reference plane 12 provides to further act on the clamping means 19 to clamp the position of the adjustment rod 16 with respect to the support body 17.

[0121] It should be noted that, after the step of inclining the support unit 11, the latter is inclined with respect to the reference plane 12 by an angle which has been previously set by the operator on the interface 24. The angle can be substantially equal to the angle of inclination of the cutting portion 101, 101a, 101b of the tool 100 with respect to the horizontal. In this case, after the inclination step, the cutting portion 101b which has to be ground is substantially horizontal (and therefore parallel to the horizontal reference plane 12, as shown in FIG. 4) so that the abrasive means 14 can grind the cutting portion 101b in an optimum manner

[0122] According to another aspect of the invention, a method is provided to command the functioning of a grinding machine for grinding tools 100, 100 which comprises the step of controlling the displacement of the operating unit 13 comprising abrasive means 14 with respect to the support unit 11 configured to support the tool to be ground.

[0123] In particular, the method provides to control the speed of displacement of the operating unit 13 along a main axis of development X of the grinding machine 10.

[0124] The method provides to detect the force exerted on the tool by the abrasive means 14 and to command the advance of the operating unit 13 in the direction indicated by the arrow F as a function of the force value detected. In particular, the step of detecting the force comprises the step of detecting the current absorbed by drive means 18 comprised in the grinding machine 10. The drive means 18 are configured to command the displacement of the operating unit 13 along the main axis of development X and/or the rotation movement of the abrasive means 14 around the main axis of development X. In particular, the drive means 18 command the displacement along the main axis of development X of a support body 17 comprised in the operating unit 13 to which the abrasive means 14 are connected.

[0125] After the step of detecting the current, it is provided to compare the current values detected with at least one predetermined threshold value.

[0126] After the comparison step, in one embodiment it is provided to decrease, or annul, the speed of advance of the support body 17 and/or the rotation speed of the abrasive means 14 if the current values detected are higher than the threshold value.

[0127] After the comparison step, in another embodiment it is provided to stop the translation of the support body 17 and/or the rotation of the abrasive means 14.

[0128] After the comparison step, in other embodiments it is provided to move the support body 17 with a speed of advance oriented in a direction opposite to that indicated by the arrow F, so that the operating unit 13 moves away from the support unit 11 by a certain distance.

[0129] It is clear that modifications and/or additions of parts or steps may be made to the machine and method as described heretofore, without departing from the field and scope of the present invention.

[0130] It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent fauns of machines and methods, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.