Method and machine for balancing disc blades

Abstract

A method for balancing a disc blade (100) comprising the steps of: determining the initial position of the center of mass of the disc blade (100) to be balanced relative to its main axis (A); calculating / determining the number, position and / or size of one or more balancing holes (109) which are off-center relative to the main axis (A) and require removal of a sufficient amount of material to bring the distance of the center of mass of the disc blade (100) from the main axis (A) below a predetermined maximum limit value; and forming the one or more balancing holes (109) in the off-center position relative to the main axis (A) in the center disc (101).

Description

[0001] Cross-reference to related applications

[0002] This patent application claims priority to Italian patent application No. 102020000027248, filed on November 13, 2020, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] The present invention relates to a method for a balance disc blade and a machine for implementing the method.

[0004] More specifically, the present invention relates to a method and machine for balancing pointed disc blades. The following description will explicitly relate to its use, but without loss of generality. Background Technology

[0005] As is well known, a pointed disc insert consists of a flat steel center disc and a set of high-resistance material inserts or tips. The center disc has multiple protruding radial teeth that cantilever from the periphery of the disc and are spaced apart from each other at equal angles. The high-resistance material inserts or tips are welded to the tips of the corresponding radial teeth to form the cutting portion of the same tooth.

[0006] To avoid unnecessary vibrations during the cutting process, the best disc inserts are balanced at the end of the production process so that the center of mass of the disc insert is located on its axis of symmetry and rotation.

[0007] The balancing of the disc blades is currently done manually by the operator, which requires manual grinding to remove a thin layer of metal material from the back of some teeth of the disc blade, thereby removing excess material that causes imbalance.

[0008] More specifically, the disc insert balancing process requires the operator to place the disc insert on a device capable of measuring the disc insert's imbalance after the drive insert has been rotated about its axis of symmetry and rotation. Once the disc insert has been analyzed, the disc insert balancing process requires the operator to remove the disc insert from the aforementioned device and then, based on their own experience and the data displayed by the aforementioned machine, manually remove a thin layer of material from the back of certain given teeth using a grinding wheel.

[0009] Finally, the disc blade balancing process requires the operator to place the disc blade back on a device capable of measuring the disc blade's imbalance, thereby checking whether selective material removal has brought the disc blade's center of mass to its axis of symmetry and rotation.

[0010] Obviously, the above balancing process can be repeated many times until the disc blade is properly balanced, that is, until the imbalance measured by the equipment meets the predetermined tolerance threshold.

[0011] Unfortunately, the balancing process described above requires a significant amount of time and a large number of skilled operators, which comes at a very high cost.

[0012] Furthermore, the aforementioned balancing process is heavily influenced by human error. In fact, it often happens that during gear grinding, the operator inadvertently removes a layer of material from the back of the tooth that is thicker than required, thereby jeopardizing the mechanical resistance of the disc insert teeth and the problems that result.

[0013] Disc blades with weak teeth cannot be sold and therefore must be discarded. Summary of the Invention

[0014] Therefore, the object of the present invention is to provide a method and machine that can accelerate the balancing of the aforementioned disc blades and make them more economical and precise, overcoming the aforementioned disadvantages.

[0015] In accordance with these objectives, a method for providing a balance disc-type blade according to the present invention is provided, the disc-type blade comprising a central disc and a set of protruding teeth cantilevered from the periphery of the central disc; the method is characterized by comprising the following steps:

[0016] - Determine the initial position of the center of mass of the disc blade to be balanced relative to its main axis;

[0017] - Calculate / determine the number, location, and / or size of one or more balancing holes that are eccentric relative to the main axis and require the removal of a sufficient amount of material so that the distance between the center of mass of the disc blade and the main axis is less than a predetermined maximum limit; and

[0018] - The one or more balance holes are formed at an eccentric position on the central disk relative to the main axis.

[0019] Preferably, but not necessarily, the method for balancing disc-shaped cutting tools is further characterized in that the step of determining the initial position of the center of mass of the disc-shaped cutting tool includes the following steps:

[0020] - To rotate the disc blade to be balanced about its main axis; and

[0021] - Determine the initial eccentricity / angle of the centroid of the disc blade.

[0022] Preferably, but not necessarily, the method for balancing disc blades is further characterized in that the step of rotating the disc blade to be balanced about its main axis includes the following steps:

[0023] - The disc insert to be balanced is rigidly locked onto the tool post spindle, so that the spindle axis of the insert is substantially coincident with the axis of rotation of the spindle; and

[0024] - The drive tool post spindle rotates about its axis of rotation, thereby causing the disc insert to rotate about its axis of rotation.

[0025] Preferably, but not necessarily, the method for a balance disc type blade is further characterized in that the step of forming the one or more balance holes on the central disc includes the following steps:

[0026] - Stop the tool holder spindle at at least at a first pre-calculated angular position, thereby aligning the predetermined first point of the center disk with the drilling assembly; and

[0027] - Drive / command the moving device of the drilling assembly to form a balance hole at the predetermined first point of the center disk.

[0028] Preferably, but not necessarily, the method for a balance disc type blade is further characterized in that the step of forming the balance hole on the central disc includes the following steps:

[0029] - Bring the tool holder spindle into a second / other pre-calculated angular position, thereby aligning the second / other point of the center disc with the drilling assembly; and

[0030] - Drive / command the moving device of the drilling assembly to form a balancing hole at the second / other point of the central disk.

[0031] Preferably, but not necessarily, the method for balancing disc blades is further characterized in that the maximum limit causes the residual imbalance of the disc blade, calculated according to ISO 1940-1, to fall into the balance class G100 or lower of ISO 1940-1.

[0032] Preferably, but not necessarily, the method for using a balance disc type blade is further characterized in that the one or more balance holes are blind holes and / or through holes.

[0033] Preferably, but not necessarily, the method for using a balance disc type blade is further characterized in that one or more balance holes are formed on the edge of the central disc.

[0034] Preferably, but not necessarily, the method for a balancing disc type blade is further characterized in that the one or more balancing holes are formed at a distance from the blade spindle greater than 50% of the radius of the central disc.

[0035] Preferably, but not necessarily, the method for using a balancing disc blade is further characterized in that the one or more balancing holes are substantially circular.

[0036] Preferably, but not necessarily, the method for using a balancing disc blade is further characterized in that the balancing holes all have the same diameter.

[0037] Preferably, but not necessarily, the method for using a balancing disc blade is further characterized in that the one or more balancing holes have a diameter of less than 15 mm.

[0038] Preferably, but not necessarily, the method for a balancing disc blade is further characterized in that the balancing hole is formed as one that is adjacent to another and / or substantially equidistant from the main axis of the blade.

[0039] Furthermore, according to the present invention, a machine for balancing disc-type blades is provided, characterized in that it comprises: a grounded, self-supporting rigid structure; a blade holder spindle fixed to the rigid structure, having the ability to rotate freely about a rotation axis and adapted to support and rigidly lock the disc-type blade so that the disc-type blade is substantially coaxial with the rotation axis on a placement plane perpendicular to the rotation axis; a motor assembly adapted to drive the blade holder spindle to rotate about the rotation axis; an electronic detection device located on the blade holder spindle and adapted to detect imbalances in the disc-type blade engaged with the blade holder spindle; a drilling assembly fixed to the self-supporting rigid structure beside the blade holder spindle, having the ability to move out of and towards the placement plane; and a moving device adapted to move the drilling assembly out of and towards the placement plane according to instructions, such that the drilling assembly can reach and pierce the disc-type blade temporarily mounted on the blade holder spindle, thereby forming one or more balancing holes in the disc-type blade.

[0040] Preferably, but not necessarily, the machine for the balance disc type blade is further characterized by including an electronic control device adapted to drive / command the motor assembly of the tool holder spindle and the moving device of the drilling assembly based on data detected by the electronic detection device.

[0041] Preferably, but not necessarily, the machine for the balancing disc type blade is further characterized in that the electronic control device is adapted to drive / command the motor assembly of the tool post spindle to drive the tool post spindle to rotate about its axis of rotation, and / or change the angular position of the tool post spindle relative to a fixed reference.

[0042] Preferably, but not necessarily, the machine for balancing disc blades is further characterized in that the electronic control device is provided with a data processing unit adapted to determine / calculate the position of one or more points on the disc blade to be formed one or more balancing holes based on data collected by the electronic detection device.

[0043] Preferably, but not necessarily, the machine for the balancing disc insert is further characterized in that the electronic control device is also adapted to drive / command the motor assembly of the tool post spindle and the moving device of the drilling assembly, thereby creating one or more balancing holes on the disc insert temporarily mounted on the tool post spindle.

[0044] Finally, according to the present invention, a disc-shaped cutting tool is provided, comprising a central disc and a set of protruding teeth extending cantilevered from the periphery of the central disc.

[0045] The disc-shaped blade is characterized in that it further includes one or more balancing holes formed on the central disc at an off-center position relative to the blade's rotation axis.

[0046] Preferably, but not necessarily, the disc-shaped blade is further characterized in that the one or more balancing holes are formed at a distance from the blade's axis of rotation greater than 50% of the radius of the central disc. Attached Figure Description

[0047] The invention will now be described with reference to the accompanying drawings, which illustrate non-limiting embodiments thereof, in which:

[0048] - Figure 1 This is a perspective view of a disc blade balancing machine implemented according to the teachings of the present invention, with parts removed for clarity;

[0049] - Figure 2 yes Figure 1 The side view of the disc blade balancing machine shown has parts removed for clarity;

[0050] - Figure 3 yes Figure 1 An enlarged perspective view of a portion of the machine shown; parts have been removed for clarity.

[0051] - Figure 4 This is a front view of a disc blade implemented according to the teachings of the present invention; however

[0052] - Figure 5 yes Figure 4 The side view of the disc blade shown is cut along section line VV, with parts removed for clarity. Detailed Implementation

[0053] refer to Figure 1 , Figure 2 and Figure 3 The number 1 generally indicates a disc blade balancing machine suitable for automatically balancing disc blades 100, which are preferably, but not necessarily, toothed.

[0054] More specifically, the machine 1 is adapted to produce one or more transverse holes of predetermined size in the disc-shaped blade 100 at an eccentric position relative to the center or main axis of the blade, that is, at an eccentric position relative to the axis of symmetry and rotation A of the blade.

[0055] The term "disc blade" specifically refers to a rotary circular tool suitable for cutting, preferably large-sized panels made of wood, plastic, and / or similar materials, and which are not necessarily flat. In other words, the term "disc blade" indicates a rotary circular tool suitable for straight cutting in said panel and preferably suitable for mounting in a cutting machine, such as a table saw, miter saw, and / or similar tool.

[0056] like Figure 4 and Figure 5 As shown, the disc blade 100 specifically includes: a central disc 101, preferably made of a metallic material, which extends coaxially to the axis of symmetry and rotation A and preferably has a central through hole 102 with a predetermined diameter; a set of protruding teeth 103 that cantilever from the periphery 104 of the central disc 101 in a substantially radial direction and are preferably spaced in a substantially regular manner along the periphery 104; and, preferably, a set of tips or inserts 105 of a high-resistance material, each tip or insert 105 being welded or brazed to the tip of a corresponding tooth 103 to form the cutting portion of the same tooth 103.

[0057] More specifically, the center disc 101 is substantially flat, and the radial teeth 103 are preferably integrally formed with the center disc 101. The radial teeth 103 extend cantileveredly from the periphery 104 of the center disc 101, while remaining substantially coplanar with the mid-plane M of the disc, which is substantially perpendicular to the axis A. The radial teeth 103, together with the insert 105, define the crown of the disc-shaped insert 100.

[0058] The high-resistivity material insert 105 is preferably made of a high-resistivity metal material and is preferably fixed sequentially to the corresponding protruding teeth 103 by welding or brazing, so that the high-resistivity material insert 105 is arranged across the tooth mid-plane, which may or may not coincide with the mid-plane M of the central disk 101. Obviously, the insert 105 may also be made of ceramic material, mixed sintered material or similar material, depending on the type of material to be cut.

[0059] Furthermore, the inserts 105 are preferably prisms with a generally trapezoidal or rectangular cross-section, and they preferably have a minimum width measured perpendicular to the midplane M, which is greater than the thickness δ of the central disk 101, such that the side of each insert 105 cantilevered out from the opposite side of the central disk 101 and the tooth 102.

[0060] In other words, the width of the insert 105 is such that, during the cutting operation, only the insert 105 contacts the workpiece / panel to be processed. Conversely, during the cutting operation, the center disk 101 should not be able to contact the workpiece / panel to be processed.

[0061] On the other hand, the central hole 102 of the central disk 101 is coaxial with the axis of symmetry and rotation of the blade A.

[0062] refer to Figure 4 Furthermore, the center disk 101 is preferably provided with a plurality of preferably through edge openings or slits 106 that extend substantially radially from the periphery 104 inside the center disk 101 and are specifically constructed to allow / support local deformation of the blade crown caused by the temperature gradient generated during cutting.

[0063] More specifically, the edge slits 106 are preferably equidistant at an angle around the blade rotation axis A, and they preferably terminate at hook-shaped segments.

[0064] In addition, the center disk 101 is preferably provided with a plurality of preferably through internal slits 107 arranged at a given distance from the periphery 104 in the center disk 101, and is specifically constructed to reduce vibrations transmitted inside the center disk 101 during cutting operations.

[0065] More specifically, the internal slits 107 are preferably equidistant at an angle around the blade rotation axis A, and are preferably shaped like an S or a winding line.

[0066] Preferably, the internal slit 107 is ultimately filled with a polymeric material, preferably of an elastomer type, which is suitable for increasing the vibration damping capability of the internal slit 107.

[0067] refer to Figure 4 Preferably, the center disc 101 is further provided with one or more annular tension bands 108, which are preferably formed by rolling on the center disc 101, spaced apart from the center hole 102 and the periphery 104, and adapted to locally reinforce the center disc 101 to reduce twisting and / or vibration of the disc insert 100 during cutting.

[0068] More specifically, one or more annular tension bands 108 are preferably located on the disc 101 at a distance from the blade rotation axis A, preferably between 50% and 75% of the radius of the central disc 101.

[0069] refer to Figure 4 Finally, the center disk 101 also has one or more preferably circular balance holes 109, and the balance holes 109 are preferably arranged along the edge of the center disk 101 at an eccentric position in the body of the center disk 101 relative to the blade symmetry and the axis of rotation A.

[0070] Preferably, one or more eccentric balancing holes 109 are through-hole type and / or have a diameter of less than 15 mm, more conveniently, also less than 6 mm.

[0071] Furthermore, the balancing holes 109 preferably all have essentially the same diameter.

[0072] In addition, refer to Figure 4 One or more eccentric balancing holes 109 are preferably located near the periphery 104 of the disc blade 100.

[0073] More specifically, the balancing hole 109 is preferably arranged in an annular portion of the central disc 101, which extends between the periphery 104 and one or more annular tension bands 108.

[0074] In other words, one or more balancing holes 109 are preferably arranged at a distance from the axis of rotation A that is greater than or equal to 50% of the radius of the central disk 101.

[0075] More specifically, one or more balancing holes 109 are preferably arranged at a distance from the axis of rotation A that is greater than or equal to 80% of the radius of the central disk 101.

[0076] refer to Figure 4 Furthermore, the balancing holes 109 are preferably adjacent to each other and / or substantially equidistant from the axis of rotation A.

[0077] Preferably, one or more balancing holes 109 are ultimately arranged in the edge of the central disk 101 such that the distance between the one or more balancing holes 109 and the adjacent edge slit 106 always exceeds a given limit, conveniently equal to 1.5 mm.

[0078] refer to Figure 1 , Figure 2 and Figure 3 Machine 1 is adapted to create one or more balancing holes 109 at one or more points on the edge of the central disc 101 in the body of the disc, thereby removing a certain amount of material to balance the mass distribution of the disc blade 100 relative to the blade's symmetry and rotation axis A.

[0079] Obviously, the number, size and / or position of the balancing holes 109 in the center disk 101 or more precisely in the edge of the center disk 101 depends on the initial position of the center of mass of the disc blade 100 relative to the blade's axis of symmetry and rotation A.

[0080] In other words, the number, size, and / or location of the balancing holes 109 depend on the amount of material that needs to be removed from the central disc 101 in order to balance the disc blade 100 as best as possible.

[0081] More specifically, the number, size, and / or location of the balancing holes 109 are determined to reduce and / or substantially eliminate the initial eccentricity of the center of mass of the disc blade 100 relative to the axis of rotation A.

[0082] Even more specifically, the number, size, and / or location of the balance holes 109 in the central disk 101, or more precisely in the edge of the central disk 101, are determined such that the distance between the center of mass of the disc blade 100 and the blade rotation axis A is less than a predetermined maximum limit, which is preferably a function of the nominal or maximum rotational speed of the disc blade 100.

[0083] Preferably, the limit is also less than 0.5 mm, and more conveniently, less than or equal to 100 μm, i.e. 0.1 mm.

[0084] More specifically, the number, size, and / or location of the balance holes 109 in the center disc 101, or more precisely in the edge of the center disc 101, are determined so that the residual imbalance of the disc blade 100 calculated according to standard ISO 1940-1 falls into the given balance class (Gx) of the ISO 1940-1 standard.

[0085] In the example shown, in particular, the number, size and / or location of the balance holes 109 in the center disc 101 are preferably determined such that the residual imbalance of the disc blade 100 calculated according to standard ISO 1940-1 falls into the balance class G100 or lower of standard ISO 1940-1, or more conveniently G40 or lower.

[0086] Clearly, one or more balancing holes 109 are arranged in a portion / sector of the central disk 101, where an excess of material initially causes imbalance. Furthermore, the one or more balancing holes 109 may also be blind holes, meaning their depth may be less than the thickness δ of the central disk 101.

[0087] In other words, some of the balance holes 109 in the center disk 101 can be blind holes, while other balance holes 109 can be through holes.

[0088] refer to Figure 1 , Figure 2 and Figure 3 The disc blade balancing machine 1 firstly includes a self-supporting rigid structure 2, which is preferably made of metal and is suitable for stable placement and optionally can be firmly anchored to the ground.

[0089] The disc blade balancing machine 1 further includes: a blade holder spindle 3, which is fixed to a rigid structure 2, has the ability to rotate freely about a preferably substantially vertical axis of rotation B, and is adapted to support and rigidly lock the disc blade 100 while making the disc blade substantially coaxial with the axis B on a placement plane P perpendicular to the axis B; a preferably electrically operated motor assembly (not shown) adapted to drive the blade holder spindle 3 to rotate about the axis B, preferably to a predetermined angular velocity ω; and an electronic detection device 4, which is located on the blade holder spindle 3 and adapted to detect possible imbalances of the disc blade 100 mounted on the blade holder spindle 3.

[0090] More specifically, the electronic detection device 4 is adapted to detect and quantify the eccentricity of the center of mass of the disc blade 100 relative to the axis of rotation B.

[0091] In other words, the electronic detection device 4 is suitable for detecting the angular position of the center of mass of the disc blade 100 relative to a fixed reference and the distance of the center of mass of the disc blade 100 relative to the axis of rotation B.

[0092] In addition, machine 1 is preferably also provided with an angular position sensor (not visible in the figure), which is mounted on the tool post spindle 3 and is adapted to detect the angular position of the tool post spindle 3 relative to the fixed reference in real time.

[0093] The motor assembly, in turn, is preferably configured such that it can change the angular position of the tool post spindle 3 relative to the aforementioned fixed reference according to instructions.

[0094] refer to Figure 3 In the example shown, in particular, the tool post spindle 3 is preferably provided with a hydraulically or pneumatically operated expansion lock head 5, which is adapted to fit and expand into the center hole 102 of the disc insert 100 according to the command, thereby rigidly locking the disc insert 100 to the tool post spindle 3, while aligning the rotation axis A of the disc insert 100 with the rotation axis B of the tool post spindle 3.

[0095] On the other hand, the electronic detection device 4 preferably includes a plurality of force sensors (not visible in the figure) that are adapted to measure centrifugal force transmitted to the tool holder spindle 3 by a disc blade 100 temporarily mounted on the tool holder spindle 3 when the tool holder spindle 3 is driven to rotate about the rotation axis B.

[0096] More specifically, the electronic detection device 4 is preferably equipped with a plurality of piezoelectric accelerometers or similar sensors, which are grouped in one or more detection groups positioned along the rotation axis B. The piezoelectric accelerometers of the plurality of detection groups or each detection group are distributed around the tool holder main shaft 3 and are placed on the same plane substantially perpendicular to the axis B.

[0097] Using a single set of sensors allows for the detection of static imbalances in the disc blade 100. Using two or more sets of sensors spaced apart along the axis of rotation B also allows for the detection of dynamic imbalances in the disc blade 100.

[0098] refer to Figure 1 , Figure 2 and Figure 3 The disc blade balancing machine 1 further includes: preferably electrically operated drilling assembly 6, which is fixed to a rigid structure 2 next to the tool holder spindle 3, and preferably, on one side of the placement plane P, has the ability to move out of and towards the placement plane P, thereby being able to reach and pierce the disc blade 100 temporarily mounted on the tool holder spindle 3 according to instructions; and preferably electrically operated moving assembly, which is adapted to move the drilling assembly 6 out of and towards the placement plane P according to instructions, so that the drilling assembly 6 can reach and pierce the disc blade 100 temporarily mounted on the tool holder spindle 3.

[0099] More specifically, the drilling assembly 6 is preferably fixed to a rigid structure 2 above the placement plane P, and optionally, is also in an eccentric position relative to the spindle rotation axis B.

[0100] Obviously, the drilling assembly 6 can also be located below the placement plane P.

[0101] Furthermore, the drilling assembly 6 is preferably fixed to the rigid structure 2, thereby enabling it to move in a straight line from and toward the placement plane in a given direction that is laterally relative to the placement plane P and, more conveniently, perpendicularly relative to the placement plane P.

[0102] Therefore, the drilling assembly 6 is adapted to reach the placement plane P / intersect the placement plane P at a single predetermined point Q in the plane, so as to drill holes in the disc insert 100 temporarily mounted on the tool holder spindle 3 only at said point Q.

[0103] For more details, see the reference. Figure 1 , Figure 2 and Figure 3 The rigid structure 2 preferably includes: a horizontal base 8 on which the tool holder spindle 3 is located; and a load-bearing column 9 that cantilevered from the base 8 parallel to axis B (i.e., in a substantially vertical direction), next to the tool holder spindle 3, and fixed to the base 8, having the ability to move out of and toward the tool holder spindle 3 in a direction d1 substantially perpendicular to axis B (i.e., substantially horizontal), preferably while remaining parallel to itself at all times.

[0104] In addition, the machine 1 is preferably provided with a first, preferably electrically or hydraulically operated actuator device 10, which can move the load-bearing column 9 out of and towards the tool holder spindle 3 along the direction d1 according to the instruction, thereby changing / adjusting the distance between the load-bearing column 9 and the axis B.

[0105] The placement plane P is preferably located above the base 8, and the drilling assembly 6 is preferably cantilevered and fixed to the support column 9. The drilling assembly 6 has the ability to move out of and to the base 8 and the placement plane P immediately above the base 8 along the support column 9 (i.e., in the direction d2 parallel to the axis B).

[0106] In addition, the machine 1 is preferably provided with a second, preferably electrically or hydraulically operated actuator device 11, which is capable of moving the drilling assembly 6 along the support column 9 in the direction d2 from the base 8 and / or the placement plane P and towards the base 8 and / or the placement plane P, so that the drilling assembly 6 comes into contact with the disc blade 100 temporarily mounted on the tool holder spindle 3.

[0107] refer to Figure 1 , Figure 2 and Figure 3 Preferably, the drilling assembly further includes 6: a rotating tool holder spindle 12, which is securely fixed to the rigid structure 2, or more precisely, to the support column 9, having the ability to move freely in the direction d2, and adapted to receive and rigidly lock the drill bit 13 or other material removal tool; and preferably electrically operated motor assembly 14, adapted to drive the tool holder spindle 12 to rotate about the rotation axis C of the tool holder spindle 12.

[0108] More specifically, the tool holder spindle 12 is adapted to receive and rigidly lock the drill bit 13 or other similar tool, while positioning the tool, or more precisely the drill bit 13, locally coaxial with and locally parallel to the spindle rotation axis C in direction d2, i.e., parallel to axis B.

[0109] refer to Figure 1 and Figure 3 In addition, the disc blade balancing machine 1 also includes: an electronic control device 15, which is adapted to drive / command the movement of the motor assembly of the tool holder spindle 3 and the drilling assembly 6 according to the data detected by the electronic detection device 4; and preferably also includes an electronic blade measuring device, which is adapted to detect the diameter of the disc blade 100 temporarily mounted on the tool holder spindle 3 and transmit the diameter to the electronic control device 15.

[0110] More specifically, the electronic blade measuring device is preferably located next to the tool holder spindle 3 and is suitable for detecting the diameter of the central disk 101 of the disc blade 100 temporarily mounted on the tool holder spindle 3.

[0111] The electronic control device 15 is adapted to command / control the motor assembly of the tool post spindle 3 to drive the tool post spindle 3 to rotate about the rotation axis B, and / or change the angular position of the tool post spindle 3 relative to the fixed reference, thereby changing / transforming the angular position of the disc insert 100 temporarily mounted on the tool post spindle 3.

[0112] Furthermore, the electronic control device 15 is adapted to drive / command the movement of the drilling assembly 6, thereby bringing the drilling assembly 6 into contact with the disc insert 100 temporarily mounted on the tool holder spindle 3. Preferably, the electronic control device 15 is also adapted to drive / command the movement of the drilling assembly 6 based on data from the electronic insert measuring device.

[0113] More specifically, the electronic control unit 15 is provided with a data processing unit adapted to determine / calculate the position of one or more points of the disc insert 100, at which one or more balancing holes 109 must be formed, based on data from the electronic detection device 4 and optionally, also based on data from the electronic insert measuring device. Furthermore, the electronic control unit 15 is also adapted to drive / command the movement of the motor assembly of the tool post spindle 3 and the drilling assembly 6, thereby creating the one or more balancing holes 109 in the disc insert 100 temporarily mounted on the tool post spindle 3.

[0114] More specifically, the electronic control device 15 is preferably programmed / configured to drive / command the motor assembly of the tool holder spindle 3 based on signals from the angular position sensor, thereby aligning the predetermined point of the disc insert 100 with the drilling assembly 6, or more precisely, the drill bit 13, time and again.

[0115] Preferably, the electronic control device 15 is also programmed / configured to automatically reject the disc blades 100 mounted on the blade holder spindle 3 if the number and / or size of the balance holes 109 to be manufactured exceeds a predetermined limit threshold.

[0116] Furthermore, the electronic control device 15 is preferably also adapted to drive / command the first actuator device 10, thereby moving the support column 9 from or toward the tool holder spindle 3 in direction d1 according to instructions. Additionally, the electronic control unit 15 is preferably also adapted to drive / command the actuator device 11, thereby moving the drilling assembly 6 along the support column 9 from or toward the base 8 and / or the placement plane P in direction d2 according to instructions.

[0117] More specifically, the electronic control device 15 is preferably programmed / configured to drive / command the actuator device 10 based on signals from one or more linear position sensors suitably located on the base 8 and / or column 9.

[0118] Similarly, the electronic control device 15 is preferably programmed / configured to drive / command the actuator device 11 based on signals from one or more linear position sensors appropriately located on the post 9 and / or the drilling assembly 6.

[0119] Preferably, the electronic control device 15 is also adapted to drive / command the motor assembly 14 of the drilling assembly 6.

[0120] The operation of machine 1 will be described below, assuming that the disc insert 100 to be balanced has been mounted on the tool post spindle 3.

[0121] The balancing method implemented by machine 1 includes the following steps:

[0122] Determine the initial position of the center of mass of the disc blade 100 to be balanced relative to the axis of rotation A;

[0123] Calculate / determine the number, location, and / or size of one or more balancing holes 109, which are eccentric relative to the axis of rotation A and require the removal of a sufficient amount of material so that the distance between the center of mass of the disc blade 100 and the axis of rotation A is less than a predetermined maximum limit; and

[0124] One or more balance holes 109 are made in a central disk 101 at an eccentric position relative to the axis of rotation A.

[0125] Clearly, the number, location, and / or size (i.e., diameter and / or depth of the holes) of one or more eccentric balancing holes 109 depend on the amount of material that needs to be removed from the central disk 101 of the disc insert 100, thereby bringing the center of mass of the disc insert 100 into the neighborhood of the axis of rotation A. Additionally, one or more balancing holes 109 may be blind holes or through holes.

[0126] Preferably, the maximum value is also less than 0.5 mm, and more conveniently less than or equal to 100 μm, thus falling within the G100 balance class of standard ISO 1940-1, or, more conveniently, within the G40 balance class or lower of standard ISO 1940-1.

[0127] Preferably, the balancing method implemented by machine 1 further includes the step of automatically rejecting the disc insert 100 mounted on the tool holder spindle 3 if the number and / or size of the eccentric balancing holes 109 to be manufactured exceeds a predetermined limit threshold.

[0128] Furthermore, the step of determining the initial position of the centroid of the disc blade 100 preferably includes the following steps:

[0129] Rotate the disc blade 100 to be balanced about its axis of symmetry and rotation A; and

[0130] Determine the initial eccentricity / angle of the centroid of the disc blade 100 (the angular position of the centroid relative to a fixed reference and the distance between the centroid and the rotation axes A and B).

[0131] Preferably, the step of rotating the disc blade 100 to be balanced about the axis of rotation A further includes the following steps:

[0132] The disc insert 100 to be balanced is rigidly locked onto the machine's tool post spindle 3, so that the rotation axis A of the disc insert 100 is substantially coincident with the rotation axis B of the tool post spindle 3; and

[0133] The drive tool post spindle 3 rotates, thereby causing the disc blade 100 to rotate around the rotation axis B.

[0134] Preferably, the disc insert 100 is also driven to rotate by the tool post spindle 3 to a given angular velocity ω, preferably greater than or equal to 400 rpm.

[0135] Furthermore, after one or more balancing holes 109 are made, the balancing method implemented by the machine 1 preferably includes the step of driving the disc blade 100 to rotate again about the rotation axis A, thereby checking whether the distance between the center of mass of the disc blade 100 and the rotation axis A is less than the maximum limit value.

[0136] Preferably, on the other hand, the step of fabricating one or more balancing holes 109 includes the following steps:

[0137] Start the drilling assembly 6, or more precisely, start the motor assembly 14, thereby driving the tool holder spindle 12 and drill bit 13 to rotate about axis C; and

[0138] Command / control the movement of the drilling assembly 6, or more precisely, command / control the actuator devices 10 and 11, to create one or more balance holes 109 in the disc insert 100 mounted on the tool post spindle 3.

[0139] More specifically, the step of creating one or more balancing holes 109 in the central disk 101 of the disc-shaped blade 100 preferably includes the following steps:

[0140] Stop the tool holder spindle 3 at the first pre-calculated angular position, thereby aligning the first predetermined point of the center disk 101 with the drilling assembly 6, or more precisely, with the drill bit 13; and

[0141] Command / control the movement of the drilling assembly 6, or more precisely, command / control the actuator devices 10 and 11, so as to create a first balancing hole 109 at the first predetermined point on the center disk 101.

[0142] Furthermore, when multiple balancing holes 109 are required to ensure that the distance between the center of mass of the disc blade 100 and the axis of rotation A is less than the maximum limit, the balancing method implemented by the machine 1 after fabricating the first balancing hole 109 preferably further includes the following steps:

[0143] Bring the tool holder spindle 3 to a second / other pre-calculated angular position, thereby aligning the second / other point of the center disk 101 with the drilling assembly 6, or more precisely, with the drill bit 13; and

[0144] Command / control the movement of the drilling assembly 6, or more precisely, command / control the actuator devices 10 and 11, thereby creating a second or another balancing hole 109 at the second / other point of the center disc 101.

[0145] Obviously, the balancing method implemented by machine 1 requires repeating the steps listed above until the pre-calculated number of balancing holes 109 is reached.

[0146] Clearly, the balancing of the disc insert can occur before and / or after the tip or insert 105 may be applied to the teeth 103 of the disc insert 100.

[0147] The advantages associated with the use of the disc blade balancing machine 1 described above and having the balancing method implemented therein are significant.

[0148] First, machine 1 makes balancing disc blades faster and more economical because it removes the exact amount of material needed to bring the blade's center of mass into the neighborhood of the axis of rotation A from the central disc 101 in a rapid and fully automated manner.

[0149] Furthermore, machine 1 does not require checking the proper balance of the blades after each material removal operation.

[0150] Furthermore, machine 1 minimizes production waste because it calculates in advance and in a precise manner the number, location, and / or size of the balancing holes 109 to be manufactured in the central disc 101, thereby balancing the disc blade 100 and eliminating the risk of having to discard the disc blade 100 due to the removal of excess material.

[0151] Furthermore, the above-described disc blade balancing method does not require the presence of a trained operator.

[0152] Ultimately, it is clear that modifications and variations can be made to the above-described disc blade balancing method and machine 1 without departing from the scope of protection of this invention.

[0153] For example, in different embodiments not shown, the eccentric balancing hole 109 may have different cross-sections, such as oval, elliptical, rectangular or similar cross-sections.

[0154] In this case, drill bit 13 will be replaced by a milling cutter.

Claims

1. A method for a balance disc blade (100), the disc blade (100) being adapted to rotate about its main axis (A) and comprising a central disc (101) and a set of protruding teeth (103) extending cantilevered from the periphery (104) of the central disc (101). The method is characterized by comprising the following steps: - Determine the initial position of the center of mass of the disc blade (100) to be balanced relative to the main axis (A); - Calculate / determine the number, location and / or size of one or more balancing holes (109) that are eccentric relative to the main axis (A) and require the removal of a sufficient amount of material so that the distance between the centroid of the disc blade (100) and the main axis (A) is less than a predetermined maximum limit. as well as - One or more balance holes (109) are formed at an eccentric position on the central disk (101) relative to the main axis (A). The step of determining the initial position of the centroid of the disc blade (100) includes the following steps: - The disc insert (100) to be balanced is rigidly locked on the tool holder spindle (3) so that the main axis (A) of the disc insert (100) coincides with the rotation axis (B) of the tool holder spindle (3); - Drive the tool post spindle (3) to rotate about the rotation axis (B), thereby causing the disc blade (100) to rotate about the spindle axis (A); and - Determine the initial eccentricity / angle of the centroid of the disc blade (100). The step of forming one or more balance holes (109) on the central disk (101) includes the following steps: - Stop the tool holder spindle (3) at least at a first pre-calculated angular position, thereby aligning the predetermined first point of the center disk (101) with the drilling assembly (6); and - Drive / command the moving device (10, 11) of the drilling assembly to form a balancing hole (109) at the predetermined first point of the central disk (101), the balancing hole (109) extending parallel to the main axis (A) and having a diameter of less than 15 mm.

2. The method for a balance disc type blade according to claim 1, characterized in that, The step of forming the balancing hole (109) on the central disk (101) includes the following steps: - Bring the tool post spindle (3) into a second / other pre-calculated angular position, thereby aligning a second / other point of the center disk (101) with the drilling assembly (6); and - Drive / command the moving device (10, 11) of the drilling assembly to form a second / another balancing hole (109) at the second / another point of the central disk (101).

3. The method for a balance disc type blade according to claim 1, characterized in that, The maximum limit causes the residual imbalance of the disc blade (100) calculated according to ISO 1940-1 to fall into balance class G100 or lower according to ISO 1940-1.

4. The method for a balance disc type blade according to claim 1, characterized in that, The one or more balance holes (109) are blind holes and / or through holes.

5. The method for a balance disc type blade according to claim 1, characterized in that, The one or more balancing holes (109) are formed on the edge of the central disk (101).

6. The method for a balance disc type blade according to claim 5, characterized in that, The one or more balancing holes (109) are formed at a distance from the main axis (A) that is greater than 50% of the radius of the central disk (101).

7. The method for a balance disc type blade according to claim 1, characterized in that, The balancing holes (109) all have the same diameter.

8. The method for a balance disc type blade according to claim 1, characterized in that, The one or more balancing holes (109) have a diameter of less than 6 mm.

9. The method for a balance disc type blade according to claim 1, characterized in that, The balancing hole (109) is shaped to be equidistant from another adjacent one and / or from the main axis (A) of the disc blade (100).

10. A machine (1) for a balance disc type blade (100), which implements the method for a balance disc type blade according to any one of claims 1 to 9, characterized in that, The machine (1) includes: a grounded self-supporting rigid structure (2); a tool post spindle (3) fixed to the rigid structure (2), having the ability to rotate freely about a rotation axis (B), and adapted to support and rigidly lock a disc insert (100) so that the disc insert is coaxial with the rotation axis (B) on a placement plane (P) perpendicular to the rotation axis (B); a motor assembly adapted to drive the tool post spindle (3) to rotate about the rotation axis (B); an electronic detection device (4) located on the tool post spindle (3) and adapted to detect imbalance of the disc insert (100) engaged with the tool post spindle (3); and a drilling assembly (6) fixed to the tool post spindle (3). The self-supporting rigid structure (2) adjacent to the tool holder spindle (3) has the ability to move out of and towards the placement plane (P) in a direction parallel to the rotation axis (B) and is configured to make holes with a diameter less than 15 mm; and the moving device (10, 11) is adapted to move the drilling assembly (6) out of and towards the placement plane (P) according to instructions, such that the drilling assembly (6) can reach and pierce the disc insert (100) temporarily mounted on the tool holder spindle (3), thereby forming one or more balance holes (109) on the disc insert (100).

11. The machine for a balance disc type blade according to claim 10, characterized in that, It also includes an electronic control device (15) adapted to drive / command the motor assembly of the tool post spindle (3) and the moving device (10, 11) of the drilling assembly based on data detected by the electronic detection device (4).

12. The machine for a balancing disc type blade according to claim 11, characterized in that, The electronic control device (15) is adapted to drive / command the motor assembly of the tool post spindle (3) to drive the tool post spindle (3) to rotate about its axis of rotation (B), and / or change the angular position of the tool post spindle (3) relative to a fixed reference.

13. The machine for a balance disc type blade according to claim 11, characterized in that, The electronic control device (15) is provided with a data processing unit, which is adapted to determine / calculate the position of one or more points on the disc blade (100) where the one or more balance holes (109) are to be formed, based on data collected by the electronic detection device (4).

14. The machine for a balance disc type blade according to claim 13, characterized in that, The electronic control device (15) is also adapted to drive / command the motor assembly of the tool post spindle (3) and the moving device (10, 11) of the drilling assembly (6) to create one or more balance holes (109) on the disc insert (100) temporarily mounted on the tool post spindle (3).

15. A disc blade (100) balanced by a method for balancing a disc blade according to any one of claims 1 to 9, the disc blade (100) being adapted to rotate about its main axis (A) and comprising a central disc (101) and a set of protruding teeth (103) extending cantilevered from the periphery (104) of the central disc (101). The disc blade (100) is characterized in that it further includes one or more balancing holes (109), which are formed on the central disc (101) at an eccentric position relative to the main axis (A), extend parallel to the same main axis (A), and have a diameter of less than 15 mm.

16. The disc blade according to claim 15, characterized in that, The one or more balancing holes (109) are formed at a distance from the main axis (A) that is greater than 50% of the radius of the central disk (101).

Images