IL287851B - Cutting insert with cooling channels, a nozzle, a base plate and a tool holder therefor - Google Patents

Description

CUTTING INSERT WITH COOLING CHANNELS, A NOZZLE, A BASE PLATE AND A TOOL HOLDER THEREFOR TECHNOLOGICAL FIELD This invention relates to cutting tools and cutting inserts, in particular cutting tools and cutting inserts comprising internal cooling mechanisms.

BACKGROUND ART References considered to be relevant as background to the presently disclosed subject matter are listed below: - US9095913B2 - US9656323B2 Acknowledgement of the above references herein is not to be inferred as meaning that these are in any way relevant to the patentability of the presently disclosed subject matter.

BACKGROUND It is known in the art to provide a cooling fluid (i.e., coolant) to a cutting interface of a cutting tool during a cutting operation on a workpiece. Provision of the cooling fluid cools the cutting interface during the cutting operation, thereby preventing damage to both the cutting edge and the workpiece.

In general, cutting tools have a rake face and at least one relief face, defining, at the intersection thereof, the tool’s cutting edge. Cooling fluid is generally provided to the cutting interface, either from the side of the rake face, or from the side of the relief face, or from both external cooling supply arrangements.

Cutting tools may also include cutting inserts, which perform the actual machining. Such cutting inserts are associated with cooling arrangements, separate from the cutting insert, which are configured for external provision of cooling fluid to the cutting insert.- 2 - GENERAL DESCRIPTION In accordance with a first aspect of the presently disclosed subject matter there can be provided a cutting insert comprising a body having a pair of upper and lower parallel horizontal surfaces and at least three sidewalls extending therebetween, and comprising at least one cutting corner region defined between two, first and second, adjacent sidewalls and the upper horizontal surface, and a cooling portion associated with said cutting corner region, said cutting corner region having a rake surface at the corresponding horizontal surface, a first relief surface at the first side sidewall, a second relief surface at the second sidewall, and having respective first and second cutting edge portions and a curved cutting edge portion therebetween, each cooling portion comprising: - a cooling channel formed in the corresponding horizontal surface, open to an exterior of the insert along a depth thereof, the cooling channel extending between a coolant inlet and a coolant outlet and comprising an upstream section associated with the coolant inlet, extending towards the curved cutting edge portion along and spaced from the first cutting edge portion, a downstream section associated with the coolant outlet, extending away from the curved cutting edge portion and extending along and spaced from the second cutting edge portion, and a curved section interconnecting the upstream and downstream sections and extending along the curved cutting corner and spaced therefrom; and - a nozzle receiving through-bore extending from the lower horizontal surface towards the upper horizontal surface, such that the coolant inlet merges with the nozzle receiving through-bore at least along a majority of the depth of the cooling channel at the coolant inlet, so as to allow a nozzle to be introduced therein from at least the lower horizontal surface for directing coolant into the cooling channel via the coolant inlet for the coolant to flow along the cooling channel via the upstream, curved and downstream sections towards the coolant outlet, in order to facilitate heat removal from the cutting corner region.

Any one or more of the following featured designs and configurations can be applied to any of the aspects of the present disclosure, separately or in combinations thereof:- 3 - The curved section of the cooling channel can be spaced from the cutting edge to a distance at least not exceeding that of the upstream section.

The cooling channel can have a channel bottom, a first wall, and a second wall extending from the channel bottom to the corresponding horizontal surface, the first wall being closer to the cutting edge than the second wall. The inclination of the first wall relative to a horizontal plane passing through the channel bottom, varies so that in the curved section the inclination can be greater than adjacent to the coolant inlet. The second wall can comprise a chip breaking formation at an area of the second wall close to the corresponding horizontal surface.

The depth of the cooling channel along at least the curved section can be between 0.5mm to 1mm, more specifically between 0.65 to 0.85 mm, and, even more specifically, can be about 0.7 mm. The first and second walls can have top edges and the width of the cooling channel between these top edges can be in the range of 0.6mm to 1mm, more specifically between 0.7 to 0.8 mm, and even more specifically, can be about 0.75 mm.

The nozzle receiving through-bore can be configured to enable the nozzle to be inserted therein only in a single orientation.

The cutting insert can be double-sided, and said cooling channel constitutes an upper cooling channel in fluid communication with the nozzle receiving through-bore at an area thereof adjacent the upper horizontal surface, and the cutting insert has a lower cooling channel in fluid communication with the nozzle receiving through-bore at an area thereof adjacent the lower horizontal surface, and wherein the nozzle receiving through- bore can be configured to receive a nozzle from both upper and lower horizontal surfaces.

The cutting insert can comprise at least two cutting edges and two cooling channels at each of its upper and lower horizontal surfaces and at least two corresponding nozzle receiving through-bores, each associated with one upper cooling channel and one lower cooling channel. the cutting insert can have a central axis X and the nozzle receiving through-bore can have a bore axis Xb defining a vertical plane with the central axis, where the cooling channel in the upper horizontal surface can be positioned at one side of the vertical plane and the cooling channel in the lower horizontal surface can be positioned at an opposite side of the plane.

The cutting insert can comprise four cutting corner regions on each of the upper and lower horizontal surfaces.- 4 - The nozzle receiving through-bore can be opened to the exterior of the insert at the sidewall closest thereto.

The nozzle receiving through-bore can be disposed at a central area of the cutting insert, and thus constitutes a central nozzle receiving through-bore. The central nozzle receiving through-bore can be associated with at least two cooling channels disposed at the upper horizontal surface and with at least two cooling channels disposed at the lower horizontal surface, each channel having a coolant inlet portion extending between a coolant inlet at the nozzle receiving through-bore and the upstream section of the cooling channel. In some cases, at least a portion of the nozzle receiving through-bore can constitute an insert mounting bore for mounting the cutting insert to a tool holder.

The upstream section can have a first end associated with the coolant inlet and second end associated with the curved section, the first end being disposed further from the cutting edge than the second end.

In accordance with a first aspect of the presently disclosed subject matter there can be provided a nozzle that can be used with a tool holder on which a cutting insert according to any one of the previous designs can be configured to be mounted. The nozzle can be configured to be received within the nozzle receiving through-bore of the cutting insert and have a proximal end to be associated with the tool holder and a distal end associated with the upper horizontal surface of the insert when the nozzle is fully received in the nozzle receiving through-bore, where the nozzle comprises an outlet orifice spaced from the distal end to a distance corresponding to the depth of the cooling channel at the coolant inlet. The nozzle can be configured for being assembled with the tool holder to which the insert can be to be mounted, and optionally integrally assembled therewith, or unitarily formed with the tool holder.

The tool holder can be a part of a tool holder assembly, which also comprises, at least in use, a base plate via which the insert can be to be mounted on the tool holder, and wherein the nozzle can be assembled with the base plate, and optionally integrally assembled therewith, or unitarily formed with the base plate. The nozzle has a vertical axis and the outlet orifice has an orifice axis oriented transversely to the vertical axis.- 5 - BRIEF DESCRIPTION OF THE DRAWINGS In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which: Fig. 1A is a perspective view of a cutting insert according to an example of the presently disclosed subject matter; Fig. 1B is an enlarged plan view of a cutting corner region of the cutting insert of Fig. 1A; Fig. 1C is a cross sectional view along a plane I-I in Fig. 1A, which a cutting insert of the presently disclosed subject matter may have, the plane I-I passing through two upper and two lower cutting corner regions; Fig. 1D is a perspective view of a coolant dispensing nozzle, according to an example of the presently disclosed subject matter, for use with the cutting insert of Fig. 1A; Fig. 2A is a perspective view of a cutting insert according to another example of the presently disclosed subject matter, when mounted on a base plate with a coolant dispensing nozzle received in a nozzle receiving through-bore of the cutting insert; Fig. 2B is a perspective view of the base plate assembled with the coolant dispensing nozzle of Fig. 2A; Fig. 2C is a cross sectional view of the cutting insert of Fig. 2A along a plane II­ II passing through two upper and two lower cutting corner regions, and an axis of the nozzle receiving through-bore; Fig. 2D is an enlarged cross-sectional view of the coolant dispensing nozzle of Fig. 2C; Fig. 3A is a perspective view of a cutting insert with a central nozzle receiving through-bore and a cover, according to another example of the presently disclosed subject matter; Fig. 3B is a perspective view of a base plate and a coolant dispensing nozzle configured for use with the cutting insert of Fig. 3A; Fig. 3C is a plan view of the cutting insert of Fig. 3A without the cover; Fig. 3D is a cross sectional view of the cutting insert of Fig. 3A when mounted on the base plate with the coolant dispensing nozzle of Fig. 3B received in the nozzle - 6 - receiving through-bore of the cutting insert along a plane III-III shown in Fig. 3C passing through two upper and two lower cooling channels; Fig. 3E is an enlarged cross-sectional view of the coolant dispensing nozzle of Fig. 3B; Fig. 3F is an exploded view of the cutting insert of Fig. 3A with a coolant dispensing nozzle thereof; Fig. 4A is a perspective view of an assembly including a cutting tool holder, a base plate and a cutting insert, according to an example of the presently disclosed subject matter; Fig. 4B is an exploded view of the assembly of Fig. 4A; Fig. 5A is a perspective view of a cutting insert according to a further example of the presently disclosed subject matter; Fig. 5B is an enlarged plan view of a cutting corner region of the cutting insert of Fig. 5A; Fig. 6A is a perspective view of a cutting tool holder, having the cutting insert of Fig 3A mounted thereon; Fig. 6B is a cross sectional view of the cutting tool of Fig. 7A, taken along a plane IV-IV; Fig. 7 is an enlarged plan view of a cutting corner region of the cutting insert, according to further example of the presently disclosed subject matter; Fig. 8A is a cross sectional view, which a cooling channel in any of the cutting inserts of Figs. 1A, 3A, 5A, and any other cutting insert of the presently disclosed subject matter may have, the cross sectional view being taken at the area of merging of an upstream section and a curved section of the cooling channel perpendicular to horizontal surfaces of the cutting insert (such as, e.g., plane V-V in Fig. 7); Fig. 8B is another cross sectional view, which a cooling channel in any of the cutting insert of Figs. 1A, 3A, 5A, and any other cutting insert of the presently disclosed subject matter may have, the cross sectional view being taken at the same area as in Fig. 8A; Fig. 8C is a cross sectional view, which the cooling channel of Fig. 8A may have, the cross sectional view being taken at the area of merging of a curved section and a downstream section of the cooling channel perpendicular to horizontal surfaces of the cutting insert (such as, e.g., plane VI-VI in Fig. 7); and- 7 - Fig. 8D is another cross sectional view, which a cooling channel of Fig. 8B may have, the cross sectional view being taken at the same area as in Fig. 8C.

DETAILED DESCRIPTION OF EMBODIMENTS The presently disclosed subject matter generally relates to a cutting insert having at least one curved cutting edge associated with a cutting corner region and comprising a cooling portion configured to allow introduction of a cooling fluid thereto during a cutting operation performed on a workpiece. The cooling portion is formed with an elongated curved cooling channel open to the exterior of the insert and seen in a plan view thereof along at least a majority of the length of the channel between inlet and outlet ends of the channel. At least a majority of the cooling channel is disposed in the vicinity of the cutting edge while being spaced therefrom. The cooling channel is configured to receive cooling fluid (i.e., coolant) in a desired orientation at the coolant inlet end of the channel, so as to let it flow along the channel to the outlet end, for removing heat from the cutting edge and area of the cutting insert disposed between the cutting edge and the cooling channel.

The cutting insert is configured to receive a coolant dispensing nozzle within the body of the cutting insert for delivering cooling fluid at the desired orientation to the inlet end of the cooling channel. The nozzle can be assembled or constitute a unitary body with a base plate and/or a cutting tool holder, on which the cutting insert is to be mounted.

It will be appreciated that in the present disclosure and claims, terms relating to direction, such as top and bottom, upper and lower, up and down, etc., and similar/related terms, are used with reference to the accompanying drawings, unless indicated otherwise or clear from the context, and should not to be construed as limiting. The terms "horizontal" with respect to a surface or line of an element, e.g., a cutting insert, normally means that the surface/line is generally horizontal when the element in its normal orientation is located on a horizontal base, and the term "vertical" with respect to a surface/line of the element means that the surface/line is generally vertical when the element in its normal orientation is located on a horizontal base. The term ‘front’ (and similar terms) refers to a direction towards a workpiece and the term ‘rear’ (and other similar terms) refers to a direction away from the workpiece.

Figs. 1A-1C illustrate a cutting insert 10 according to one example of the presently disclosed subject matter. The cutting insert 10 has two horizontal surfaces, an upper horizontal surface 12 and a lower horizontal surface 13, which are generally parallel to - 8 - each other, and side-walls 14 extending therebetween and having a generally vertical orientation. The cutting insert 10 comprises a mounting bore 15 configured for engaging a fastening element (not shown), by which the cutting insert 10 can be fixedly held on a cutting tool holder or base plate.

The mounting bore can be in the form of a vertical through bore and the fastening element can be in the form of a screw configured to be received therein and to be threaded into a corresponding insert receiving seat in a tool holder. In other cases, the mounting bore can be configured for being engaged by a clamping device associated with the tool holder. For example, the mounting bore can have upper and lower recesses, which are concentric with a central axis of the cutting insert, and have a partition therebetween, into which the clamping device can be inserted for fixedly attaching the cutting insert to the cutting tool holder.

In the example of Fig. 1A-1C, the mounting bore 15 is a centrally disposed through-bore extending between the upper horizontal surface 12 and the lower horizontal surface 13 of the cutting insert 10 and has an axis constituting a central axis X of the cutting insert 10.

The cutting insert 10 has a generally square configuration and is double-sided.

More particularly, the cutting insert 10 has eight similar upper and lower cutting corner regions 18, each having a cutting edge 20 defined at the intersection of associated areas of one of the horizontal upper and lower surfaces 12 and 13 and two adjacent side-walls 14. The cutting insert 10 thus has 8 indexable cutting edges 20.

In other examples, a cutting insert according to the presently disclosed subject matter can have different configurations and a number of indexable cutting edges. For example, the cutting insert can have indexable cutting edges only at its upper surface, or can be double sided, but have less or more than four indexable cutting edges on each side.

The cutting insert can have a polygonal shape other than square, or can have a generally circular shape.

The cutting edges of the cutting insert can each have a first cutting edge portion, a second cutting edge portion, and a curved cutting corner portion therebetween, in which case the areas of the upper and lower horizontal surfaces adjacent the first, second and corner portions of the cutting edge constitute its respective first, second and corner rake surfaces, and areas of the sidewalls adjacent the first, second and corner portions of each cutting edge constitute its respective first, second and corner relief surfaces.- 9 - In the further description of the cutting insert 10 of Fig. 1A, reference will be made only to one cutting corner region 18 with a cutting edge 20 and a cooling portion associated therewith. The cutting edge has a first cutting edge portion 21, a second cutting edge portion 22, and a curved cutting edge portion 23 therebetween. The first cutting edge portion 21 has a first relief surface 21relief and a first rake surface 21rake, the second cutting edge portion 22 has a second relief surface 22relief and a second rake surface 22rake and the curved cutting edge portion 23 has a corner relief surface 23relief and a corner rake surface 23rake. It should be understood that the description regarding one cutting edge and its associated cooling portion should be considered as being applicable to each of the cutting edges of the cutting insert 10 and its corresponding cooling portion.

As mentioned above, the cooling portion comprises an elongated curved cooling channel extending between inlet and outlet ends of the cooling channel, at least a portion of which extends along the corresponding cutting edge, while being spaced from the cutting edge. In the present description and claims, the term "channel" means a region having at least one coolant directing wall, at least a part of which is spaced from the remainder of the horizontal surface associated with the cutting edge in the direction towards the other horizontal surface. The cooling channel can have a single coolant directing wall, to function in a manner similar to a banked turn, or it can be in the form of a trough carved into the corresponding horizontal surface and have two coolant directing walls, at different distances from their associated cutting edge portion.

In any cutting insert according to the presently disclosed subject matter, the cooling channel has an upstream section extending away from the coolant inlet end towards the curved cutting edge corner portion, a downstream section extending towards the coolant outlet end away from the curved cutting edge corner portion, and a curved section connecting therebetween and curving generally along the curved cutting edge.

With respect to Fig. 1B, the cutting corner region 18 comprises a cooling channel 32 in the form of a trough carved into the upper horizontal surface 12. The cooling channel 32 has a coolant inlet end 34 adjacent the first cutting edge portion 21, a coolant outlet end 36 adjacent the second cutting edge portion 22, a first, outer coolant directing wall 50, and a second, inner coolant directing wall 60 extending therebetween. The cooling channel 32 comprises an upstream section 38 extending away from the coolant inlet end 34 towards the cutting corner region 18, a downstream section 42 extending from the - 10 - cutting corner region 18 towards the coolant outlet end 36, and a curved section 40 connecting therebetween and curving generally along the curved cutting edge portion 23.

The cooling channel, in particular its geometry and orientation relative to the coolant inlet end, can be configured so as to enable directional flow of the coolant along the channel at a desired speed, for providing a sufficient amount of surface area exposed to the coolant, and for mitigating the amount of fluid escaping from the channel prior to reaching the coolant outlet. For example, the upstream section of the cooling channel can be at least slightly curved to provide the coolant flow with a radial speed vector prior to its entrance into the curved section.

Additionally, or alternatively, the outer coolant directing wall of the channel, at least at the upstream portion thereof, can have inclination relative to a horizontal plane towards the corresponding cutting edge, gradually increasing from the coolant inlet towards the curved section, and optionally maintaining its increased inclination along the curved section.

The width of the cooling channel, as seen in a plan view thereof, can also vary along its length. For example, the upstream section can have a first width adjacent to the coolant inlet and a second reduced width adjacent to the curved section, so as to increase the pressure of coolant flow therein at the entrance to the curved section. The width of the cooling channel along the curved section can be greater than that at the upstream section. The width of the cooling channel along its downstream section can be the same as, smaller than, or greater than that in the curved section.

In some examples of a cutting insert of the presently disclosed subject matter, the width of the cooling channel and its distance from the cutting edge can be selected so that, at pre-determined conditions under which the cutting insert is to be used in a cutting operation, chips formed during the cutting operation will cover the cooling channel, thereby improving the cooling efficiency at the covered portions thereof.

In Fig. 1B, the cooling channel 32 is shown in operation, in which a directional flow of coolant is provided, and is designated by arrow A. To enable such flow, the upstream section 38 of the cooling channel 32 is curved from its coolant inlet end 34 towards the curved section 40, so as to provide the coolant flow with a radial speed vector towards the central axis X prior to its entrance into the curved section 40. The upstream section 38 has a width gradually decreasing from adjacent to the coolant inlet end 34, towards the curved section 40.- 11 - In order to supply coolant fluid to the cooling channels of the cutting insert, the cutting insert comprises at least one nozzle receiving through-bore, extending between the two horizontal surfaces and configured to receive therein a coolant directing nozzle.

Each nozzle receiving through-bore extends along a vertical axis parallel to the central axis X of the cutting insert, and has a geometric shape enabling the coolant dispensing nozzle (hereinafter nozzle) to be received therein. The nozzle receiving through-bore can be configured to enable the nozzle to be inserted into the nozzle receiving through-bore from either one of the horizontal surfaces to the other, thereby enabling indexable use of the cutting insert. Each of the nozzle receiving through-bores is in fluid communication with one or more cooling channels by means of respective one or more bore outlet openings spaced from each other along the height of the bore. When the cutting insert is double-sided, its at least one nozzle-receiving bore can have a bore upper outlet in fluid communication with a cooling channel in the upper horizontal surface, and a bore lower outlet in fluid communication with a cooling channel in the lower horizontal surface for providing coolant fluid thereto when the insert is turned over.

Reverting to Fig. 1A, the cutting insert 10 comprises four nozzle receiving through-bores 80, and, as seen in Fig. 1C, each nozzle receiving through-bore 80 extends between the upper and lower horizontal surfaces 12 and 13, along a bore axis Xb which is parallel to the central axis X of the cutting insert 10. Each nozzle receiving through- bore 80 comprises a bore upper end 81’ at the upper horizontal surface 12, a bore lower end 81" at the lower horizontal surface 13, a sidewall 82 extending therebetween, a bore upper outlet opening 83' in the sidewall 82 adjacent to and spaced from the bore upper end 81’, and a bore lower outlet opening 83'' in the sidewall 82 adjacent to and spaced from the bore lower end 81". As seen in Fig. 1C, the bore upper outlet opening 83' coincides with the coolant inlet of the cooling channel at the upper horizontal surface 12 of the cutting insert 10, and the bore lower outlet opening 83'' coincides with the coolant inlet 34 end of the cooling channel 32 at the lower horizontal surface 13 of the cutting insert 10. The former cooling channel is designated as 32’ and it extends to the left from the bore upper outlet opening 83', and the latter cooling channel is designated as 32" and it extends to the right of the bore lower outlet opening 83''.

The nozzle and the nozzle receiving through-bore can have such a cross-sectional shape, so as to allow the nozzle to be inserted into the bore only in such orientation, in - 12 - which the nozzle is aligned with the bore upper outlet opening of the cutting insert for dispensing coolant in an optimal manner.

As seen in Figs. 1A and 1B, the nozzle receiving through-bore 80 has an irregular shape, mating that of the nozzle of Fig. 1D, to allow the nozzle to be inserted into the bore only in such orientation, in which the nozzle is aligned with the bore upper outlet opening 83’.

The nozzle has an elongated hollow body of a height corresponding to that of the nozzle receiving through bore and having a nozzle lower end with a nozzle inlet, at which coolant can be introduced into the nozzle, a closed nozzle upper end, a nozzle sidewall axially extending therebetween, and a nozzle outlet formed in the nozzle sidewall, so that, when pressurized, coolant enters the nozzle at the open lower end, and it exits the nozzle from the nozzle outlet opening in a radial direction. The nozzle can constitute a part of, or can be assembled with a base plate or insert seat in a tool holder, to which the insert is to be mounted. To facilitate such assembly, the nozzle can have a base associated with the nozzle lower end that can be fitted within a dedicated socket/recess formed in the base plate or insert seat, and via which coolant can enter the nozzle. The base has a footprint larger than that of the nozzle upper end.

One example of a nozzle 90 configured to be received in a nozzle receiving through bore 80 of the cutting insert of Fig.1A, is illustrated in Fig. 1D. The nozzle 90 has a base 91 and an elongated hollow body 95 extending vertically therefrom. The base 91 constitutes a nozzle lower end having a nozzle inlet 92 via which coolant can be axially introduced into the nozzle 90, and a base mounting bore 93, through which the nozzle can be mounted, for example via a connector, to the base plate or tool holder. The elongated hollow body 95 has a closed nozzle upper end 96, nozzle sidewall 97 axially extending from the base 91 to the nozzle upper end 96, and a nozzle outlet 98 formed in the nozzle sidewall 97 so that, when coolant under pressure enters the nozzle axially at the open lower end, it exits the nozzle from the nozzle outlet 98 in a radial direction.

In any nozzle according to the presently disclosed subject matter, the nozzle outlet may have a configuration facilitating entrance of a coolant flow into the cooling channel in a desired orientation/direction. In particular, the desired orientation of the nozzle outlet relative to the coolant inlet end of the cooling channel can be achieved by an irregular cross-sectional shape of the nozzle and the nozzle receiving through-bore, causing the nozzle opening to be disposed in a certain position with respect to the cooling channel - 13 - when the nozzle is received within the nozzle receiving through-bore. Also, the nozzle outlet can be directed to a portion of the first cutting edge prior to its merger with the curved cutting edge portion, such that the coolant will be dispensed with radial speed vectors enhancing its flow in the cooling channel.

Alternatively, the desired orientation of the nozzle relative to the coolant inlet of the cooling channel can be achieved by mounting thereof to a base plate in a predetermined orientation. In this case, the nozzle and the nozzle receiving through-bore can have a regular cross-sectional shape. One example of this option is illustrated in Figs. 2A to 2D, which show a cutting insert 10' with its nozzle receiving through-bore 80’ and coolant dispensing nozzle 90' having a circular cross-sectional shape. The above description of the cutting insert 10 is fully applicable to the cutting insert 10’, except for the shape of its nozzle receiving through-bore 80 and coolant dispensing nozzle 90.

If a base plate is to be used for mounting of a cutting insert of the presently disclosed subject matter, to a tool holder, such a base plate can have an insert facing surface, upon which the corresponding cutting insert can be mounted, a tool facing surface, and base sidewalls extending therebetween. The insert facing surface may be formed correspondingly with the lower horizontal surface and the side-walls of the corresponding cutting insert. The insert facing surface can have a nozzle receiving recess formed therein configured to accommodate at least a portion of the nozzle, specifically at a predetermined orientation. The base plate can also comprise a coolant pipe passing from an inlet formed at the tool facing surface, to an outlet formed at the nozzle receiving recess for providing coolant to the portion of the coolant dispensing nozzle accommodated therein, and, specifically, to be snuggly fitted therein, so as to be flush with the insert facing surface.

In the example of Figs. 2A-2D, a base plate 100 is used with the cutting insert 10’ and comprises an insert facing surface 102, a tool facing surface 104 and base plate sidewalls 106 extending therebetween. The insert facing surface 102 has holder connecting bore 101, through which it can be connected via a connector to a cutting tool holder, and a nozzle receiving recess 110 formed therein to accommodate at least a portion of the nozzle 90 and shaped to do so at a predetermined orientation. The base plate 100 comprises a coolant pipe 111 passing from an inlet 112 formed at the tool facing surface 104, to an outlet 114 formed at the nozzle receiving recess 110 for - 14 - providing coolant to the portion of the coolant dispensing nozzle 90 accommodated therein.

The nozzle receiving through-bore can be disposed between the horizontal surfaces while being sufficiently spaced from the associated cutting edge portion, so as to prevent mechanical failure thereof up to the mounting bore, e.g. in the middle between two opposite corners of the cutting insert. In some cases, the nozzle receiving through- bore can be located centrally and constitute a portion of the mounting bore itself.

In the cutting insert of Figs. 1A, 1B and 2A, 2B each nozzle receiving through bore is located in the middle, between two adjacent cutting corner regions. In a cutting insert of Figs. 3A to 3D, the nozzle receiving through-bore constitutes a portion of the mounting bore, and in a cutting insert of Fig. 5A-5B, each nozzle receiving through bore is opened to the exterior of the insert at the sidewall closest thereto.

In Figs. 3A to 3F, there is illustrated a cutting insert 10'’ with a nozzle receiving through-bore 80’' constituting a portion of its mounting bore 15'' with a nozzle 90'' fitted therein. The cutting insert 10'' has a diamond shape with two opposing cutting corner regions 18 on each horizontal surface thereof. The nozzle receiving through-bore 80 of this cutting insert has two cooling channels 32'', each facing an opposite cutting corner region 18, and being connected to the central mounting bore 15'' via two opposing coolant inlet portions 35 interconnecting the upstream sections 38 of their corresponding cooling channels 32'' with the mounting bore 15''. The cutting insert 10'' of this example further comprises an inlet cover 410, corresponding to each horizontal surface of the cutting insert (i.e., upper and lower inlet covers 410' and 410''), and attachable thereto by a plurality of connectors 413. The inlet cover 410 is configured to cover the exterior facing portion of the coolant inlet end 34, and optionally, at least a portion of the cooling channel 32 as well, while directing coolant into the channel. In further examples, the inlet cover 410 can also direct the coolant flowing into the channel towards the channel bottom by inlet ramps 411 protruding from an insert facing side 412 of the inlet cover 410, for further preventing coolant from escaping the cooling channel 32.

The cutting insert 10'' is shown in Figs. 3A and 3C positioned onto the base plate 100' and having the coolant dispensing nozzle 90'' fitted within its mounting bore 15’, specifically, fitted about half of the size of the mounting bore 15’ leaving enough space for enabling mounting of the insert to occur. As shown, the base plate 100’ comprises a nozzle receiving recess 110'' about its center. While the base portion 91'' of the coolant - 15 - dispensing nozzle 90'' remains about same, the nozzle portion 220 is shaped as a semi­ circle. The nozzle outlet of the coolant dispensing nozzle 90'' is directed away from its cutting corner region 18, in contrast to the nozzles of Figs. 1D and 2D.

As aforementioned, the mounting bore can be configured to enable a portion of a clamping device to be received therein, while applying force on at least one of the sidewalls and/or bottom of the mounting bore, so as to fixedly attach the cutting insert to the cutting tool holder to which the clamping device is connected.

Figs. 4A and 4B illustrate an assembly comprising a cutting tool holder 300 that is configured to be used with a cutting insert of the kind shown in Figs. 1A and 2A, and a base plate of the kind shown in Figs. 2A and 2B, which thereby constitute cutting tool holder 300. The cutting tool holder 300 comprises a clamp 310 rotatably attached thereto, in a manner allowing the clamp 310 to securely attach the cutting insert 10 thereto. The cutting tool holder 300 further comprises the base plate 100, for example made of Widia, disposed between the cutting insert 10 and a seat surface 302 of the tool holder 300. It will be appreciated that features described herein with reference to and/or illustrated in the accompanying drawings, and/or recited in the appended claims, as constituting elements of the base plate 100, may be provided on the tool holder 300, and vice versa.

The clamp 310 has a front tip 312 configured to be received in the mounting bore of the cutting insert. The cutting tool holder 300 further comprises a cooling provisioning arrangement. The cooling provisioning arrangement comprises a conduit, for example along the length of the tool holder, and has a discharge end 304, to which the base plate can be connected via a screw, for example, threaded into bore 306.

The coolant dispensing nozzle 90 is disposed between the base plate 100 and the cutting insert 10, configured with a base portion 91 configured to be snuggly received in the base plate 100 and having a base mounting bore 92, and a nozzle portion 95 configured to be threaded/inserted, either snuggly or loosely, from both sides of the nozzle receiving through-bore 80 of the cutting insert 10. In this example, coolant is provided, via the tool holder 300, through the base plate 100, by the coolant dispensing nozzle 90 to the cooling portion 30 of the cutting insert.

Fig. 5A illustrates a cutting insert 10' which differs from the previously described cutting inserts in that each nozzle receiving through-bore is formed as a vertical trough formed in the sidewalls, providing it with a lateral opening, as in the nozzle through-bore of Fig. 1T. Fig. 5B illustrates an enlarged view of the cooling portion 30. As - 16 - aforementioned, the outer coolant directing wall 50 extends along the cutting edge while balancing the proximity to the cutting edge. As shown, the distance between the upstream section 38 to the first cutting edge is a first distance D1, and the end of the curved section 40 the outer coolant directing wall 50 is distanced from the cutting corner edge portion, specifically to the area thereof meeting the second cutting edge (the point where the corner ends) to a second distance D2, smaller than the first distance D1. For example, the distance D1 can be about 0.3mm and D2 can be about 0.2mm.

Figs. 6A and 6B illustrate the use of the cutting tool holder 10'' of Fig 3A and the base plate 100' for mounting thereon a cutting insert and the coolant dispensing nozzle 90'' of the kind illustrated in Figs. 3A to 3F, where the front tip 312 of the clamp 310 is dimensioned to be positioned within the space formed between the coolant dispensing nozzle 90'' and the mounting bore 15''.

Cooling channels in cutting inserts according to the presently disclosed subject matter can have their shape in a plan view of the insert, and their cross-sectional shape at different locations along the length thereof, designed to meet different purposes.

For example, the outer coolant directing wall can have an orientation with respect to the corresponding horizontal surface, such as to function as a banked turn, mitigating the spillage of coolant flowing along the cooling channel from the upstream section to the downstream section. The curvature of the curved section can be same throughout the entire section thereof, or it can decrease towards the downstream section in order to reduce the spacing, and hence the amount of material, between the cooling channel and the curved cutting edge portion. The downstream section can have a depth gradually decreasing towards the coolant outlet end, which can be flush with adjacent areas of the corresponding horizontal surface.

In examples of a cutting insert of the presently disclosed subject matter where the cooling channel has only an outer coolant directing wall, the height of the wall can vary along the upstream, curved, and downstream sections of the channel. In examples of a cutting insert of the presently disclosed subject matter, where the cooling channel has outer and inner coolant directing walls, each having a wall top and a wall bottom, the cooling channel having a channel bottom extending between the bottoms of the two walls, the depth of the cooling channel can vary along its length, as well as its geometry. In some cases, the channel bottom can be concaved or inclined to match the curvature or inclination of the walls.- 17 - Consequently, the outer coolant directing wall can be configured to provide balance between two contradicting features: being as close as possible to the cutting edge for increasing heat removal and leaving the minimal amount of insert material between the cooling channel and the closest sidewall necessary to prevent weakening of the cutting edge. In particular, the distance between the channel and its corresponding cutting edge may vary, depending on the forces applied during the cutting operation thereon. For example, the upstream section can be spaced from the first cutting edge to a first distance, and the end of the curved section can be spaced from the cutting corner edge portion to a second distance, smaller than the first distance.

The cooling channel 32 has a channel bottom 70 connecting the outer and inner coolant directing walls 50 and 60 and spaced from the corresponding horizontal surface.

In this example, the depth of the cooling channel 32 is the same in the upstream section 38 and the curved section 40, and gradually decreases along the length of the downstream section 42 away from the curved section 40. For example, the depth of the cooling channel can be between 0.5mm to 1mm at the upstream and curved sections, and gradually decrease to 0 at the coolant outlet end 36, thereby becoming flush with the corresponding horizontal surface.

In cases where more efficient cooling is required in a specific region of the cooling channel, such as the area of merging between the curved section and the downstream section of the cooling channel, e.g., at the area of the channel where the curved portion ends, this region of the cooling channel can be formed as a cooling bay. The cooling bay can be characterized by having geometry of the outer coolant directing wall therealong, different from that of the other areas of the wall. For example, the cooling bay can be characterized by the outer coolant directing wall being closer to the associated cutting edge portion, and/or having a larger distance from the inner coolant directing wall, and/or having a larger slope towards the associated cutting edge, than at other areas of the outer coolant directing wall. The cooling bay can have minimal spacing from the cutting edge associated with a maximal inclination of the outer coolant directing wall.

The cooling bay can differ from the remainder of the insert in the surface treatment when the cutting insert is manufactured. For example, the portion of the cooling channel with the cooling bay can be manufactured without coating, or with a different coating – to increase the heat removal capacity/performance in that area.- 18 - Fig 7. illustrates one example of a cooling channel 32 with a cooling bay portion 500, formed at the merger between the curved section 40 and the downstream section 42 of the cooling channel 32. Specifically, the cooling bay portion 500 is distanced from the corresponding cutting edge at a smaller distance than the upstream portion, and less material is positioned at the between the outer coolant directing wall 50 and the corresponding cutting edge, typically the curved cutting edge portion 23 or the second cutting edge portion 22. As shown the inclination of the outer coolant directing wall 50 increases the merger between the upstream section and the curved section, in which the outer coolant directing wall 50 is spaced to a first distance D1 from the first cutting edge portion 21, towards a portion of the cooling channel 32 where the curved section 40 and the downstream section 42 merges, in which it is spaced to a second distance D2 from the second cutting edge portion 22, being smaller than D1.

Each of the outer and inner coolant directing walls of the cooling channel according to the presently disclosed subject matter can have a varying inclination angle relative to a horizontal plane along a least a part of the cooling channel. This angle can vary continuously, in which case the corresponding wall can be continuously curved, or rather the coolant directing wall can have a number of planar wall surfaces having different inclination angles. For example, each of the outer and inner coolant directing walls can have a lower wall surface comprising the wall bottom and an upper wall surface comprising the wall top, wherein the angle of inclination of the upper wall surface of any of the walls can be smaller than that of the lower wall surface, with respect to a horizontal plane. In some cases, the upper wall surface can have a larger height than that of the lower wall surface allowing the former surface to constitute a chip breaking surface.

Instead of different inclination, the cooling bay portion can have two topographic regions defined in the outer or inner coolant directing walls. Such lateral topographic regions can comprise a beveled face, forming an angled protrusion or recess in the corresponding walls. Such a lateral topographic region can run parallel to at least some of the length of the cooling channel, more specifically, at least about the curved section thereof.

Figs. 8A to 8D illustrate two examples of coolant directing walls with varying topography along their length due to cooling bay portions. In Figs. 8A and 8B, cross sectional views of exemplary cooling channels are shown, viewed from a line matching the position of line V-V of Fig. 7. In Figs. 8C and 8D, cross sectional views of exemplary - 19 - cooling channels are shown, viewed from a line matching the position of line VI-VI of Fig. 7.

The inner coolant directing wall 60 of the cooling channel comprises a lower wall surface 62 having vertical or close to vertical orientation in all sections of the cooling channel and an upper wall surface 64 inclined (8A) or curved (8B) to the horizontal plane at an angle β1/curvature S1 in the direction away from the outer coolant directing wall 50 at the upstream sections 38 of their respective cooling channels. In Fig. 8B, the upper wall surface 64 slightly protrudes upwardly from the level of the outer coolant directing wall 50, about the level of its corresponding rake surface, which is inclined in this example, so that when a cutting insert having coolant directing walls is mounted in a cutting tool, the upper wall surface 64 is capable of functioning as a chip breaker.

The outer coolant directing wall 50 of the cooling channel of Figs. 8A and 8B, forms, with respect to the horizontal plane, a first inclination angle α1, and first curvature S1, respectively, at the merger between the upstream section 38 and the curved section 40. However, at the cooling bay portion 500 at the merger between the curved section 40 and the downstream section 42, the outer coolant directing wall 50 has a lower wall surface 52 with the first inclination angle α1 and an upper wall surface 54 with a second inclination angle α2 smaller than the first inclination angle α1 in Fig. 8C, and an upper wall surface 54 with a second curvature S2 being opposite (i.e., convex) to the first curvature S1 (which is concave) in Fig. 8D.12 Sheets No Screw Ltd. Sheet No. 1 Xb X 12 22rake 22 I 18 22relief 80 21 13 I 23 Fig. 1A 14 23relief 21relief 23rake 36 34 22 32 A 42 60 22rake 23rake 70 50 40 21rake 23 21 38 Fig. 1B12 Sheets No Screw Ltd. Sheet No. 2 80 Xb 83’ 36 81’ 12 18 18 83’’ 36 81’’ 82 13 Fig. 1C 90 96 95 92 91 Fig. 1D12 Sheets No Screw Ltd. Sheet No. 3 80’ II ’ 90 34 32 II 100 101 Fig. 2A 110 90 102 93 106 91 100 104 Fig.2B12 Sheets No Screw Ltd. Sheet No. 4 80’ 90 110 102 106 114 104 111 Fig. 2C 112 96 95 98 90 97 91 Fig. 2D 9212 Sheets No Screw Ltd. Sheet No. 5 ’’ 12 ’’ 410 Fig. 3A 90’’ 93’ 101 110’ 102 100’ Fig.3B12 Sheets No Screw Ltd. Sheet No. 6 III 12 ’’ 32’’ Fig. 3C III 222 90’’ 32’’ 110 102 106 ’ 104 114 111 Fig. 3D12 Sheets No Screw Ltd. Sheet No. 7 90’’ 98 95 92 91 97 Fig. 3E 93 410’ 413 ’’ 32 Fig. 3F 413 411 410’’ 90’’12 Sheets No Screw Ltd. Sheet No. 8 310 300 100 Fig. 4A 310 312 90 110 100 302 300 306 304 Fig. 4B12 Sheets No Screw Ltd. Sheet No. 9 ’ 80’’ 34 Fig. 5A 36 60 32 D2 42 34 40 50 38 D1 Fig. 5B12 Sheets No Screw Ltd. Sheet No. 10 IV 300 IV Fig. 6A 310 312 ’’ 100 80’ 90’’ Fig. 6B12 Sheets No Screw Ltd. Sheet No. 11 32 36 40 500 V 22 D2 VI 42 60 VI D1 50 21 V Fig. 712 Sheets No Screw Ltd. Sheet No. 12 54 54 64 64 S1 α1 62 62 52 70 52 70 Fig. 8A Fig. 8B 54 54 64 α2 S2 S1 52 α1 52 62 60 70 62 Fig. 8D Fig. 8C 70 - 20 - 287851/3

Claims (27)

1. A cutting insert comprising a body having a pair of upper and lower parallel horizontal surfaces and at least three sidewalls extending therebetween, and comprising at least one cutting corner region defined between two, first and second, adjacent sidewalls and the upper horizontal surface, and a cooling portion associated with said cutting corner region, said cutting corner region having a rake surface at the corresponding horizontal surface, a first relief surface at the first side sidewall, a second relief surface at the second sidewall, and having respective first and second cutting edge portions and a curved cutting edge portion therebetween, each cooling portion comprising: - a cooling channel formed in the corresponding horizontal surface, open to an exterior of the insert along a depth thereof, the cooling channel extending between a coolant inlet and a coolant outlet and comprising an upstream section associated with the coolant inlet, extending towards the curved cutting edge portion along and spaced from the first cutting edge portion, a downstream section associated with the coolant outlet, extending away from the curved cutting edge portion and extending along and spaced from the second cutting edge portion, and a curved section interconnecting the upstream and downstream sections and extending along the curved cutting corner and spaced therefrom; and - a nozzle receiving through-bore extending from the lower horizontal surface towards the upper horizontal surface, such that the coolant inlet merges with the nozzle receiving through-bore at least along a majority of the depth of the cooling channel at the coolant inlet, so as to allow a nozzle to be introduced therein from at least the lower horizontal surface for directing coolant into the cooling channel via the coolant inlet for the coolant to flow along the cooling channel via the upstream, curved and downstream sections towards the coolant outlet, in order to facilitate heat removal from the cutting corner region.

2. The cutting insert of Claim 1, wherein the curved section of the cooling channel is spaced from the cutting edge to a distance at least not exceeding that of the upstream section. 02816032\82-01 - 21 - 287851/3

3. The cutting insert of Claim 2, wherein the merger between the curved section and the downstream section of the cooling channel is spaced from the cutting edge to a distance at least not exceeding that of the upstream section.

4. The cutting insert of Claim 3, wherein the merger between the upstream section and the curved section of the cooling channel is spaced to a first distance D1 from the first cutting edge portion and the merger between the curved section and the downstream section of the cooling channel is spaced to a second distance D2 from the second cutting edge portion, being smaller than D1.

5. The cutting insert of any one of Claims 1 to 4, wherein the cooling channel has a channel bottom, a first wall, and a second wall extending from the channel bottom to the corresponding horizontal surface, the first wall being closer to the cutting edge than the second wall.

6. The cutting insert of Claim 5, wherein the inclination of the first wall relative to a horizontal plane passing through the channel bottom, varies so that in the curved section the inclination is greater than adjacent to the coolant inlet.

7. The cutting insert of Claim 5, wherein the second wall comprises a chip breaking formation at an area of the second wall close to the corresponding horizontal surface.

8. The cutting insert of any one of Claims 1 to 7, wherein the depth of the cooling channel along at least the curved section is between 0.5mm to 1mm, more specifically between 0.65 to 0.85 mm, and, even more specifically, is about 0.7 mm.

9. The cutting insert of any one of Claims 5 to 7, and Claim 8 when dependent on Claim 5, wherein the first and second walls have top edges and the width of the cooling channel between these top edges is in the range of 0.6mm to 1mm, more specifically between 0.7 to 0.8 mm, and even more specifically, is about 0.75 mm. 02816032\82-01 - 22 - 287851/3

10. The cutting insert of any one of Claims 1 to 9, wherein the nozzle receiving through-bore is configured to enable the nozzle to be inserted therein only in a single orientation.

11. The cutting insert of any one of Claims 1 to 10, wherein the cutting insert is double-sided, and said cooling channel constitutes an upper cooling channel in fluid communication with the nozzle receiving through-bore at an area thereof adjacent the upper horizontal surface, and the cutting insert has a lower cooling channel in fluid communication with the nozzle receiving through-bore at an area thereof adjacent the lower horizontal surface, and wherein the nozzle receiving through-bore is configured to receive a nozzle from both upper and lower horizontal surfaces.

12. The cutting insert of any one of Claims 1 to 11, wherein the cutting insert comprises at least two cutting edges and two cooling channels at each of its upper and lower horizontal surfaces and at least two corresponding nozzle receiving through-bores, each associated with one upper cooling channel and one lower cooling channel.

13. The cutting insert of Claim 11 or 12, wherein the cutting insert has a central axis X and the nozzle receiving through-bore has a bore axis Xb defining a vertical plane with the central axis, wherein the cooling channel in the upper horizontal surface is positioned at one side of the vertical plane and the cooling channel in the lower horizontal surface is positioned at an opposite side of the plane.

14. The cutting insert of any one of Claims 1 to 13, wherein the cutting insert comprises four cutting corner regions on each of the upper and lower horizontal surfaces.

15. The cutting insert of any one of Claims 1 to 14, wherein the nozzle receiving through-bore is opened to the exterior of the insert at the sidewall closest thereto.

16. The cutting insert of any one of Claims 1 to 14, wherein the nozzle receiving through-bore is disposed at a central area of the cutting insert, and thus constitutes a central nozzle receiving through-bore. 02816032\82-01 - 23 - 287851/3

17. The cutting insert of Claim 16, wherein the central nozzle receiving through-bore is associated with at least two cooling channels disposed at the upper horizontal surface and with at least two cooling channels disposed at the lower horizontal surface, each channel having a coolant inlet portion extending between a coolant inlet at the nozzle receiving through-bore and the upstream section of the cooling channel.

18. The cutting insert of Claim 16 or 17, wherein at least a portion of the nozzle receiving through-bore constitutes an insert mounting bore for mounting the cutting insert to a tool holder.

19. The cutting insert of any one of Claims 1 to 18, wherein the upstream section has a first end associated with the coolant inlet and second end associated with the curved section, the first end being disposed further from the cutting edge than the second end.

20. A nozzle for use with a tool holder on which a cutting insert according to any one of Claims 1 to 17 is configured to be mounted, the nozzle being configured to be received within the nozzle receiving through-bore and having a proximal end to be associated with the tool holder and a distal end associated with the upper horizontal surface of the insert when the nozzle is fully received in said nozzle receiving through-bore, wherein the nozzle comprises an outlet orifice spaced from the distal end to a distance corresponding to the depth of the cooling channel at the coolant inlet.

21. The nozzle of Claim 20, wherein the nozzle is configured for being assembled with the tool holder to which the insert is to be mounted, and optionally integrally assembled therewith.

22. The nozzle of Claim 20, wherein the nozzle is unitarily formed with the tool holder.

23. The nozzle of Claim 20, wherein the tool holder is a part of a tool holder assembly, which also comprises, at least in use, a base plate via which the insert is to be mounted on the tool holder, and wherein the nozzle is assembled with the base plate, and optionally integrally assembled therewith. 02816032\82-01 - 24 - 287851/3

24. The nozzle of Claim 20, wherein the tool holder is a part of a tool holder assembly, which also comprises, at least in use, a base plate via which the insert is to be mounted on the tool holder, and wherein the nozzle is unitarily formed with the base plate.

25. The nozzle of any one of Claims 20 to 24, wherein said nozzle has a vertical axis and the outlet orifice has an orifice axis oriented transversely to the vertical axis.

26. A tool holder comprising the nozzle of any one of Claims 20 to 25.

27. A base plate comprising the nozzle of any one of Claims 23 or 24. 02816032\82-01