Patent Application
20250128333
The present invention relates to tool holders for cutting inserts, and more particularly to tool holders with through coolant clamps for securing a cutting insert to a tool holder and for providing controlled coolant flow to the cutting insert.
Cutting inserts are often secured to tool holders through the use of a clamp. Cutting inserts generate heat during operation and coolant may be used to cool the inserts during use. The coolant may pass through the clamp and be directed toward the cutting inserts. However, due to operating conditions, the flow behavior of the coolant may not be optimal.
The present invention provides a tool holder for cooling a cutting insert. The tool holder may include a tool holder body, a cutting insert mounted on the tool holder body, and a through coolant clamp mounted to the tool holder body that secures the cutting insert to the tool holder body and provides coolant fluid to the cutting insert. The through coolant clamp may include a base portion with a fluid chamber extending radially outward from a clamp screw hole. A nose portion extends radially outward from the base portion, and at least one nozzle is provided within the nose portion extending along a nozzle axis. The nozzle includes a nozzle inlet and a nozzle outlet with a nozzle surface therebetween. The through coolant clamp may further include a transition outer surface in fluid communication with the fluid chamber and the nozzle inlet. The transition outer surface forms a smooth transition between the fluid chamber and the coolant channel inlet that provides controlled flow of the coolant through the coolant clamp.
An aspect of the present invention is to provide a tool holder assembly comprising: a tool holder body; a cutting insert mounted on the tool holder body; a through coolant clamp mounted on the tool holder body structured and arranged to secure the cutting insert on the tool holder body and to provide coolant fluid to the cutting insert and comprising a clamp screw hole having a longitudinal axis; and a clamp screw extending through the clamp screw hole fastening the coolant clamp to the tool holder body and comprising an internal axial coolant fluid passage. The through coolant clamp comprises: a base portion; a coolant fluid reservoir chamber within the base portion extending radially rearward from the clamp screw hole surrounding at least a portion of the clamp screw and in fluid communication with the internal axial coolant fluid passage of the clamp screw; a nose portion extending radially forward from the base portion; and at least one nozzle within the nose portion extending along a nozzle axis. The at least one nozzle comprises: a nozzle inlet in fluid communication with the coolant fluid reservoir chamber; a nozzle outlet opposite the nozzle inlet; and a nozzle coolant channel extending between the nozzle inlet and the nozzle outlet along a nozzle coolant channel axis; and a transition outer surface in fluid communication between the coolant fluid reservoir chamber and the nozzle inlet of the at least one nozzle forming a smooth transition between the coolant fluid reservoir chamber and the nozzle inlet such that a transition angle measured in a plane perpendicular to the longitudinal axis of the through coolant clamp between at least a portion of the transition surface and the nozzle coolant channel axis is less than 60°.
Another aspect of the present invention is to provide a through coolant clamp for providing coolant fluid to a cutting insert comprising: a base portion; a coolant fluid reservoir chamber within the base portion extending radially rearward from a clamp screw hole extending from a clamp top surface of the through coolant clamp to a clamp bottom surface of the through coolant clamp; a nose portion extending radially forward from the base portion; and at least one nozzle within the nose portion extending along a nozzle axis. Each nozzle of the at least one nozzle comprises: a nozzle inlet in fluid communication with the coolant fluid reservoir chamber; a nozzle outlet opposite the nozzle inlet; and a nozzle coolant channel extending between the nozzle inlet and the nozzle outlet along a nozzle coolant channel axis; and a transition outer surface in fluid communication between the coolant fluid reservoir chamber and the nozzle inlet of the at least one nozzle forming a smooth transition between the coolant fluid reservoir chamber and the nozzle inlet such that a transition angle measured in a plane perpendicular to the longitudinal axis of the through coolant clamp between at least a portion of the transition surface and the nozzle coolant channel axis is less than 60°.
A further aspect of the present invention is to provide a clamp screw for a through coolant tool holder clamp assembly, the clamp screw comprising: a threaded lower portion; a head at an end of the clamp screw opposite the threaded lower portion; an upper portion between the threaded lower portion and the head; an internal coolant axial passage having an inlet opening adjacent the threaded lower portion and extending to the upper portion; and at least one coolant radial channel in fluid communication with the coolant axial passage and having a radial outlet opening through an outer surface of the upper portion.
These and other aspects of the present invention will be more apparent from the following description.
Tool holder assemblies of the present invention address the issues mentioned above by providing a through coolant clamp that provides controlled flow of cooling fluid at operating conditions through gradual changes in surfaces within the through coolant clamp, as more fully described below. As used herein, the term “fluid” refers to any flowable coolant such as water, oil, other liquids and gas that may pass through a through coolant clamp to cool a cutting insert during cutting operations of a tool holder.
Referring to
In the illustrated embodiment, a cutting insert 30 is seated in the insert-receiving pocket 22. The cutting insert 30 may have an insert top surface 32 and a generally diamond shape. However, it will be appreciated that the cutting insert 30 may have any suitable shape, such as a triangle, rectangle, pentagon, circle and the like. An optional seat member 40 can be disposed between the cutting insert 30 and the pocket bottom surface 24 of the insert-receiving pocket 22. The seat member 40 may be fixedly secured to the insert-receiving pocket 22 by means of a threaded fastener 42, such as a screw, or the like. In an alternative embodiment, the insert 30 can be disposed on the pocket bottom surface 24 of the insert-receiving pocket 22 without the use of the seat member 40 or the threaded fastener 42.
The cutting insert 30 may be clamped within the insert-receiving pocket 22 of the tool holder 10 by a through coolant clamp 100. As shown in
As shown in
As shown in
As shown in
A clamp pad 124 may extend from the nose bottom surface and at least partially surround the outer perimeter of the nub base 122. The clamp pad 124 may be structured and arranged to contact the insert top surface 32 and apply a clamping force against the insert top surface 32 to thereby secure the cutting insert 30 in the insert-receiving pocket 22 of the tool holder 10.
As shown in
As shown in
As shown in
As shown in
As shown in
The screw upper portion 52 may include a screw head 58 with a screw recess 59 for accommodating a tool. For example, the screw recess 59 may be a cross, line, square shape, hexagonal shape and/or the like for accommodating a flat head screwdriver, Phillips head screwdriver, square screwdriver, Allen wrench, and/or the like. The screw upper portion 52 may have a generally smooth cylindrical surface, and screw lower portion 54 may have a threaded outer surface. The clamp screw 50 may be made of any suitable material such as hardened steel and the like, and may have a hardness less than a hardness of the through coolant clamp 100, which may be made of carbide or the like.
The screw lower portion 54 of the clamp screw 50 may include a screw coolant opening 61 in fluid communication with a body fluid channel 13 of the tool holder body 12 and a screw axial coolant passage 62 extending from the screw coolant opening 61 along the clamp screw central longitudinal axis S of the clamp screw 50 to the screw upper portion 52 of the clamp screw 50. The body fluid channel 13 may be encased within the tool holder body 12.
The coolant axial passage 62 may be formed in the clamp screw 50 such that the clamp screw axis S is substantially aligned with the clamp securing hole axis C of the base portion 110 when assembled on the tool holder 10. In addition, the coolant axial passage 62 may be in fluid communication with one or more screw coolant radial channels 64 that provide coolant through a respective screw coolant port 66 formed in the screw upper portion 52 of the clamp screw 50. Each screw coolant radial channel 64 may extend radially outward from the coolant passage 62 substantially perpendicular to the clamp screw central longitudinal axis S. However, it will be appreciated that each coolant radial channel 64 can be formed in such a way to be non-perpendicular to the clamp screw axis S.
Each screw coolant radial channel 64 and respective port 66 is in fluid communication with the fluid chamber 135 of the base portion 110 when secured to the tool holder body 12. In the embodiment shown, the clamp screw 50 has three coolant radial channels 64. However, there may be one, two, four, five, six, or more screw coolant radial channels 64. Each screw coolant radial channel 64 may extend in a different radial direction than the other screw coolant radial channels 64, and the coolant radial channels may be equally spaced around the circumference of the screw upper portion 52. Thus in the three-channel embodiment shown in the figures, the coolant radial channels 64 are equally spaced at 120° intervals around the circumference of the upper portion 52.
As shown in
As shown in
As shown in
The coolant reservoir chamber 135 may include a rear reservoir portion 136 extending radially rearward from the clamp screw hole 130. The rear reservoir portion 136 may include a concave rear reservoir wall 138. At least a portion of the rear reservoir wall 138 may extend in a direction parallel with the central axis C between an upper reservoir wall 139 and a lower reservoir wall 137. The upper reservoir wall 139 may be located between the rear reservoir wall 138 and the clamp top surface 112 and may comprise a concave surface. The lower reservoir wall 137 may be located between the rear reservoir wall 138 and the clamp bottom surface 114 and may comprise a concave surface.
The surfaces of the rear reservoir wall 138, upper reservoir wall 139 and lower reservoir wall 137 of the rear reservoir portion 136 may merge directly into the nozzle inlets 164. The coolant reservoir chamber 135 may include one or more transition channels 140 extending in substantially the same direction as each of the nozzle centerlines N1 and N2. Each transition channel 140 may be structured and arranged to direct fluid flow from the rear reservoir portion 136 to the nozzle inlet 164 of each coolant nozzle 160. The rear reservoir portion 136 may gradually merge into the transition channels 140. The merging surface 145 may be concave or straight in shape. The merging surface 145 may be structured and arranged such that fluid which passes over the merging surface 145 during operation of the tool holder 10 flows in a controlled manner through the nozzle outlet 162, e.g., the flow may have reduced turbulence and may be at least partially laminar. There may be no sharp edges along the merging surface 145 or between the rear reservoir portion 136 and the transition channel 140.
Each transition channel 140 may include a transition outer surface 142 radially outward from the clamp screw hole 130 that connects to a respective nozzle inlet 164. As shown in
As shown in
The coolant reservoir chamber 135 may be structured and arranged to interact with each coolant nozzle 160 such that fluid flow out of the nozzle outlet 162 is in a reduced turbulence or substantially laminar flow at typical volumetric flow rates of coolant fluid during operation of the tool holder 10. For example, coolant entering the relatively large volume of the coolant reservoir chamber 135 may fill and remain in the chamber for an average dwell time depending on the selected flow rate of the coolant. While inside the coolant reservoir chamber 135, the coolant fluid may undergo a flow pattern that facilitates controlled flow of the coolant into the coolant nozzle 160. The volumetric flow rate of the coolant fluid during operating may be at least 0.1 L/min, for example, at least 0.5 L/min or at least 1 L/min, or at least 5 L/min. The volumetric flow rate of the coolant fluid during operation may typically be up to 200 L/min, for example, up to 100 L/min, or up to 50 L/min, or up to 25 L/min. The volumetric flow rate of the coolant fluid during operation may typically range from 0.1 to 200 L/min, for example, from 0.5 to 100 L/min, or from 1 to 50 L/min, or from 5 to 25 L/min. It is to be understood that the flow rates may vary based upon inlet coolant pressures and varying designs.
The controlled flow of coolant fluid out of each nozzle outlet 162 may be caused at least in part by the flow path and increased dwell time in the coolant reservoir chamber 135 through each reservoir transition channel 140 along each transition outer surface 142 between the rear reservoir portion 136 and each coolant nozzle 160. Each reservoir transition channel 140 may cause a gradual transition of the fluid during the flow through the through coolant clamp 100 such that the fluid does not interact with any sharp edges between the nozzle outlet 160 and the clamp screw 50. The gradual transition may be structured and arranged to reduce turbulent flow of the fluid and allow for more direct targeting of the coolant fluid flow. The controlled flow may allow the coolant fluid to form a beam upon exiting the nozzle outlet 162. This may allow for increased cooling of the cutting insert as well as more efficient use of the fluid.
When the tool holder 10 is in operation, the coolant fluid may flow from the tool holder body 12 through the clamp screw 50, then through the through coolant clamp 100, and out toward the cutting insert 30. The fluid may flow from a conventional fluid source (not shown) into tool holder body 12 through the body fluid channel 13. The fluid may then flow from the body fluid channel 13 into the screw coolant passage 62 of the clamp screw 50 through the screw coolant opening 61. The fluid may flow through the screw coolant passage 62 into one or more screw coolant channels 64 of the clamping screw 50. The fluid may then flow through the screw coolant channels 64 to the screw coolant port 66 into the coolant reservoir chamber 135. As described above, a portion of the fluid may contact an outer surface of the coolant reservoir chamber 135, such as the lower reservoir wall 137, rear reservoir wall 138 or upper reservoir wall 139. The coolant reservoir chamber 135 may direct the fluid flow to one or more coolant nozzles 160. The fluid flow may flow from a rear reservoir wall 136 of the coolant reservoir chamber 135 to a transition channel 140 and along the transition channel outer surface. The fluid flow may then flow from the transition channel 140 into the one or more coolant nozzles 160. The fluid flow may then pass through the coolant nozzle 160 and out of the nozzle outlet 162. The fluid flow may exit the nozzle outlet 162 in a controlled manner with reduced turbulence. The fluid flow may be directed toward the cutting insert 30.
As used herein, “including,” “containing” and like terms are understood in the context of this application to be synonymous with “comprising” and are therefore open-ended and do not exclude the presence of additional undescribed or unrecited elements, materials, phases or method steps. As used herein, “consisting of” is understood in the context of this application to exclude the presence of any unspecified element, material, phase or method step. As used herein, “consisting essentially of” is understood in the context of this application to include the specified elements, materials, phases, or method steps, where applicable, and to also include any unspecified elements, materials, phases, or method steps that do not materially affect the basic or novel characteristics of the invention.
Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard variation found in their respective testing measurements.
Also, it should be understood that any numerical range recited herein is intended to include all sub-ranges subsumed therein. For example, a range of “1 to 10” is intended to include all sub-ranges between (and including) the recited minimum value of 1 and the recited maximum value of 10, that is, having a minimum value equal to or greater than 1 and a maximum value of equal to or less than 10.
In this application, the use of the singular includes the plural and plural encompasses singular, unless specifically stated otherwise. In addition, in this application, the use of “or” means “and/or” unless specifically stated otherwise, even though “and/or” may be explicitly used in certain instances. In this application and the appended claims, the articles “a,” “an,” and “the” include plural referents unless expressly and unequivocally limited to one referent.
Whereas particular embodiments of this invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details of the present invention may be made without departing from the invention as defined in the appended claims.
