Devices, systems, and methods for cooling tools

Abstract

The present invention relates to a device for cooling a tool, the device comprising a base body, contact elements, at least one inlet into the base body, and one outlet from the base body, wherein the inlet and outlet are connected to each other by one or more internal channels within the base body, the device is connectable to a tool such that the contact elements contact the tool, and the one or more internal channels are configured to conduct a coolant. The one or more internal channels comprise contact sections, the contact sections are in contact with contact elements, and the contact sections comprise a plurality of flow guide elements configured to locally increase the turbulence and velocity of the liquid passing through the contact sections. The present invention further relates to a system comprising the device and a tool, and a cooling method using this system.

Description

Technical Field

[0001] The present invention relates to a device for cooling a tool, the device comprising a base body, a contact element, at least one inlet into the base body, and one outlet from the base body, the inlet and the outlet being connected to each other by one or more internal channels within the base body, the device being connectable to the tool such that the contact element contacts the tool, and the one or more internal channels being configured to conduct a coolant. The one or more internal channels comprise a contact section which contacts a contact element that contacts the contact element, the contact section comprising a plurality of flow guide elements configured to locally increase the turbulent flow and the flow rate of the coolant passing through the contact section. The present invention further relates to a system comprising the device and the tool, and a cooling method using this system.

Background Art

[0002] The present invention relates to the field of industrial manufacturing, particularly turning for machining workpieces with tools.

[0003] In industrial manufacturing processes such as turning, an effective cooling strategy is crucial for reducing the heat generated between the tool and the workpiece during chip formation. The most commonly used method to date in metalworking is flood cooling using a coolant lubricant. In this method, the coolant lubricant is supplied at a volumetric flow rate of several hundred liters per hour to cool the tool and / or the workpiece and is applied through an external nozzle as close as possible to the machining zone between the tool and the workpiece. If these conditions are not achieved during turning, insufficient cooling lubrication occurs. In addition, the use of large amounts of coolant lubricant, its limited service life and associated high maintenance and disposal costs pose a considerable economic and health-related burden for enterprises.

[0004] In recent years, specific cooling strategies, such as minimal lubrication and cryogenic cooling, have been developed to ensure efficient cooling while reducing the use of cooling lubricants. All processes are continuously being further developed with the aim of achieving maximum sustainable production. However, these still have inherent drawbacks, such as high energy and resource consumption, as well as costly disposal of working materials. Consequently, research and development are increasingly focusing on innovative methods to improve cooling in industrial manufacturing processes to enable maximum sustainable production.

[0005] To address the shortcomings of insufficient process control and inconsistent performance, a novel closed-circuit-based cooling strategy can be employed, where external cooling lubricants are not introduced into the machining zone. As a result, heat generated during machining is dissipated both by the cutting tool and by the closed-circuit internal cooling system. Heat transport within the internal cooling system occurs indirectly through conduction and forced convection, thereby enabling targeted and uniform tool cooling of the coolant, resulting in improved temperature control and enhanced process stability. Furthermore, internal cooling significantly reduces the need for cooling lubricants, minimizing associated storage and disposal costs.

[0006] In general, methods and systems that enable the use of closed circuits for internal cooling are already known. The following prior art has emerged in this field.

[0007] German Patent No. 19730539(C1) describes a heat sink located within a modified tool holder, which features a segmented plate-shaped microstructure with channels less than 300 μm in diameter to increase cooling efficiency. Heat transfer is performed by a material having good thermal conductivity on the underside of the tool. The heat sink may be positioned on two opposing sides.

[0008] International Publication No. 2018046489(A1) describes a modified tool holder that enables improved cooling and temperature control of cutting inserts. The tool comprises a cutting plate and a cooling device. The cooling device consists of a double tube that allows for both supply and discharge of a cooling fluid. This double tube directs the cooling medium specifically to the underside of the tool.

[0009] Former Soviet Patent Application Publication No. 795883(A1) describes a tool holder or turning tool with internal cooling, which has a housing with an axial channel. This channel is connected to a tube made of a thermally conductive material, which is partially filled with a coolant such as water. By evaporating the coolant, heat is dissipated from the cutting plate and transferred to a distant, cooler region. The tube is articulated to an internal chamber and is adjustable to various angles to allow cooling at any position of the tool holder or turning tool.

[0010] None of the technologies described so far require the adaptation of tools or tool holders, which does not provide a solution suitable for industrial use with standardized contact surfaces and geometric shapes. Furthermore, no investigations have been conducted regarding cooling performance in terms of flow parameters and heat transfer mechanisms. Therefore, there is a need for a novel cooling strategy that is industrially applicable based on prior art, more efficiently transfers heat away from the tool, and improves the energy efficiency of the tool system without requiring changes to the tool or tool holder. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] German patent number 19730539 (C1) [Patent Document 2] International Publication No. 2018046489(A1) [Patent Document 3] Former Soviet Union Patent Application Publication No. 795883(A1) [Overview of the Initiative] [Problems that the invention aims to solve]

[0012] An object of the present invention is to provide a technical solution for cooling tools that avoids the release of toxic or irritating coolants into the environment and reduces the consumption required for cooling. A further object of the present invention is to provide an economical solution for cooling tools that ensures high, reproducible cooling performance and allows the coolant to be brought particularly close to the heat dissipation contact area between the tool and the workpiece. [Means for solving the problem]

[0013] This objective is resolved by the features of the independent claim. Advantageous embodiments of the present invention are described in the dependent claims.

[0014] In a first aspect, the present invention relates to a device for cooling a tool, the device comprising a base body, a contact element, at least one inlet into the base body, and one outlet from the base body. The inlet and outlet are connected to each other by one or more internal channels within the base body. The device is connectable to a tool such that the contact element is in contact with the tool. One or more internal channels are configured to guide a coolant. One or more internal channels include a contact section, the contact section is in contact with the contact element to enable heat transfer. The contact section includes a plurality of flow guide elements, which are configured to alter the flow velocity of the coolant through the contact section and locally increase turbulence, leading to increased heat transfer from the contact element.

[0015] Internal channels within the device's base allow for continuous guidance of coolant through the device. Therefore, the coolant can be kept in a closed circuit to cool the device and the tools connected to it, preventing uncontrolled release of coolant into the environment. Furthermore, preferably, a closed circuit through which an environmentally friendly cooling fluid flows is provided, eliminating the need for external cooling lubricants to be introduced into the machining zone. As a result, the health and safety risks associated with conventional flood cooling can be completely eliminated from the cooling process. People are not exposed to the cooling fluid, and there is no risk of spills contaminating the workpiece and machine surfaces. At the same time, the consumption required for cooling is reduced. Because the internal channels can be connected to the surrounding system to form a closed fluid circuit, a considerably smaller amount of coolant (compared to, for example, flood cooling) can be used for a longer period before replacement is necessary. This is particularly economical and environmentally friendly.

[0016] Because the device according to the present invention can be connected to a tool, it is possible to bring the coolant flowing through the internal channel particularly close to the tool. In particular, the coolant can be brought very close to the contact area between the tool and the workpiece being machined. Since this is the area where most of the heat is generated, the cooling process is much more efficient due to this close contact. This is particularly advantageous compared to flood cooling systems, where the coolant typically cannot reach this area or evaporates into the environment before reaching this region.

[0017] A further advantage of the present invention is that the device for cooling the tool is a component independent of the tool itself. The device according to the present invention can be connected to a tool, but the tool does not necessarily have to be part of the device according to the present invention. Therefore, the device can be used directly with any suitable tool without changing the tool. The fact that it is not necessary to change the tool to attach the device can particularly mean that no changes to the tool are required. This advantageously means that it is not necessary to adapt the established machining process by implementing a new tool. Furthermore, since no channel passing through the inside of the tool is required, the strength of the tool is advantageously not adversely affected. In addition, it is not necessary to interrupt the coolant circuit when the tool is replaced, thereby no contamination or leakage occurs as a result. Since tools are typically consumable parts that are frequently replaced, it is economically beneficial that this part does not need to be changed for the implementation of the cooling solution according to the present invention. Instead, the device itself can be manufactured or modified to include the internal channel and flow guide element according to the present invention. Since the device is not involved in the machining process, it experiences significantly less wear compared to the tool, or even no wear at all. Therefore, the device can be used repeatedly over a long service life. Therefore, modifications made to the base body material are more economical in the long run than modifications made to wear parts. The fact that there is no need to modify the tool holder for fastening the tool and mounting the device can particularly mean that there is no need to drill or similar modifications to the tool holder, and thus there is no need to replace or adapt the existing range of tool holders. There is no need to readjust the tool, which advantageously means there is no significant increase in setup time. The ability to continue using the existing range of tool holders, along with the absence of a significant increase in setup time, makes the present invention very economically attractive. Furthermore, advantageously, there is no need to interrupt the coolant circuit when replacing the tool holder. In particular, components independent of the tool and tool holder can also be easily transferred from one tool to another.This advantageously allows the device according to the present invention to be used with different tools without the need to individually adapt each tool. However, it is also possible and not ruled out that channels for the coolant be integrated within the tool or tool holder.

[0018] For example, the tool holder may include a flow guide cavity, and the flow inside the tool holder flows along the surface that contacts the tool. The inlet and / or outlet for the coolant may be located on any surface of the tool holder. However, this may also be connected to the cooling unit, base body and / or clamping fingers. Thus, the inlet and outlet for the coolant leading to the flow guide cavity inside the tool holder may pass through a device for cooling the tool and / or be located directly on the tool holder. Additional flow guide cavities inside the tool holder can, advantageously, contribute to particularly efficient cooling performance.

[0019] The presence of a base body within the device allows the device to have an easily manageable three-dimensional shape that can achieve secondary functions, such as clamping fingers. Furthermore, the base body provides internal space within which internal channels can be freely positioned, for example, in different planes, at different angles of incidence to the contact section. Since the base body is a separate component from the contact elements, different materials may be used for these two components, and the material of the base body can be selected to be easy to process or particularly economical. In contrast, the material of the contact elements can be designed to have maximum thermal conductivity and very high thermal resistance.

[0020] The contact elements are positioned so that they come into contact with the tool when the device is connected to the tool. Therefore, the material of the contact elements can be selected specifically for this purpose. Since extremely high conductive materials can be costly, it is advantageous to have the contact elements provided separately from the base body of the device.

[0021] However, the contact element and the base body may be made of the same material, and thus may form a monolithic structure that as a whole serves the role of heat transfer. When the contact element and the base body are made of the same material, a thickness of the contact element of 1 mm or less, preferably 0.5 mm or less, and particularly preferably 0.2 mm or less may be provided.

[0022] The monolithic structure advantageously reduces the number of manufacturing steps required and allows for excellent flexibility in the geometric configuration of the contact surface between the contact element and / or the tool and the cooling device. The reduction in the number of manufacturing steps advantageously eliminates assembly steps and joining processes and reduces production costs by using less expensive materials for the contact element. By reducing the number of materials in contact with each other, heat transfer is further improved, which can contribute to a particularly efficient cooling process. This also makes it possible to use smaller-sized flow guide elements on the contact section.

[0023] A wall thickness of 1 mm or less in the case of the monolithic structure of the contact element and the base body advantageously enables effective heat transfer from the tool to the coolant, mainly with a high stability of the wall.

[0024] A preferred wall thickness of 0.5 mm or less in the case of the monolithic structure of the contact element and the base body advantageously provides a particularly good heat transfer rate into the cooling fluid while maintaining high strength. This configuration is particularly preferred when the cooling device is used as a clamping finger.

[0025] A particularly preferred wall thickness of 0.2 mm or less in the case of the monolithic structure of the contact element and the base body results in an increase in the heat flux into the coolant, compared to the heat flux achieved by a separate contact element with a slightly larger wall thickness that does not form a monolithic unit with the base body.

[0026] System peripherals can be connected to the inlet and outlet of the base body, which may include commercially available components (pumps, hoses, condensers / cooling units) or customer-specific arrangements for continuously pressurizing coolant into the device. The coolant preferably circulates within the fluid circuit. Therefore, even if the coolant evaporates while flowing through the device, it is not lost into the atmosphere. This eliminates health risks and is particularly environmentally friendly.

[0027] By providing a contact section in the internal channel of the device that contacts a contact element, this section can be specialized for maximum heat exchange. Using multiple flow guide elements within the contact section of the internal channel allows for localized restriction of the cross-section of the contact section, resulting in a localized increase in flow velocity. The shape and position of the flow guide elements can be further selected to guide the coolant to form vortices, which increase turbulence within the contact area.

[0028] The increased flow velocity and increased turbulence synergistically contribute to increasing the heat transfer rate from the tool into the coolant through the contact elements, particularly by increasing the kinetic energy of the turbulence along the contact section. This increases the rate of heat dissipation from the tool compared to the prior art, giving the solution according to the present invention remarkable effectiveness.

[0029] However, the flow from the inlet through the contact section and then through the outlet may function without the placement of additional flow guide elements inside the contact section. In this case, the inlet, contact section, and outlet preferably act together as flow guide elements. This advantageously allows for particularly simple and cost-effective production of a device for cooling a tool with low flow resistance.

[0030] In the sense of the present invention, a “device for cooling a tool” is preferably a device that can be connected to and used with a tool to reduce the temperature of the tool during machining of a workpiece, particularly during turning of a workpiece. Preferably, the device is configured to reduce the local temperature of the tool at the contact point between the tool and the workpiece.

[0031] In the sense of the present invention, “base body” is preferably essentially made of a uniform material and is a three-dimensional unit having an inlet, an outlet, and an internal channel including a contact section. Preferably, the base body has dimensions greater than the contact element. Particularly preferably, the base body has a thickness of at least twice, preferably at least three times, the thickness of the contact element, and this thickness is measured in the direction extending from the surface of the tool through the contact element and through the base body. Preferably, the base body has a length of at least 110%, preferably at least 120%, the length of the contact element, and this length is preferably measured along the main flow direction through the contact section. Preferably, the base body has a width of at least three times, preferably at least five times, the width of the contact element. The base body may preferably have recesses for receiving the contact element, so that the base body surrounds the contact element from above and one or more sides. Typically, the base body may surround one or all of the surfaces of the contact element, except for the surface intended to contact the tool.

[0032] In the sense of the present invention, “contact element” is preferably a plate made of a material that ensures a higher thermal conductivity than the material of the base body. The contact element is also preferably particularly thermally resistant. The contact element is intended to contact a tool on at least one of its surfaces, and this contact is preferably direct mechanical contact. The opposite surface of the contact element is intended to contact a contact section of an internal channel of the base body. This opposite surface may also form part of the contact section, particularly its base surface. Alternatively, the opposite surface of the contact element may contact an independent solid base of the contact section, formed from the material of the base body or another material. Preferably, the contact element may also have a longer length and / or wider width than the contact section so as to contact the material of the base body at the boundary of the contact section.

[0033] In the sense of the present invention, the “internal channel” is preferably a cavity extending between the inlet and outlet of the base body and defining the flow direction along the longitudinal axis. The cross-section of the internal channel may take any form and may vary along the flow direction.

[0034] In the sense of the present invention, the “contact section” is preferably a cavity or recess within the base body, along which the cooling fluid guided through an internal channel is directed along its path between an inlet and an outlet. The contact section is in contact with a contact element, and this contact is preferably direct. In the case of direct contact, for example, the base surface of the contact section is in mechanical contact with the contact element, or the contact element forms the base surface of the contact section, thereby no additional components are inserted between the cavity of the contact section and the contact element. This supports rapid heat transfer from the contact element to the coolant.

[0035] In the sense of the present invention, “flow guide element” is preferably a three-dimensional geometric element (also called “geometric figure”) that generates a local restriction of the cross-section of the contact section. The flow guide element is connected to or protrudes from at least one inner wall of the contact section. For example, the flow guide element is connected to the base surface, side wall, or both side walls of the contact section. The flow guide element preferably has a geometric shape configured such that it increases turbulence at least locally within the contact section, and preferably increases the kinetic energy of the turbulence in a region adjacent to the contact element. The flow guide element may have a fixed or amorphous geometric shape.

[0036] In preferred embodiments of the present invention, the contact elements form the inner wall of the contact section, and one or more flow guide elements also preferably contact the contact elements, be permanently connected to the contact elements, or form part of the contact elements. Preferably, the multiple flow guide elements are configured to facilitate conductive heat transfer from the contact elements to the coolant. In particular, it is preferable that the flow guide elements are made of the same material as the contact elements, or of an alternative material having high thermal conductivity. This is advantageous in that particularly efficient heat transfer and a uniform temperature distribution are possible.

[0037] When the contact element forms the inner wall (particularly the "base surface") of the contact section, contact between the contact element and the coolant is established without an additional layer. As a result, the coolant can be brought closer to the tool, especially to the contact area with the greatest heat. Because the contact element has high thermal conductivity, its temperature is the same as or very close to that of the tool. A high temperature gradient is achieved between the contact element and the coolant, thereby supporting a high heat flow rate and excellent cooling.

[0038] The heat transfer from the tool to the coolant can be increased by having one or more flow guide elements that are in contact with, permanently connected to, or form part of the contact element. Since the flow guide elements may have more complex geometric shapes and larger surface-to-volume ratios than the contact element, they can also increase the contact surface area between the contact element and the coolant.

[0039] In a further preferred embodiment of the present invention, the flow guide element protrudes from the inner wall of the contact section, particularly from the base, or from the contact element. Preferably, the flow guide element creates a local limitation of the cross-section of the contact section. Preferably, at least one surface of the flow guide element, together with the inner wall of the contact section, forms an external angle of 90° to 175°, particularly 100° to 150°. The internal angle may preferably be between 5° to 90°, particularly 30° to 80°, and most preferably 40° to 60°. This surface of the flow guide element is preferably oriented downstream. The surface of the flow guide element may also have internal and external angles within the same preferred range, and particularly in the case of an isosceles triangular prism, a rounded triangular prism, or a symmetric trapezoidal prism, the surface oriented upstream may have the same angle as the surface oriented downstream.

[0040] Surprisingly, it was found that flow guide elements with the preferred angles mentioned above resulted in flow separation and, consequently, forced vortex formation. Furthermore, positioning the flow guide elements on the base of the contact section, particularly on the contact elements, resulted in vortex formation in the immediate vicinity of the contact elements, thereby significantly increasing the kinetic energy of the turbulence in this region. This contributes to maintaining a high temperature gradient between the contact elements and the majority of the cooling fluid.

[0041] Therefore, these preferred shapes and angles result in particularly favorable optimization of flow dynamics and improved heat transfer through turbulence in the flow. The preferred angles also favorably minimize the dead zone (the zone where the coolant stagnates), thereby promoting a particularly uniform distribution of the coolant.

[0042] In a further preferred embodiment of the present invention, the flow guide elements are positioned along one or more inner walls of the contact section. Preferably, one or more flow guide elements are positioned such that at least one of their surfaces is struck by the coolant flowing along the contact section and / or preferably by the coolant entering the contact section in a manner directed toward the contact element. This advantageously allows for particularly efficient cooling of the contact element.

[0043] In a further preferred embodiment of the present invention, at least one flow guide element is connected to two parallel inner walls of the contact section. Preferably, the flow guide element is simultaneously separated from the rest of the inner walls of the contact section, in particular, so that a clearance is formed between the flow guide element and the contact element. The two parallel inner walls to which the flow guide element is connected are preferably upright and substantially perpendicular to the contact element. In the sense of the present invention, such a flow guide element is referred to as an “exposed flow guide element”.

[0044] The use of exposed flow guide elements allows for the generation of additional secondary flow, particularly through the clearance between the exposed flow guide elements and the base of the contact section, thereby locally increasing flow velocity and turbulence. This further increases heat transfer.

[0045] In a further preferred embodiment of the present invention, one or more inner walls of the contact section include at least one cavity. The cavity preferably represents a local enlargement of the cross-section of the contact section, and each cavity is preferably bounded by a chamfered edge. The chamfered edges preferably form an external angle between 90° and 175° with respect to the respective inner walls in which they are located.

[0046] Preferably, the cavity contains a material different from the material of the base body. For example, the cavity may contain an insert or coating of another material, which preferably has a higher thermal conductivity than the material of the base body. Preferred materials for the cavity include copper, diamond, silver, or a combination thereof. These materials advantageously allow for particularly rapid heat dissipation.

[0047] Furthermore, it may be preferable for the cavity to be positioned between supply sections, or between the supply section and the discharge section of a contact section.

[0048] The chamfered edges of the cavities have a positive effect on flow separation and can be adapted by changing the obtuse external angle relative to the inner wall of the contact section. Furthermore, this can be achieved by shifting the chamfered edges in the direction of the supply channel or in the direction of the subsequent cavity, and in particular by shifting the tip of the chamfered edges.

[0049] A vortex can form inside the cavity, thereby generating turbulent flow. The chamfered edge of the cavity can facilitate this vortex formation, in which case the external angle of the chamfered edge directed upstream is preferably between 90° and 175°. For example, orthogonal or downward external angles between 90° and 120° can generate impacting flows and, consequently, particularly strong vortex formation. The angle of the upstream chamfered edge may also serve to direct the coolant towards the contact element, thereby causing the coolant to impact the base surface area of ​​the contact section and form a vortex near the contact element.

[0050] Furthermore, the combined use of cavities and flow guide elements has been shown to synergistically increase turbulence along the contact section. Particularly between supply channels, or between supply channels and discharge channels, cavities and flow guide elements may be positioned within the contact section to adapt the coolant flow, thereby achieving improved heat flux and cooling performance. The integration of cavities and flow guide elements enables a uniform temperature distribution within the coolant across the entire cross-section of the contact section.

[0051] Furthermore, the cavities and flow guide elements result in forced deformation of the flow due to separation effects and vortex formation equivalent to those of impinging flows. Due to the separation effects and vortex formation, the main flow is guided toward the underside of the contact section (particularly toward the contact elements).

[0052] Furthermore, the cavities and flow guide elements allow for a more precise fit of the flow cross-section of the contact section, which positively impacts the turbulent behavior in terms of flux and cooling performance.

[0053] In a preferred embodiment of the present invention, the coolant is supplied to the contact section through a single supply channel and discharged from the contact section through a single discharge channel. In such embodiments, it may be preferable to arrange multiple cavities in a row along the inner wall of the contact section between the supply channel and the discharge channel. This makes it possible to achieve a remarkably effective turbulent effect with minimal pressure loss.

[0054] The length of the cavity in the flow direction or along the longitudinal axis of the contact section can be selected to control the turbulent effect. Preferably, the length of the cavity is designed to increase turbulent flow at the base surface or contact element of the contact section.

[0055] In preferred embodiments of the present invention, the contact section comprises a plurality of cavities, each having a length of 2% to 40% of the contact section. Preferably, the length of each cavity is between 6% and 30% of the length of the contact section, particularly between 15% and 25%. Preferably, the height (also referred to as "depth") of each cavity is between 10% and 85% of the thickness of the contact section. Preferably, the cavity height is between 30% and 60% of the thickness of the contact section, particularly about 45%. Cavities with greater height may also be preferred to increase the surface base or volume ratio of turbulent vortices, thereby enhancing the forced turbulence effect. These preferred dimensions have been found to be particularly suitable for increasing turbulence along the contact section. Furthermore, the preferred dimensions can advantageously contribute to particularly favorable cooling performance combined with high structural integrity.

[0056] In the sense of the present invention, “cavity” is preferably a recess in one or more inner walls of a contact section that locally enlarges the cross-section of the contact section. The cavity preferably has a base or ceiling surface at its deepest point, and the base or ceiling surface preferably extends substantially parallel to each inner wall of the contact section. Other embodiments of the cavity that do not have a distinguishable base or ceiling surface may also be preferred, for example, if the deepest point of the recess is merely a point between chamfered edges. This may be particularly true if one or more chamfered edges of the cavity have a very gentle slope.

[0057] In a further preferred embodiment of the present invention, an internal angle between 5° and 60° is formed in the downstream-oriented chamfered edge within the cavity to achieve targeted backflow of the coolant within the contact section and to increase turbulence. This angle allows for a gentle slope between the inner wall of the contact section and the deepest point of the cavity. Preferably, the downstream-oriented chamfered edge transitions seamlessly from its deepest point back to the highest level of the inner wall through the internal radius within the upstream corner of the cavity. This arrangement has been shown to particularly effectively increase turbulence.

[0058] In some preferred embodiments of the present invention, the exposed flow guide element is positioned within the cavity together with the chamfered edge and internal radius as described above. Preferably, the exposed flow guide element is positioned within the radius region.

[0059] In a further preferred embodiment of the present invention, the cavities having chamfered edges, gentle slopes, and rounded internal corners as described above are arranged in direct succession.

[0060] In the sense of the present invention, the "chamfered edge" (also referred to as the "runout edge") preferably represents a transition from the inner wall of the contact section to the deepest point of the cavity, particularly to the base or ceiling surface of the cavity.

[0061] In a further preferred embodiment of the present invention, the flow guide element has the shape of a prismatic, pyramidal, polyhedral, spherical, or ellipsoidal body, or a combination thereof. "A combination thereof" preferably means that the same flow guide element has different morphological features. It may also be preferable that flow guide elements having different shapes be used within the contact section.

[0062] Preferably, the shape of the flow guide element includes at least a first inclined or curved surface on the upstream side and at least a second inclined or curved surface on the downstream side. However, the number of surfaces of the flow guide element is not limited. Particularly preferably, at least a portion of the flow guide element has a prism shape with an isosceles triangular cross-section and preferably a rounded tip. The prism shape is preferably oriented perpendicular to the longitudinal axis of the contact section, so that the first side of the triangle is oriented upstream, the second side of the triangle is oriented downstream, and the third side of the triangle faces the base surface or connects to the base surface of the contact section or contact element. Preferably, the internal angle between the third side of the triangle and the first side of the triangle is between 5° and 85°, particularly between 5° and 60°. Preferably, the internal angle between the third side of the triangle and the second side of the triangle is within the same preferred range. This makes it possible to generate particularly advantageous turbulent flow while advantageously enabling simple manufacturing.

[0063] In a preferred embodiment of the present invention, the interior angle of the triangle between the first and third sides (i.e., the upstream side) is greater than the interior angle of the triangle between the second and third sides (i.e., the downstream side). This allows for a collision flow of coolant onto the flow guide element and subsequent direction of the coolant toward the contact element (e.g., from the supply channel or cavity).

[0064] The flow separation generated by the flow guide element can be modified, particularly by adding features such as a radius between the first and second sides of the triangular cross-section, thereby regulating turbulent flow.

[0065] In a further preferred embodiment of the present invention, the height-to-width ratio of the flow guide element is between 1:10 and 3:1. This provides a remarkably effective balance between local reduction of the cross-section of the contact section and an appropriate incidence angle between the coolant and the flow guide element. When selecting the shape and size of the flow guide element, it is particularly preferable that the outer angle of the surface facing the upstream side of the flow guide element is 175° or less, or that the inner angle is at least 5°. This enables impingement flow.

[0066] In a further preferred embodiment of the present invention, ductile materials with high thermal conductivity, such as copper alloys, may be advantageous for the flow guide element. Furthermore, geometric shapes such as cylindrical, prismatic, irregular sponge-like shapes, or airfoil profiles can be precisely realized within the contact section.

[0067] In a further preferred embodiment of the present invention, the flow guide elements locally reduce the cross-section of the contact section by at least 20%, and particularly at least 30%. Thus, the flow guide elements represent more than mere anomalies on the inner surface of the contact section. Rather, they are individual elements of significant size that can substantially redirect the flow of the coolant. This can advantageously contribute to increasing the flux. Furthermore, this can advantageously achieve a particularly uniform temperature distribution.

[0068] In a further preferred embodiment of the present invention, the contact element is at least 100 Wm -1 K -1 The material comprises a material having a thermal conductivity and a melting point above 600°C, and the material is preferably selected from the group consisting of diamond, copper, gold, silver, aluminum, or alloys of copper, gold, silver, or aluminum. Diamond is particularly preferred. These preferred materials have proven to be particularly efficient in transferring heat from the tool to the coolant. At the same time, these materials have high thermal resistance and mechanical strength to withstand tool vibrations.

[0069] The contact elements are connected to the base body, for example, by clamping, screwing, or soldering, but preferably by adhesive bonding. Preferably, the contact elements are integrated into the base body and form the base surface of the contact section. It is even more preferable that the contact elements make direct surface contact with the tool. Taking into account the thermal and mechanical properties of the contact elements, the contact elements are preferably designed to be as thin as possible. The use of one of the preferred materials makes it possible to keep thermal latency as low as possible.

[0070] In a further preferred embodiment of the present invention, the thickness of the contact element is up to 2 mm, and particularly up to 0.5 mm. At such a thickness, the thermal latency of the contact element can be kept particularly low, thereby efficiently transferring heat from the tool to the coolant. By minimizing the thickness of the contact element, the heat flux from the tool into the contact section is further increased according to Fourier's law. Taking into account the properties of the selected material, the temperature of the tool, and the temperature of the coolant, those skilled in the art can select a contact element thickness suitable for keeping thermal latency low while maintaining high thermal conductivity.

[0071] The temperature difference in the contact elements along the flow axis within the contact section preferably does not exceed 20K, and in particular does not exceed 5K.

[0072] In a further preferred embodiment of the present invention, the surface of the contact element facing the contact section has a roughness between 0.1 μm and 200 μm, particularly between 25 μm and 50 μm. Such roughness may correspond to the grain size of the untreated CVD diamond layer. The surface roughness of the contact element allows for increased heat transfer to the coolant.

[0073] In a further preferred embodiment of the present invention, the distance between the contact element and the contact surface of the tool is selected to be as small as possible. Preferably, this distance does not exceed half the distance between two symmetrically facing tool edges.

[0074] Preferably, the surface of the contact element facing the tool has a roughness of less than 0.1 μm, particularly between 0.01 μm and 0.06 μm. This surface is preferably polished. This allows for optimal, gapless contact between the contact element and the tool, thereby enabling good heat conduction.

[0075] In a further preferred embodiment of the present invention, the surface of the contact element facing the tool covers at least 10% and up to 100% of the tool's surface area. Particularly preferably, the contact element is in contact with at least the rake face of the tool. It may also be preferable that another surface of the contact element facing the tool occupies between 10% and 100% of the tool's surface being cooled. In this way, costly materials such as diamond can be used in a targeted manner, and the contact section can be restricted to generate a high flow velocity.

[0076] Preferably, the "cooled surface" of the tool is the rake face, clearance face, and / or surface in contact with the tool holder. Particularly preferably, the cooled surface is the rake face.

[0077] The internal channels of the device can be divided into different sections, particularly depending on the flow direction relative to the contact elements. One or more sections of the internal channels that carry coolant from the inlet to the contact elements may be referred to as “supply channels” or “supply sections.” One or more sections of the internal channels that carry coolant away from the contact elements may be referred to as “discharge channels” or “discharge sections.” The contact sections are preferably located between the supply channels and the discharge channels, in contact with the contact elements.

[0078] In a further preferred embodiment of the present invention, one or more internal channels comprise one or more, preferably one to fifteen, particularly three to eight, supply sections and one or more discharge sections. Preferably, the supply sections are located in a supply section plane above the discharge plane occupied by the contact section and / or discharge sections. The arrangement of supply and discharge sections in different planes is preferably made possible by sufficient dimensions of the base body. It should be noted that the supply sections do not need to pass parallel to the discharge sections. Rather, the supply sections may enter the contact section from a different plane. Furthermore, the supply and discharge sections may be straight or take spatial courses. As a result, the supply sections may pass at least partially obliquely to the contact elements so that the coolant can strike the base of the contact section, which may be formed by the contact elements themselves. If the contact elements form the lower portion of the device, the “supply section plane” is preferably a higher plane above the “discharge plane”.

[0079] In a further preferred embodiment of the present invention, the feed section opens into the contact section, and the flow direction of the feed section is preferably positioned at 0° to 90°, particularly 30° to 60°, with respect to the surface of the contact element facing the tool. The flow direction is preferably considered to be in a plane perpendicular to the surface of the contact element.

[0080] By supplying coolant or perpendicularly or obliquely into the contact section at a preferred angle, impinging flows occur within the contact element. Furthermore, the shape, size, and position of flow guide elements and / or cavities may work synergistically with the oblique supply to ensure increased turbulence within the contact section. Flow guide elements induce flow separation, and consequently forced turbulence. It may be particularly preferable to position the flow guide elements opposite the supply portion and / or opposite one or more cavities. This may mean that the flow guide elements are placed on the base surface of the contact section and the supply portion or cavity is located at the same longitudinal position on the upper surface of the contact section. Alternatively, this may mean that the flow guide elements are exposed in the supply portion or cavity. Such an arrangement allows the flow guide elements to be impinged by both the supply portion or cavity and the main flow direction along the contact section, which may further increase turbulence.

[0081] The cross-sections of the supply and discharge sections may have any desired shape, such as circular, elliptical, rectangular, or freeform. Circular or elliptical cross-sections are particularly preferred. Such cross-sections allow for layered flow and can minimize pressure loss due to friction of the coolant against the inner wall of the channel.

[0082] In a further preferred embodiment of the present invention, the supply and / or discharge sections have a diameter between 0.1 mm and 5 mm, preferably between 0.3 mm and 3 mm, and particularly between 0.5 mm and 2 mm. Such a small diameter allows for a very high flow velocity relative to the volumetric flow rate of the coolant used. This makes the cooling process remarkably efficient.

[0083] In a further preferred embodiment of the present invention, the supply section is designed in a tapered shape. This reduces pressure loss along the supply section and increases the flow velocity of the coolant entering the contact section.

[0084] The supply section may preferably be configured to include, for example, insulation in the form of a suitable coating and / or to minimize convection losses. The material of the base body and / or its coating may also be selected to match the insulation of the supply section. This insulation makes it possible to prevent undesirable heating and condensation of the coolant due to ambient temperature. The temperature difference between the coolant and the contact elements in the contact section can thereby be maximized.

[0085] Preferably, at least one supply section and one discharge section are present to transport the coolant through the contact section. This is advantageous, for example, by reducing the required operating pressure in the cooling circuit due to the larger cross-section resulting from the separation of the supply and discharge sections compared to a concentric bore. This is advantageous when the flow velocity is changed to increase heat transport. The supply and discharge sections may be arranged horizontally, vertically, or at any desired angle to each other. This is advantageous, as it provides flexibility in designing the cross-sections of the supply and discharge sections within the base body. The cross-sections of the supply and discharge sections should preferably be selected to be as large as possible to maximize the volumetric flow of the coolant at the maximum allowable operating pressure.

[0086] In a further preferred embodiment of the present invention, the invention comprises one to three discharges from the contact section, with the use of a single discharge being particularly preferred. The cross-section of the discharge is preferably selected to be as large as possible, but should not exceed twice the cross-section of the outlet of the base body. Preferably, the cross-section of the discharge does not exceed the cross-section of the outlet. This ensures a low system pressure at the outlet. It may also be preferable that the flow through the discharge and / or from the outlet of the base body be a stacked flow. As a result, the pressure difference and load on the downstream components of the system peripheral equipment for coolant handling are reduced.

[0087] In a further preferred embodiment of the present invention, the cross-section of the discharge section is greater than or equal to the cross-section of a single feed section. Particularly preferably, the cross-section of the discharge section does not exceed the sum of the cross-sections of all feed sections. The discharge section preferably opens within the longitudinal end of the contact section, preferably within the last 30% of the length of the contact section when viewed in any direction.

[0088] Preferably, the supply and discharge sections are connected to a contact section at one end and to an inlet or outlet of the base body at the other end. Preferably, the inlet and outlet each include a connector for connecting the device to system peripherals.

[0089] In some preferred embodiments of the present invention, the device comprises a plurality of contact elements and a plurality of contact sections, for example, a plurality of contact elements having two associated contact sections, a plurality of contact elements having three associated contact sections, or more such arrangements. It may also be preferable that the number of contact elements does not correspond to the number of contact sections. For example, multiple contact sections may be in contact with different areas of the same contact element.

[0090] In a further preferred embodiment of the present invention, the contact section includes a longitudinal axis. In this embodiment, the contact section comprises a plurality of feeders, the first feeder opening into the contact section at a lateral distance from the longitudinal axis of the contact section, different from that of the second feeder. In other words, two or more feeders open into the contact section at different lateral positions. The lateral distance of the center of the cross-section of each feeder may be offset from the longitudinal axis (also referred to as the "centerline") of the contact section. Preferably, the center of the cross-section of the feeder does not extend beyond the bottom surface of the contact section. By changing the lateral position of the feeders, vortices can be formed in the contact section as flows from one feeder collide with flows from another. This further increases turbulence and cooling rates.

[0091] In a further preferred embodiment of the present invention, all feed sections open within the longitudinal axis of the contact section. This can result in more predictable flow conditions, where the impact angle of the feed section, flow guide elements, and / or cavities determine vortex formation.

[0092] When multiple feeders are used, the spacing between them may be selected as needed. It may be preferable that the feeders be equally spaced along the longitudinal direction of the contact section. Similarly, the distance between one feeder and the next may vary.

[0093] The contact section may have any desired shape, and the minimum dimension of the contact section is its thickness. The contact section preferably has a longitudinal axis representing the main flow direction. Preferably, the supply section is located along the longitudinal axis (optionally offset therefrom), and the discharge section is located near one end of the longitudinal axis. The cross-section of the contact section is preferably the size of its opening in a plane traversing the longitudinal axis. Preferably, the cross-section of the contact section is 0.008 mm 2 From 20mm 2 During the interval, especially 0.2mm 2 3.5mm 2 These values ​​are between these two ranges. If the cross-section varies over the length of the contact section, these values ​​preferably represent the average value.

[0094] The base surface (or "base surface") of the contact section may be circular, elliptical, rectangular, or designed as a freeform shape. Preferably, the base surface is rectangular, and the edges of the contact section may have corner radii. This can reduce pressure loss.

[0095] In a further embodiment, the present invention relates to a system for cooling a tool for machining a workpiece as described in any of the prior claims, and means for connecting the tool and devices to the tool. Furthermore, the system comprises a fluid circuit for delivering a coolant into an inlet and directing the coolant from the outlet of a device for cooling the tool.

[0096] The system according to the present invention is preferably based on a closed circuit through which an environmentally friendly coolant flows. Therefore, the coolant lubricant (KSS) does not need to be supplied externally to the cutting zone. The heat generated during machining is dissipated partly by the cutting tool and partly by closed internal cooling. Heat transfer for internal cooling occurs indirectly by conduction and forced convection. This is made possible by contact between the tool and the device for cooling the tool, as well as by the coolant flowing through the device and fluid circuit (part of the "system peripherals").

[0097] The fluid circuit preferably serves to process, move, and / or regulate the temperature of the coolant. An advantage is that the coolant remains within the fluid circuit. Therefore, the operating cost of the system is significantly reduced compared to flood cooling. Furthermore, the limited cross-section of the internal channels of the fluid circuit and devices plays a role in increasing the flow velocity and flow pressure. Compared to flood cooling, the required pressure and volumetric flow rate are reduced by up to 100 times. As a result, the pump power of the fluid circuit can be significantly reduced. Moreover, very small amounts of coolant are required. The amount of coolant required can be up to 10 times less than in flood cooling. The closed-circuit design and targeted heat extraction provide significant advantages in terms of energy and resource consumption.

[0098] The means for connecting the device to the tool are preferably releasable means. These may include, for example, a base body, a contact element, and a screw passing through the tool. When a screw is used to connect the device to the tool, the screw may preferably serve to secure both the device and the tool simultaneously. This is advantageous in reducing the number of additional components. Furthermore, particularly precise positioning of the device relative to the tool can be achieved. Additional or separate screws may also be used for connection. This is advantageous in allowing particularly good flexibility in the use and / or positioning of the device. Alternatively, the device may also be connected to the tool by clamping or coupling. This is advantageous in potentially allowing particularly flexible and easy positioning of the device. The device may be used as a clamping finger or as an additional component that does not interfere with any existing clamping system. The cooling device may be positioned above, below, or in combination with the tool. The terms “above” and “below” refer to the normal orientation of the tool in use with respect to the workpiece. This orientation is known to those skilled in the art.

[0099] The device may also be positioned laterally and / or on multiple surfaces of the tool. This advantageously allows for particularly effective cooling of the tool. Multiple surfaces may be cooled simultaneously, for example, by using multiple cooling elements and / or a single cooling element that can extend across several surfaces.

[0100] Depending on the positioning of the device, the device may also serve a dual function, for example, clamping and / or cooling. This is advantageous because it is possible to keep the number of components used as small as possible, thereby minimizing the detrimental effects of the cooling device on process behavior. In particular, it is advantageous because it allows for the vibration behavior of the tool holder, cutting depth (a p ) and / or harmful effects on setup time can be avoided.

[0101] Alternatively, the device may also be an additional component that has no function other than cooling within the tool system and does not affect the existing clamping system. This makes it particularly easy and advantageous to integrate the device into the existing tool system.

[0102] In a preferred embodiment of the present invention, the system comprises a tool seat, and the cooling device either acts as the tool seat or is integrated within the tool seat. According to this embodiment, the device may cool the tool from below.

[0103] The advantage of this system is that it does not require changes to tools, tool holders, or optional tool sheets. Therefore, the use of standard components such as tools and tool holders is maintained.

[0104] In a further preferred embodiment of the present invention, the cooling device is configured as a tool seat, preferably designed to cool the tool from below. This configuration can additionally be combined with another cooling device, which may be configured as clamping fingers or otherwise connected to the tool from above, thereby cooling the tool from both above and below. Such cooling devices can interact synergistically to reduce the temperature of the tool.

[0105] In a further preferred embodiment of the present invention, the device for cooling the tool functions as a clamping finger for clamping the tool. In this case, the device may be integrated within the clamping finger. The clamping finger may also be modified to implement the features of the device.

[0106] Preferably, the base body of the device includes a metallic material. However, it may also have an additional insulating layer. If the device functions as a clamping finger for clamping a tool, the base body is made of steel or a similar material having similar thermal and / or mechanical properties. This ensures the necessary stability to withstand the mechanical load on the tool.

[0107] When the device is used as an additional component that does not serve to clamp the tool, the base body may include a metallic material such as steel, or an insulating material such as plastic. As described for the device, the use of insulating material has the advantage of maximizing the temperature difference between the coolant and the contact elements in the contact section.

[0108] In a further embodiment, the present invention relates to a method for cooling a tool using a system according to the present invention. In this method, a coolant is continuously supplied to the inlet of a device for cooling the tool at a volumetric flow rate between 0.01 L / min and 20 L / min, and the coolant circulates throughout through a closed-loop internal channel of the device. Preferably, the coolant is supplied to the inlet of the device at a pressure of up to 10 bar, and particularly up to 4 bar.

[0109] Heat removal from the tool may be carried out with an uncooled or temperature-controlled cooling fluid. Preferably, a coolant with a high specific heat capacity (cp), such as water of any quality, e.g., demineralized water, deionized water, or ultrapure water, is used. To suppress corrosion, environmentally friendly additives are used in preferred embodiments of this method. Furthermore, when using a cooling fluid temperature below the freezing point, the addition of further additives or glycols is preferable. The mechanical and thermal material properties of the coolant mixed with additives are preferably designed so that the properties of water have minimal influence.

[0110] In a further preferred embodiment of the present invention, the volumetric flow rate of the coolant is 0.01 L / min to 4 L / min, preferably 1 L / min to 3 L / min. These flow rates work synergistically with preferred dimensions of the contact sections, cavities, and flow guide elements to enable particularly rapid heat removal and generate a turbulent effect. At the same time, the flow rates are low enough to allow the use of particularly economical pumps.

[0111] In a further preferred embodiment of the present invention, the coolant is conditioned to a temperature between -20°C and 35°C, with a temperature between 5°C and -10°C being particularly preferred, especially around -5°C.

[0112] In a further preferred embodiment of the present invention, the method for cooling a tool by the system according to the present invention is combined with a flood cooling and / or minimum quantity lubrication (MQL) strategy. This can synergistically enhance cooling.

[0113] Those skilled in the art will recognize that the preferred features and advantages of the device according to the present invention also apply to the system and method according to the present invention, and vice versa.

[0114] The present invention will be described in more detail below with reference to examples and figures, but will not be limited thereto. [Brief explanation of the drawing]

[0115] [Figure 1] This is a schematic diagram of a system for processing a workpiece with cooling, according to a preferred embodiment of the present invention. [Figure 2] This is a schematic cross-sectional view of a device for cooling a tool according to a preferred embodiment of the present invention. [Figure 3] This is a schematic top view of a device for cooling a tool according to a further preferred embodiment of the present invention. [Figure 4A] This is a schematic top view of a contact section according to a preferred embodiment of the present invention. [Figure 4B] This is a schematic top view of a contact section according to an alternative preferred embodiment of the present invention. [Figure 5A] This is a schematic top view of a device for cooling a tool, showing a preferred deviation of the contact element's position from the center point. [Figure 5B] This is a schematic top view of a device for cooling a tool, showing the preferred minimum distance between the heat source of the tool and the base surface of the contact element. [Figure 5C]This is a schematic cross-sectional view of a device for cooling a tool, showing a preferred deviation of the position of the contact element from the center point. [Figure 5D] This is a schematic cross-sectional view of a device for cooling a tool, showing the preferred minimum distance between the heat source of the tool and the base surface of the contact element. [Figure 6] This is a schematic diagram of a contact section of a device according to a preferred embodiment of the present invention. [Figure 7] This is a schematic diagram of a contact section of a device according to a further preferred embodiment of the present invention. [Figure 8] This is a schematic diagram of a contact section of a device according to a further preferred embodiment of the present invention. [Figure 9] This is a schematic diagram of a preferred embodiment of a flow guide element. [Figure 10] This is a schematic diagram of a further preferred embodiment of the flow guide element. [Figure 11] This is a schematic diagram of a further preferred embodiment of the flow guide element. [Figure 12] This is a schematic diagram of a further preferred embodiment of the flow guide element. [Figure 13] This is a schematic diagram of a preferred embodiment of the cavity. [Figure 14] This is a schematic diagram of a further preferred embodiment of the cavity. [Figure 15] This is a schematic diagram of a further preferred embodiment of the cavity. [Modes for carrying out the invention]

[0116] Figure 1 shows a schematic diagram of a system for machining a workpiece under cooling according to a preferred embodiment of the present invention. A device 1 for cooling the tool and a tool 2 are shown. Device 1 comprises a base body 4. The base body 4 of device 1 is in direct contact with the tool 2. The internal components of device 1 are not shown in this figure. The base body 4 has inlets and outlets that are fluidly connected to system peripherals 3. The tool 2 is placed on a tool seat 6, and device 1 is configured as clamping fingers for securing the tool 2 and the tool seat 6 on a tool holder 5. The tool holder 5 may have associated contact surfaces with the tool seat 6 and / or the tool 2, such as a polygonal shank tapered portion or a square contact surface.

[0117] The coolant prepared by the system peripheral 3 flows through device 1 and is then returned to the system peripheral 3 to form a closed fluid circuit for tool cooling.

[0118] Figure 2 shows a schematic cross-sectional view of the device 1 along a supply channel 8 (see Figure 3 for reference number). The supply channel 8 extends through the base body 4 into space 11 and opens into the contact section 7 at a collision angle 12 of 60°. The contact section 7 represents a cavity within the device 1 and is positioned directly above the contact element 10, which forms the base surface of the contact section 7. The contact section 7 is fluidly connected to the inlet and outlet of the base body via an internal channel comprising at least one supply section 8 and at least one discharge section 9 (not shown, see Figure 3). The contact section 7 is further equipped with flow guide elements, which locally increase the turbulence and velocity of the coolant through the contact section. In this embodiment, the contact element 10 is a diamond plate having a thickness 13 of 0.5 mm. The contact element 10 transfers heat from the tool 2 to the coolant, thereby ensuring that the temperature difference along the longitudinal axis of the contact element 10 does not exceed 5 K.

[0119] Figure 3 shows a schematic top view of device 1 having a contact section 7, showing internal components that are not necessarily coplanar. Device 1 includes an inlet 14 configured as a fluid connection to system peripherals 3. A supply section 8 having a constant diameter (solid line) connects the inlet 14 to the contact section 7. A dashed line shows an alternative embodiment in which the supply section 8 has a tapered diameter in the flow direction. The contact section 7 is positioned above a contact element 10 having a width and length slightly greater than the contact section. The contact section 7 is connected to an outlet via a discharge section 9. The longitudinal and central axes of the supply and discharge sections are shown, representing the main flow direction of the coolant through the base body 4.

[0120] Figures 4A and 4B show two alternative embodiments of multiple supply outlets 8 opening into the contact section 7. In the embodiment of Figure 4A, the contact section 7 has an essentially rectangular base surface with rounded corners 19. A longitudinal axis 16 extends along the contact section 7 and defines the main flow direction. The contact section 7 is supplied with coolant through at least one supply outlet 8. If only one supply outlet 8 is used, it preferably opens at or near the end of the longitudinal axis 16. At least one supply outlet 8 is shown as a solid line. At least one discharge outlet 9 removes the coolant from the contact section 7 and is preferably located at or near the opposite end of the longitudinal axis 16. Between the first supply outlet 8 and the discharge outlet 9, there may be further supply outlets 8, three further in this example. In the embodiment of Figure 4A, all supply outlets 8 are equally spaced along the longitudinal axis 16; that is, the distance 17 between consecutive supply outlets 8 is uniform. Furthermore, all supply sections open into the contact section 7 such that their center 15 lies on the longitudinal axis 16 without lateral deviation.

[0121] In the embodiment shown in Figure 4B, the first and third supply sections 8 and the discharge section 9 are aligned along the longitudinal axis 16. A variable lateral deviation 18 of the centers 15 of the second and fourth supply sections 8 from the longitudinal axis 16 is provided.

[0122] Figures 5A–5D show preferred relative dimensions and positions of the contact element 10 relative to the tool 2. The base surface of the contact element 10 is indicated by reference numeral 20 and is exemplary rectangular. The area 21 to be cooled over the entire tool surface 22 is indicated by a dashed line in Figure 5B. As shown, the base surface 20 of the contact element 10 covers between 10% and 100% of the area 21 to be cooled. To enhance cooling performance, the contact element 10 can extend along the area 21 to be cooled at the cutting edge of the tool 2. This may require a shift in the position of the contact element 10 toward the edge of the area 21 to be cooled, indicated by reference numeral 23. Extending of the device 1 beyond each area 21 of the tool 22 to be cooled is possible, but this will result in reduced cooling performance.

[0123] Figures 5A to 5D show the distance 24 from the contact area 25 on the tip surface of the tool to the contact element 20. The contact area 25 can be considered a heat source. Preferably, the distance 24 is kept as small as possible to achieve optimal heat transfer from the tip surface to the coolant. Displacement 23 of the contact element 20 can make this possible. Furthermore, the distance 24 from the contact element 20 to the heat source 25 should not exceed half the distance between the two symmetrical opposing edges of the tool 2. When reducing the distance 24, adverse effects on tip removal should usually be avoided.

[0124] Figure 6 shows a schematic cross-sectional view of the contact section 7 along the longitudinal axis 16 according to a preferred embodiment of the present invention. The impingement flow of coolant from the supply section 8 to the contact element 10 is indicated by reference numeral 26. This impingement occurs in a plane perpendicular to the observation plane at an impingement angle 12 of 90° with respect to the base surface 31 of the contact section 7. This maximum impingement angle 12 generates a high heat flux based on the turbulent effect. In addition, by selecting such a large impingement angle, it is possible to reduce the flow velocity for the same turbulence, making this solution more efficient.

[0125] A thermal boundary layer is formed along the base surface 31 due to the temperature difference between the coolant and the contact element 10 at the base surface 31. The resulting temperature gradient and boundary layer thickness affect heat transfer toward the coolant. In this embodiment, the base surface 31 is the surface of the contact element 10. Cooling performance depends on the temperature difference of the contact element 10 along the flow axis within the contact section 7, which is less than 5K. To further reduce the temperature difference, multiple supply units 8 supply temperature-controlled coolant along the entire contact section 7.

[0126] Cavities 27 are provided between consecutive supply sections 8 and between the last supply section 8 and the discharge section 9. These locally enlarge the cross-section of the contact section 7 and are bounded by chamfered edges 32. Geometrically shaped flow guide elements 28 are also positioned in front of or between the supply sections 8 on the base surface 31 of the contact section 7. By integrating the cavities 27 and the flow guide elements 28, forced flow deformation occurs through separation effect 29 and vortex formation 30. The impinging flow 26 from the supply sections 8 and the inclined surfaces of the flow guide elements 28 and chamfered edges 32 direct the coolant toward the base surface 31 for high heat transfer from the contact elements 10. The region 51 of the impinging flow on the base surface is highlighted with a dashed line.

[0127] Figure 7 shows possible deformations of the chamfered edges 32 of the cavity 27. The main flow direction runs from right to left along the contact section 7. The solid line shows the upstream-oriented outer angle of the chamfered edges 32 (the first three chamfered edges 32 on the right) relative to the inner wall of the contact section 7 at 90°. The coolant impacts these edges, generating vortices within the cavity 27. Variations in flow behavior can be achieved by changing the outer angle, for example by shifting the tip 34 of the chamfered edges 32 (indicated by the leftward arrow). This also changes the obtuse angle 33 of the downstream chamfered edges 32. These variations can be combined with the positioning of the flow guide element 28 and the inclination of its inclined surface to direct the coolant towards the base 31. Reference numeral 35 indicates possible adjustments to the diameter of the feeder 8, for example by tapering, so that the feeder 8 functions as a nozzle spraying coolant at high speed into the contact section 7.

[0128] Figure 8 further illustrates the parameters of the cavity 27 that can be adjusted to change the flow conditions. For example, the distance 36 between the consecutive tips 34 of the chamfered edge can be changed to manipulate vortex formation near the base 31. Additionally, the height or depth 37 of the cavity 27 can be adjusted to generate vortices of a larger radius.

[0129] Figure 9 shows a schematic diagram of a preferred embodiment of a flow guide element 28 for generating an impinging flow 26. The supply section 8 generates an impinging flow 26 on the contact element 10. The flow guide element 28 is implemented to control the interaction of flows along the flow channel 7 and the supply section 8. These elements induce flow separation and, consequently, forced turbulence. In this embodiment, the flow guide element 28 is located within a cavity 27, and its cross-section is preferably described as an isosceles triangle with an internal angle 38 of up to 60°. By adding a radial section 37, the separation effect is modified and the turbulent flow is enhanced. In another preferred embodiment, the internal angle 38 of the flow guide element 28 is in the range of 5° to 60°, modifying the flow paths in both the supply section 8 and the separated flow 29.

[0130] Figure 10 shows preferred embodiments of flow guide elements 28 at different positions. Preferably, the flow guide element 28 is positioned along the flow channel between the supply section 8 and the outlet edge 32 of the cavity, with one side of the element 28 on the bottom 31 of the flow channel. By reducing the distance 41 between the flow guide element 28 and the outlet edge 32, the resulting flow velocity is increased, thereby changing the coolant separation position 29.

[0131] Figure 11 shows a preferred embodiment of a flow guide element 28 having different heights 42 and widths 43 to achieve the desired resulting flow velocity. The height 42 can be reduced or the width 43 can be increased. Preferably, the edge angle 38 required for the separated flow 29 is not less than 5°. The aspect ratio of height 42 to width 43 is preferably between 1:10 and 3:1.

[0132] Figure 12 shows a preferred embodiment of the flow guide element 28. Preferably, it is positioned on or parallel to the longitudinal axis 11 of the supply section 8 and collinear with the contact element 10. In another embodiment, the flow guide element 28 is positioned away from the contact element 10, creating a clearance 44. This results in secondary flow 45, which increases the flow velocity and turbulence in this region.

[0133] Figure 13 shows a preferred embodiment of a cavity 27 for generating targeted backflow within the flow channel on the side surface of the contact element 10 and increasing turbulence. An angle 46 of 5° to 60° is applied to the upper part 47 of the cavity. In another preferred embodiment, a radial section is applied to the cavity corner 48 to enhance turbulence. The flow guide element 28 is preferably positioned inside the cavity 27 at a vertical distance 49 from the bottom 31 of the flow channel / contact element 10, 15% to 90%. The flow guide element 28 does not touch the cavity edge and is free within the flow channel. A preferred range is 20% to 40% of the vertical distance 49. The lower edge of the flow guide element 28 is preferably upstream of the first outlet edge 32. This allows for flow separation above and below the element 28 along the flow channel. Turbulent vortices due to backflow are formed above the element 28, increasing turbulent flow at the bottom 31 of the flow channel.

[0134] Figure 14 shows a preferred embodiment of the series-arranged cavities 27. The cavities 27 have both an angle 46 and a radius 48, generating a repeatable flow pattern and, as a result, turbulence along the flow channel 7 from the supply section 8 to the discharge section 9.

[0135] Figure 15 shows a preferred embodiment of the cavity 27 and the flow guide element 28. The distance 50 from the first outlet edge 32 to the center of the flow guide element 28 is greater than 0 mm, allowing turbulent vortices due to reverse flow to form in the upper flow stream, and these turbulent vortices increase the turbulence below the element 28. By increasing the vertical size of the element 28 and reducing the vertical distance 49 between the element 28 and the outlet edge 32, the cross-section of the flow channel 7 is narrowed, increasing turbulence at the bottom. The corner radius allows for flow separation within the cavity 27. [Explanation of Symbols]

[0136] 1. Device for cooling tools 2 tools 3. System Peripherals 4. Base unit 5 Tool holders 6 Tool Sheet 7 Contact section 8. Supply Channel 9 Emission Channels 10 Contact elements 11 Spatial course of supply or discharge channel 12. Incidence angle between the channel axis and the base area of ​​the contact section 13. Thickness of contact elements 14. Entrance or Exit 15 Cross-section of the supply section or discharge channel 16 Longitudinal axis of the contact section 17 Distance between the central axes of the supply channel 18 Distance between the central axis of the supply channel and the longitudinal axis of the contact section 19 Edge of a contact section having a corner radius 20. Base area of ​​contact elements 21 Area of ​​the tool to be cooled 22. Tool plate shape 23 Distance between the center point of the tool and the preferred center point of the contact element 24. Distance between the contact element and the heat source of the tool, particularly the contact area of ​​the cutting edge of the tool. 25 Contact area of ​​the cutting edge of the tool 26 Coolant flow from the supply channel 27 Cavity 28 Flow Guide Elements (Stromungsleitelement) / Geometric Shapes 29. Flow separation (separation position) 30 Vortex formation 31 Lower surface / base of the contact section 32 Hollow runout or chamfered edge 33. External angle (obtuse angle) of the chamfered edge relative to the cavity 34 Displacement of the tip of the chamfered edge from the orthogonal position toward the supply channel 35 Diameter of the supply section or discharge channel 36 Width of the cavity 37. Height (or depth) of the cavity 38 Internal angle of the flow guide element relative to the inner wall of the contact section 39 Displacement of the tip of the flow guide element by changing the internal angle of the contact section relative to the inner wall. 40. Position of flow guide elements 41 Upstream distance between the tip of the flow element and the tip of the chamfered edge of the nearest cavity 42 Flow guide elements with reduced height 43 Flow guide element with increased width 44 Clearance between exposed flow guide elements and contact elements 45 Secondary flow of coolant through clearance 46 Angle of the inclined inner wall of the cavity relative to the inner wall of the contact section 47 Inner wall of the cavity 48 Inner corner of the cavity 49 Distance between the exposed flow guide element and the contact element within the cavity 50 Upstream distance between the exposed flow guide element in the cavity and the nearest chamfered edge 51. Impact flow in the direction of the base (region)

Claims

1. A device for cooling tool (2), The device comprises a base body (4), a contact element (10), at least one inlet into the base body (4), and one outlet from the base body (4), wherein the inlet and the outlet are connected to each other by one or more internal channels within the base body (4). The device is connectable to the tool (2) such that the contact element (10) contacts the tool (2), In a device, the one or more internal channels are configured to guide a coolant, The device is characterized in that one or more internal channels comprises a contact section (7), the contact section (7) is in contact with the contact element (10), and the contact section (7) comprises a plurality of flow guide elements (28), the flow guide elements being configured to locally increase the turbulence and flow velocity of the coolant passing through the contact section (7).

2. The contact element (10) forms the inner wall of the contact section (7), The device according to claim 1, wherein one or more flow guide elements (28) also preferably contact the contact element (10), are permanently connected to the contact element (10), or form part of the contact element (10) and are configured to facilitate conductive heat transfer from the contact element (10) to the coolant.

3. The device according to claim 1 or 2, wherein the flow guide element (28) protrudes from the inner wall of the contact section (7), particularly from the base, or from the contact element (10), creating a local restriction of the cross-section of the contact section (7), and preferably, at least one surface of the flow guide element (28) forms an external angle of 90° to 175°, particularly 100° to 150°, with respect to the inner wall of the contact section (7).

4. The device according to any one of claims 1 to 3, characterized in that at least one flow guide element (28) is connected to two parallel inner walls of the contact section (7) and separated from the other inner wall of the contact section (7), and the two parallel inner walls are essentially perpendicular to the contact element (10).

5. The device according to any one of claims 1 to 4, wherein one or more inner walls of the contact section (7) include a cavity (27), the cavity (27) representing a localized enlargement of the cross-section of the contact section (7), the cavity (27) preferably bounded by a break-off edge (29), the break-off edge (29) preferably forming an external angle between 90° and 175° with respect to each of the inner walls.

6. The flow guide element (28) may have the shape of a prism, pyramid, polyhedron, sphere, or ellipsoid, or a combination thereof, and a prism shape having an isosceles triangular cross-section and a rounded tip is preferred. The device according to any one of claims 1 to 5, characterized in that the height-to-width ratio of the flow guide element (28) is preferably between 1:10 and 3:

1.

7. The contact element (10) has a capacity of at least 100 Wm －１ K －１ It consists of a material having a thermal conductivity and a melting point exceeding 600°C. The device according to any one of claims 1 to 6, characterized in that the material is preferably selected from the group consisting of diamond, copper, gold, silver, aluminum, or an alloy of copper, gold, silver, or aluminum.

8. The device according to any one of claims 1 to 7, characterized in that the surface of the contact element (10) facing the contact section (7) has a roughness of 0.1 μm to 200 μm, particularly 25 μm to 50 μm, and the surface of the contact element (10) facing the tool (2) has a roughness of less than 0.1 μm.

9. The one or more inner channels, one to fifteen, particularly three to eight, each comprise a supply section (8) and one or more discharge sections (9), The device according to any one of claims 1 to 8, characterized in that the supply unit (8) is located in the supply unit plane above the discharge plane occupied by the contact section (7) and / or discharge unit (9).

10. The device according to claim 9, characterized in that the supply unit (8) opens into the contact section (7), and the flow direction of the supply unit (8) is preferably arranged at 0° to 90°, particularly 30° to 60°, with respect to the surface of the contact element (10) facing the tool (2).

11. The device according to any one of claims 1 to 10, characterized in that the contact section (7) includes a longitudinal axis, and the one or more inner channels comprise a plurality of supply units (8), wherein the first supply unit opens into the contact section (7) at a lateral distance (18) from the longitudinal axis (16) of the contact section (7), different from the second supply unit.

12. The flow element locally reduces the cross-section of the contact section (7) by at least 20%, and particularly at least 30%, so that the cross-section of the contact section (7) is preferably 0.008 mm ２ 20mm ２ During the interval, especially 0.2 mm ２ 3.5 mm ２ The device according to any one of claims 1 to 11, characterized in that it is between [a certain range].

13. A system for processing workpieces under cooling conditions, The system comprises a device for cooling a tool (2) as described in any one of claims 1 to 12, a tool (2), and means for connecting the device to the tool (2), The system is characterized in that it further comprises a fluid circuit for transporting coolant into an inlet and for transporting the coolant out of the outlet of the device for cooling the tool (2).

14. The system according to claim 13, wherein the device for cooling the tool (2) acts as a clamping finger for clamping the tool (2) or as a cooling unit, and the base body (4) of the device preferably includes a metallic material.

15. A method for cooling a tool (2) using the system described in claim 13 or claim 14, A method characterized in that a coolant is continuously introduced into the inlet of the device for cooling the tool (2) at a volumetric flow rate between 0.01 L / min and 20 L / min, and the coolant circulates within a closed circuit comprising the internal channel of the device.

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