CUTTING TOOL, TOOL ARRANGEMENT AND CUTTING ELEMENT TEMPERATURE CONTROL PROCESS

Description

[0001] The present invention relates to a cutting tool according to the preamble of claim 1. JP S58 160001 A discloses an example of such a cutting tool.

[0002] Furthermore, the present invention relates to a method for tempering a cutting element connected to a tool holder.

[0003] In the field of machining, it is well known that high temperatures can occur in the interface between the cutting element and the workpiece, due to the machining action itself. Particularly when machining high-alloy chips, very high temperatures occur at the cutting edge due to their high toughness and low thermal conductivity. This leads to increased wear of the cutting element. Furthermore, high temperatures can cause diffusion processes, chemical reactions, and thermal softening. Cooling the interface between the cutting element and the workpiece using fluids has been a long-standing practice. Traditionally, this can be achieved using lubricants, which facilitate the cutting process but also absorb heat. The fluid used in this process must be collected, cleaned, and possibly disposed of, which makes the machining process expensive.

[0004] For cooling machining processes involving high-alloy chips or similar materials, it is also known to introduce liquid nitrogen or CO₂ externally and allow it to evaporate. However, this so-called "cryogenic" machining can lead to hardening of the workpiece due to the nitrogen or carbon in the supplied fluid. Furthermore, this method is particularly expensive because the cooling medium is lost during the process. Additional equipment measures may be necessary to protect the surrounding environment.

[0005] The cooling fluids can be applied externally to the area of ​​engagement between the cutting element and the workpiece. Alternatively, they can be supplied through channels inside a tool holder to which a cutting element is attached.

[0006] If the cutting material used in the cutting element is, for example, PCD (polycrystalline diamond), there is a high risk of carbon diffusing from the diamond material into a steel tool. Therefore, PCD is generally unsuitable for machining iron and is also very expensive.

[0007] Against this background, it is an object of the invention to provide an improved cutting tool and an improved method for temperature control of a cutting element.

[0008] The above problem is solved in the case of the aforementioned cutting tool by the cutting tool according to claim 1.

[0009] Finally, the above problem is solved by a method for tempering a cutting element according to claim 6.

[0010] A significant advantage of the machining tool according to the invention lies in the fact that the cooling device has a closed coolant circuit, so that cooling can be carried out without the uncontrolled distribution of a cooling medium or coolant, which then has to be collected and possibly cleaned. The coolant circuit according to the invention is a closed circuit in which the coolant is heated in the area of ​​the heat exchanger and thereby absorbs heat from the machining process. The coolant thus heated is then returned to the closed coolant circuit and cooled there again in a suitable manner.

[0011] The coolant is a refrigerant, and the closed cooling circuit includes a refrigeration unit. When a refrigeration unit is in use, the refrigerant can evaporate and be discharged as vapor from the heat exchanger housing.

[0012] The cutting element can be made of PCD, but preferably of CBN (cubic boron nitride). Generally, it is also conceivable to use steel, cemented carbide, cermet, or other cutting ceramics as the cutting material.

[0013] By placing a heat-conducting element between the cutting element and the heat exchanger housing, it is possible to effectively transfer the heat generated in the area of ​​the cutting element to the heat exchanger housing. The heat-conducting element has a higher conductivity than the tool holder. The tool holder is preferably made of steel. The heat-conducting element is preferably made of copper, but can also be made of another highly thermally conductive material. Furthermore, the heat-conducting element can also be made of CBN.

[0014] By arranging the heat exchanger within the tool holder and coupling the cutting element to the heat exchanger housing via a heat-conducting element, the cutting element can be cooled very efficiently. This ensures that the tool holder remains thermally stable during the machining process. Furthermore, such a cutting tool can be used for machining operations that typically require a high energy input into the cutting element and the holder. This energy input can be compensated for. This allows either an increase in the machining speed or an extension of the tool life of the cutting element.

[0015] Overall, coolant savings can be achieved. Machining can be performed dry. The machining process can be carried out at low temperatures. Furthermore, it is possible to machine workpieces made of novel materials such as nickel-based alloys, titanium, magnesium, etc., with reduced wear of the cutting element.

[0016] The heat-conducting element can be plate-shaped or rod-shaped. It is particularly preferred that the heat-conducting element contact a cutting element connected to the tool holder in order to achieve low thermal resistance. For the same reason, it is preferred that the heat-conducting element contact the heat exchanger housing, the heat exchanger housing preferably also being made of a material with good thermal conductivity, such as steel, or even better, a material with high thermal conductivity, such as copper.

[0017] The cutting tool according to the invention is preferably a tool that is linearly movable in one or more dimensions, in which the workpiece to be machined is driven by rotation. In this case, the design of the closed coolant circuit is comparatively simple. However, it is also generally conceivable that the cutting tool is driven by rotation and that a machining process is achieved through linear relative movements between the workpiece and the cutting tool. In this case, it is preferred if the closed coolant circuit is established via a rotary union on the cutting tool.

[0018] The task is thus completely solved.

[0019] It is particularly advantageous if the heat exchanger housing has an end face that is in contact with the heat conducting element, wherein a coolant channel is arranged in the heat exchanger housing in such a way that coolant supplied via the coolant channel can be directed onto the inside of the end face.

[0020] In this way, the cooling medium can be effectively used to cool the cutting element, via contact with the tool holder, but especially via contact with the heat-conducting element.

[0021] According to a further preferred embodiment, a return flow channel is arranged concentrically to the coolant channel in the heat exchanger housing.

[0022] In this way, the heated (possibly evaporated) coolant can be effectively returned to the closed coolant circuit. The return flow channel is preferably arranged around the outside of the coolant channel.

[0023] According to a further preferred embodiment, the heat exchanger housing is inserted into a heat exchanger receptacle in the form of a blind hole in the tool holder, wherein the blind hole is adjacent to or opens into the heat conducting element and / or wherein the blind hole has a vent opening in the area of ​​its bottom.

[0024] By ensuring that the blind hole is adjacent to or extends into the heat-conducting element, so that the blind hole extends into the heat-conducting element, effective thermal coupling between the heat exchanger housing and the heat-conducting element can be achieved.

[0025] By providing a vent at the bottom of the blind hole, any air that may have been drawn in during the axial insertion of the heat exchanger housing into the blind hole can be removed, thus preventing an air cushion from forming between an end face of the heat exchanger housing and the heat-conducting element. Such an air cushion could have an insulating effect.

[0026] According to a further overall preferred embodiment, the tool holder has a holder base and a cutting element seat for the cutting element, wherein the tool holder is formed from a heat-insulating material in the area of ​​the cutting element seat and / or around the heat exchanger housing and / or around the heat conducting element in order to reduce heat transfer from the cutting element seat towards the holder base.

[0027] This measure makes it possible, in particular, to prevent excessive cooling of the holder base. In some cases, the holder base includes a holder shaft that is held by a holder receptacle. If the cooling is too great, this retention may be released, especially if the holder base is inserted into a holder receptacle due to shrinkage stress.

[0028] The heat-insulating material can be, for example, a ceramic material. This heat-insulating material can form part of the tool holder. The insert made of the heat-insulating material can, for example, be arranged concentrically around the heat exchanger housing and / or concentrically around the heat-conducting element.

[0029] Furthermore, it is advantageous if the tool holder has a holder base and a cutting element seat for the cutting element, which is spaced apart from the holder base, with a holder base heating device integrated into the holder base.

[0030] Such a heating device can raise the temperature of the holder base if the cooling device cools the holder base too much, which could lead to problems with shrinkage stress or similar issues. The holder base heating device can be used as an alternative or additional measure to incorporate a heat-insulating material on the tool holder in the area of ​​the cutting element seat.

[0031] It is also preferred if the tool holder has a cutting element seat for the cutting element, wherein the cutting element seat has a flat seating surface and wherein the heat conducting element forms at least a part of the flat seating surface.

[0032] The seating surface is flat to ensure precise alignment of the cutting element with the tool holder. Furthermore, by ensuring that the heat-conducting element integrated into the tool holder forms at least part of this flat seating surface, contact between the cutting element and the heat-conducting element can be achieved with minimal thermal resistance.

[0033] The flat seating surface is preferably machined, for example by grinding or similar processes, after the heat-conducting element has been integrated into the tool holder. This ensures that the seating surface is uniformly flat, even if the heat-conducting element only forms part of the seating surface.

[0034] In general, it is possible to arrange the heat exchanger housing and the heat conducting element in any way within the tool holder, as long as the heat conducting element can provide thermal coupling between the heat exchanger housing and the cutting element.

[0035] However, it is particularly advantageous if a longitudinal axis of the heat exchanger housing and a longitudinal axis of the heat conducting element are aligned perpendicular to each other.

[0036] This allows the heat exchanger housing to be inserted along its longitudinal axis into a receiving bore of the tool holder, which, due to its sufficient rigidity, already maintains a certain distance from the cutting element seat. The heat-conducting element, which is oriented transversely to this bore, can then bridge this gap in a simple and effective way.

[0037] According to the invention, the cooling device and a cutting element heating device are integrated into the tool holder in such a way that it is possible to regulate the cutting element to a target temperature range.

[0038] This aspect of the invention enables a machining process in which the temperature of a cutting element remains essentially constant (within a predetermined target temperature range), preferably covering a temperature range of no more than 100°C, and particularly no more than 50°C. In other words, it is preferably possible to maintain the temperature of the cutting element within a target temperature range of 50°C or less.

[0039] According to a further preferred embodiment, the target temperature range lies in a span of 1 / 5 to 1 / 20 of a target temperature sought for a specific machining process.

[0040] The machining process can therefore be carried out at a substantially constant temperature. This can lead to significantly improved cutting performance and / or longer tool life.

[0041] The invention provides that the temperature control is achieved by means of a regulation system. Here, the temperature of the cutting element is measured, preferably as close as possible to the area of ​​the cutting edge that comes into contact with the workpiece.

[0042] Such temperature measurement can be done without contact, using a pyrometer, or with contact using a thermocouple.

[0043] It is particularly advantageous if the cutting element is detachably connected to the tool holder by means of a fastening device, whereby a temperature sensor is integrated into the fastening device.

[0044] The temperature sensor can, for example, be formed by a thermocouple, which is preferably in contact with the cutting element via integration into the fastening device or is at least directly adjacent to it.

[0045] It is particularly advantageous if the fastening device has a continuous recess or bore into which the thermocouple can be inserted and through which the temperature of the cutting element can be measured.

[0046] In the method according to the invention, it is therefore preferred if the temperature of the cutting element is regulated to a target temperature range of the type described above using the cooling device and a cutting element heating device.

[0047] Furthermore, it is advantageous if the cooling capacity of the cooling device is kept constant for a predetermined period, whereby the temperature is regulated by adjusting the heating capacity of the cutting element heating device.

[0048] Preferably, the cooling capacity is set to a value at which the temperature of the cutting element is below a target temperature. The target temperature can then be set relatively easily by simultaneously heating the component.

[0049] The reason for this measure is that the cooling capacity of a cooling device is usually only adjustable relatively slowly, whereas the adjustment of the heating capacity of a heating device can usually be done relatively quickly.

[0050] The heating device can preferably be an electric heating device.

[0051] In some embodiments, the temperature of the cutting element can be regulated to values ​​below 600°C, which makes it possible to machine steel using a cutting tool that incorporates a carbon-based material (cutting material), such as diamond, in the cutting edge area. The cutting material could, for example, be PCD.

[0052] The closed coolant circuit preferably includes a compressor for compressing discharged and heated coolant and a condenser that provides the coolant that is supplied to the heat exchanger housing.

[0053] The closed refrigerant circuit can therefore be formed by a refrigeration machine, which essentially corresponds to the principle of a compressor refrigerator. In this system, a gaseous refrigerant is adiabatically compressed by a compressor, causing the refrigerant to heat up. In the condenser, the heat is released to the surroundings, causing the medium to condense. It then flows through a throttle to reduce the pressure and from there into an evaporator.

[0054] In this case, the evaporator is preferably implemented by the heat exchanger. The evaporation preferably takes place within the heat exchanger housing.

[0055] Alternatively, the closed coolant circuit can also be formed by a heat pipe, or by another closed coolant circuit in which, for example, a fluid is introduced into the heat exchanger housing, where it heats up and from where it is returned to a cooler, within which the fluid is cooled down to a target temperature in order to then be fed back to the heat exchanger housing.

[0056] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or on their own, without leaving the scope of the present invention.

[0057] Exemplary embodiments of the invention are shown in the drawing and are explained in more detail in the following description. They show: Figure 1 is a schematic representation of a tool arrangement with a schematic representation of a cutting tool according to the invention; Figure 2 is a perspective view of a further embodiment of the cutting tool according to the invention; Figure 3 is a further perspective view of the cutting tool of the Fig. 2 Figure 4 shows a top view of a cutting element of the machining tool. Figs. 2 and 3 Figure 5 shows a side view of a mounting area for a cutting element of the cutting tool. Figs. 2 and 3 Figure 6 shows a sectional view along line VI-VI of the Fig. 4 Figure 7 shows a sectional view along line VII-VII of the Fig. 4 Figure 8 shows a sectional view along line VIII-VIII of the Fig. 5 Figure 9 shows a sectional view along line IX-IX of the Fig. 5Figure 10 shows a schematic representation of a further embodiment of a cutting tool according to the invention; Figure 11 shows a schematic representation of a further embodiment of a further cutting tool according to the invention; and Figure 12 shows a flowchart of a cutting process according to the invention.

[0058] In Fig. 1 A tool arrangement for machining is shown schematically and is generally designated by 10. The tool arrangement 10 serves to carry out a machining process on a workpiece 12, which is clamped on a workpiece clamping device 14 that can be driven to rotate about a rotary axis 18 by means of a motor 16.

[0059] The tool arrangement 10 includes a cutting tool 20, which in this case is a turning tool. The cutting tool 20 is clamped in a workpiece clamping device 22, which can be moved in one or more dimensions relative to the rotating workpiece 12 by means of an actuator 24 in order to carry out the machining or turning process.

[0060] The cutting tool 20 comprises a tool holder 28 and a cutting element 30. The cutting element 30 can be designed as a cutting insert, in particular as an indexable insert. The cutting element 30 is detachably connected to the tool holder by means of a fastening device 32. In this case, the fastening device 32 is formed by a clamp 34, which presses the cutting element 30 against the tool holder 28 by means of a screw 36 that is screwed into a threaded bore in the tool holder 28.

[0061] The tool holder 28 has a holder base 38 on which a tool holder shank 40 can be formed. The tool holder shank 40 is clamped in the workpiece clamping device 22, for example by a shrink clamping mechanism.

[0062] At the holder base 38, at an axial end opposite the tool holder shank 40, a cutting element seat 42 is formed into which the cutting element 40 is inserted. The cutting element seat 42 has a seating surface 44, which is designed as a flat seating surface. The cutting element 30 is placed onto the flat seating surface 44 and then clamped from the side opposite the seating surface 44 by means of the fastening device 32, i.e., pressed against the seating surface 44. The cutting element 30 has a cutting edge 46 in a manner known per se, which engages the workpiece 12 during the machining process. The cutting element 30 preferably has a geometrically defined cutting edge 46.

[0063] The cutting tool 20 further includes a cooling device 50. The cooling device 50 includes a heat exchanger 52, which has a heat exchanger housing 54. The heat exchanger housing 54 is designed as an elongated, preferably cylindrical housing and is aligned along a longitudinal axis 55.

[0064] The heat exchanger 52 is part of a closed coolant circuit 56 of the cooling device 50, in which a refrigerant circulates. Coolant 58 is supplied to the heat exchanger 52. Coolant heated in the heat exchanger 52 is discharged from the heat exchanger 52, as shown at 60, and then cooled again to a lower temperature before being supplied to the heat exchanger at 58 at this even lower temperature.

[0065] The heat exchanger 52 is mounted in a heat exchanger receptacle 62 of the tool holder 28. The heat exchanger receptacle 62 can, for example, be a bore into which the heat exchanger housing 54 is inserted along the longitudinal axis 55.

[0066] The heat exchanger housing 54 has an end face 64 which is located in the area of ​​the cutting element seat 42 within the tool holder 28. The end face 64 is preferably the coldest surface of the heat exchanger 52, since the coolant 58 is preferably directed onto the end face 64 and / or evaporates there.

[0067] A heat-conducting element 66 is integrated into the tool holder 28. The heat-conducting element 66 is arranged in the tool holder 28 such that it extends between the heat exchanger 52 and the cutting element seat 42. Preferably, the heat-conducting element 66 forms at least a part of the seat surface 44. The heat-conducting element 66 can, for example, be substantially cylindrical, with a longitudinal axis 68 oriented transversely to the seat surface 44 and preferably also transversely to the longitudinal axis 55 of the heat exchanger housing 54. The heat exchanger housing 54 is preferably arranged with respect to the heat-conducting element 66 such that the end face 64 contacts the heat-conducting element 66 or is recessed in the heat-conducting element 66. For this purpose, the heat-conducting element 66 can, for example, form part of the heat exchanger receiving bore 62.

[0068] The heat conducting element 66 is preferably made of a material that has a higher conductivity than the material of the tool holder 28 in the area of ​​the cutting element seat 42.

[0069] The cutting tool 20 further includes a temperature sensor 70 for detecting the temperature of the cutting element 30. In this case, this temperature sensor 70 is mounted in an unspecified receptacle, in particular a bore, in the clamp 34 of the fastening device 32 and can, for example, be formed by a thermocouple. The temperature sensor 70 provides a temperature signal T, which is made available to a control unit 72 (at A).

[0070] The control unit 72 is designed to perform a refrigeration control, as schematically indicated in 74.

[0071] The closed coolant circuit 56 is designed in the manner of a coolant circuit and includes a compressor 76 to which the heated coolant 60 is supplied. The compressor 76 (for example, a compressor) is connected in a manner known per se to a condenser 78, the outlet of which is in turn connected via a throttle 80 to a supply of coolant 58 to the heat exchanger 52.

[0072] Instead of such a coolant circuit, a conventional coolant circuit can also be used, in which the heated coolant 60 is fed to a radiator. However, the coolant circuit shown can provide very high cooling capacities and coolant at temperatures below the freezing point of water.

[0073] During a machining process, the temperature T of the cutting element 30 is measured, and the controller 72 regulates the closed coolant circuit 56 so that the temperature of the cutting element 30 remains below a predetermined limit. By coupling the heat exchanger 52 to the cutting element 30 via the heat conduction element 66, the machining heat generated in the area of ​​the cutting element 30 can be efficiently dissipated, thus preventing excessively high temperatures during the machining process.

[0074] The control unit 72 can also be used for actuator control, as shown in Figure 82, in which case it is connected to the actuator 24. The control unit 72 can also be configured to control the motor 16, as shown in Figure 82. Fig. 1 however, it is not described in more detail.

[0075] The cutting tool 20 further includes a cutting element heating device 86. The cutting element heating device 86 is received in a heating device receptacle 87 of the tool holder 28. The cutting element heating device 86 is also arranged near the cutting element 30 within the tool holder 28 and can also be coupled to the heat-conducting element 66, but can also be decoupled from it, as shown in Fig. 1 The cutting element heating device 86 is connected to a heating current source 88, which provides a heating current i H. The cutting element heating device 86 is preferably an electric heating device in which electric current is converted into heat.

[0076] The heating power source 88 is connected to the control unit 72 via a heating control 90.

[0077] The heating element 86 makes it possible to regulate the temperature of the cutting element 30, in particular to maintain it within a predetermined target temperature range. The cooling device 50 is preferably used to set a temperature in the lower part of the target temperature range or even below. The cooling device 50 is generally relatively slow to respond. However, the heating element 86 can be switched on and off or regulated very quickly. Therefore, the heating control 90 is preferably used here to quickly set the temperature and maintain it within the target temperature range.

[0078] In this way it is possible to carry out machining processes that do not exceed certain temperatures, such as temperatures that could lead to diffusion of cutting material into the workpiece or the like.

[0079] Figure 94 shows that an additional heating device in the form of a holder base heating device 94 can optionally be integrated into the tool holder 28, which is heated by a corresponding heating current i HS. Such a holder base heating device 94 is preferably arranged in a clamping area of ​​the tool holder 28, particularly in the area of ​​the tool holder shank 40. If the cooling device 50 cools the tool holder 28 too much, the clamping of the tool holder shank 40 by means of the workpiece clamping device 22 can loosen, especially if this is implemented as a shrink clamping device. The holder base heating device 94 can raise the temperature in the area of ​​the tool holder shank 40 sufficiently to ensure secure clamping.

[0080] in the Figs. 2 to 9A further embodiment of a cutting tool 20' is shown, which in terms of design and function is generally similar to the cutting tool 20 of Fig. 1 This corresponds to the system. Identical elements are therefore identified by the same reference symbols. The differences are explained below.

[0081] As it is in the Figs. 2 and 3As shown, in the cutting tool 20, the heat exchanger receptacle 62 and the heating element receptacle 87 are each formed by bores oriented transversely to a longitudinal axis of the toolholder shank 40. The heat exchanger receptacle 62 is designed as a blind bore, whereas the heating element receptacle 87 is oriented as a through bore. The receptacles 62 and 87 are preferably oriented approximately parallel to the seat surface 44. The heat exchanger receptacle 62 is oriented transversely to the longitudinal axis of the toolholder shank 40 between the cutting element seat 42 and the heating element receptacle.

[0082] In Fig. 3 It can be seen that the heat exchanger receiving bore 62 has a vent opening 98 in the area of ​​its bottom, which is located approximately below the seat surface 44.

[0083] The heat exchanger housing 54 is inserted into the heat exchanger receiving bore 62 along its longitudinal axis 55, with a warm conductive paste optionally placed between them. This can seal the circumferential area, so that the formation of an air bubble in the area of ​​the blind bore 62 can be prevented through the vent opening 98.

[0084] The figures also show a temperature sensor bore 100 in the claw 34 at 100, which is best located in Fig. 7 The temperature sensor bore 100 extends as a through-bore through a front part of the claw and is preferably inclined to a surface of the cutting element 30 on which the claw 34 engages.

[0085] In Fig. 6 It can be seen that the heat exchanger receiving bore 62 extends into the heat conducting element 66 in order to achieve the largest possible heat transfer surface.

[0086] In the Figs. 10 and 11 Further embodiments of cutting tools are shown schematically, which in terms of structure and function are generally similar to cutting tool 20. Fig. 1 They correspond. Identical elements are therefore identified by the same reference symbols. The differences are explained below.

[0087] At the in Fig. 10In the cutting tool 20" shown, a heat exchanger receiving bore 62 is generally oriented perpendicular to the seat surface 44. The heat-conducting element 66 can, for example, be formed by a disk or plate arranged between the end face 64 and the seat surface 44. However, even in this case, a heat-conducting element 66 is preferably provided in between, since in this way the seat surface 44 can be at least partially formed by the heat-conducting element 66 and, furthermore, direct contact between the heat exchanger housing 54 and the cutting element 30 can be avoided, thus better protecting the heat exchanger housing 54.

[0088] In Fig. 10It can further be seen that the heat exchanger 52 can be designed such that it has a coolant circuit 104 extending centrally into the heat exchanger housing 54, which terminates shortly before the end face 64, so that the coolant can be directed onto the end face 64. Furthermore, the heat exchanger 52 includes a return flow channel 106 arranged concentrically around the coolant circuit 104, through which the heated coolant can be discharged, as shown in Figure 60. Such a heat exchanger design can also be used in the preceding or subsequent embodiments.

[0089] In Fig. 11A cutting tool 20 is shown in which an insulating section 108 made of a heat-insulating material, such as ceramic, is arranged around the heat exchanger receptacle 62. This is intended to ensure that the tool holder 28 is cooled as concentratedly as possible, or exclusively, in the area of ​​the cutting element seat. In other words, this measure can be provided in addition to or supplementing a holder base heating device 94. The insulating section 108 can prevent the tool holder 28 from becoming too cold in the area of ​​its tool holder shank, which could lead to the clamping mechanism loosening.

[0090] In Fig. 12 A schematic representation of a method for temperature control of a cutting element during a machining process is shown.

[0091] The process begins with step S1 and then proceeds to a query S2, which checks whether the temperature T of the cutting element is greater than a first predetermined temperature T1. If this is the case (Y), the process proceeds to step S3, in which coolant 52 is supplied to the heat exchanger, i.e., cooling takes place (C).

[0092] If, however, the temperature T in query S2 is less than or equal to T1, the procedure proceeds to step S4, in which it is checked whether the temperature is less than a second predetermined temperature T2. If this is the case, i.e., the temperature of the cutting element is too low, the procedure proceeds at Y to step S5, in which the cutting element 30 is heated by means of the heating device 86.

[0093] Provided the temperature is neither too high nor too low, the process either returns to the starting point and a query is made again at S2.

Claims

1. Cutting tool (20) comprising a tool holder (28) and a cutting element (30), which is connected to the tool holder (28), and a cooling device for cooling the cutting element (30), wherein the cooling device (50) comprises a closed coolant circuit (56) comprising a heat exchanger (52) to which coolant (58) is supplied and from which heated coolant (60) is discharged, a heat conducting element (66) is inserted into the tool holder (28), and wherein a control system is provided for controlling the temperature of the cutting element (30) to the target temperature range and a pyrometer or a thermocouple (70) is provided for measuring the temperature of the cutting element (30), the cooling device (50) and a cutting element heating device (86) are integrated into the tool holder (28) in such a way that it is possible to control the temperature of the cutting element (30) to a set temperature range, characterized in that the closed cooling circuit contains a refrigeration machine, the heat exchanger (52) has a heat exchanger housing (54), which is inserted into a heat exchanger receptacle (62) of the tool holder (28), in which the coolant (58) in the form of a refrigerant can evaporate, and from which the coolant (58) can be discharged in vapor form, the heat conducting element (66) is not designed as a heat pipe and extends between the cutting element (30) and the heat exchanger housing (54).

2. Cutting tool according to claim 1, characterized in that the cutting element heating device (86) is accommodated in a heating device receptacle (87) of the tool holder (28).

3. Cutting tool according to claim 1 or 2, characterized in that the cutting element heating device (86) is connected to a heating current source (88) via which a heating current can be provided.

4. Cutting tool according to claim 3, characterized in that the heating current source (88) is connected to a control device (72) via a heating control (90).

5. Cutting tool according to claim 1, characterized in that the tool holder (28) has a holder base (38) and a cutting element seat (42) for the cutting element (30) which is spaced apart from the holder base (38), a holder base heating device (94) being integrated in the holder base (38).

6. Method for controlling the temperature of a cutting element (30) which is connected to a tool holder (28), comprising the steps: providing a cutting tool (20) according to any one of claims 1 to 5; machining of a workpiece (12) by means of the cutting tool (20); and influencing the temperature of the cutting element (30) using the cooling device (50), wherein the temperature of the cutting element (30) is controlled to a target temperature range using the cooling device (50) and a cutting element heating device (86).

7. Method according to claim 6, wherein the target temperature range covers a temperature range of at most 100°C.

8. Method according to claim 7, wherein the target temperature range covers a temperature range of at most 50°C.

9. Method according to claim 6, wherein the target temperature range lies within a range of 1 / 5 to 1 / 20 of a target temperature aimed at for a specific machining process.

10. Method according to claim 6, wherein a cooling power of the cooling device (50) is kept constant for a predetermined period of time, wherein the temperature is controlled by adjusting the heating power of the cutting element heating device (86).