JP5128646B2 - Shrink fit device for tool holder - Google Patents

Description

  The present invention relates to a shrinking arrangement for at least one tool holder for press-fitting a rotary tool into a central receiving opening.

  In order to be able to insert or remove the shank of the rotary tool, for example by heating the shank of the rotary tool, such as a drill bit or a milling cutter, in its own area. Tool holders that press fit into the central receiving opening to be widened are known from WO94 / 07646A1 or EP0830917A1 or DE29820838U1. A gas flame or electric heat-resistant collar that can be brought into abutting contact with the tool holder can serve as a heat source. A particularly suitable induction coil is supplied with alternating current or pulsed current and is located in the middle of the area of the tool holder to be heated. The transducer attracts eddy currents into the tool holder. Such an induction heating device has the advantage that the tool holder need not be in contact with the coil for the heating operation.

  In order to perform the thermal expansion at a sufficiently high level, the tool holder should be heated to a few 100 ° C, for example from 250 ° C to 350 ° C. In the case of a sufficiently powerful heating device, the heating phase of the shrink-fit operation can be kept relatively short, thereby avoiding other overheating of the work holder or tool. However, with conventional shrink fit devices, the tool holder cooling phase is relatively long. It is therefore well known to position the cooling body on the tool holder and to expose the cooling body to the air flow created by the fan to accelerate cooling. Despite air cooling, the cooling phase of the shrink fit operation still continues for several minutes.

International Publication No. 94/07646 Pamphlet European Patent Application Publication No. 0830917 German utility model No. 29820838 specification

  The object of the present invention is to describe a method by which the shrink-fitting time of a shrink-fitting device of the type described above can be greatly reduced.

  To achieve this object, the present invention is specially configured as an induction heating device and is press-fitted into a central receiving opening having a heating device intended to thermally expand the tool holder in the receiving opening region. Based on shrink fit device for at least one tool holder to hold. The invention is provided with a cooling device comprising at least one cooling collar through which liquid refrigerant can flow to cool the receiving opening area of the tool holder and which can be positioned on the tool holder. Such cooling collars are much smaller than conventional cooling bodies used for air cooling and reduce the cooling time to a fraction of a fraction, for example 30 seconds, in view of the high heat absorption capability of the liquid refrigerant. The operating speed at which the tool can be inserted into or removed from the tool holder can thus be very fast compared to conventional shrink-fitting devices.

  Water is sufficient as a liquid refrigerant. In the simplest case, the cooling collar can be connected to the water distribution line of the building. In order to operate the device independently of the building's distribution pipe connection, the cooling device preferably still comprises a cooling subassembly that directs the liquid refrigerant to the closed cooling circuit via one or more cooling collars.

  In order to be useful for the operational purpose of cooling different tool holder diameter collars or to be able to cool multiple tool holders in overlapping time, the shrink fit device includes Conveniently, multiple cooling colors are assigned. Although the cooling collar can be connected in parallel to the liquid refrigerant circuit, the cooling collar is placed in series in the cooling circuit back and forth so that the supply lines required for connection purposes can be reduced as a result.

  The cooling collar may be provided in a stationary manner on the shrink fit device. However, it is advantageous if these collars are free to move when connected to a flexible tube that facilitates handling. The cooling collar can be positioned on the heated tool holder without having to remove the tool holder from its mounting. The tool holder is heated in its own mounting, as is necessary in the case of a conventional shrink fit tool with air cooling.

  In a preferred configuration, the shrink-fitting device comprises a plurality of mounts for tool holders, in particular comprising a turret plate which can rotate around a vertical axis of rotation and which can be moved relative to each other through the working area of the heating and cooling devices. Is provided. Each of the tool holders is held on one of a plurality of mounts. One or more cooling collars may be coupled to a flexible liquid refrigerant tube. As a result, the tool holder can follow the rotational movement of the turret plate. Without having to remove the heated tool holder from these mounts, the time for the heated tool holder to cool can already be used to heat the next tool holder.

  The turret plate is provided with a rotational direction locking device which prevents a rotational movement in a rotational direction from a region of the heating device which is predetermined, in particular in the working side direction of the shrink fitting device. In this way, the heated tool holder can only move away from the operator, which reduces the risk of injury.

  The turret plate mount may be rigidly connected to the turret plate for operational purposes. Alternatively, the turret plate is provided with guiding or fixing means in which the tool holder mounts are respectively held so that the tool holder can be exchanged for operating purposes. In order to make it easier to exchange a plurality of mounts, it is advantageous to provide a hub with a plurality of receiving bodies that are substantially central to the rotation axis of the turret plate and that constitute the mounts. . The tool holder is held on the hub with play and is guided by the turret plate guide device. In this way, the entire mount of the turret plate can be exchanged in one operation. The play of the receiving body ensures that the tool holder does not become clogged in the guide, taking into account thermal expansion.

  In a relatively simple configuration that can nevertheless operate straight and effectively, the heating device comprises an induction coil unit, which can move with its coil axis vertical, and For example, it is connected to an induction coil generator fixed to a support via a flexible cable. A contact switch that can be manually operated is arranged on the induction coil unit. With this contact switch, the supply of the induction current to the induction coil unit is switched on and off in a freely selectable manner for at least a limited time. For this purpose, the tool holder is arranged with its axis vertical, so that the tool can penetrate into the receiving opening, either taking into account its own weight or with manual assistance. . Thus, the tool holder is only heated to the extent that it needs to avoid overheating on its own, or allows a short cooling time on the other hand. However, it goes without saying that induced current generators have predetermined operating time limits to prevent inadvertent overheating damage.

  The induction coil unit can preferably be captured in a selectable vertical position of the guide strut by a capture and clamping device that can be released in a direction opposite to the prestressing direction of the spring. Since the catch-and-clamp device is locked in consideration of the spring force in an inoperative state, accidental release is prevented. For one-handed operation, the capture and clamping device may comprise a handle that is positioned sufficiently close to the contact switch for one-handed operation and configured to release the capture action.

  The cooling collar must meet two requirements. The cooling collar, on the one hand, ensures good heat transfer from the tool holder to the liquid refrigerant, and on the other hand, this cooling despite the predetermined dimensional tolerance of the abutment surface of the tool holder configured for the cooling collar. The collar is often conventional for tool holders, but it must ensure the greatest possible abutting contact that should be accurate even when the abutting surface is more or less conical. The cooling collar includes a sleeve member configured to contact and abut against the tool holder, and has a radially continuous slit extending in the axial direction over the entire length of the sleeve, and the cooling collar is a liquid refrigerant. The cooling collar meets these requirements if it is connected to the walls of the channel or integrally forms the wall or part of the wall of the liquid refrigerant channel.

  A relatively high level of thermal stress can be absorbed when the inner sleeve member configured to abut against the tool holder is generally covered in a radially outwardly sealed manner by the outer sleeve member. A mechanically stable embodiment is obtained. At least one groove is integrally formed in the inner and / or outer sleeve member for the purpose of constituting a liquid refrigerant channel for the reasons described above. It is advantageous to form the grooves in the inner and / or outer sleeve member in a helical configuration that allows a relatively large heat exchange surface. Conveniently, the thickness between adjacent areas of the grooves extending side by side and / or the thickness of the sleeve member in the base region of the groove is smaller than the transverse dimension of the groove in the radial and / or axial direction with respect to the cooling collar. It is. Such a sleeve member is relatively flexible and can adapt itself particularly well to the outer casing of the tool holder. The outer sleeve of the inner sleeve member is preferably provided with a groove, while the outer sleeve member is provided with an inner casing that complements the outer sleeve profile of the inner sleeve member in close proximity. In some cases, such grooves cannot be easily made. Rather, it also has the advantage of extending close to the tool holder that facilitates heat transfer.

  The outer sleeve member may be configured as a substantially cylindrical sleeve closed in a ring configuration. It is therefore easy to make. If the inner sleeve member is flexible, it is sufficient to be easily made possible by a suitable elastic seal between the two sleeve members. The outer sleeve member can be rigid. As a result, it can withstand rough handling during operation.

  In one variation, both the inner and outer sleeve members each comprise a slit aligned with each other that is axially and radially continuous. In order to be accurate even when the inner and outer sleeve members are configured as conical sleeves, such a cooling collar adapts itself to the tool holder contour dimension tolerances. Even in the case of a sleeve member that is relatively easy to bend, it is necessary to apply a stress in advance by a spring means in the circumferential direction in which the slit width or widths of the cooling collar is narrowed in order to securely contact the sleeve member. The description proved convenient.

  As another embodiment of the slit for cooling the collar described above, the collar comprises a plurality of circumferentially adjacent sleeve sections. These sleeve sections are rigidly connected to the walls of the liquid refrigerant channel section and can also form a wall or part of the wall of the liquid refrigerant channel section. The sleeve sections are interconnected in the circumferential direction, and a part of the liquid refrigerant channel sections provided in the individual sleeve sections are connected to each other, in particular in series with each other. A collar divided into such areas can adapt itself particularly well to the circumferential contour of the tool holder. For the elastic connection of the sleeve section, an annular spring is provided that sits in the groove of the sleeve section and at the same time the sleeve sections are fixed together in the axial direction.

  It is also true that, as already described above for the sleeve area of the slit, by means of the sleeve area, each liquid refrigerant channel area can consist of a serpentine tube or a groove formed in the inner or outer sleeve area, for example. Here too, the groove is expediently formed in the inner sleeve area. See the description regarding the contour with the slit sleeve section.

  The induction coil unit of the induction heating device should be shaped so that this induction coil unit concentrates the magnetic field on the tool holder. Conventional induction coil units thus comprise a yoke device which is usually made of a ferromagnetic material. The yoke device extends axially along the outer circumference of the induction coil and radially along at least one of the two axial end faces and ensures that the magnetic field is concentrated inside the induction coil. In order to adapt the induction coil unit to tool holders of different diameters, it is usually possible to replace a part of the yoke device or replace the induction coil unit as a whole. In a preferred configuration of such an induction coil unit, this induction coil unit can be used in shrink-fitting devices other than those described above and thus has a unique inventive significance. If the region of the ferromagnetic yoke member adjacent to and / or away from the tool insertion end comprises a plurality of yoke members made of a ferromagnetic material, these yoke members will extend the inner circumference of the induction coil. Beyond, it projects radially inward and is guided so that it can move relative to each other. The radial protrusion beyond the inner circumference of the induction coil of the yoke member can be changed for replacement purposes. Thus, the opening of the yoke member configured to receive the tool or tool holder may be adapted to the current dimensions of the induction coil or part of this induction coil to be changed. The induction coil unit can thus be used generally.

  The yoke members may be guided so that they move relative to each other or pivot. These yoke members overlap so as to guide the magnetic flux well.

  The yoke members are considered to be individually adjusted in each case. A user-friendly modification is that the yoke member can be adjusted by a common control member. The yoke member can rotate in an equiaxed direction with respect to the induction coil and is connected to the yoke member by a control surface / cam follower. For example, by means of the control member configured as a control plate arranged in a manner perpendicular to the axial direction with respect to the induction coil unit, the inner opening width of the yoke device is currently reduced to the tool holder to be shrink-fitted for operating purposes. Can fit.

  In order to allow the tool for the shrink fit operation to be introduced more easily into the receiving opening of the tool holder, the tool holder thermally expands the tool holder at its receiving opening. It is preferable to provide a width expanding portion that can be inserted in a manner of being positioned at the center before being made. This form of central expansion and width expansion is described, for example, in the publication EP 0 830 917. However, centering and expanding the width should reduce the torque transmitting surface of the receiving opening of the tool holder and therefore provide the shortest possible axial extent. However, if the center position and width expansion are short dimensions, then if the tool is placed in place with its axis tilted, it will clog upon insertion. EP 08301717 therefore proposes an additional introduction aid configured to prevent such axial tilt errors.

  The risk of clogging of the tool in the tool holder when the tool is inserted in an inclined manner is that the receiving opening of the tool holder is radially concentric with the receiving opening at its tool insertion end. An annular bead that protrudes inward, and a cylindrical fastening region that can be expanded by thermal expansion at a predetermined distance in the axial direction from the annular bead and configured for a tool shank. The axial longitudinal cross-sectional shape of the annular bead is separated from the axis of the receiving opening at all positions by a predetermined radial distance greater than the inner diameter of the clamping area. Between the annular bead and the fastening region, a conical transition region is provided that widens in the direction of the annular bead. Such tool holders other than those mentioned above and which can also be used in shrink-fitting devices with this independent importance of the invention are such that the tool shank is introduced into the annular bead with an inclination error. It is guaranteed to be pre-centered on the annular bead to be accurate even at times. The conical transition area provided between the annular bead and the clamping area installs the tool in an upright position when more tool shanks are inserted and accounts for tool tilt errors despite the diameter dimensional tolerances of the tool shank. Match. The axial distance between the positions where the tool shank is adjacent on the one hand to the annular bead and on the other hand to the conical transition region is relatively large in spite of the fact that this total introduction region is relatively small, and the tool Rather than just centering the tool shank against the holder in advance, guide the tool shank without tilting until the clamping area is thermally expanded to a diameter that allows the tool shank to be introduced. Guarantee. The axial extent of the conical transition region herein is advantageously less than 10 times and preferably less than 5 times the axial extent of the annular bead to facilitate the initial introduction of the tool shank. The annular bead preferably has a contour whose longitudinal longitudinal section is in the form of a part of a circle, and the conical transition region is also larger than the minimum inner diameter of the annular bead.

  Exemplary embodiments of the features of the invention are described below with reference to the drawings.

1 is a perspective view showing an exemplary embodiment of a shrink fit device according to the present invention for a shrink fit tool holder of a rotary tool. FIG. It is sectional drawing cut | disconnected through the induction coil unit of the said shrink fitting apparatus seen along line II-II of FIG. It is detail sectional drawing cut | disconnected through the induction coil unit. It is a partial sectional side view of the cooling collar of the shrink fitting device. FIG. 7 is an axial longitudinal sectional view taken through the cooling collar as viewed along line VV in FIG. 6. FIG. 6 is an axial sectional view taken through the cooling collar as viewed along line VI-VI in FIG. 5. It is a perspective view of the deformation | transformation embodiment of the said cooling collar. FIG. 8 is an axial sectional view taken through the cooling collar as viewed along line VIII-VIII in FIG. 7. It is a perspective view which shows the inner sleeve member of the said cooling collar of FIG. FIG. 6 is a partially removed perspective view showing a further alternative embodiment of a cooling collar. FIG. 11 is an axial direction view in which the cooling collar of FIG. 10 is partially removed. FIG. 2 is an axial longitudinal sectional view cut through an induction coil unit that can be used in the shrink-fitting device of FIG. 1 and includes an adjustable yoke device. FIG. 13 is a detailed cross-sectional view cut through the induction coil unit of FIG. 12. It is an axial direction top view of the said induction coil unit of FIG. It is detail drawing of the yoke member of the said induction coil unit of FIG. FIG. 13 is a schematic axial view of a variant embodiment of an adjustable yoke device that can be used in the induction coil unit according to FIG. FIG. 13 is a schematic axial view of a variant embodiment of an adjustable yoke device that can be used in the induction coil unit according to FIG. It is a schematic sectional drawing of the said yoke apparatus seen along line XVIII-XVIII of FIG. FIG. 13 schematically shows a further variant embodiment of an adjustable yoke device that can be used in the induction coil unit of FIG. FIG. 13 schematically shows a further variant embodiment of an adjustable yoke device that can be used in the induction coil unit of FIG. 2 is an axial longitudinal section taken through an exemplary embodiment of a tool holder for a rotating tool that may be used with the shrink fit device of FIG. FIG. 22 is an axial longitudinal sectional view taken through a detailed portion of the tool holder indicated by an arrow XXII in FIG. 21.

  FIG. 1 shows a portable unit type shrink fit device 1 for a tool holder 3 of a rotary tool 5 such as drill bits or milling cutters. Such tool holders, for example as shown in FIG. 21, are in the form of, for example, steep tapered shanks or hollow steep tapered shanks, which allow these rotary tools to be placed in machine tools. A coupling shank 7 that can be clamped in the center of the tool and a centrally and substantially cylindrical receiving opening 11 for the shank 13 of the tool 5, which is axially opposite to the coupling shank 7. A tool receiving area 9 is provided. In the fastening region 12 of the tool holder 3, the inner diameter of the receiving opening 11 is somewhat smaller than the outer diameter of the shank 13. As a result, the receiving area 9 of the tool holder 3 must be heated before the shank 13 of the tool 5 can be guided into the clamping area 12 of the receiving opening 11 taking into account thermal expansion. Once the receiving area 9 is cooled, then the shank 13 is pressed into the tool holder 3 and seated.

  The shrink fitting device 1 (FIG. 1) can heat the receiving area 9 of the tool holder 3 within a few seconds (for example, 10 seconds) and heat the receiving area 9 of the tool holder 3 to a sufficient degree, for example, 300 ° C. Then, it can be cooled to ambient temperature in a relatively short time (eg, 30 seconds).

  In order to heat the receiving area 9, the shrink-fitting device 1 comprises an induction coil unit 15 that is powered by an induction current generator 18 via a flexible cable 17. In the exemplary embodiment shown, the induced current generator 18 generates alternating current or pulsed direct current at a variable frequency between 50 Hz and several kHz, for example 20 kHz, which alternating current or pulsed direct current is induced coil unit 15. Is positioned substantially in the center of the receiving area 9 of the tool holder 3 by the interior 19 of its own induction coil 21, as described in more detail below, induces eddy currents in the metal body of the tool holder 3. And this tool holder is induction-heated. The induced current generator 18 may be configured in a conventional structure and may be provided with a frequency converter, for example, supplied with current from a DC link and capable of adjusting its output and frequency.

  For the shrink-fit operation, the tool holder 3 is described in more detail below, with its axis line vertical and its receiving opening 11 facing upwards, part of which is on the vertical guide column 25. In the opening on the mounting base or receiving body 23 on the turret plate which can be rotated around the vertical axis in order to be accurately aligned axially with the induction coil 21 of the induction coil unit 15 which is guided so that it can be moved manually. Sit down. The induction coil unit 15, on the other hand, facilitates handling of the induction coil unit 15 during the vertical adjustment movement as shown in FIG. 2, and on the other hand, the friction of the induction coil unit 15 that is automatically fixed when stationary. A handle 27 is provided to allow the capture device to be released. For this purpose, the handle 27 is a spring that is fixed on the pin 31 and supported on the induction coil unit 15 so that it can tilt about a pivot axis that extends transversely to the guide column 25. A stress is applied in advance to the guide column 25 overlapping the handle 27 by 33. In the overlap region, the handle 27 carries the friction member 35. When the handle 27 is tilted against pre-stressing of the spring 33, the friction member 35 is then lifted from the guide column 25 and the induction coil unit 15 can move along the guide column 15. . The handle 27 enables both the movement operation of the induction coil unit 15 and the release of the clamping capture device 29 with one hand. For easier handling, the top end of the guide post 25 is provided with a cable winding drum (not specifically shown) comprising a cable guided in the winding direction along the guide post 25 to the induction coil unit 15. A driving spring motor (FIG. 1) is arranged. The spring motor 37 at least partially balances the weight of the induction coil unit 15.

  As shown in FIGS. 2 and 3, the induction coil unit is held on the guide column 25 so that the induction coil unit 15 can be removed for operating purposes. As a result, the induced current generator 18 can be coupled to different induction coil units 15. A handle 27 including a locking catch device 29 is attached to a carriage 41 that can be moved by ball bearings along a guide post 25 and guided so that it can be moved by a dovetail guide rail 43 that extends across the guide rail 25. The coil unit 15 is fixed. The capture pin 47 guided in the carriage so that the supplemental pin 47 can move in the opposite direction of the spring 45 is guided on the carriage 41 by releasably engaging inwardly from the latching cutout of the induction coil unit. The coil unit 15 is fixed.

  For the heating operation, the tool holder 3 is inserted into the receiving body 23 of the turret plate 24 and the induction coil unit 15 is lowered from the raised position shown in FIG. 1 until the induction coil 21 surrounds the receiving area 9. The By pushing a contact switch 46 disposed on the induction coil unit 15 sufficiently close to the handle 27 for one-hand operation, an induction current is supplied to the induction coil 21 displayed by the display lamp 48, and the current is similarly supplied. It is arranged on the induction coil unit 15 during the flowing period. An induced current flows during a freely selectable operating period of the switch 46. In order to prevent damage to the tool or tool holder due to unintentional overheating, the current generator 18 subsequently cuts off the current for a predetermined period of time. The operator of the shrink-fitting device 1 will only contact the switch until such time that the tool 5 sinks into the vertically oriented receiving opening 11 of the tool holder 3, either with its cooperation or with some manual assistance. 46 is activated. Immediately thereafter, the induced current can be cut off and unnecessary heating of the tool holder 3 can be prevented.

  In order to eliminate the need to remove the tool holder 3 from the receiving body 23 for the subsequent cooling stage, a part of the receiving body 23 is arranged on the turret plate 24 and seated in the turret plate and the receiving body 23. The receiving body together with the tool holder 3 is in a state in which the cooling collar 53 supplied with the liquid refrigerant from the cooling subassembly 51 through the tube 50 which is easily bent is in contact with the surface area on the receiving area 9 of the tool holder 3. It is positioned with. Cooling of the cooling collar 53 by the liquid refrigerant circulating in the closed circuit through the cooling collar 53 and the cooling subassembly 51 through contact of the surface area of the inner casing of the cooling collar 53 with the outer casing of the receiving area 9 of the tool holder 3. Ensures that the tool holder 3 is cooled very rapidly to ambient temperature. In order to avoid burning the seated tool holder to several hundred degrees, the turret plate is provided with a catch that operates depending on the direction of rotation, and this turret plate can only rotate in the direction indicated by arrow 54 To. By this rotation, the tool holder 3 is moved away from the shrink fitting device 1 side and moved from the heating position directly below the induction coil unit 15 to a position intended to position the cooling collar 53.

  As shown in FIG. 1, two or more turret plates 24 distributed over the outer periphery of the turret plate 24 carry three receiving bodies 23 in this embodiment, and cooling sub-assemblies 51 simultaneously include a plurality of cooling collars. 53 is supplied. This allows multiple tool holders to be cooled at the same time without induction heating resulting in blocking the passage of the tool holder. The cooling collar 53 includes a small hole 55 by which the cooling collar is suspended in a manner that allows the cooling collar to be detached from the holding wall 57 of the shrink fitting device 1. Furthermore, slots 59 are provided in the holding wall, and the liquid refrigerant tube 50 of the cooling collar 53 is movable in the longitudinal direction in these slots and is guided in order.

  The cooling collar 53 can have different inner diameters and different shapes depending on the tool holder 3 to be cooled. However, if only one and the same type of tool holder is shrink fitted, the cooling collar can be the same size. The receiving body can also be held on the turret plate 24 in a removable manner. In the exemplary embodiment shown, three receiving bodies 23 are fixed with play on a common hub 61 so that these groups of receiving bodies 23 can be exchanged as one unit. The play of the fastened hub prevents the receiving body 23 from failing in the central ring 63 provided for receiving the receiving body 23 on the turret plate 24.

  The cooling subassembly 51 is preferably a subassembly that operates according to the principle of a heat pump, although other cooling subassemblies are suitable. The individual cooling collars 53 can be connected to the cooling subassembly in parallel to each other and can preferably be individually switched on / off. In the illustrated embodiment, the cooling subassemblies are connected in series to a common cooling circuit and are cooled by the liquid refrigerant whether or not these cooling subassemblies are used.

  4 to 6 show details of the cooling collar 53. FIG. The cooling collar 53 comprises two sleeves 67, 69, one inner surface of which is arranged in a coaxial relationship with the other inner surface, and the outer sleeve members 69 of these sleeves are closed in a relatively thick wall and thus in an annular form. Is configured as a mechanically stable cylindrical tube section and comprises a cylindrical inner casing surface 71. The inner sleeve member 67 has a slit 73 continuous in both the axial direction and the radial direction in its own tube wall, and a protruding portion whose own cylindrical outer peripheral surface 75 is adjacent to the inner casing surface 71 of the outer sleeve member 69. Is provided. The inner casing surface 72 of the inner sleeve member 67 is adapted to be mounted close to the dimensions corresponding to the clamping or receiving area 9 of the tool holder 3 to be cooled with respect to its open width and its cone angle. As a result, with the cooling collar positioned on the tool holder 3, the inner sleeve member 67 directly contacts and contacts the tool holder over the largest possible surface area. In order to prevent the inner sleeve member 67 from failing on the tool holder 3 and to adapt the shape of the abutment surfaces of the inner sleeve member 67 and the tool holder, the wall of the inner sleeve member 67 is radial. And a slit 73 continuous in both the axial direction and extending in the axial direction.

  The outer casing 75 of the inner sleeve member 67 includes a serpentine groove 77 that does not overlap the slit 73 and terminates in a connection opening for the cooling tube 49. This connection opening penetrates the outer sleeve member 69 (FIG. 1). This groove 77 together with the inner casing 71 of the outer sleeve member 69 forms a liquid refrigerant channel in the cooling collar 53. The region of the outer casing surface 75 of the inner sleeve member 67 that is entirely covered by the groove 77 is closed in an annular form and is circumferentially along the axial ends of the inner sleeve member 67 and the axial directions of both sides of the slit 73. Is entirely covered by a sealing ring 81 extending to The sealing ring 81 accurately seals the region of the groove 77 outward so that it can be deformed with some radial expansion to compensate for the dimensional tolerances of the conical inner casing surface 72 relative to the tool holder 3. . In order to ensure sufficient elasticity of the inner sleeve member 67, the distance between the base of the groove 77 and the inner casing surface 72 is substantially constant and relatively small over the length of the groove 77. The radius and axial dimension of the groove cross section of this embodiment, on the other hand, is larger than the solid area between adjacent areas of the groove 77 and the radial thickness of the sleeve cross section of the groove base area.

  In the following, modifications of the cooling collar that can be used in the shrink fitting apparatus of FIG. 1 in place of the cooling collars of FIGS. 4 to 6 will be described. Equivalent members are provided with reference numerals from FIGS. 4 to 6 and are provided with letters for different purposes. For a description of the structure and function, reference should be made in particular to each successive description of FIGS.

  Although the outer sleeve member 69 of the exemplary embodiment of FIGS. 4 to 6 is cylindrical and has no slits, the outer sleeve member 69a of the cooling collar 53a shown in FIGS. 7 to 9 is a conical sleeve. Thus, the inner sleeve member 67a comprises a conical outer casing 75a. Next, the inner sleeve member 67a includes a slit 73a that is continuous in the axial direction and the radial direction and extends in the axial direction. In alignment with the slit 73a, the outer sleeve 69a is provided with a slit 83 that is continuous with the slit 73a in the axial direction and in the radial direction so that the expansion of the cooling collar 53a can be compensated. The pre-stressed spring 84 acts on the outer sleeve member 69a across the slit 83 and pre-stresss the slit boundary relative to each other. The prestressed springs 84 can be mounted on the outer sleeve member 69a by the ends of these springs. However, it is also possible to configure the spring as an annular spring that closes in the form of a ring and to surround the sleeve member 69a.

  The cooling collar described above is constituted by a sleeve member that extends into a piece over the entire outer periphery, suitably away from the expansion slit. FIGS. 11 and 11 show a variation of the cooling collar comprising a plurality, four in this embodiment, each self-contained color area 85 where each color area forms a color channel region. Each of the collar sections 85 comprises an inner sleeve section 67b bounded by a circumferential end wall 87, and an outer sleeve section 69b whose own inner casing 71b is adapted to the outer casing 75b of the inner sleeve section 67b. A serpentine groove 77b is then formed in the outer casing 75b of the inner sleeve section 67b to form a liquid refrigerant channel that is blocked by the outer sleeve section 69b. At both ends of the groove is for a liquid refrigerant tube 50 or other similar flexible tube 89 that connects the liquid refrigerant area of one sleeve area 85 to the liquid refrigerant channel area of the circumferentially adjacent sleeve area 85. A connection opening 79b is provided that extends through the outer sleeve section 69b. Each of the sleeve sections 85 of this embodiment is itself sealed by a sealing ring 81b, as described above for the sealing ring 81.

  In the illustrated exemplary embodiment, the outer sleeve section 69b is configured as a section of a cylindrical tube, so that the inner sleeve section 67b comprises an outer contour in the form of a cylindrical section, while the inner casing 72b is tool holding. It is adapted to the outer contour of the implement, for example a conical shape. Needless to say, the outer sleeve section 69b can also be constructed from a conical profile as shown in FIG.

  The sleeve section 85 is held together in a radially elastic manner on both sides of the cooling collar 53b as shown axially by a single annular spring 91 surrounding the end extension of the inner sleeve section 67b. The annular spring 91 may suitably be held on the outer sleeve 69b. The annular spring 91 of this embodiment is seated over at least half the helical diameter of these annular springs with a small amount of play in the groove 92 of the extension. The grooves are circumferentially aligned with each other and at the same time the sleeve sections 85 are axially oriented and secured relative to each other.

  12 to 15 show details of the induction coil unit 15. The induction coil unit 15 carries the wire winding 99 of the induction coil 21 in the cylindrical receiving opening 93 of the base body 95 made of a nonmagnetic material. This wire winding is wound around the coil body 97. A yoke device 101 made of a ferromagnetic material, for example ferrite, is placed outside the winding 99 in order to concentrate the magnetic field on the tool holder which is to be introduced into the winding 99 and to be induction-heated. Be placed. The yoke device 101 includes an axial yoke member 103 that surrounds the outer periphery of the sleeve-shaped winding 99, and is suitably composed of a plurality of spaced plates and has a radius beyond both ends of the winding 99 in the axial direction. Coupled by a yoke member 105 engaging in the direction. The yoke member 105 is configured as an annular disk or other similar material as a spaced-apart plate.

  The inner diameter of the opening 19 is shaped for the maximum diameter of the tool holder to be heated. In order to obtain a sufficiently large induced current even when the winding 99 is separated from the tool holder by a relatively large radial distance, it projects radially into the opening 19 through the inner circumference of the winding 99, A pole piece device 107 with a variable inner diameter, which can be adapted in a selectable manner to the outer diameter of the tool holder for operating purposes, is seated on at least one axial end of the winding 99. A radial protrusion 111 (FIG. 13), preferably made of a ferromagnetic material such as a ferrite material, preferably also overlapping in the circumferential direction, distributed in the circumferential direction of the winding 99 and fixed in the base body 95. The pole piece device 107 comprises a number of preferably circumferentially overlapping yoke devices 109, each of which is guided separately, so that it can be moved radially in the upper direction. Furthermore, the control plate 113 is guided on the base body 95, so that the control plate can rotate equiaxially with respect to the induction coil 21, extends obliquely with respect to the circumferential direction, and the yoke member 109. And a control slot 115 that engages a cam follower pin 117 projecting from the yoke member 109. As the control plate 113 rotates, the yoke member 109 can move radially coupled into the opening 19 or can be withdrawn from the opening. Thus, the inner diameter of the pole piece device 107 can be changed for operational purposes by rotating the control plate 113.

  In a considerable number of embodiments, this pole piece device can now overlap the end side of the tool holder, so that a pole piece device 107 of the type described is arranged on the top side of the induction coil 21. Is enough. 107 ′ shows a further pole piece device on the underside of the induction coil 21, which allows it to be provided in addition to the pole piece device 107 or as another alternative. If the pole piece device 107 or 107 ′ is provided at both ends in the axial direction of the winding 99, the radial yoke member 105 can be distributed to both ends in the axial direction.

  Various aspects of the pole piece device that can be used in the induction coil unit 15 of FIGS. 12 to 15 will be described below. Equivalent members are indicated by the above-mentioned notation and are marked with letters for the purpose of representing differences. See above for a description of structure and function.

  In the case of the pole piece device of FIGS. 12 to 15, these yoke members are guided so that they can move radially on the base body of the induction coil unit. 16 to 18 show a modification in which a plurality of disc-shaped yoke members 109c are attached to the base body 95. FIG. These yoke members can be rotated eccentrically with respect to the center of the disk of these yoke members on the protruding portion 119 extending parallel to the coil axis. Here again, the yoke member 109c can be coupled to and rotated in the opening 19 of the induction coil unit by the control plate 113c that can rotate in the center with respect to the coil axis, or can be rotated out of this opening. The variable pole piece device 107c to be obtained is configured. For this purpose, the control member 109c is then provided with a central cam follower projection 117c guided into a slot 115c extending obliquely with respect to the circumferential direction of the control plate 113c. FIG. 16 shows the yoke member 109c at a position away from the coil axis in this embodiment, while FIG. 17 shows the position where these yoke members are close to the coil axis.

  In the embodiment shown in FIGS. 16 to 18, the yoke member has a disk shape. 19 and 20 show a modification that is elongate and attached to its end remote from the induction coil axis so that these yoke members can be rotated in the end face of the induction coil 21 by means of the engagement pin 119d. . The yoke member 109d also carries a cam follower protrusion 117d that engages in a slot 115d that extends obliquely with respect to the circumferential direction of the common control plate. FIG. 19 shows the yoke member 109d located away from the coil axis. FIG. 20 shows the yoke member in a position close to the coil axis.

  In the shrink-fitting device according to FIG. 1, as soon as the receiving opening 11 expands to a sufficient extent due to heat, the tool 5 to be inserted into the tool holder 3 receives the receiving opening from above with its own shank vertical. 11 is inserted. As shown in FIGS. 21 and 22, the introduction area 121 of the receiving opening 11 has its smallest diameter larger than the diameter of the receiving opening 11 and slightly larger than the outer diameter of the tool shank 13 to be inserted into the receiving opening 11. Provided at the tool introduction end. Therefore, even if the tool holder 3 is not yet thermally expanded, the tool shank 13 can be inserted into the introduction region 9 that is pre-centered with respect to the receiving opening 11 by its shank bottom end.

  The device is configured to achieve a situation in which the tool shank 13 is free of faults, i.e. the tool shank is automatically held in the receiving area 11 which is continuously thermally expanded and held upright in the introduction region 121. In this case, the introduction area 121 must have a predetermined minimum length in the axial direction. On the other hand, the introduction area 121 reduces the torque transmitting surface area of the receiving opening 11 and thus the torque that can be transmitted by the tool holder, so that this introduction part should not be too long. The unsupported length of the tool holder 3 increases as a result and the extension of the receiving opening 11 cannot always be achieved since the tool can prevent vibration during operation.

  FIG. 22 not only greatly facilitates the introduction of the shank 13 with the relatively short axial length introduction region 121, but also substantially reduces the shank 13 of the tool 5 despite the short axial length. It can be centered with respect to the receiving opening 11 in a non-tilted manner. For this purpose, the introduction region 121 is provided at the insertion end of the introduction region 121 with a surrounding annular bead 123 with a cross-sectional profile in the form of a part of a circle in the longitudinal section of the tool holder 3 in the axial direction. The radial distance between the annular bead 123 and the axis of rotation of the tool holder 3 is greater than the radius 127 of the receiving opening 11 at all points of the annular bead 123 and thus greater than the radius of the tool shank 13. A conical transition between the annular bead 123 and the end of the receiving opening 11 proximate to the insertion opening substantially directly coupled to one side of the receiving opening 11 on the other side and the annular bead 123 of the clamping region 12 The area extends. Accordingly, the minimum diameter of the transition region 129 corresponds to the diameter of the receiving opening 11. The maximum diameter of the transition region 129 is larger than the inner diameter of the annular bead 123.

  Since the annular bead 123 has a contour in the form of a circular portion but is at least convex, it is possible to insert the tool shank 13 at least initially with a relatively large inclination error with respect to the axis of the tool holder 3. To. The tool shank is placed in an upright position that subsequently contacts the conical transition region 129. The conical transition region comprises an axial extension which is less than 10 times, preferably less than 5 times, and this axial extension is that of the annular bead 123. Although the axial length of the introduction region 121 can be kept short as described above, the guide length at which the tool shank 13 is installed in the upright position is sufficiently long.

DESCRIPTION OF SYMBOLS 1 Shrink fitting apparatus, 3 Tool holder, 11 Receiving opening, 15 Induction coil unit, 17 Flexible cable, 18 Inductive current generator, 21 Induction coil, 23 Receiving body, 24 Turret plate, 25 Guide strut, 27 Handle, 29 Clamping device, 45 spring, 49 cooling tube, 51 cooling subassembly, 53 cooling collar, 53a cooling collar, 61 hub, 63 center ring, 67 sleeve, 67a inner sleeve member, 67b inner sleeve section, 69 sleeve, 69a outer sleeve member, 69b outer sleeve area, 71 inner casing surface, 73 slit, 73a slit, 77 groove, 77b serpentine groove, 91 annular spring, 101 yoke device, 109 yoke device, 109c yoke member, 109d yoke member, 113 control Board, 115 Your slot 117 cam follower pin 119 protruding portions, 123 annular beads, 129 conical transition region

Claims (7)

A shrink fit device for at least one tool holder (3) for press-fitting and holding a rotary tool in a central receiving opening (11),
An induction heating device (15, 18) configured to thermally expand the tool holder (3) in the receiving opening (11) region, wherein the induction heating device (15, 18) is an induction coil unit. An induction heating device (15, 18) having (15),
The induction coil unit (15) is
An induction coil (21) configured to be positioned in a substantially coaxial relationship with the receiving opening (11) region of the tool holder (3) for thermal expansion purposes;
A yoke made of a ferromagnetic material and extending axially along the outer circumference of the induction coil (21) and radially along at least one of the two axial end faces of the induction coil (21) a device (101), among the yoke device (101), at least one of the realm away from the region between the tool insertion end adjacent to the tool insertion end of the tool holder (3) Comprises yoke members (109 , 109c, 109d ), the yoke members (109 , 109c, 109d ) are made of a ferromagnetic material and project radially inward beyond the inner circumference of the induction coil (21), The yoke members (109 , 109c, 109d ) are guided so that the yoke members can move relative to each other, and the amount of protrusion in the radial direction exceeding the inner circumference of the induction coil (21) is the target for operation. Yoke device (101), which can be changed for
Equipped with a,
The yoke members (109, 109c, 109d) overlap each other in the circumferential direction, and the yoke members are guided so as to be moved in the radial direction with respect to the induction coil (21), or the induction characterized Rukoto is rotatably guided around a pivot pin (119,119A) extending in a parallel manner in the axial direction relative to the coil (21), shrink fitting device. The induction coil unit (21) is guided on the vertical guide column (25) so that the induction coil unit (21) can move in a state where the coil axis is vertical,
The tool holder (3) is configured with a central receiving opening (11) that is coaxial with the coil axis and has an upper end surface;
The yoke members (109, 109c, 109d) overlap each other in the circumferential direction and are guided so as to be movable in the radial direction with respect to the induction coil (21) or axially with respect to the induction coil (21) Is pivoted around pivot pins (119, 119a) extending in a manner parallel to the
The shrink-fitting device according to claim 1, wherein the yoke member (109, 109c, 109d) overlaps the upper end surface of the tool holder in the radial direction. The yoke member (109) is adjusted by a common control member (113),
The control member is rotated equiaxially with respect to the induction coil (21) and connected to the yoke member (109) via a control surface / cam follower device (115, 117). The shrink-fitting device according to claim 1 or 2 . The shrink-fitting device includes a turret plate (24) rotating around a vertical rotation axis, and a plurality of mounts (23) for the tool holder (3),
Each of the tool holders held by one of the plurality of mounting bases (23) moves relative to each other through operating regions of the heating devices (15, 18) and the cooling devices (51, 53). ,
One or more of the cooling collar (53) is connected to the liquid refrigerant tube (49) liable to deflection, as a result, characterized in that it follows the rotational movement of the turret plate (24), from claim 1 The shrink-fitting device according to any one of claims 3 to 4 . Rotation direction locking device in which the turret plate (24) prevents the rotational movement in a predetermined rotational direction, particularly in the direction of the operator of the shrink fit device from the region of the heating device (15, 18). The shrink-fitting device according to claim 4 , further comprising: 6. Shrink fit device according to claim 4 or 5 , characterized in that the mounting base (23) is arranged in a unit held in a replaceable manner on the turret plate (24). . The unit comprises a hub (61) substantially central to the axis of rotation of the turret plate (24);
A plurality of receiving bodies constituting the mounting base (23) are held on the hub (61) with play and are guided in a guide (63) of the turret plate (24). The shrink-fitting device according to claim 6 .

Images