Container adapted to be inserted in a tool holder, a tool holder and a system

The present invention concerns a container/cartridge especially suitable to be build into machine tools and tool holders. The container provides a stable and strong attachment to the tool and at the same time channels for conveying cooling medium, typically a cutting liquid is held open. The invention also concerns a tool holder adapted for installation of the above mentioned container, and a use of a container for accommodating sensors or damper systems.

During machining, it can evolve a need to build various elements into the tool/tool holder. The elements may include sensors for monitoring for instance temperature, vibrations, forces or similar properties, or elements that imposes particular properties to the tool. Damping of vibrations is typically such a property. Such vibrations emerges when the natural frequency of the tool is in the same frequency area as the force variations in the machining. The vibrations can also emerge when the machining parameters are unfavourable and is particularly common when it is discontinuous cutting (typically milling).

During damping of vibrations it is frequently mounted a damping system internally in the tool. There are several patents that all shows such damping systems. Common for most of these is that they are installed directly in a cavity in the tool. The result is that the cooling medium not can be brought forward, or that it has to be lead through the damping system with dedicated tubes or particularly designed means.

Tool- holders are normally manufactured of a solid material, with outer geometries to hold cutting edges and for being fixed to a machine or clamping units. Frequently the tool has internal ducting for bringing forward cooling medium. The cooling medium (cutting liquids) is often necessary to be able to perform the machining.

An example of a tool holder with a damping apparatus installed is shown in US 4.061.438. The tool holder includes a damping element placed in a capsule at the forward end of the tool holder. However, attachment of the capsule will be complicated and the cooling medium can not be brought passed the tool holder.

The present invention concerns a system with a container and a tool holder. The system is designed for use in connection with chip cutting machining and eases attachment, placement and connection of vibration damping devices and

the localization of sensors, at the same time as cooling medium can be brought forward. The tool holder has two ends. One end is adapted for being fixed in a machine tool and the other end is adapted for attaching a cutting edge. The tool holder includes an internal cavity surrounded by a cavity wall. The cavity contains the container. One end of the cavity is adapted for being connected to a supply for a cooling medium and the other end is connected to an outlet for cooling medium. The outlet is typically in connection with a nozzle for leading the cooling medium towards a cutting edge, and the inlet is typically in connection with a source for cooling medium and a pump. The cavity includes an opening for installation of the container. At least one recess for leading the cooling medium is made between the container and the cavity wall.

The recess can be made as at least one cut out in the container.

The recess can be made as at least one cut out in the cavity wall.

The recess can be made in the cavity wall and in the container. Furthermore, it is described a container, a cartridge or sleeve to be inserted in a cavity with a cavity wall in a tool holder. The container includes at least one central part and end parts. At least one of the end parts is releasably connected to the central part. The central part includes an outer surface with at least one area adapted to be in contact with the cavity wall in the tool holder and at least one area adapted for contact with a cooling fluid when the tool holder with the container is in use. The area adapted for contact with the cooling medium is adapted to abut one clearance between the outer surface of the central part and the cavity in the machine tool. The purpose of the clearance or clearances is to bring forward a cooling medium, for instance a gas or typically a cutting liquid. The size of the clearance will typically be affected by the amount of cooling medium that has to pass the container.

The container may include a smooth surface and can be adapted for being inserted in a cavity with recesses in the cavity wall.

The at least one area of the container that is adapted to be in contact with a cooling fluid, can be adapted to provide one clearance between the outer surface of the central part and the cavity wall in the tool holder.

The central part may include an external cylindrical part with a number of ridges placed placed along the cylindrical part, as these ridges provides areas for

contact with the cavity of the tool holder and where the areas between the ridges are adapted to create the clearances for bringing forward the cooling medium between the container and the tool holder.

The cylindrical part does not necessarily have to extend along the entire 5 length of the container. The central element is that the container can get a stable localization in the cavity at the same time as fluid can pass the container.

The container will typically be cylindrical with recesses milled into the cylinder, but other shapes may well be used. For instance, the container may be shaped as a rectangular or square bar, have an oval cross section etc. If for io instance the container is oval and the cavity is cylindrical, it will be provided both contact faces and recesses. The same can be said about a square container in a cylindrical cavity.

The at least one area for contact with the cavity in the machine tool can form contact points placed in a circular configuration to be adapted for contact with i5 a cylindrically shaped cavity in the machine tool. The contact points may not extend along the entire length of the container, but can be formed by discontinuous elevations of any shape on the outside of the container. The end parts or lid can also form the contact points towards the cavity wall and may include recesses for bringing forward the cooling medium.

20 The central part may include one or several cylindrical parts with a central axis and the elevations can be made as ridges that extend parallel to this central axis. The elevations can be arc shaped, straight, curved or include any other suitable shape.

The central part may include one or several cylindrical portions with a 2s central axis, and the elevations can be shaped as ridges that extend in a spiral or helix around the central axis.

The central part may include one substantially cylindrical cavity, and one of the end parts may be integrated in the central part.

The central part may include a substantially cylindrical cavity, and both of 30 the end parts may be releasably connected to the central part.

That or the releasably connected end parts can be adapted with a press fit to the central part, such that installation of the end part in the central part will lead

to an expansion of the central part. Alternatively, it can be used other designs for installation, for instance threads, screws, bayonet joint etc.

One of the ends of the container may include a recessed section for contact with the cavity of the machine tool. Furthermore, the invention concerns a tool holder with two ends, where one of the ends is adapted for being secured in a machine tool and the other end is adapted for being secured to at least one cutting edge. The cutting edge or edges do not need to be secured directly to the holder, but can be secured in a further part or a cutting edge holding unit that holds the edge or edges. The holder may include an internal cavity with a cavity wall. The cavity is adapted to take up a container as described above in that one of the ends of the cavity is connected to a supply for cooling medium and the other end is connected to an outlet for cooling medium. The cavity includes an opening for installation of the container.

The largest dimension of the container, the releasable end part of the container and the tool holders internal cavity, can be mutually adapted such that the container is pressed fixedly towards the cavity wall in the internal cavity of the tool holder when the releasable end part of the container is pressed in place in the central part of the container.

The cavity wall may include recesses for leading cooling fluid instead of, or in addition to recesses or cut outs in the container.

The internal cavity of the tool holder can be chamfered, for mutual interfitting contact with a chamfered section of the container.

Furthermore, the invention concerns a tool holder with two ends, where one end is adapted for being fixed to a machine too and the other end is adapted for fixing a cutting edge, with an internal cavity. The cavity is adapted to take up a container as described above, in that one end of the cavity is connected to a supply for a cooling medium, and the other end is connected to an outlet for cooling medium. The cavity includes an opening for installation of the container. The opening for installation of the container can be directed towards the machine tool.

The opening for installation of the container can alternatively be directed towards the at least one cutting edge or towards the end where it is situated an element for fixing one or several cutting edges.

The cavity may include at least one cylindrical portion for contact with the at least one area of the container for contact with the cavity wall.

The largest dimension of the container, the releasable end part of the container and the internal cavity of the tool holder can be mutually interfittingly adapted such that the container is pressed towards the cavity wall and is thereby fixed in the internal cavity of the tool holder when the releasable end part of the container is pressed into the central part of the container.

The internal cavity of the tool holder can be chamfered for mutual interfitting contact with the chamfered section of the container. The invention also concerns use of a container as described above for containing one or several sensors for measuring parameters in connection with the machine tool and/or for accommodating a damping system.

According to the present invention the cutting fluid can be brought forward on the outside of the container. Thereby it is not necessary with a tube through the damping system. The damping system can be isolated inside the cartridge sleeve. The cutting liquid or air that is lead past the cartridge on the outside contributes to cool the cartridge and its content. The function of the damping system is therefore less affected by the heat that is supplied by the cutting process, compared to similar damping systems where the cutting liquid not can be lead on the outside of the damping system.

With a container according to the invention in combination with a tool holder according to the invention it can also be achieved a very simple installation of the tool. Few parts are required, and the use of adhesives, sealing compounds etc. can be avoided. Furthermore, the cooling medium can be brought forward effectively. The container is given a cooling effect, the container is fixed well in the tool holder, and the content of the container is given good protection. The clearance areas or the recesses of the container can be cylindrical external recesses. Furthermore, the recesses may be spiral shaped. The container may also have loose lids at both ends, and the length of the container, the diameters and the remaining geometry can be adapted to the required needs. Furthermore, the end face geometry can be adapted to the cavity. If needed the elements of the container can communicate with the surroundings through ordinary sender/receiver technology, transceiver technology, data can be logged to an

integrated memory unit of the container that can be read at frequent intervals, data can be directly transferred by slip rings on the tool holder etc.

Short description of the enclosed figures: Fig. 1 shows a side elevation of a container according to one embodiment of the invention;

Fig. 2 shows a cross section of the container shown on fig. 1 ;

Fig. 3 shows a cross section of a container according to a further embodiment of the invention; Fig. 4 shows a cross section of a container according to further embodiment of the invention;

Fig. 5 shows a cross section of a container according to a further embodiment of the invention;

Fig. 6 shows a cross section of a container according to one further embodiment of the invention;

Fig. 7 shows a cross section of a container according to a further embodiment of the invention;

Fig. 8 shows a cross section of the tool holder according to the invention;

Fig. 9 shows in detail a part of the cross section shown on fig. 8; Fig. 10 is a perspective view of an embodiment of the invention;

Fig. 11 is a perspective view of the invention as shown on fig. 1 and 2; and

Fig. 12 is a cut through perspective drawing of still a further embodiment of the invention.

Detailed description of embodiments of the invention with reference to the enclosed figures. Fig. 1 shows a container 1 with a central part 2, an integrated part 3 and a releasable end part or lid 4. From fig. 1 it is further more shown the contact areas 5 for contact with a cavity in a machine tool, and clearance areas 6 creating a clearance in the cavity of the machine tool. The clearances 6 are shown as recesses in the container 1 , and these include a helical spiral or screw configuration. These clearances are adapted for leading a cooling medium, for instance cutting liquid or air. A spiral or helical configuration can be preferable to increase the length of the channels or clearances 6, such that the time the cooling medium resides around the container is increased.

The end part 3 that is integrated in the central part is shown with recesses 7 for contact with adapted recesses in the cavity where the container 1 is to be placed.

One of the recesses is shown as a conical recess 7 to ensure that the container 1 is centred and is given a fixed position without the container 1 being movable in relation to the cavity where it is to be placed.

Fig. 2 shows the container shown on fig. 1 in cross section. The container of fig. 2 includes a damping system 8 or a damping body. From fig. 2 it is also shown the cross section of the lid or the end part 4 and how this is adapted to the central part 2. The lid 4 and the geometry 10 at the end of the central part 2 is such that the lid 4 has been given a diameter 9 that is adapted to the inner diameter 10 of the central part 2, such that it in one operation is possible to secure the lid 4 to the main part or central part 2 and at the same time clamp the walls of the main part 2 and thereby the entire container 1 to an inner wall of the cavity where the container 1 is to be placed. This design enables the container to be given a rigid clamping force towards the cavity where the container 1 is to be placed both in a radial and axial direction. The other end 3 of the main part or central part 2 has been given a geometric shape or recess 7 that opposes the clamping force and includes at the same time channels for leading the cooling medium forward. Furthermore, it is shown a gradual reduction or chamfering 11 that can be adapted to the inner geometry of the cavity, and/or can contribute to improved flow conditions around the end or can improve the elasticity of the container at the end to accommodate tolerances between the container 1 and the end part of the cavity where this is chamfered to abut the container. In fig. 2 the lid 4 is shown, and how the inner geometry 9 of the lid is adapted to the inner geometry 10 of the container 2. A damping system is schematically shown as 8. From fig. 2 the contact areas 5 and the clearances areas, the channels or recesses 6 are clearly shown.

When assembling the container 1 into the cavity of the tool, the lid 4 is first placed in the container 2, but is not pressed entirely into its final position. The container 1 is thereafter installed in the cavity of the machine tool and is placed such that the end part 3 with the geometry 7 abuts the end wall of the cavity. The lid 4 is thereafter pressed to its final position with a suitable tool. This gives an

elastic deformation between the lid 4 and main part 2, that again gives a clamping force towards the cavity.

In fig. 3 it is shown and alternative embodiment of a container, where this is shown with two integrated end pieces 3 and where a damping body 8, adapted to be placed in a damping fluid, is shown with transversal rifles to increase the influence the damping fluid has on the damping body 8.

In fig. 4 it is shown an alternative embodiment of a container 1 , shown with an integrated end piece 4, releasable lid and particular damping 8 with particles adapted to be placed in a damping fluid. The end part 3 that is integrated in the central part is shown with chamfering 7 for contact with adapted chamfering in the cavity where the container 1 is to be placed. The contact areas 5 for contact with a cavity in the machine tool, and the clearances area 6 that creates a clearance to the cavity in the machine tool.

In fig. 5 it is shown an alternative embodiment of a container, where this is shown with two releasable end pieces 4 and with a damping body 8. In this embodiment, one of the end pieces is shown with a chamfering 7, an extra channel 12 for the cooling media and with a profile 9 adapted to the central part. In fig. 6 it is shown an alternative embodiment of a container, where this is shown with two releasable end pieces 4, and an empty cavity for instalment of for instance different measuring equipment and sensors etc.

In fig. 7 it is shown an alternative embodiment of a container 1 , where this is shown placed in a cavity 25 in a tool holder 20, where the container 1 has a releasable end piece 4 and an integrated end piece 3. A damping body 8, is shown secured to two elastic bodies 13 placed inside the container 1. The damping body 8 is shown with two pins 14 that go into the elastic bodies 13. Alternatively the damping body 8 could have had plane ends secured with adhesive bonding or in another way secured to the ends 3, 4 of the container 1 , such that the forces are being imposed on the elastic elements 13 as shear forces on the elastic body 13 instead of in compression as shown on the figure. The damping system 8 shown on fig. 2 can be an ordinary damping system, and there are several patents that shows such damping systems. Common for all these is that they are assembled directly into a cavity at the tool.

The clamping system 8 may include a free damping body in a damping fluid, damping masses suspended in spring systems, damping masses suspended in elastomer materials etc. The damping system may also include active damping systems that are adjusted according to a predetermined frequency area for the damping etc.

Fig. 8 shows an example of a tool holder 20 according to the invention. Tool holder 20 include two ends 21 , 22 where one of the ends 21 is adapted to be secured to a machine tool and the other end 22 is adapted to be secured to a cutting edge. Beyond this, the tool holder 20 includes any outer geometry, common for tool holders. The tool holders include channels 24 for leading a cooling fluid to the cutting edge. A cavity 23 for accommodating a container 1 according to the invention is clearly shown. The cavity is adapted for containing the container 1 in that boring 25 also forms a channel for supply of a cooling medium. The diameter of the boring 25 is adapted to the outer diameter of the container 1 as previously described. Furthermore, it is shown a second end adapted to an outlet 24 for a cooling medium. In the embodiment shown on fig. 8 an opening 2 for installation of the container 1 is directed towards the machine tool. However, the opening 25 may just as well be directed towards the end 22 for securing the cutting edge. Fig. 9 shows a detail of fig. 8, where the lid 4 of the container 1 is clearly shown, and where a damping system 8 is shown placed in the container 1. The areas with clearance between the container 1 and machine tool 20, defined as 6, are also clearly shown. Similarly the areas 5 for contact between the container 1 and the cavity in the machine tool 20 is shown. Fig. 9 also shows how the end 3 of the container 1 includes a geometry 7 that is adapted to the geometry of the cavity in the machine tool 20. A cut out 12 in the end part 3 contributes to lead cooling fluid from the clearance area 6 and to the outlet 24 for the cooling fluid.

On fig 10 and 11 it is shown recesses that forms the clearance areas 6 and the contact areas 5 for contact with the cavity, that are parallel to the central axis of the container 1. The contact areas 5 and recesses 6 are clearly shown.

Furthermore, the releasable end lid 4, the geometric shape 7 at the end of the container 1 and a further end recess 12 is shown. Fig. 10 shows recesses that are parallel to the central axis of the container.

Fig. 11 is perspective view of the container 1 as shown on fig. 1 and 2. The container 1 is shown with a central part 2 with a contact area 5 for contact with the inner cavity of a machine tool, and a clearance area 6 that forms a clearance with the container 1 and the cavity of the machine tool. Fig. 11 shows recesses that are shaped as spirals around the central axis of the container.

Fig. 12 shows a system with a container and a tool holder 20 where the cavity 23 of the tool holder is shown with recesses 6 for leading forward the cooling medium and where the container has a smooth outer surface. Furthermore, it is shown a damping body 8, a lid 4, channels 24 for bring forward the cooling medium to the cutting edge and the end 22, for securing a cutting edge.