Abstract:
A cutting tool setting system contains a tool head for the settable holding of a cutting tool, the head having an adjustment device for the cutting tool. The cutting tool setting system has a setting tool which can be mechanically removably engaged in the tool head at an interface for adjusting the adjustment device in the tool head. The setting tool contains a shaft body having a key part. A key engagement for actuating the adjustment device is designed on the tool head. The key part can be displaced relative to the shaft body in the direction of the longitudinal axis of the body in order to selectively couple and release the key part of the setting tool and the key part at the interface of the tool head.

Description:
FIELD OF THE INVENTION 
     The invention relates to a cutting tool setting system comprising a tool head for the settable holding of a cutting tool, which head has an adjustment device for the cutting tool, and comprising a setting tool, which can be made to engage with the tool head in a mechanically detachable manner at an interface for the adjustment of the adjustment device in the tool head, wherein the setting tool has a shank body with a key part and wherein a key engaging means for the actuation of the adjustment device is formed on the tool head. 
     Cutting tool setting systems are used for setting cutting inserts on cutting tools for metal working. This involves the cutting inserts being exposed to wear. There is the need to set the cutting edges to exact dimensions. The cutting inserts must therefore be readjusted from time to time. 
     DESCRIPTION OF THE RELATED ART 
     A cutting tool setting system of the type mentioned at the beginning is known from EP-0 491 74 B1. This cutting tool setting system comprises a tool head which is designed for connection to the machine spindle of a machine tool. The tool head has an adjustable slide, on which a cutting tool receptacle is formed. This slide acts as a cutting tool adjustment device. For adjusting the slide, the tool head contains a hexagon socket screw. This hexagon socket screw is coupled to a toothed gear mechanism, which acts on the slide. The slide can be adjusted at the hexagon socket screw by a hexagon key as a setting tool. For sensing the tool setting, the tool head includes an electrical measuring device. The electrical measuring device is arranged in the adjustable slide in the tool head. The tool head has a connector interface, via which measurement information can be read from the electrical measuring device. For activating the measuring device and for displaying measurement data, on the tool head there is an electrical switching unit with momentary-contact switches and a display. 
     In EP-1 758 710 B1, a cutting tool setting system with an adjustable cutting tool carrier is described. For the setting of a cutting tool, the cutting tool carrier has a key engaging means. At this key engaging means, the cutting tool carrier can be adjusted by a setting tool, which has a key element. The cutting tool carrier includes an electronic measuring circuit. The electronic measuring circuit serves the purpose of sensing an adjustment of the cutting tool carrier. The setting tool has a display, in order to display a setting of the cutting tool sensed by means of the electronic measuring circuit. For the operation of the measuring circuit, on the cutting tool carrier there are two electrical connection contacts. These connection contacts are designed for electrical contact with corresponding connection contacts on the setting tool. During the adjustment of the cutting tool carrier, in the setting tool the measuring circuit is supplied with electrical power via these contacts. At the same time, these contacts serve the purpose of transmitting measurement signals from the measuring circuit to the display on the setting tool. 
     In CNC machines, in particular, there is the problem that, as a result of soiling and poor illumination of a tool head or a cutting tool carrier, cutting inserts can often only be accurately set by an operator with great effort. This makes the adjustment of the cutting tools time-consuming and results in correspondingly prolonged machine downtimes. 
     OBJECT OF THE INVENTION 
     The object of the invention is to provide a cutting tool setting system with which cutting tools can be exactly set in a short time. 
     This object is achieved by a cutting tool setting system of the type mentioned at the beginning in which the setting tool has a key part which can be moved in relation to the shank body of the setting tool in the direction of the longitudinal axis of the latter, in order optionally to couple or release the key part of the setting tool and the key engaging means on the interface of the tool head. 
     This achieves the effect that the setting tool can be placed against the tool head, for example in order to read out measurement information from the electrical measuring device, without the key part of the setting tool and the key engaging means on the tool head having to be mechanically brought into engagement for this purpose. 
     For sensing the setting of the cutting tool, the tool head includes an electrical measuring device. In order to transmit the measurement information to the outside, the tool head has an electrical connection element, which interacts with an electrical connection element on the setting tool. 
     The electrical connection element on the tool head and on the shank body of the setting tool may be designed for optical and/or capacitive and/or inductive transmission of measurement information or for the transmission of measurement information by means of radio. The electrical connection element on the tool head and the electrical connection element on the setting tool preferably comprise one or more galvanic contacts. 
     In a development of the invention, the key part is arranged on a shaft part which is mounted displaceably in the shank body. In this case, a latching device is provided for the shaft part, which device latches the shaft part in a first position for the engagement of the key part in the key engaging means on the interface of the tool head and/or in a second position, in which the key part is retracted into the shank body. In this way, an exact adjustment with the setting tool is made possible. 
     The setting tool preferably has a shank body which has a tool-head engaging part, in which there is formed a mechanical coupling device which is separate from the electrical connection element and brings about a rotationally fixed coupling of the shank body and the tool head when the setting tool engages in the tool head. In this way, a more secure seating of the setting tool on the tool head for a tool setting is ensured and undesirable wearing of electrical contacts of the arrangement is avoided. In addition, almost play-free engagement of the key part of the setting tool in the key engaging means on the tool head is made possible in this way. 
     The coupling device on the setting tool is preferably assigned a coupling device on the tool head, wherein the coupling device on the setting tool has at least one coupling lug for which there is an associated receptacle on the tool head. The coupling lug and the receptacle are formed in such a way that, when the setting tool engages in the tool head, a galvanic contact on the setting tool always lies against an identical associated galvanic contact on the interface of the tool head. This makes a defined assignment of the galvanic contacts for different functionalities possible. 
     In order to ensure more secure seating of the setting tool on the tool head, in the cutting tool setting system there are means for the nonpositive connection of the interface for the setting tool on the tool head and the tool-head engaging part of the setting tool. This means may take the form, for example, of a spring, a bayonet closure or a hook-and-loop closure. By providing a magnet on the tool-head engaging part of the setting tool and arranging magnetizable material in the region of the interface for the setting tool in the tool head, a particularly secure seating of the setting tool on the tool head can be achieved. As an alternative to this, it may be envisaged to arrange magnetizable material on the tool head engaging part of the setting tool and to provide a magnet in the region of the interface in the tool head. The tool head can then be exactly adjusted by the setting tool, without a loose electrical contact occurring at the interface of the tool head. The magnet is preferably configured as a ring magnet, which has a magnetic polarity oriented perpendicular to the ring surface. In this case, the axis of the ring magnet is oriented parallel to the longitudinal axis of the shank body when the setting tool is placed against the interface of the tool head. Consequently, the magnetic force helps to obtain correct seating of the setting tool on the tool head. 
     The invention is based on the realization that, at high rotational speeds, enormous centrifugal forces occur in a tool head that is connected to the machine spindle of a machine tool. This has the consequence that electrical subassemblies in such a tool are exposed to high mechanical loads. It is found that digital displays, for example in the form of LCD displays, i.e. liquid-crystal displays, do not withstand these centrifugal forces in continuous operation. 
     The invention is also based on the realization that the unfavorable conditions in terms of space and lighting with which an operator is faced when setting a tool head in a machine tool can be successfully counteracted by allowing the display device in a cutting tool setting system to be arranged flexibly, independently of the position of the tool head in the machine tool and independently of the position of the setting tool. This is so because a display on the display device can then be received in a reliable and ergonomically favorable manner by an operator even when on a machine tool. 
     A further realization of the invention is that a high level of productivity can also be achieved with a cutting tool setting system in which, though a fine adjustment of cutting inserts is only possible when the tool is stationary, a corresponding tool head with cutting inserts can be reliably operated at very high rotational speeds, in particular in the speed range of over 15 000 rpm. 
     The invention therefore envisages not to integrate a display device for displaying the adjustment of the tool head in the tool head itself but to arrange it separately. In this case, measurement information is transmitted from the electrical measuring device in the tool head wirelessly to the display device via the setting tool. The tool head can consequently be designed to be very small. This measure particularly brings about a reduction in the moment of inertia of the tool head. 
     A handle or an automatable drive, for example an electric motor, is provided for the actuation of the key part on the setting tool. The setting tool includes an electrical power source, which may take the form, for example, of a battery or a power capacitor. An LED with a position measuring device, i.e. a measuring device with a position-sensitive light sensor, or an LED with a CCD measuring device, i.e. a measuring device with a light-sensitive line or image sensor with charge displacement, is provided as the electrical measuring device in the tool head. These measuring devices have a small dead weight and are very small. They are therefore extremely suitable for integration in a tool head that rotates at high speed. The transmission unit in the setting tool and the transmission unit in the display unit are designed for radio transmission technology, i.e. for Bluetooth transmission technology. Bluetooth transmission technology is a technology for devices to be linked by radio transmission over short distances in accordance with the industry standard IEEE 802.15.1. Bluetooth transmission technology operates with microwaves in the frequency range between 2.402 GHz and 2.480 GHz, but the frequency band is divided into different frequency stages that are alternated up to 1600 times per second. Bluetooth transmission technology permits a data transmission rate of up to 706.25 kbit/s. In this way, reliable data transmission is made possible between the setting tool and the tool head for the display device, without a line-of-sight link between the subassemblies being required. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       An advantageous exemplary embodiment of the invention is described below and schematically represented in the drawings, in which: 
         FIG. 1  shows a cutting tool setting system with a setting tool, a tool head and a display device; 
         FIGS. 2   a  and  b  show a longitudinal section of the setting tool in the cutting tool setting system with the key part retracted and extended; and 
         FIGS. 3   a  to  c  show various views of the tool head in the cutting tool setting system. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The cutting tool setting system  100  in  FIG. 1  comprises a setting tool  10 , a tool head  50  and a display device  90 . 
     The setting tool  10  has a shank body  12 , on which a tool-head engaging part  14  is formed. This tool-head engaging part  14  is designed for engagement in an interface  52  on the tool head  50 . On the tool-head engaging part  14  there is a coupling device  16 . The coupling device comprises two differently shaped coupling lugs  18  and  20 , which lie opposite each other. Formed on the tool-head engaging part  14  as an electrical connection element is a connection unit with four electrical contacts  21 ,  22 ,  23  and  24 . 
     The setting tool  10  has a key part  26 , which is located on the end face of a shaft part. By using a handle  30 , the shaft part with the key part  26  can be turned about the axis  32  and displaced in the direction of the axis  32  in accordance with the double-headed arrow  34  between an engaging position for the key part  26  and a disengaged position of the key part  26 . 
     By turning the handle  30  in the engaging position of the key part  26  in accordance with the double-headed arrow  35 , a setting of the tool head  50  is brought about when the setting tool  10  is lying against the interface  52  of the tool  50 . 
     On the tool head  50 , the interface  52  is formed on a cover element  53 , which consists of magnetizable material. The tool head  50  has a coupling portion  54  for the connection of the tool head  50  to the machine spindle of a machine tool (not represented any further). The tool head  50  includes an adjustment device with a settable slide  55 . On the settable slide  55  there is a holding device for a cutting tool  56 . 
     The interface  52  on the tool head  50  comprises a key engaging means  58  for the key part  26  of the setting tool  10 . The interface  52  of the tool head  50  also has a coupling device  60  with receptacles  62 ,  64  for the coupling lugs  18  and  20  on the setting tool  10 . The coupling device  60  with the receptacles  62 ,  64  is designed for interacting with the coupling device  16  on the setting tool  10 . On the interface  52  of the tool head  50  there are electrical contacts  66 ,  67 ,  68 ,  69 . The geometry of these electrical contacts  66 ,  67 ,  68 ,  69  on the tool head  50  is made to match the geometry of the electrical contacts  21 ,  22 ,  23  and  24  on the setting tool  10 . The coupling lugs  18 ,  20  of the coupling device  16  on the setting tool  10  and the receptacles  62 ,  64  on the coupling device  60  ensure that the setting tool  10  can only be placed against the interface  52  of the tool head  50  in a specific orientation: in this single possible orientation, only the electrical contact  21  on the setting tool  10  can ever be connected to the electrical contact  66  on the interface  52  of the tool head  50 , the contact  22  of the setting tool  10  to the contact  67  of the tool head  50 , the contact  23  to the contact  69  and the contact  24  to the contact  68 . 
     When the setting tool  10  is placed against the interface  52  of the tool head  50  in the orientation predetermined by the coupling devices  16 ,  60 , a galvanic connection of the electrical contacts  66  to  69  on the tool head  50  to the corresponding electrical contacts  21 ,  22 ,  23  and  24  on the setting tool is obtained. This initiates the activation of the measuring device in the tool head: electrical measurement signals are then read from the measuring device in the tool head  50  via a conductor connection and the contacts into the setting tool  10 . 
     The setting tool  10  has a radio transmission unit. The display device  90  includes a radio transmission unit  92 . By means of this radio transmission unit, the setting tool  10  transmits measurement information from a measuring device in the tool head  50  to the display device  90 . 
     The display device  90  comprises operator buttons  91  and  93 , with which the display device  90  can be controlled. The display information received from the setting tool  10  is displayed at the display device  90  on an LCD display  98 . The operator buttons make it possible in particular to switch the display  98  over between S/I measuring units and the measuring unit “inch”. 
     The display device  90  has a battery  96  as an electrical power supply. As an alternative to this, a power capacitor, for example a so-called Gold Cap, may also be provided in the display device  90  as the electrical power supply. The display device  90  includes control electronics  94 . The control electronics  94  have the effect that the LCD display  98  switches off automatically if the setting of the slide  55  on the tool head  50  has not been changed over a defined time period, for example for 30 s, or if the setting tool  10  is no longer transmitting measurement information to the display device  90  by means of radio transmission technology. 
     The display device  90  includes a permanent magnet  95 . The permanent magnet  95  acts as a latching-holding device. It makes it possible to position the display device  90  on a magnetizable metal body, for example on a machine tool, in a position that is ergonomically favorable for an operator. 
       FIG. 2   a  shows a longitudinal section of the setting tool  10 , wherein the key portion  26  on the shaft part  28  is retracted into the shank body  12 . The shaft part  28  is rotatably mounted in the shank body. In the region of the shaft part  28  that is facing the handle  30 , a first peripheral groove  36  and a second peripheral groove  38  are formed. The grooves  36 ,  38  are designed for interacting with a latching element in the form of a ball thrust screw  40  on the shank body  12 . When the shaft part  28  moves along the axis  32  in accordance with the double-headed arrow  34 , latching of the shaft portion  28  is brought about, both in a retracted position on the shank body  12  and in an engaging position for the key part  26  on the end face  28 . 
     On the tool-head engaging portion  14  of the shank body  12  there is an annular permanent magnet  42 . The annular permanent magnet  42  has magnetic polarity oriented in accordance with the axis  41 , perpendicular to the ring surface. The magnetic polarity of the annular permanent magnet  42  is in line with the longitudinal axis  32  of the shank body  12 . 
     The permanent magnet serves the purpose of magnetizing the cover-shaped covering element  53  on the tool head  50  when the setting tool  10  is connected to the interface  52 : the shank body  12  of the setting tool  10  and the covering element  53  on the tool head  50  then draw each other together. In this way, reliable, play-free abutment of the tool-head engaging portion  14  on the shank body  12  of the setting tool against the interface  52  on the tool head  50  is ensured when the setting tool  10  is connected to the tool head  50 . 
       FIG. 2   b  shows a longitudinal section of the setting tool  10  for the extended position of the key part  26  with respect to the shank body  12 . The shank body  12  includes an electrical energy store  43  with a number of batteries, which supply electrical power to an electronics unit  44  and a radio transmission unit  45 . As an alternative to batteries, one or more power capacitors may also be provided as an energy store. The Bluetooth transmitting unit  45  is designed for a microwave output power in the range of 150-200 mW at a frequency of approximately 2 GHz. The concept of the wireless data transmission from the setting tool  10  to the display device  90  with simultaneous transmission of measurement information by means of electrical conductors and contacts from the tool head  50  into the setting tool  10  makes it possible that only very little electrical power has to be provided for the sensing of measurement information by the electrical measuring device in the tool head and the transmission of this measurement information: electrical power that lies in the range of mW, i.e. about 2 orders of magnitude less than the power required for data transmission by means of Bluetooth technology, is sufficient. It is therefore adequate to provide only small, low-power energy stores for data transmission and displacement measurement in the tool head  50 . 
     As an alternative to this, the tool head  50  could also be configured without an integrated electrical energy store: then the measuring device in the tool head  50  must be supplied with electrical power from the setting tool. In any event, the transmission of measurement information by means of a data link from the tool head  50  into the setting tool  10  makes it possible that less installation space, or no installation space, has to be provided for electrical energy stores in the tool head  50 . The overall volume for the tool head  50  can therefore be kept small. 
     When the setting tool  10  is connected to the interface  52  of the tool head  50 , the electrical contacts  21  to  24  on the setting tool and the electrical contacts  66  to  69  on the interface  52  of the tool head come into engagement. The electronics unit  44  in the setting tool is then activated. This has the consequence that measurement information is read from the measuring device in the tool head  50  into the setting tool  10 . The electronics unit  44  in the setting tool  10  passes the measurement data obtained from the tool head  50  to the radio transmission unit  45 . The radio transmission unit  45  in the setting tool  10  then sends the measurement data to the display device  90 . In principle, the electronics unit  44  could also be arranged in the tool head  50 . 
       FIG. 3   a  shows the tool head  50  from  FIG. 1  in a rear view. The slide  55  in the tool head  50  can be adjusted parallel to the planes defined by means of the line IIIc-IIIc. 
       FIG. 3   b  shows a longitudinal section of the tool head  50 . The tool head  50  has a main body  77 . The slide  55  is guided on the main body  77  of the tool head  50  in a sliding bearing. It is held on the main body  77  by a cover  87 . Formed in the tool head  50  is a receptacle  70  for two button cell batteries  71 ,  72 , which are located in the main body  77  of the tool head. By means of the button cell battery  71 ,  72 , the measuring device  82  in the tool head  50  is supplied with electrical power. As an alternative to button cell batteries  71 ,  72 , other electrical energy sources of small dimensions, for example high-power capacitors in the form of so-called Gold or Super Caps, may also be provided for the tool head  50 . In order to ensure uniform concentricity of the tool head even at high rotational speeds, two adjustable compensating weights  73  and  75  are provided on the main body of the tool head  50 . 
       FIG. 3   c  shows a section of the tool head  50  along the line IIIc-IIIc from  FIG. 3   a . In this section, the interface  52  with the coupling device  60  and the key engaging means  58  can be seen. The key engaging means  58  is located on the end face of a drive element  76 . The drive element  76  is rotatably mounted in the main body  77  of the tool head  50 . The drive element  76  is in operative connection in a portion  78  with a thread  79 , which is formed on the slide  55  of the tool head  50 . By turning the drive element  76  about the axis  80 , the slide  55  can consequently be displaced in accordance with the double-headed arrow  81 . 
     The electronic measuring device  82  in the tool head is arranged in a portion in the tool head  50  that is opposite from the drive element  76 . The measuring device  82  in the tool head  50  is a displacement measuring system. It comprises an LED  84 , which is fixedly connected to the slide  55 . The LED  84  is assigned a module  85  for position sensing in the main body  77  of the tool head  50 . The tool head  50  includes evaluation electronics  83 , which comprise a controller. The evaluation electronics  83  are connected via a flexible conductor  88  to the electrical contacts on the interface  52  of the tool head  50 . Instead of the flexible conductor, conventional electrical line connections may also be provided. At the electrical contacts of the interface  52 , the evaluation electronics  83  provide measurement data concerning the position of the slide  55  with respect to the axis  86  of the tool head  50 . When the setting tool  10  is connected to the interface  52  in the tool head  50 , these measurement data are transmitted through an electrical line via the contacts  66  to  69  on the tool head  50  and the contacts  21  to  24  on the setting tool. The evaluation electronics  83  in the tool head  50  make it possible to measure an adjustment of the slide  55  exactly. This arrangement of the measuring and evaluation electronics within the main body  77  in the tool head  50  particularly ensures reliable, play-free operation under the high mechanical loads for the measuring device that occur at very high tool head rotational speeds in the range of 15 000 rpm. 
     To sum up, the following can be stated: The invention relates to a cutting tool setting system  100  comprising a tool head  50  for the settable holding of a cutting tool  56 . The tool head  50  has an adjustment device  55  for the cutting tool  56 . The cutting tool setting system  100  comprises a setting tool  10 , which can be made to engage with the tool head  50  in a mechanically detachable manner at an interface  52  for the adjustment of the adjustment device  55  in the tool head  50 . The setting tool  10  has a shank body  12  with a key part  26 . A key engaging means  58  for the actuation of the adjustment device  54  is formed on the tool head  50 . The key part  26  can be displaced in relation to the shank body  12  in the direction of the longitudinal axis  32  of the latter, in order optionally to couple and release the key part  26  of the setting tool  10  and the key engaging means  58  on the interface  52  of the tool head  50 .