Abstract:
An exhaust system for housing-type enclosures of machine tools is provided for removing air by suction from the interior of the enclosure. The cuttings which are produced during machining of the workpieces are distributed within the working chamber and are thrown to the exhaust location and removed by suction. The cuttings collect in the exhaust area and present a safety risk. In order to prevent undesirable components in the exhaust air from reaching the exhaust system, an air-permeable catch device is provided in the exhaust area in front of the exhaust location. On the catch device, the undesirable components are caught while the exhaust action itself is not impaired. The catch device is a basket having walls made of mesh.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to an exhaust system, in particular, for housing-type enclosures of machine tools, comprising at least one exhaust location, preferably, an exhaust socket connected to a mounting frame: 
   2. Description of the Related Art 
   Exhaust systems are known which are provided on housing-type enclosures of machine tools. During operation of the machine tool, air is constantly removed from the interior of the enclosure by this exhaust system. In general, the culling speeds of the machine tools are high so that during machining of the workpieces cuttings are distributed in the entire working space of the enclosure and are thrown toward the exhaust location and removed by suction. Residual cuttings in the exhaust area, for example, in the exhaust pipe, result in the formation of nests of cuttings which represent a high safety risk. 
   SUMMARY OF THE INVENTION 
   It is an object of the invention to configure the exhaust system of the aforementioned kind such that unwanted components in the exhaust air cannot enter the exhaust device. 
   This object is solved according to the invention for the exhaust system of the aforementioned kind in that the exhaust system has at least one air-permeable catch device in the exhaust area in front of the exhaust location. 
   In the exhaust system according to the present invention, the catch device prevents undesirable components in the exhausted medium from reaching the exhaust device. The undesirable components are intercepted by the catch device. Since the catch device is air-permeable, the exhaust action itself is not impaired. 
   In a special configuration, the catch device is in the effective range of at least one cleaning unit. By means of the cleaning unit, the catch device can be freed of caught components which should not be exhausted. Since the cleaning unit is provided on the exhaust system, a manual cleaning of the catch device is not required. In this way, the exhaust system according to the invention can be mounted also where a manual cleaning of the catch device is not possible or possible only with great expenditure. Often, the exhaust unit is positioned at a great height so that auxiliary means such as ladders are required for cleaning the catch device. When the exhaust unit is provided on an enclosure for a machine tool, the machine tool must be shut down for cleaning the catch device. With the exhaust system according to the invention, cleaning of the catch device can be performed even while the machine tool is operating. 
   According to a further embodiment, the exhaust socket of the exhaust system according to the invention is provided with a positive-locking counter element which interacts with the positive-locking element of the clamping ring. It is seated on the exhaust hose and inserted into the exhaust socket against whose inner wall it is positioned under tension. By means of the positive-locking connection, it is ensured in a simple and reliable fashion that the exhaust hose cannot be accidentally pulled out of the exhaust socket. 
   The exhaust system according to the invention is characterized in that it has three interfaces which can be arranged closely adjacent to one another so that the exhaust system has a compact configuration. The first interface is formed by the catch device which is positioned in the exhaust direction in front of the exhaust location. The second interface is formed by the cleaning unit with which, as needed, the caught particles contained in the exhausted air can be removed from the catch device. The third interface finally is formed by the exhaust socket to which a flexible exhaust hose can be connected in a simple way. 
   It is particularly advantageous when the exhaust system is detachably mounted. It is then possible to detach it easily, when needed, in order to service it, for example. 
   According to a further configuration according to the invention, the exhaust system is attached by a clamping device on the mounting location. The clamping device enables simple mounting and demounting. 
   Further features of the invention result from the additional claims, the description, and the drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be explained in more detail with the aid of an embodiment illustrated in the drawings. It is shown in: 
       FIG. 1  a perspective illustration of an exhaust system according to the invention; 
       FIG. 2  a plan view onto the exhaust system according to  FIG. 1 ; 
       FIG. 3  a view in the direction of arrow III of  FIG. 2 ; 
       FIG. 4  a schematic illustration of the end of a hose which is to be connected to the exhaust socket of the exhaust system; 
       FIG. 5  an axial section of an end of the exhaust socket; 
       FIG. 6  a schematic illustration in a side view of a second embodiment of the exhaust hose secured in a plug-in receptacle; 
       FIG. 7  a perspective illustration of the exhaust system according to the invention with clamping elements. 
   

   DESCRIPTION OF PREFERRED EMBODIMENTS 
   The exhaust system is used in connection with enclosures of machine tools. Such machine tools are, for example, machining centers which are arranged within a housing-type enclosure. At least during processing of the workpieces on the machine, the exhaust system is switched on. The enclosure is illustrated in  FIGS. 1 and 3  by profiled sections  1 . The enclosure is, of course, provided with closed sidewalls and a closed ceiling. For receiving the exhaust system, the enclosure  1  is provided with a corresponding mounting opening  2  which is provided in the sidewalls and/or in the corner of the enclosure. 
   The exhaust system comprises a mounting frame  3  which, in this embodiment, has a square contour but, of course, can have any other suitable contour. The frame sides  4  to  7  have an edge  8  to  11  angled outwardly at a right angle, and the mounting frame  3  overlaps with its edge the rim of the mounting opening  2 . By means of these angled edges  8  to  11 , the mounting frame  3  rests on the outer side of the sidewall or ceiling of the housing-type enclosure  1 . 
   The frame sides  4  to  7  are positioned at a right angle relative to the base plate  12 , which is recessed relative to the angled edges  8  to  11  of the frame sides  4  to  7 . 
   In order for the mounting frame  3  to be mounted and, if needed, detached easily, it is provided on two opposed frame sides  4 ,  6  with an upwardly extending handle  13 ,  14 , respectively, which is fastened on the corresponding frame sides in a suitable way. 
   The base plate  12  has preferably centrally an opening  15  to which is connected an exhaust socket  16 . It has a circular cross-section and is positioned with an annular flange  17  on the base plate  12 . The annular flange  17  is mounted by means of screws or the like on the rim of the opening  15  on the base plate  12 . 
   In the area underneath the exhaust socket  16 , a cuttings basket  18  is provided which is comprised of a wire mesh or plastic mesh. The cuttings basket  18  has sidewalls  19  to  21  which adjoin one another at a right angle and a bottom  22  which connects the sidewalls  19  to  21  with one another. The sidewalls  19  to  21  reach down to the baseplate  12  and are connected to its inner side in a suitable way. The cuttings basket  18  serve for catching the cuttings, which are produced in the working space of the enclosure when machining the workpieces by means of the machine tool and which are sucked away, so that they cannot reach the exhaust socket  60 . The cuttings are caught on the outer side of the cuttings basket  18  whose mesh is so fine that the cuttings cannot penetrate. In order to compensate at least as much as possible the cross-sectional loss caused by the presence of the mesh of the cuttings basket  18 , the mesh basket is formed in the described way as a hood with four lateral walls and a bottom so that the air can enter via five sides of the cuttings basket  18 . The air resistance is maximally approximately 20 Pa. Since it is prevented that workpiece cuttings reach the exhaust system, no deposits will form in the hose connected to the exhaust socket  16 . In this way, damage of the exhaust device is reliably prevented without this going hand in hand with an increased air resistance at the exhaust location. 
   In order to be able to remove from the cuttings basket  18  the cuttings which have collected on the exterior side of the cuttings basket  18 , the exhaust system is provided with at least one cleaning unit  23 . It has a cleaning nozzle  24  which projects into the cuttings basket  18  and which is provided with a nozzle opening  24  (not illustrated) from which a cleaning medium emerges in a way to be described in the following. The cleaning nozzle  24  is supported in a holder  26  so as to be rotatable about its axis  25  (FIG.  3 ); the holder projects through the base plate  12  and is connected to the base plate. The cleaning unit  23  is provided in an area between the exhaust socket  16  and a corner area of the base plate  12 . The axis of rotation  25  of the cleaning nozzle  24  is positioned perpendicularly to the base plate  12 . 
   A supply line  27  is connected to the holder  26  and a cleaning medium, preferably, a cooling lubricant, is supplied via the supply line. A solenoid valve  28  is positioned in the supply line  27  for controlling the supply of the cleaning medium. The solenoid valve  28  is electrically controlled in order to open or close the supply line  27 . Instead of the solenoid valve  28 , it is also possible to provide a manually operated valve. 
   When a cleaning process is to be performed, the solenoid valve  28  is actuated and the supply line  27  opened. In this way, the cleaning medium can be supplied to the cleaning unit  23 . Under the pressure of the supplied cleaning medium, which reaches the cleaning nozzle  24  via the holder  26 , the nozzle is rotated about its axis  25 . Via the nozzle openings provided at the lower end of the cleaning nozzle  24 , the cleaning medium exits and is thrown against the sidewalls  19  to  21  and the bottom  22  of the cuttings basket  18 . By means of the cleaning medium, which impacts from the inner side the sidewalls  19  to  21  and the bottom  22  of the cuttings basket  18 , the cuttings adhering to it are thrown back inwardly into the machine enclosure. 
   Depending on the size of the cuttings basket  18 , it is possible to provide more than one cleaning unit  23 . 
   By means of the cleaning unit  23 , the sidewalls  19  to  21  and the bottom  22  of the cuttings basket  18  can be flushed to free them so that clogging of the cuttings basket  18  by means of cuttings generated by workpiece machining can be reliably prevented. For cleaning the cuttings basket  18 , it is not required to have personnel because the cleaning of the cutting basket  18  can be carried out automatically in the described way. Even when the enclosure of the machine tool is tall and the exhaust system is mounted on the ceiling of the enclosure, a reliable cleaning of the cuttings basket  18  is ensured. Since cleaning of the cuttings basket  18  is carried out without personnel, the machine tool positioned within the enclosure must not be shut down for the cleaning operation. Cleaning of the cuttings basket  18  can be carried out optimally as soon as the exhaust output/effect decreases. In this way, a continuous exhaust efficiency/effect with continuous under pressure in the working space within the enclosure of the machine tool is ensured. The cleaning medium, in particular, cooling lubricant, does not reach the machine surroundings so that even in the surrounding areas of the enclosure there is no atmosphere that would present a health hazard. 
   Since the mounting frame  3  of the exhaust system is formed by angled profiled sections, it can be attached to and detached from the enclosure  1  in a simple way; also, in particular, because of the two handles  13  and  14 . This is a great advantage for servicing purposes and for possible modifications. Because of the described configuration, the exhaust system has three interfaces, i.e., for the cuttings basket  18 , for the cleaning unit  23 , and for the exhaust socket  16 . These three interfaces are mounted in a space-saving way on the exhaust system. 
   In  FIGS. 1 and 3 , a conventional exhaust socket  16  is provided which is connected to the exhaust pipe in a way known in the art. 
     FIGS. 4 and 5  show an exhaust socket  16  to which a flexible hose  29  can be connected in a simple way. On the connecting end  34  of the hose  29 , a clamping ring  31  is attached which is embodied as a spring ring and, for generating the spring properties, is provided with a slot  32 . The clamping ring  31  is surrounded by a clamping device  33  which is formed, for example, as a hose clamp. 
   In order to prevent sliding of the clamping ring  31  on the hose  29 , it is advantageously configured such that it is seated with a high clamping force on the hose end  34 . Of course, it is also possible to connect the clamping ring  31  fixedly to the hose end  34 . 
   Advantageously, the end  35  of the clamping ring  31  facing the exhaust socket  16  is folded inwardly in a U-shape. This has the advantage that the hose end  34  can be inserted simply to such an extent into the clamping ring  31  until the free hose end contacts the bottom  41  of the folded portion  35 . In this way, it is ensured that the hose end  34  is inserted sufficiently far into the clamping ring  31 . 
   Near the free end, at least one positive-locking element  36  is fastened on the clamping ring which, in the illustrated embodiment, is a ring having a cross-section that is approximately semi-circular and interrupted in the area of the slot  32 . This positive-locking element  36  is advantageously a metal ring which is welded onto the peripheral surface of the clamping ring  31 . The positive-locking element  36  must not be formed as a ring. It can be, for example, in the form of individual sections which in the circumferential direction of the clamping ring  31  are positioned at a distance from one another. The positive-locking element  36  serves for reliably securing the hose  29  axially fixedly on the exhaust socket  16  in the mounted position. Accordingly, the positive-locking element  36  is configured such that it can reliably perform this axial securing function. 
   Since in the preferred embodiment the positive-locking element in cross-section has a curved exterior, it can be moved easily into the mounting position during the attachment process of the hose  29  on the exhaust socket  16 . 
   At a spacing from its free end face  37 , the exhaust socket  16  has in its inner wall  38  a positive-locking counter element  39  which is engaged positive-lockingly by the positive-locking element  36  in the mounted position of the hose  29 . When the positive-locking element  36  is a ring, the positive-locking counter element  39  is an annular groove in the inner wall  38  of the socket  16 . The cross-sectional shape of the positive-locking counter element  39  is matched to the cross-sectional shape of the positive-locking element  36  so that the positive-locking element in the mounted position rests areally against the wall of the positive-locking counter element  39 . 
   The clamping ring  31 , relative to its outer diameter, is configured such that it can be inserted into the socket  16  only in the compressed state. For this purpose, the clamping ring  31  is elastically compressed by the clamping device  33  to such an extent that it can be inserted with the positive-locking element  36  into the socket  16 . When the clamping device  33  is a hose clamp, the clamping ring  31  can be reduced continuously to any required diameter. Advantageously, the clamping ring  31  is compressed elastically to such an extent that the positive-locking element  36  upon insertion rests against the inner wall  38  of the socket  16 . In this way, the hose end  34  can be inserted without problems until the positive-locking element  36  is at the level of the positive-locking counter element  39 . The clamping device  33  is released again so that the clamping ring  31  is elastically widened. When doing so, the positive-locking element  36  moves into the positive-locking counter element  39 . 
   The clamping ring  31  is configured such that in the mounted position it rests at a high pressing force against the inner wall  38  of the socket  16 . The slot  32  is so wide that the clamping ring  31  can be compressed elastically sufficiently in order to insert it together with the positive-locking element  36  into the socket  16 . 
   In order to simplify the connecting action of the hose  29  on the socket  16 , the clamping device  32  is advantageously fastened on the clamping ring  31  such that it comes into contact with the end face  37  of the socket  16  when the positive-locking element  36  is at the level of the positive-locking counter element  39 . Then it is only necessary during mounting to release the clamping device  33  so that the positive-locking element  36 , as a result of the radial elastic widening of the clamping ring  31 , moves into the positive-locking counter element  39  of the socket  16 . Advantageously, the clamping device  33  is completely released so that the clamping ring  31  rests at a high clamping force against the wall  38  of the socket  16 . 
   Since the hose  29  with its lower end  34  rests against the bottom  41  of the folded portion  35  of the clamping ring  31 , escaping of the sucked-in medium through the slot  32  is reliably prevented. With this configuration, escaping of the removed medium and a return flow is prevented when the exhaust device is switched off. 
   In the described embodiment, the clamping force by which the clamping ring  31  is forced against the inner wall  38  of the socket  16  is derived from the spring force of the clamping ring  31  itself. However, it is also possible to configure the clamping ring  31  and the clamping device  33  such that the clamping force can be adjusted in the mounted position of the clamping ring  31 . This is achieved in that the fastening device  33  is attached to the clamping ring  31 . As a result of the fixed connection, the clamping ring  31  is widened or compressed mandatorily by the clamping device  33  when the clamping device  33  is actuated. 
   In the initial position, the clamping ring  31  and the positive-locking element  36  are configured such the clamping ring can be inserted into the socket  16 . In contrast to the preceding embodiment, the clamping ring  32  is now widened with the clamping device  33 . The positive-locking element  36  reaches in this way the positive-locking counter element  39 . By means of the clamping device  33 , the pressing force with which the clamping ring  31  rests against the inner wall  38  of the socket  16  can thus be adjusted to the respective mounting conditions, in particular, the pressing force can be readjusted anytime. 
   The clamping device  33  is preferably configured as a hose clamp where, by means of a clamping screw  40 , a hose clamp can be widened or compressed in a way known in the art. 
   In the described second embodiment, the hose clamp  33  has its smallest diameter in the initial state. As soon as the clamping ring  31  is inserted into the socket  16 , the hose clamp  33  is widened by actuation of the adjusting screw  40  as is known in the art. Since the clamping ring  31  is fastened on the hose clamp  33 , the clamping ring  31  is widened accordingly. 
   In the first embodiment, in which the hose clamp  33  is not fixedly connected with the clamping ring  31 , the hose clamp  33 , before insertion of the clamping ring  31  into the socket  16 , has a correspondingly small diameter. For attachment of the clamping ring  31  in the socket  16 , the hose clamp  33  is then widened by actuation of the adjusting screw  40 . The clamping ring  31  is also elastically widened correspondingly. 
   The exhaust system has been described in connection with an enclosure of a machine tool. The exhaust system can also be used anywhere where exhausting of rooms, devices, other machines and the like must be performed. 
   In the exhaust system, it is possible to eliminate the cuttings basket  18  when, for example, no cuttings are generated by using the machine tool. This is, for example, the case when within the housing-type enclosure  1  grinding processes are performed. By means of the exhaust device, air is exhausted also in this situation from the interior of the enclosure. The grinding dust generated during grinding is then entrained in the airflow and reliably removed from the interior of the enclosure. 
   The cleaning unit  23 , in deviation from the illustrated embodiment, can also have a stationery cleaning nozzle  24  which does not rotate about its axis. In this case, about the circumference of the cleaning nozzle several nozzle openings are provided via which the cleaning medium can be expelled. In order to be able to reach all sidewalls and also the bottom of the cuttings basket  18  with the cleaning medium, it is advantageous when the cleaning nozzle projects centrally into the cuttings basket  18 . The nozzle openings are provided on the cleaning nozzle  24  such that the sidewalls  19  to  21  as well as the bottom  22  of the cuttings basket  18  are completely within reach of the cleaning medium. 
   It is moreover possible to provide several such cleaning units  23 . For example, each sidewall  19  to  21  and/or the bottom  22  of the cuttings basket  18  can have correlated therewith a cleaning unit, respectively. 
     FIG. 6  shows an embodiment in which the hose  29  with its connecting end  34  is inserted into a sleeve-shaped plug-in receptacle  42  and is fastened thereto. The plug-in receptacle  42  has a sleeve section  43  widened with respect to the inner and outer diameters into which the connecting end  34  is inserted. The hose  29  is positioned with its end face  34  on an annular shoulder  44  which is formed at the transition from the sleeve section  43  at the end into an insertion section  45  of the plug-in receptacle  42 . The outer diameter of the connecting end  34  of the hose  29  is smaller than the inner diameter of the sleeve section  43 . Into the annular space  46  formed in this way, a sealing compound is introduced by which the hose  29  is fixedly connected to the plug-in receptacle  42 . 
   The plug-in receptacle  42  is inserted with its plug-in section  45  into the exhaust socket  16  until the plug-in receptacle  42  contacts with its annular shoulder  44  the exhaust socket  16 . 
   As shown in  FIG. 7 , the exhaust socket  16  is provided on diametrically opposed sides with suspension brackets  47  of which only one is shown in FIG.  7 . Clamping levers (not illustrated) are suspended therefrom, as is known in the art, which are supported pivotably on the outer side of the plug-in receptacle  42 . Upon insertion of these clamping levers into the suspension brackets  47  and clamping action, the plug-in receptacle  42  is clamped with its annular shoulder  44  against the end face of the exhaust socket  16 . Such quick clamping devices are known and, therefore, will not be explained in more detail in this connection. By means of these quick-clamping closures, the hose  29  can be quickly mounted and detached. 
   The entire exhaust system can be inserted very easily into the mounting opening  2  of the enclosure as well as removed from it. For this purpose, the exhaust system has on two opposed sides slidable clamping bars  48 ,  49  and  50 ,  51  ( FIGS. 1 ,  3  and  7 ) which can be moved relative to one another. The slidable clamping bars  48  to  51  are arranged on the base plate  12  adjacent to the angled edges  8 ,  10  of the mounting frame  3 . The slidable clamping bars  48  to  51  are, for example, formed as approximately U-shaped profile sections which overlap one another telescopingly. In the area in which they are overlapped by the slidable clamping bars  48 ,  50 , the slidable clamping bars  49 ,  51  are provided with an opening (not illustrated) extending in the longitudinal direction; a wing screw  52 ,  53  projects through the opening and clamps the two slidable clamping bars relative to one another in the clamping position. At their ends facing away from one another, the slidable clamping bars  48  to  51  are provided with two parallel clamping stays  54 ,  55  which project past them in the sliding direction, are arranged upright, and advantageously are monolithic parts of the sliding clamping bar, respectively. 
   After loosening the screws  52 ,  53 , the slidable clamping bars can be moved on the base plate  12  to such an extent that the clamping stays  54 ,  55  are retracted and do not project past the sidewalls  56 ,  57  by which the base plate  12  is connected with the angled edges  9 ,  11  of the mounting frame  2 . As illustrated in  FIG. 7 , two slot-shaped openings  58 ,  59  are provided in the sidewall  56  for allowing penetration of the clamping stays  54  through which the clamping stays  54  project in the clamping position. The opposite sidewall  57  is also provided with corresponding slot-shaped openings (not illustrated) for the clamping stays  55  of the slidable clamping bars  48 ,  50 . 
   In the position illustrated in  FIG. 7 , the slidable clamping bars  48  to  51  are retracted to such an extent that the clamping stays  54 ,  55  do not project past the sidewalls  56 ,  57 . In this way, the mounting frame  3  can be inserted simply into the mounting opening  2  of the enclosure  1  such that the mounting frame  3  rests with the outwardly angled edges  8  to  11  on the rim of the mounting opening  2 . Subsequently, the slidable clamping bars  48  to  51  are moved outwardly relative to one another such that the clamping stays  54 ,  55  project through the slot-shaped openings  58 ,  59  in the sidewalls  56 ,  57 . By means of these clamping stays  54 ,  55 , the rim of the mounting opening  2  is engaged from below and, in this way, the entire exhaust system is safely secured against being lifting from the enclosure  1 . The clamping stays  54 ,  55  are provided such that the mounting frame  3  with its angled edges  8  to  11  are pulled tightly against the exterior side of the rim of the mounting opening  2 . Advantageously, the end face of the clamping stays  54 ,  55  facing the mounting opening  2  of the enclosure  1  extend at a slant or are rounded so that tolerances can be compensated effortlessly when tightening the exhaust system on the enclosure  1 . After securing the exhaust system, the screws  52 ,  53  are tightened so that the slidable clamping bars  48  to  51  are clamped against one another and can no longer be pushed back into the release position. 
   When the exhaust system is to be demounted, only the wing screws  52 ,  53  must be released and the sliding clamping bars  48  to  51  must be pushed back to such an extent that the clamping stays  54 ,  55  no longer project past the sidewalls  56 ,  57  of the mounting frame  3 . By means of the two handles  13 ,  14 , the exhaust system can be lifted effortlessly. 
   The exhaust system with the cuttings basket  18  prevents the cuttings from being exhausted. Without the exhaust system the cuttings which have been sucked in would form nests of cuttings within the suction hose or would deposit within the exhaust device. This would result in an increased servicing expenditure, in an increased fire risk when using cooling lubricants as cleaning medium, in a limited return flow of the cooling lubricant, in additional resistance of the airflow, and would cause operational disruptions. By employing the cuttings basket  18 , these advantages are reliably prevented in a constructively simple way. The mesh of the cuttings basket  18  can have a wire diameter of, for example, 0.8 mm and a mesh width of, for example, 2.5 mm. Depending on the type of application of the cuttings basket  18 , other dimensions can be provided also. The cuttings basket  18  can be reliably and even permanently cleaned by means of the cleaning unit  23 .