Abstract:
The invention relates to a quick chucking unit with a chuck receptacle formed by a basic body, with at least one chucking element that can move relative to the basic body between an unlatched and latched position, with a cylinder and a piston element situated within the cylinder, which together with the cylinder, borders at least one pressure region, wherein pressurizing the pressure region moves the chucking element into the latched or unlatched position, wherein the piston element is designed as a piston element fixed in place relative to the basic body, and the cylinder is designed as a cylinder element that can move relative to the basic body and piston element. The invention also relates to a sealing unit for such a quick chucking unit, as well as to a quick chucking system.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a quick chucking unit with a chuck receptacle formed by a basic body, with at least one chucking element that can move relative to the basic body between an unlatched and latched position, with a cylinder and a piston element situated within the cylinder, which, together with the cylinder, borders at least one pressure region, wherein pressurizing the pressure area with a pressurizing means moves the chucking element into the latched or unlatched position. The invention also relates to a sealing unit for sealing the chuck receptacle of a quick chucking unit, as well as to a quick chucking system comprising a quick chucking unit and sealing unit. 
     The quick chucking units mentioned above are already known from prior art, e.g., form DE 103 17 336 A1 or DE 20 2004 009 283 U1. In these quick chucking units, the piston element is situated in a cylinder so that it can move axially, wherein the piston element moves the chucking element into the unlatched or latched position when the pressure area is pressurized. The chucking elements can thereby take the form of balls, pins or sliders. 
     SUMMARY OF THE INVENTION 
     The object of this invention is to propose a quick chucking unit that exhibits an advantageous design and reliable function. 
     Proposed for this purpose is a quick chucking unit of the aforementioned type that also exhibits the features of the independent claim. As a consequence, the piston element is designed as a piston element that is fixed in place relative to the basic body, and the cylinder is designed as a cylinder element that can move relative to the basic body and piston element. According to the invention, the cylinder element, and not the piston element, is then moved when pressurizing the pressure region with a fluidic pressurizing means, e.g., in particular compressed air or hydraulic fluid. Because a fixed piston element is provided, subassemblies or units can be arranged and secured to the piston element. In particular, the pressure region can take the form of a ring running around the piston element. 
     The piston element is advantageously designed as a hollow piston element. The use of a hollow piston element provides structural space within the hollow piston element for arranging subassemblies or units. The subassemblies or units can be secured directly to the inside of the hollow piston element. The hollow piston element is thereby open on at least one side, or accessible from at least one side, so that corresponding subassemblies or units can be incorporated into the hollow piston element. 
     The inside of the piston element designed as a hollow piston element preferably extends in an axial elongation of the chuck receptacle in order to sectionally and axially guide a pulling bolt that reaches into the chuck receptacle. In other words, the piston element, or its inside, assumes a guiding function as the pulling bolt is introduced into the chuck receptacle. 
     The cylinder element is thereby advantageously situated on the piston element so that it can shift axially, and directly coupled, preferably by means of inclined guides, with the chucking element for motion in order to radially move at least one chucking element. The inclined guides can thereby be designed as a wedge-shaped hook drive: as the cylinder element moves axially, the inclined arrangement of interacting guides results in a radial movement of the at least one chucking element preferably designed as a chucking slider. 
     To border the pressure area in an axial direction, the piston element can exhibit a continuous piston section that projects radially outward like a ring collar. This piston section advantageously tightly abuts the inner wall of the cylinder element. 
     According to the invention, at least one spring element can be provided for acting on the cylinder element in such a way as to hold the chucking elements in the latched position to ensure that the chucking elements can be latched independently of pressure. Several spring elements can advantageously be provided, supported on the piston section of the piston element at one end, and on the cylinder element at an other end. 
     To border the pressure region on the side facing away from the chuck receptacle, the cylinder element can encompass a cover element that envelops the piston element like a ring. Providing such a cover element makes it possible to achieve an advantageous assembly; the cylinder element can be pushed onto the piston element without a cover element, wherein the pressure region is then sealed by the cover element. 
     In another especially preferred embodiment of the invention, the basic body exhibits a cylinder area that holds the cylinder element and can be pressurized to movably accommodate the cylinder element. The cylinder element itself can move within the cylinder area, thereby receiving the function of a piston. The advantage of such a design is that the cylinder area is easily accessible to a pressure line, which ensures a reliable supply of pressure. 
     The pressure region can here be pressurized via a radial opening in the cylinder element, which corresponds with a pressure supply line, independently of the axial position of the cylinder element. To this end, for example, a pressure gap limited in the two axial directions, into which a compressed air line from the basic body empties, can be situated between the cylinder element and the basic body comprising the cylinder area. 
     The cylinder area and pressure region are here preferably designed in such a way that the chucking element assumes its latched position during pressurization of the cylinder area, and its unlatched position during pressurization of the pressure region, which happens to lie between the piston element and cylinder element. 
     The cylinder area can in turn be sealed on the side facing away from the chuck receptacle with a sealing element that tightly abuts the piston element. The piston element can, in particular, be arranged between the basic body and sealing element under an initial load. In addition, the sealing element can exhibit a passage toward the inside of the piston element, designed as a hollow piston element, at least in the area of the central longitudinal axis of the piston element. For example, a corresponding subassembly or corresponding unit can be introduced via this passage into the hollow piston element and/or electric lines can be passed through this passage. 
     Stops or attachment sections for subassemblies or units to be incorporated in the hollow piston element can be provided inside the hollow piston element. This permits a reliable and accurate positioning of the subassemblies or units inside the hollow piston element. 
     The object mentioned at the outset is also achieved by means of a sealing unit to be situated in a chuck receptacle, which closes the chuck receptacle of a quick chucking unit, in particular, a quick chucking unit according to the invention. Such a sealing unit has a pressure element that can be moved to a sealed position from an insertion position in which it can be introduced into the chuck receptacle. In addition, such a sealing unit exhibits an elastic sealing element, which is pressed by the pressure element against the area of the basic body enveloping the chuck receptacle with the pressure element in the sealed position. In the insertion position, the diameter of the pressure element with the sealing element is smaller than the chuck receptacle, making it possible to introduce the pressure element with sealing element into the chuck receptacle. By shifting the pressure element into the sealed position, the elastic sealing element is pressed, in particular, radially outward against the radially inward section of the basic body comprising the chuck receptacle. 
     To shift the pressure element from the insertion position to the sealed position, use is advantageously made of a chucking element of the quick chucking unit. Such a chucking element advantageously interacts with the pressure element in such a way that the chucking element brings the pressure element into the sealed position while the chucking element is moved to its latched position. To this end, inclined guides can be secured, in particular to the pressure element or to the chucking element, which transfer the pressure element into the sealed position as a chucking element that moves radially inward. 
     The pressure element can here advantageously be designed as a ring, and axially move from the insertion position into the sealed position on a carrier section. As already mentioned, corresponding inclined guides can be provided, which move the sealing element in the corresponding axial direction, given a chucking element that moves radially inward. 
     The sealing element is preferably designed as a sealing bellows, which is situated on the pressure element and on a ring- or plate-shaped edge of the carrier section that projects radially outward. The diameter of the sealing bellows is smaller with the pressure element in the insertion position than when moving the pressure element axially into the sealed position. The increasing diameter of the sealing element as the pressure element moves into the sealed position makes it possible to seal the chuck receptacle. 
     The carrier section as such can provide a valve body that is axially exposed to an initial stress by a spring, which is arranged in the carrier section, and which extends through the carrier section, through which compressed air can escape from the carrier section given an excess pressure inside the sealing unit, in particular to remove chips and contaminants in the area of the chuck receptacle. 
     The valve body can here encompass a valve plate supported on the upper side of the carrier section, along with a carrier section that extends in an axial direction through the carrier section. The valve body can have a T-shaped cross section. In addition to sealing the chuck receptacle with the sealing unit, providing such a valve body makes it possible to remove chips and contaminants in the area of the chuck receptacle of an accompanying chucking unit. 
     Another preferred embodiment of the invention provides a spring element that pushes the carrier section from a resting position to an activation position in the chuck receptacle and/or holds the carrier section in the activation position upon removal of a pulling bolt introduced in the chuck receptacle. If the carrier section is in the activation position, and a pulling bolt is introduced into the chuck receptacle in this activation position, the pulling bolt moves the carrier section into the resting position against the force of the spring. The resting position is thereby located inside the chuck receptacle. The spring element can be supported on the quick chucking unit or its basic body or sealing element and on the carrier section or an adapter situated between the carrier section and spring element. The advantage of providing such a spring element is that the carrier section can be automatically shifted to the activation position while removing the pulling bolt from the chuck receptacle. For example, if the at least one chucking element is also automatically shifted to the latched position by providing corresponding spring elements, the pressure element can be brought into the sealed position as a result, so that the sealing element seals the chucking element to a largely tight extent. This prevents chips or contaminants from getting into the chuck receptacle or into the quick chucking unit. 
     The carrier section can be guided from the resting position to the activation position and from the activation position to the resting position by means of a telescoping adapter, which, in particular, can rest against the quick chucking unit or on the inside of the piston element. The adapter can resemble a sleeve, wherein the spring element that moves the adapter into the activation position can be situated inside the adapter and act directly on the carrier section. The sealing unit according to the invention is provided, in particular for purposes of accommodation, in the piston element designed as a hollow piston element of a quick chucking unit according to the invention. 
     The object specified at the outset is also achieved with a quick chucking system comprising a quick chucking unit according to the invention and a sealing unit according to the invention situated therein. 
     Additional details and advantageous embodiments of the invention can be gleaned from the following specification, based on which the embodiments of the invention shown in the figures are described and explained in greater detail. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  is a first chucking unit according to the invention in exploded view; 
         FIG. 2  is a longitudinal section through the chucking unit according to  FIG. 1 ; 
         FIG. 3  is a second quick chucking unit according to the invention; 
         FIG. 4-6  are various operating states of the chucking unit according to  FIGS. 1 and 2 ; 
         FIG. 7  is a perspective view of a sealing unit according to the invention; 
         FIG. 8-11  are various operating states of the sealing unit according to  FIG. 7 ; 
         FIG. 12-14  is a chucking system according to the invention in various operating states. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The quick chucking unit  10  shown on  FIGS. 1 ,  2 ,  4 - 6  comprises a basic body  12 , which has a chuck receptacle  14 . The chuck receptacle  14  can accommodate a pulling bolt  16 , which can be latched in the quick chucking unit  10  by means of two opposing chucking elements  18  designed as chucking sliders. The pulling bolt  16  is here shown in a latched position in  FIGS. 2 and 4 , and in an unlatched position in  FIGS. 5 and 6 . 
     To make it easier to introduce the pulling bolt  16  into the chuck receptacle  14  and additionally achieve a concentric gripping of the pulling bolt  16 , the area  20  of the basic body  12  that forms the chuck receptacle  14  is slightly conical. 
     The two chucking elements  18  can be moved in a radial direction toward each other into a latched position and away from each other into an unlatched position in order to latch the pulling bolt  16 . To this end, the chucking elements  18  define inclined guides  22 , which interact with corresponding inclined guides, which are provided on a cylinder element  24  that can shift in an axial direction relative to the basic body  12 . The cylinder element  24  is here situated on a piston element designed as a hollow piston element  26  so that it can axially shift. The hollow piston element  26  is fixed concentrically around the central longitudinal axis  28  relative to the basic body  12 , and exhibits a piston section  30  that projects radially outward like a ring collar. 
     The cylinder element  24  has a cover element  34  that envelops the hollow piston element  26  like a ring in order to border a pressure area  32  between the hollow piston element  26  or its piston section  30  and the cylinder element, wherein said pressure area can be pressurized with a pressurizing means, in particular compressed air or hydraulic fluid. The cover element  34  is secured to the cylinder element  24  by means of a straining ring  35 . 
     As further evident from  FIG. 2 , the side  27  of the hollow piston element  26  facing the chuck receptacle  14  extends in an elongation of the chuck receptacle  14 , and is used to axially guide the pulling bolt  16  that reaches into the chuck receptacle  14 . The upper edge of the hollow piston element  26  provides inclined guides as an insertion aid for the pulling bolt  16 . 
     As is evident in particular from  FIGS. 1 and 2 , several spring elements  36  are arranged coaxially around the central longitudinal axis  28  between the cylinder element  24  and piston section  30  of the hollow piston element  26 , which exert an axially upward force on the cylinder element  24 . The cylinder element  24  is situated inside a cylinder area  38  on the basic body so that it can axially move. The cylinder area  38  is sealed by means of a sealing element  40  on its axially lower side, which fixes the hollow piston element  26  to the basic body  12 . One face of the hollow piston element  26  acts against the basic body  12 , while the other face of the hollow piston element  26  acts against the sealing element  40 . 
     The sealing element  40  has a passage  42  toward the interior space  44  of the hollow piston element  26  in the area of the central longitudinal axis  28 . As depicted on  FIG. 12-14 , the interior space  44  can be provided with a sealing unit for sealing the chuck receptacle  14 . In addition, other subassemblies or units can be arranged in the interior space  44 , e.g., a monitoring camera or monitoring sensors. 
     The quick chucking unit  50  shown in  FIG. 3  essentially corresponds to the quick chucking unit  10  according to  FIGS. 1 and 2 , wherein corresponding components are labeled with corresponding reference numbers. The fundamental difference is that the basic body  12  does not exhibit a cylinder area  38  for the cylinder element  24 . Rather, the side of the piston section  30  facing away from the pressure area  32  is provided with a second pressure area  52 , which can be pressurized to move the cylinder element  24  axially upward. The pressure space  32  can be pressurized to move the cylinder element  24  axially downward. The hollow piston element  26  can here be flanged to the basic body  12 . 
       FIG. 4-6  show various operating states of the quick chucking unit  10  according to  FIGS. 1 and 2 .  FIG. 4  depicts the quick chucking unit  10  with a pulling bolt  16  latched in the chuck receptacle  14 . The chucking elements  18  are here situated in their radially inward latched position. Even without pressurizing the cylinder area  38 , the force exerted by the spring elements  36  automatically maintains this latched position. If the pressure area  32  is pressurized via a pressure line  60  connected with the pressure area  32  as shown on  FIG. 5 , the cylinder element  24  moves axially downward. The inclined guides  22  simultaneously move the chucking elements  18  radially outward to their unlatched position. This releases the pulling bolt  16 , so that it can be removed from the chuck receptacle  14 , as depicted in  FIG. 6 . 
     The pressure area  32  is relieved of pressure in order to shift the chucking elements  18  out of the unlatched position into the latched position. To enhance the force applied by the spring elements  36 , the cylinder area  38  is pressurized via a pressure line  62  also provided in the basic body  12  (see  FIGS. 4 and 6 ). By contrast, the pressure area  52  is pressurized to move the cylinder element axially upward in the quick chucking unit  50  according to  FIG. 3 . 
     To pressurize the pressure area  32  with the cylinder element  24  in any position on the hollow piston element  26 , the cylinder element  24  has an intermediate pressure area  64  on its radially outer side that is bordered axially from above and axially from below by two continuous ring collars  66 . The intermediate pressure area  64  is situated in such a way as to correspond with the pressure line  60  in any pressure setting of the cylinder element  24 . The area of the intermediate pressure area  64  is provided with a passage  68 , through which the pressure means gets into the pressure area  32 . 
       FIG. 7-11  show a sealing unit  80  to be arranged in the interior space  44  of the chucking unit  10  according to  FIGS. 1 ,  2  and  4 - 6 . The sealing unit  80  here encompasses an annular pressure element  84  that can move on a carrier section  82  axially between an inserted position shown in  FIGS. 8 and 9  and a sealed position shown in  FIGS. 10 and 11 . A bellows-type elastic sealing element  88  is arranged between the pressure element  84  and a radially projecting edge  86  of the carrier section  82 . The carrier section itself can consist of several parts, as depicted in the figures. 
     With the pressure element in the inserted position, the sealing element  88  projects only insignificantly, if at all, radially past the pressure element  84  or the edge  86 . In the sealed position of the pressure element shown in  FIGS. 10 and 11 , the sealing element  88  is pressed radially outward, and projects radially past the pressure element  84  and the edge  86 . 
     As is evident from  FIG. 8-11 , the carrier section  82  accommodates a sealing body  92  arranged below in the carrier section  82  under the initial stress of a spring  90 . The sealing body  92  encompasses a sealing plate  94  extending in a radial direction, which covers almost all of the upper side of the carrier section  82 . In addition, the sealing body  92  encompasses a sealing rod  96  extending in an axial direction, which runs in the area of the central longitudinal axis  98  and passes axially through the carrier section  82 . When the pressure inside the carrier section  82  increases, the sealing body  92  lifts from the upper side of the carrier section  82  when incorporated in a chucking unit, allowing air  83  to stream radially out from inside the carrier section  82  between the sealing plate  94  and upper side of the carrier section, as denoted on  FIG. 11 . This makes it possible to remove chips and contaminants. 
     The carrier section  82  with sealing body  92  and pressure element  84  can be shifted axially upward from a resting position depicted in  FIG. 8  into an activation position illustrated in  FIGS. 9-11 . To this end, a telescoping adapter  100  is provided for specifically guided motion, which interacts with the carrier section  82 , and with the hollow piston element  26  when incorporated in the chucking unit  10 , as depicted in  FIGS. 12-14 . 
     In  FIG. 12-14 , the sealing unit shown in  FIG. 7-11  is used in the quick chucking unit depicted on  FIGS. 1 ,  2  and  4 - 6 . The sealing unit is completely within the interior space  44  of the hollow piston element  26 . A spring element  102 , supported on the inside of the sealing element  40  and on the side of the carrier section  82  facing the sealing element  40 , shifts the adapter  100  and the carrier section  82  from the resting position into the activation position. The resting position of the carrier section  82  is shown in  FIG. 12 , wherein the pulling bolt  16  is arranged in the quick chucking unit  10  in the latched state in this position. When the chucking elements  18  are shifted to their unlatched position by pressurizing the pressure area  32 , and the pulling bolt is removed from the chuck receptacle  14  in an axial direction, the spring element  102  causes the carrier section  82  to move into the activation position, in which it is located in the chuck receptacle  14 , as depicted in  FIG. 13 . However, there still remains a gap between the area  20  of the basic body bordering the chuck receptacle  14  and the packing element  88  in this state. If the chucking elements  18  are shifted to their latched position, e.g., as the result of force exerted by the spring elements  36  and/or pressurization of the cylinder area  38 , as depicted in  FIG. 14 , the pressure element  84  is moved axially upward into the sealed position by the chucking elements  18 . To this end, the chucking elements  18  are provided with inclined guides  104 , and a conical guide section  106  that corresponds with the inclined guides  104  provided on the pressure element  84 . 
     As evident from  FIG. 14 , the sealing element  88  is pressed radially outward, and at least to a large extent tightly, against the wall  20  of the basic body bordering the chuck receptacle  14  with the pressure element  84  in the sealed position. This prevents chips or contaminants from penetrating into the quick chucking unit  10  via the chuck receptacle  14 . 
     In order to axially limit the stroke of the adapter  100  within the hollow piston element  26 , the hollow piston element  26  has a continuous stop  112 , which interacts with a ring collar  114  located at the adapter with the carrier section  82  or adapter  100  in the activation position, as shown on  FIG. 14 . Accordingly, the axially upper end of the adapter  100  exhibits an inwardly projecting stop  116 , which, in the activation position, interacts with a ring collar  120  that is situated on the lower side of the adapter  82  and exhibits a counter-stop  118 , as shown in  FIGS. 9 ,  10 ,  11  and  13 ,  14 . 
     As explained on  FIG. 11 , in order to remove contaminants or chips arising on the upper side  108  of the basic body  12 , the interior space  110  of the carrier section  82  or hollow piston element  26  can be pressurized with compressed air, thereby lifting the sealing body  92  against the force exerted by the spring  90 , and letting the compressed air blow away contaminants or chips that may be present on the upper side  108 .