Abstract:
A detachable connecting device for connecting first and second functional components to each other has a connecting element arranged in a connecting element receptacle of the first functional component so as to be force-transmitting. A bushing that is circumferentially closed is arranged on the connecting element. A bushing receptacle is provided on the second functional component. The bushing together with the connecting element is arranged in the bushing receptacle for realizing force transmission between connecting element and second functional component. The bushing receptacle has a circumferential side relative to the connecting axis that is provided with an insertion section with insertion opening to insert the bushing from outside of the circumferential side into the interior of the bushing receptacle or to remove the bushing from the interior of the bushing receptacle through the circumferential side.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. German patent application No. 10 2013 017 166.0 filed Oct. 16, 2013. 
     BACKGROUND OF THE INVENTION 
     The invention concerns a detachable connecting device for connecting at least two functional components, in particular an intake pipe housing with a cylinder head, in particular of an internal combustion engine, in particular of a motor vehicle, comprising at least one pin-like connecting element that, by means of a rotary and/or plug-in movement relative to an imaginary connecting axis of the connecting device, can be arranged so as to be force-transmitting in at least one connecting element receptacle of a first one of the functional components. 
     Also, the invention concerns a functional component, in particular an intake pipe housing, comprising at least one part of at least one detachable connecting device, in particular of a connecting device according to the invention, for connecting the functional component with at least one other functional component, in particular a cylinder head, in particular of an internal combustion engine, in particular of a motor vehicle, wherein the connecting device comprises at least one pin-like connecting element that, by means of a rotary and/or plug-in movement relative to an imaginary connecting axis of the connecting device, can be arranged in at least one connecting element receptacle of the at least one other functional component in a force-transmitting way. 
     A commercially available intake pipe of an air intake system of an internal combustion engine is detachably connected by means of screws on a cylinder head of the internal combustion engine. At locations that are difficult to access, in particular in an engine compartment of a motor vehicle, it may be difficult to actuate the screws. 
     The invention has the object to design a connecting device and a functional component of the aforementioned kind such that the connection between the at least two functional components can be realized and actuated in a simple way. 
     SUMMARY OF THE INVENTION 
     This object is solved according to the invention in that the connecting device comprises at least one bushing, which is circumferentially closed relative to the connecting axis and can be arranged on the at least one connecting element, and at least one bushing receptacle of a second one of the functional components in which the at least one bushing with the at least one connecting element can be arranged for realizing force transmission between the second functional component and at least the connecting element, wherein the at least one bushing receptacle, at a circumferential side relative to the connecting axis, comprises an insertion section with an insertion opening for inserting the at least one bushing into the interior of the at least one bushing receptacle from outside of the circumferential side and/or for removal of the at least one bushing from the at least one bushing receptacle through the circumferential side, i.e., in radial direction to the connecting axis. 
     According to the invention, at least one sleeve-shaped bushing is provided which is closed circumferentially. For closing the connecting device, the at least one bushing is arranged on the at least one connecting element. The at least one connecting element can be inserted for this purpose into the at least one bushing. The at least one bushing can be removed together with the connecting element from the at least one bushing receptacle through the circumferential side. In reverse, the at least one bushing for connecting the functional components can be inserted with the at least one connecting element through the circumferential side into the at least one bushing receptacle. In this way, the at least one bushing together with the at least one connecting element can remain on the first functional component. The at least one connecting element can thus be mounted also at locations that are difficult to access. In particular in motor vehicles, the functional components can be mounted so as to be difficult to access in an engine compartment. In this case, it can be advantageous that the at least one connecting element must not be removed completely in order to be able to separate the functional components. 
     Accordingly, at least one connecting element can remain in a bushing upon disassembly when, for example, this at least one connecting element is not accessible due to mounting space limitations at the time of disassembly of the functional component. 
     Advantageously, the connecting device can comprise one or several bushing receptacles with an insertion opening with parallel orientation as well as several further bushing receptacles without insertion opening of an insertion section at the circumferential side. 
     Advantageously, the at least one bushing receptacle, in particular the insertion section, can be matched to the employed at least one bushing. In this way, it is not required that the at least one bushing is matched especially to the at least one connecting element and/or the at least one bushing receptacle. In this way, commercially available bushings can be employed. For all connecting devices the same bushings can be employed which simplifies greatly handling and mounting of the components. 
     A height of the at least one bushing axial to the connecting axis can be advantageously between approximately 14 mm and approximately 40 mm, preferably between approximately 20 mm and approximately 30 mm. 
     A height of the at least one bushing receptacle, in particular a receiving section, axial to the connecting axis can be advantageously between approximately 14 mm and approximately 40 mm, preferably between approximately 20 mm and approximately 30 mm. 
     Advantageously, the at least one bushing can be comprised of metal or comprise metal. In this way, the mechanical stability of the at least one bushing can be improved. 
     Advantageously, at least one bushing of the connecting device can have a non-round, for example, an oval, shape or can be provided with a slotted hole. 
     The bushings can be turned, rolled or produced by a pressing method. 
     An expansion of the insertion section, in particular a width of inner sides of sidewalls of the insertion section, transverse to the connecting axis, can be advantageously between 2 mm and 6 mm, preferably approximately 4 mm. In this way, the at least one bushing upon insertion into the at least one bushing receptacle and upon removal from the bushing receptacle can be guided easily and stably within the insertion section, in particular between the sidewalls of the insertion section. 
     The at least one connecting element can advantageously be suitable for transmission of tensile forces or pressure forces which are oriented axially to the connecting axis. 
     Advantageously, the at least one connecting element can be a screw, in particular a machine screw, or can comprise one. The at least one connecting element can thus be screwed by means of a turning movement into a corresponding thread in the first functional component. Instead of a screw, a different kind of rotary/plug-in connecting element, in particular a connecting element of a bayonet-like connection, can be provided also. 
     The at least one connecting element receptacle of the first functional component can be advantageously provided with a thread. At least one part of the first functional component that is provided with the thread can be comprised of metal or comprise metal. In this way, the mechanical stability of the thread can be increased. Advantageously, the first functional component can be comprised of metal or comprise metal. The thread can be arranged directly in the first functional component. Instead, a thread insert can be employed also. 
     The at least one bushing can be connected frictionally and/or with form fit with the at least one bushing receptacle. The at least one bushing can advantageously be clamped in the at least one bushing receptacle. By means of the at least one bushing, appropriate forces can be transmitted between the at least one connecting element and the second functional component. The at least one bushing can prevent in this context that the force is directly transmitted from the at least one connecting element onto the second functional component, in particular the bushing receptacle. The risk of damaging the at least one bushing receptacle can thus be reduced. Also, positional tolerance between the functional components can be compensated better. 
     The insertion opening of the insertion section of the at least one bushing receptacle can be designed such that the at least one bushing can be inserted from outside of the circumferential side into the interior of the at least one bushing receptacle. For separation, the at least one bushing can be accordingly removed through the circumferential side from the at least one bushing receptacle. 
     An axial expansion of the insertion opening relative to the connecting axis can be advantageously at least as large as the corresponding axial expansion of the at least one bushing. In this way, the at least one bushing can be simply inserted and also removed in its final orientation, which it is to assume in the bushing receptacle, from outside of the circumferential side into the interior of the at least one bushing receptacle. 
     The at least one bushing can advantageously be inserted transversely to the connecting axis, in particular approximately in radial direction, into the at least one bushing receptacle. The at least one bushing receptacle can form with the at least one bushing a kind of clamping connection or a locking connection. The clamping connection or locking connection can be simply closed and separated. 
     Advantageously, one end of the at least one connecting element that is facing away from the at least one connecting element receptacle can be accessible from the exterior of the functional component. In this way, the connecting element can be actuated easily, in particular released or fixed. 
     Advantageously, the detachable connecting device can be provided for attachment of an intake pipe housing on a cylinder head of an internal combustion engine. The cylinder head can be the first functional component or comprise it. The intake pipe housing can be the second functional component or comprise it. The at least one connecting element receptacle can advantageously be arranged on the cylinder head. The at least one bushing receptacle can advantageously be arranged on the intake pipe housing. 
     The invention is not limited to functional components of an internal combustion engine of a motor vehicle. Instead, it can also be used in other kinds of internal combustion engines, in particular industrial motors. It can also be used independent of internal combustion engines, in particular in motor vehicles. 
     In an advantageous embodiment, the at least one bushing receptacle can comprise an approximately U-shaped inner profile. The at least one bushing can thus be inserted in a simple way through the opening of the “U”. The legs of the “U” can form in this context sidewalls of the insertion section that delimit the insertion opening. The sidewalls can stabilize the insertion section. Moreover, the sidewalls can serve as guide means for the at least one bushing upon installation or disassembly. 
     In a further advantageous embodiment, an inner width of the insertion opening at least in one clamping area of the at least one bushing receptacle, viewed in circumferential direction relative to the connecting axis, can be smaller than an outer diameter of the at least one bushing at least in a section of the at least one bushing which is located, when the bushing is mounted, axially relative to the connecting axis at the level of the clamping area. In its installed state, the at least one bushing can be secured in the clamping area. At least in the clamping area a type of clamping connection or locking connection can be realized. The at least one clamping area can thus prevent that the at least one bushing can escape undesirably from the at least one bushing receptacle. 
     In the clamping area, a mechanical, in particular elastic, resistance can be realized which must be overcome for removal of the at least one bushing from the at least one bushing receptacle. The mechanical resistance can advantageously be so small that the at least one bushing can be inserted easily into the at least one bushing receptacle and removed from it with minimal force expenditure. On the other hand, the required force expenditure can be sufficiently large so that the at least one bushing in the at least one bushing receptacle can be stably secured. 
     The inner width of the insertion opening can be advantageously between approximately 5 mm and approximately 20 mm, preferably between approximately 10 mm and approximately 15 mm, preferably approximately 12.5 mm. 
     An expansion of the clamping area axial to the connecting axis can advantageously be between approximately 8 mm and approximately 18 mm, preferably approximately 14.2 mm. 
     Advantageously, an outer diameter of the at least one bushing can be at least as large as an inner diameter of the at least one bushing receptacle, in particular of the receiving section of the at least one bushing receptacle, in particular at the level of the clamping area. In this way, the at least one bushing can be clamped stably in the at least one bushing receptacle. 
     The outer diameter of the at least one bushing can advantageously be between approximately 5 mm and approximately 20 mm, preferably between approximately 10 mm and approximately 15 mm, preferably approximately 13 mm. 
     An inner diameter of the at least one bushing receptacle, in particular of the receiving section of the bushing receptacle, in particular at the level of the clamping area can advantageously be between approximately 5 mm and approximately 20 mm, preferably between approximately 10 mm and approximately 15 mm, preferably approximately 12.8 mm. 
     Advantageously, the inner width of the insertion opening at least in the clamping area of the insertion section, viewed in circumferential direction relative to the connecting axis, can be smaller than the inner diameter of the at least one bushing receptacle, in particular of the receiving section of the bushing receptacle, at least in the section of the bushing receptacle that is located axially relative to the connecting axis at the level of the clamping area of the insertion section. In this way, upon insertion the at least one bushing, after passing the insertion section, can lock in the at least one bushing receptacle, in particular in the receiving section. 
     In a further advantageous embodiment, the at least one bushing receptacle can comprise at least one undercut at a transition of the insertion section into a receiving section, in particular in a clamping area of the bushing receptacle. With the at least one undercut, a tapered section or constriction of the insertion opening relative to the receiving section can be realized in a simple way. 
     Advantageously, at least two undercuts can be arranged on sides of the insertion section, in particular of the insertion opening, which are positioned circumferentially opposite to each other relative to the connecting axis. In this way, a uniform constriction and thus a uniform securing action of the at least one bushing in the at least one bushing receptacle can be realized. 
     Advantageously, an axial expansion of the at least one undercut relative to the connecting axis can correspond to the corresponding expansion of the clamping area. The expansion of the at least one undercut axial to the connecting axis can advantageously be between 8 mm and approximately 18 mm, preferably approximately 14.2 mm. 
     In a further advantageous embodiment, at least the insertion section of the at least one bushing receptacle can be at least partially elastic at least in a direction transverse to the connecting axis. In this way, at least a part of the insertion section can elastically yield for insertion and removal of the at least one bushing. In this way, an elastic clamping force, i.e., an elastic mechanical resistance can be realized which must be overcome for removal or insertion of the at least one bushing. By means of the elasticity, in particular mounting-related, component-related and/or operation-related tolerances can be compensated in a simple way. Also, in particular operation-related vibrations can be dampened in this way. 
     Advantageously, at least one sidewall of the insertion section can be elastic. 
     In a further advantageous embodiment, at least the bushing receptacle may comprise plastic material or be comprised of plastic material. Advantageously, the plastic material can be elastic. In this way, at least a part of the insertion section can be elastically yielding. Plastic material moreover can be processed easily. 
     Advantageously, at least the second functional component may comprise plastic material or be comprised of plastic material. In this way, the functional component can be realized in a weight-optimized fashion. 
     In a further advantageous embodiment, a radial inner circumferential side relative to the connecting axis of the at least one bushing receptacle, in particular of the receiving section, viewed in axial direction toward the connecting element receptacle can widen conically. In this way, mechanical contact between the at least one bushing receptacle and the at least one bushing can be reduced in the widened section. Advantageously, a radial outer circumferential side of the bushing can be spaced apart from the radial inner circumferential side of the bushing receptacle. As a whole, in this way a proportion of the pressing force, which is acting through the at least one connecting element onto the at least one bushing and can be transmitted from the latter onto the at least one bushing receptacle, can be reduced. Moreover, in this way tolerances of various kinds can be compensated better. 
     An opening angle of the radial inner circumferential side of the at least one bushing receptacle can be advantageously between approximately 0.5 degrees and approximately 5 degrees, in particular 4.5 degrees. 
     In a further advantageous embodiment, the radial inner circumferential side of the at least one bushing receptacle, in particular the receiving section, can comprise at its end face rim which is facing the connecting element receptacle at least one widened section for receiving at least one projection at the radial outer circumferential side of the at least one bushing. In the at least one widened section the at least one projection of the at least one bushing can be positioned easily. An area of the at least one bushing receptacle which realizes the at least one widened section advantageously can act as a kind of stop for the at least one projection of the at least one bushing. In this way, an insertion depth of the at least one bushing into the at least one bushing receptacle can be limited. 
     The at least one widened section can be realized by a step in the radial inner circumferential side of the at least one bushing receptacle. The step can be open at one end face of the at least one bushing receptacle. In this way, the at least one bushing can be resting directly on the first functional component, in particular the connecting element receptacle. Accordingly, force transmission between the at least one bushing and the first functional component can be improved. 
     The at least one widened section can be circumferentially continuous relative to the connecting axis. However, it can also be circumferentially interrupted. 
     The at least one projection at the radial outer circumferential side of the at least one bushing can be circumferentially continuous or interrupted. Several projections may be provided also. 
     Moreover, the object is solved according to the invention for the functional component in that the functional component has at least one bushing receptacle in which at least one bushing, which is circumferentially closed relative to the connecting axis and into which the at least one connecting element can be inserted, can be arranged for realizing force transmission between the functional component and the at least one connecting element, wherein the at least one bushing receptacle at a circumferential side relative to the connecting axis comprises an insertion section with an insertion opening for insertion of the at least one bushing into the interior of the at least one bushing receptacle from outside of the circumferential side and/or for removal of the at least one bushing from the at least one bushing receptacle through the circumferential side. 
     The advantages and features indicated in connection with the connecting device according to the invention and their advantageous embodiments apply likewise to the functional component according to the invention and its advantageous embodiments, and vice versa. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages, features, and details of the invention result from the following description in which an embodiment of the invention will be explained in more detail with the aid of the drawing. A person of skill in the art will consider the features disclosed in combination in the drawing, the description, and the claims also expediently individually and combine them to other meaningful combinations. 
         FIG. 1  shows an intake pipe of an internal combustion engine of a motor vehicle with several closed connecting devices and an open connecting device for attachment of the intake pipe on a cylinder head, wherein the open connecting device comprises an open bushing receptacle with a bushing and a screw. 
         FIG. 2  shows a longitudinal section of the intake pipe of  FIG. 1  through the open bushing receptacle with the bushing. 
         FIG. 3  is a detail view of another longitudinal section of the intake pipe of  FIGS. 1 and 2  through the open bushing receptacle with the bushing. 
         FIG. 4  shows the intake pipe of  FIGS. 1 to 3 , wherein the bushing is located herein outside of the open bushing receptacle. 
         FIG. 5  is a detail view of the open bushing receptacle of the intake pipe of  FIGS. 1 through 4 , here without bushing. 
     
    
    
     In the Figures, same components are provided with same reference characters. 
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     In  FIGS. 1 to 5 , a suction pipe  10  of an air intake system of an internal combustion engine of a motor vehicle is illustrated in various views and sections. 
     The intake pipe  10  is detachable fastened by several screws  14  on the cylinder head  12  of the internal combustion engine. The cylinder head  12  is indicated in  FIGS. 1 and 2 . In  FIGS. 1 and 2 , two, respectively, one of the screws  14  is indicated in an exemplary fashion in dashed lines. 
     The housing of the suction pipe  10  is made of plastic material. It comprises, distributed on its outer side, a plurality of closed connecting devices  16  and an open connecting device  18  with which the intake pipe  10  is attached on the cylinder head  12 . Each of the connecting devices  16  and  18  comprises one of the screws  14 . 
     The closed connecting devices  16  are substantially functionally of a similar design. They each comprise a closed bushing receptacle  20 . In each closed bushing receptacle  20 , there is a bushing  24  coaxial to a respective imaginary connecting axis  22 . A screw  14  is seated in each one of the bushings  24 . 
     The closed bushing receptacles  20  each comprise an approximately circular cylindrical radial inner circumferential side relative to the appropriate connecting axis  22 . On the radial inner circumferential sides, the bushing receptacles  20  are stepped, respectively. The bushing receptacles  20  each comprises on their end faces which are facing the cylinder head  12  a cross section-widening receptacle for a projection  26  of the bushing  24  which will be explained infra in more detail. 
     The bushings  24  each are inserted into the closed bushing receptacles  20  from the side facing the cylinder head  12 . The bushings  24  are identical. In an exemplary, fashion, they are commercially available standard bushings. The bushings  24  are comprised of metal. They have substantially the shape of a hollow circular cylinder. The projections  26  already mentioned above are located each on one of the end faces of the bushings  24  at the radial outer circumferential sides. The projections  26  each extend circumferentially continuously in radial outward direction. An outer diameter  28  of the bushings  24  in the area outside of the projections  26  is, for example, 13 mm. The height  30  of the bushing  24  axial to the connecting axis  22  is, for example, 25 mm. 
     The cylinder head  12  has on the side that is facing the intake pipe  10  several threaded bores  32  for the screws  14 . The threaded bores  32  are arranged in accordance with the connecting devices  16  and  18 . 
     The open connecting device  18  comprises an open bushing receptacle  34 . The open bushing receptacle  34  is comprised of a receiving section  36  and an insertion section  38  with an insertion opening  40 . In the receiving section  36  the appropriate bushing  24  is arranged which corresponds to the bushings  24  of the closed connecting device  16 . Through the insertion opening  40 , the bushing  24  can be inserted into the open bushing receptacle  34  and/or removed from the open bushing receptacle  34  from the side which is the circumferential side relative to the connecting axis  22 . 
     An inner cross-section of the open bushing receptacle  34 , viewed in the direction of the connecting axis  22 , is approximately u-shaped. The legs of the “U” are formed by sidewalls  41  of the insertion section  38 . The sidewalls  41  delimit the insertion opening  40  relative to the connecting axis  22  at circumferentially opposite sides. The insertion opening  40  extends across the entire axial height of the open bushing receptacle  34  relative to the connecting axis  22 . 
     In the clamping area  42  of the bushing receptacle  34  which is facing away from the cylinder head  12 , a radial inner circumferential side of the receiving section  36  has approximately the course of an envelope of an imaginary semi-circular cylinder. An inner diameter  44  of the receiving section  36  in the clamping area  42  is, for example, approximately 12.85 mm. The clamping area  42  extends across an axial height  46  of approximately 14.2 mm. 
     On the side of the clamping area  42  which is facing the cylinder head  12  the radial inner circumferential side of the receiving section  36  widens conically. An opening angle  48  of the receiving section  36  is, for example, approximately 4.5 degrees. 
     At its end face which is facing the cylinder head  12 , the receiving section  36  has at its radial inner circumferential side a circumferentially extending receptacle  50  for the projection  26  of the bushing  24 . The receptacle  50  extends into the two sidewalls  41  of the insertion section  38 . 
     The facing inner sides of the sidewalls  41  extend parallel to each other. The width  52  of the inner sides of the sidewalls  41  transverse to the connecting axis  22  approximately 4 mm is, for example. The spacing of the inner sides of the sidewalls  52  which defines a width  54  of the insertion opening  40 , i.e., an inner width of the insertion opening  40 , is 12.5 mm, for example. The width  54  of the insertion opening  40  is smaller than the outer diameter  28  of the bushing  24  and smaller than the inner diameter  44  of the receiving section  36  in the clamping area  42 . 
     At the respective transition of the sidewalls  41  of the insertion section  38  into the receiving section  36 , there is an undercut  56 , respectively. The inner sides of the sidewalls  52  are located within an area which is delimited by two parallel tangential surfaces of the radial inner circumferential side of the receiving sections  38 . 
     For mounting the intake pipe  10  at the cylinder head  12 , first the bushing  24  of the open connecting device  18  is fixedly screwed on with the appropriate screw  14  in the appropriate threaded opening  32  of the cylinder head  12 . In this context, the end face of the bushing  24  with the projection  26  is arranged on the side which is facing the cylinder head  12 . 
     Subsequently, the intake pipe  10  with the open bushing receptacle  34  is positioned on the fixedly screwed-on bushing  24  such that the radial outer circumferential side of the bushing  24  is resting within the insertion opening  40  on the sidewalls  41  of the insertion section  38  of the open bushing receptacle  34 . The cylinder head  12  is pushed with a movement in an insertion direction  58  radially to the connecting axis  22  onto the bushing  24 . The insertion direction  58  in  FIG. 4  is indicated by an arrow. Upon insertion of the bushing  24  into the insertion opening  44 , the sidewalls  41  of the insertion section  38  are elastically pushed away from each other. In this context, an appropriate elastic force must be overcome. 
     After passing the undercuts  56 , the bushing  24  locks in the receiving section  36 . The bushing  24  is secured by the elastic clamping connection in the open bushing receptacle  34 . 
     The conical widened section of the receiving section  36  enables positional tolerance. The contact of the radial inner circumferential side of the receiving section  36  with the radial outer circumferential side of the bushing  24  is avoided. In this way, force introduction through the pressing force between the bushing  24  and the open bushing receptacle  34  can be reduced. 
     Subsequently, the screws  14  of the closed connecting devices  16  are inserted into the appropriate bushings  24  and fixedly screwed into the appropriate threaded bores  32  of the cylinder head  12 . 
     For removal of the intake pipe  10  from the cylinder head  12 , first the screws  14  of the closed connecting devices  16  are removed. Subsequently, the clamping connection between the open bushing receptacle  34  and the bushing  24  of the open connecting device  18  is released. For this purpose, the intake pipe  16  is pulled opposite to the insertion direction  52  from the bushing  24  of the open connecting device  18 . In this context, the elastic clamping force of the sidewalls  41  must be overcome when passing the insertion section  38 . 
     The screw  14  of the open connecting device  18  must not be released for removal of the intake pipe  10 . The appropriate bushing  24  can remain on the cylinder head  12 . 
     Advantageously, the detachable connecting device can be provided for attachment of an intake pipe housing  10  on a cylinder head  12  of an internal combustion engine. The cylinder head  12  can be the first functional component or comprise it. The intake pipe housing  10  can be the second functional component or comprise it. The at least one connecting element receptacle  54  can advantageously be arranged on the cylinder head  12  and may be realized as a threaded bore  32 . 
     While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.