Backplane-System

Abstract

The invention relates to a backplane system for environments exposed to vibrations and / or shocks, which backplane system comprises a housing having a housing rear wall to which a backplane board with at least one connector is fastened, and a module which can be inserted into the housing in an insertion direction and has a module board which is connected to a module rear wall which has at least one plug contact, wherein the at least one plug contact forms at least one plug connection with the at least one connector when the module is inserted into an end position in the housing in the insertion direction.According to the invention, a projection is fixedly arranged on the housing rear wall, which extends through the backplane board and has an end section remote from the housing rear wall, which can be inserted into an opening in the module rear wall in the insertion direction when the module is brought into the end position in the insertion direction, wherein the end section and the opening are designed such that they limit a deflection of the module rear wall relative to the backplane board perpendicular to the insertion direction such that the at least one plug connection is protected.

Description

The present invention relates to a backplane system for environments subject to vibrations and / or shocks according to the preamble of independent claim 1.Such a backplane system comprises a housing having a housing rear wall to which a backplane board with at least one plug connector is attached, and a module that can be inserted into the housing in an insertion direction and comprises a module board connected to a module rear wall having at least one plug contact, wherein the at least one plug contact forms with the at least one plug connector at least one plug connection when the module is inserted into an end position in the insertion direction into the housing.When such backplane systems are used in environments subject to vibrations and / or shocks, such as in the automotive or aircraft sector or preferably in the crash test sector, the known backplane systems are susceptible to errors and defects and do not allow for the continuous use of the backplane system.The object of the present invention is to provide such a backplane system that allows improved durability and operation in environments subject to vibrations and / or shocks.The object is achieved by the features of independent claim 1.Accordingly, a solution according to the invention to the object is present if a projection is arranged fixedly on the housing rear wall, which projection reaches through the backplane board and has an end section which is remote from the housing rear wall and can be inserted into an opening in the module rear wall in the insertion direction when the module is brought into the end position in the insertion direction, wherein the end section and the opening are designed such that they limit a deflection of the module rear wall with respect to the backplane board perpendicularly to the insertion direction such that the at least one plug connection is prevented.As a result, the transverse forces perpendicular to the insertion direction absorbed by the at least one plug connection can be significantly reduced and in particular limited, since as soon as a deflection of the module rear wall relative to the backplane board perpendicular to the insertion direction, which deflection is maximally permitted by the interaction of end section and opening, is achieved, additional transverse forces perpendicular to the insertion direction are transmitted from the end section and the opening from the housing to the module rear wall and not from the at least one plug connection. This is advantageous in particular because the at least one plug connection between the plug contact of the module rear wall and the plug connector of the backplane board is particularly susceptible to errors and defects.According to the invention, the projection is arranged fixedly on the housing rear wall when it is fixedly connected to the housing rear wall and / or is formed partly or completely as part of the housing rear wall.In most plug connections, wherein the at least one plug connection is preferably designed as such a plug connection, at least the plug contact or the plug connector has a resilient contact element which establishes the contact with the contact element of the other. In this case, the deflection of the module rear wall with respect to the backplane board perpendicular to the insertion direction is preferably limited by the interaction of the end section and the opening in such a way that a spring travel of a resilient contact element of the at least one plug contact or of the at least one plug connector remains greater than 0. As a result, the at least one plug connection is particularly protected, since at least in the direction of the spring travel of the resilient contact element the portion of the transverse force which is absorbed by the plug connection is absorbed exclusively resiliently.Advantageous embodiments of the present invention are the subject matter of the dependent claims.In a preferred embodiment, a mating tolerance of the at least one plug connection is greater than a clearance between the end section and the opening, wherein the mating tolerance is preferably at least 5% and / or 0.005 mm greater than the clearance between the end section and the opening. As a result, the at least one plug connection is particularly effectively protected, since no transverse force transmission takes place between non-resilient elements of the plug connector and of the plug contact.According to a further particularly preferred embodiment, the end section is formed by a fitting pin and the opening is formed by a fitting bore, wherein a fit between the fitting pin and the fitting bore is an interference fit, transition fit or preferably a clearance fit, wherein the clearance fit further preferably has at most a clearance of a clearance fit of type H7 / g6, particularly preferably at most the clearance of a clearance fit of type H7 / h6. In this case, the fitting bore must be able to be slid over the module by hand onto the fitting pin. By such a configuration of the end section and the opening, the possible deflection of the module rear wall with respect to the backplane board can be set exactly. In addition, the required manufacturing methods of the end section and the opening are known from the prior art.According to a preferred embodiment, the housing rear wall has two pins, onto which the backplane board is plugged and by which a backplane board position of the backplane board relative to the housing rear wall and to the protrusion is fixed, and at least one positioning element with at least one positioning protrusion is arranged on the module rear wall, against which the module board abuts such that the positioning protrusion engages in a counterbore in the module board and that a module board position of the module board relative to the module rear wall and the opening is fixed. As a result, the position of the at least one plug connector with respect to the projection and the position of the at least one plug contact with respect to the opening are fixed. Accordingly, a secure and recoverable connection of the at least one plug connection results when the opening of the module is pushed onto the end section.Preferably, at least two positioning elements are arranged on the module rear wall, each with at least one, preferably two, positioning projections, against which the module printed circuit board abuts in such a way that the positioning projections engage in bores, preferably counterbores, in the module printed circuit board and that a module printed circuit board position of the module printed circuit board is fixed relative to the module rear wall and the opening. The positioning elements can be screwed to the module rear wall.In a further embodiment, the housing has two parallel housing side walls which project from the housing rear wall in the insertion direction and between which the module can be inserted into the housing in the insertion direction, wherein the module has a module front wall which is connected to the module printed circuit board on a side opposite the module rear wall and which can be screwed to the ends of the housing side walls opposite the housing rear wall when the module is in the end position, wherein the module printed circuit board is preferably aligned perpendicularly to the housing rear wall and the housing side walls when the module is in the end position. This allows the module to be securely fixed in and to the housing.In a preferred embodiment, the module printed circuit board is arranged perpendicular to the module rear wall and the projection is arranged centrally on the housing rear wall, wherein the projection is preferably arranged centrally between the housing side walls. This is an advantageous arrangement of the individual components of the backplane system. The central arrangement of the projection results in an advantageous transmission of the transverse forces from the housing to the module rear wall.According to a further preferred embodiment, the module has two module side walls which are arranged between the module rear wall and the module front wall, wherein the housing side walls have a guide projection along the insertion direction and the module side walls have a guide groove along the insertion direction, which guide groove engage in one another when the module is inserted into the housing. As a result, the module is inherently more stable and the module printed circuit board has to absorb less forces. In addition, the module can be inserted into the housing in the insertion direction in a simple and guided manner.In a preferred embodiment, the protrusion forms a first stop adjacent to the end section in the insertion direction, so that the module rear wall rests against the first stop when the module is in the end position. As a result, the position of the module relative to the housing rear wall in the insertion direction is limited and the at least one plug connection can be configured such that no excessive forces are applied to it in the insertion direction. This increases the life of the backplane system.In a preferred embodiment, the dowel pin forming the end section is fastened in a bore in the first stop. This simplifies the production and the dowel pin can be produced as a standard element in large numbers. Preferably, the projection is formed as part of the housing rear wall except for the dowel pin. As a result, the projection is partially part of the housing and a force transmission inside the component takes place. In addition, fewer individual components have to be manufactured and connected to one another, which simplifies the structure of the backplane system.Furthermore, the housing rear wall and the projection, apart from the dowel pin, are manufactured as part of the housing rear wall as a milling part. This enables efficient production.In a particularly preferred embodiment, the housing rear wall forms a cutout behind the backplane board, in which cutout further plug connectors can be mounted on the backplane board, wherein the protrusion is preferably arranged in the cutout and forms a second stop in the insertion direction, on which the backplane board rests. As a result, the backplane board can be easily fitted with further plug connectors.According to a preferred embodiment, the recess is accessible from outside the housing in a connection direction perpendicular to the insertion direction and perpendicular to a normal on the housing side walls, and the further plug connectors have a connection direction in the connection direction. As a result, the further plug connectors can be connected in an efficient manner to connections to devices external to the backplane system.The further plug connectors preferably have a distance from a base of the recess, wherein the distance is preferably designed such that the further plug connectors do not touch the base of the recess if the backplane board oscillates due to external force influences on the housing.In a further particularly preferred embodiment, at least one spring bolt is arranged on the housing rear wall in such a way that it exerts a spring force against the insertion direction on the module rear wall when the module is in the end position. In this way, in particular the fastening of the module relative to the housing with respect to vibrations on the housing can be improved.The spring bolt is preferably designed such that it pushes the module out of the housing counter to the insertion direction when the module is not fastened to the housing such that the at least one plug connection is released and the module moves out of the end position. As a result, there is no need for an expensive and defect-prone ejection mechanism, such as the lever mechanisms often used, for ejecting the module relative to the housing.In a preferred embodiment, the spring pin is fastened in a receptacle in the housing rear wall and reaches through the backplane board. A compact design of the backplane system can thereby be achieved.According to a further embodiment, the backplane system has two spring pins which are arranged symmetrically to the projection on the housing rear wall. This enables a symmetrical force transmission of the spring bolts to the module rear wall.In a preferred embodiment, the backplane system has at least one second module, wherein the second module can be inserted into the housing in an insertion direction and has a second module printed circuit board which is connected to a second module rear wall which has at least one second plug contact, wherein the at least one second plug contact forms at least one second plug connection with a plug connector of the backplane printed circuit board when the respective module is inserted into an end position in the insertion direction, wherein a second projection is arranged fixedly on the housing rear wall, which projection reaches through the backplane printed circuit board and has a second end portion which is remote from the housing rear wall and can be inserted into a second opening in the second module rear wall in the insertion direction when the second module is brought into the end position in the insertion direction, wherein the second end section and the second opening are configured such that they limit a deflection of the second module rear wall with respect to the backplane board perpendicular to the insertion direction such that the at least one second plug connection is saved. Thus, the backplane system may include multiple modules that have increased durability in environments subject to vibration and / or shocks. The exemplary embodiments shown above, which relate to the interaction of the module and the housing, can also be designed in the same way for the at least one second module.According to a preferred embodiment, the end portion of the protrusion and the second end portion of the second protrusion are each formed as a dowel pin, and the protrusion and the second protrusion other than the dowel pin are formed as part of the housing rear wall. This simplifies the production of the backplane system and makes it less susceptible to defects.An exemplary embodiment of the invention is explained in more detail below with reference to drawings.The following are shown: FIG. 1 a shows a sectional view from above of an embodiment of the backplane system according to the invention, wherein the module is not in the end position and the sectional plane intersects the dowel pin, FIG. 1 b is a sectional view from above of the exemplary embodiment of the backplane system according to the invention shown in FIG. 1 a, wherein the module is not in the end position and the sectional plane intersects the fastening screws, FIG. 2 a is a sectional view from above of the embodiment of the backplane system according to the invention shown in FIG. 1 a, wherein the module is in the end position and the sectional plane intersects the dowel pin, FIG. 2 b is a sectional view from above of the exemplary embodiment of the backplane system according to the invention shown in FIG. 1 a, wherein the module is in the end position and the sectional plane intersects the fastening screws, and FIG. 3 shows a sectional view of a module of the exemplary embodiment of the backplane system according to the invention in the insertion direction in the sectional plane A 1, wherein the sectional plane A 1 is drawn in FIG. 2 b.For the following discussion, like parts are denoted by like reference numerals. If reference numerals are contained in a figure, which will not be discussed in more detail in the associated description of the figures, reference is made to the preceding or following descriptions of the figures.The figures show an exemplary embodiment of a backplane system 1 according to the invention, which has a housing, with a housing rear wall 2 and two housing side walls 3, wherein the housing can have a housing top wall and housing bottom wall, not shown, and a module 4.The module 4 has a module printed circuit board 5 which is connected to a module rear wall 6, a module front wall 7 and two module side walls 8. The module rear wall 6 in this case again has a plurality of plug contacts 9 and an opening in the form of a fitting bore 10 in a socket. The module front wall 7 has a plurality of external component terminals 11. On the module side walls 8, a guide groove 12 is formed for guidance with respect to the housing side walls 3. For positioning the module printed circuit board 5 relative to the module rear wall 6 and accordingly relative to the fitting bore 10, three positioning elements 23 are fastened to the module rear wall 6 by means of a bore. The positioning elements 23 each have two positioning projections and the module printed circuit board is arranged on the three positioning elements in such a way that the positioning projections engage in bores in the module printed circuit board 5. Accordingly, the position of the module board 5 relative to the fitting bore 10 is fixed by the three positioning elements, in that preferably three counterbores in the module rear wall align the rear wall without play with the positioning elements on the module board.In the housing, a backplane board 13 is mounted on the housing rear wall 2. For this purpose, the housing rear wall 2 has two pins, onto which the backplane board 13 is plugged. In this position, the backplane board 13 is then screwed to the housing rear wall by means of backplane screws. The backplane board 13 has a plurality of plug connectors 14 which form plug connections with the respective plug contacts 9 of the modules 4. In addition, spring bolts 15 are arranged on the housing rear wall 2, which extend through the backplane board 13. Furthermore, the housing rear wall 2 forms a cutout 16 behind the backplane board 13, in which cutout a projection 17 is formed, which is partially formed as part of the housing rear wall 2 and reaches through the backplane board 13. One end portion of the projection 17 is formed as a dowel pin 18 which is fastened in a bore in the remaining part of the projection 17. In addition, further plug connectors 19 are arranged in the cutout 16 on a rear side of the backplane board 13. These further plug connectors 19 are accessible from a direction parallel to the housing side walls 3 and the housing rear wall 2 from outside the housing, so that external components can be connected to the backplane system 1 via the further plug connectors 19. On the housing side walls 3 guide projections 20 are arranged for guiding the module 4.How the module 4 is inserted into the housing and executed and how the module 4 is advantageously fastened in the embodiment of the backplane system 1 according to the invention will be described below with reference to the sectional views shown in FIGS. 1 a, 1 b, 2 aand 2 b.FIGS. 1 aand 1 b show a module 4 that is not in the end position. From this position, the module can be inserted into the housing in the insertion direction 21 between the housing side walls 3 until it reaches an end position shown in FIGS. 2 aand 2 b, in which the plug contacts 9 and plug connectors 14 are connected to one another.In FIG. 1a, the structure of the projection 17 is visible. The projection 17 is partially formed as part of the housing rear wall 2, wherein this part of the projection 17 forms a second stop in the insertion direction 21, on which the backplane board 13 rests and forms a first stop in the insertion direction 21, in which the bore for fastening the dowel 18 is seated.For guidance during the insertion process, as described above, the module side walls 8 have guide grooves 12 and the housing side walls 3 have guide projections 20 which run parallel to the insertion direction 21. Furthermore, the fitting bore 10 is pushed onto the fitting pin 18 towards the end of the insertion process until the module rear wall 6 bears against the first stop of the projection 17. This is then also synonymous with the end position. In this position, the module front wall 7 is screwed to the housing side walls 3 by means of the fastening screws 22.When the module 4 is brought into the end position, two symmetrically arranged spring bolts 15 engage on the module rear wall 6 and press the latter and thus the module 4 against the screw connection. As a result, the screw connection is prestressed and is released significantly less frequently in the case of vibrations of the housing. In addition, the connection between the plug contacts 9 and the plug connectors 14 is released by the force of the spring bolts 15 when the screw connection is loosened, so that the module 4 can then be easily removed from the housing without additional mechanisms.The fit between the fitting bore 10 and the fitting pin 18, which is preferably a clearance fit of the type H7 / h6, is designed in such a way that it limits a deflection perpendicular to the insertion direction 21 of the module rear wall 8 with respect to the backplane board 13. This is done in such a way that the plug connections between the plug contacts 9 and plug connectors 14 transmit transverse forces perpendicular to the insertion direction 21 from the housing to the module rear wall 6 to only a very limited extent, and the additional transverse forces perpendicular to the insertion direction 21 are then transmitted only from the projection 17 via the fitting bore 10. This protects the plug connections that represent the most error-prone components of the backplane system 1. This is particularly relevant and advantageous in environments in which the backplane system 1 is subjected to vibrations and impacts.A part of the plug connectors 14 and a part of the plug contacts 9 have resilient contact elements, wherein each plug connector has at least one resilient contact element. In the exemplary embodiment of the backplane system 1 shown in the figures, these resilient contact elements are arranged in such a way that they have spring paths perpendicular to the insertion direction 21 and in the plane shown in FIGS. 6 and 7. The fit between the fitting bore 10 and the fitting pin 18 is designed such that they only allow such a deflection of the module rear wall 6 relative to the backplane board 13 in the direction of these spring displacements that these spring displacements always remain greater than 0.Reference numerals denote reference numerals1 Backplane system 2 Housing rear wall 3 Housing side wall 4 Module 5 Module printed circuit board 6 Module rear wall 7 Module front wall 8 Module side wall 9 Plug contact 10 Mating bore 11 Terminal 12 Guide groove 13 Backplane printed circuit board 14 Plug connector 15 Spring bolt 16 Recess 17 Protrusion 18 Mating pin 19 Further plug connector 20 Guide protrusion 21 Insertion direction 22 Fastening screw 23 Positioning element

Claims

A backplane system for environments subject to vibrations and / or shocks, comprising a housing having a housing rear wall to which a backplane board with at least one connector is attached, and a module insertable into the housing in an insertion direction and having a module board connected to a module rear wall having at least one connector, wherein the at least one connector forms at least one connector when the module is inserted into an end position in the insertion direction into the housing, characterized in that a protrusion is fixedly arranged on the housing rear wall, which protrusion extends through the backplane board and has an end portion remote from the housing rear wall, which may be inserted into an opening in the module rear wall in the insertion direction, when the module is brought into the end position in the insertion direction, wherein the end portion and the opening are configured such that they limit a deflection of the module rear wall with respect to the backplane board perpendicular to the insertion direction such that the at least one plug connection is protected.Backplane system according to claim 1, characterised in that a plug tolerance of the at least one plug connection is greater than a clearance between the end section and the opening, wherein the plug tolerance is preferably at least 5% and / or 0.005 mm greater than the clearance between the end section and the opening.The backplane system according to claim 2, characterized in that the end portion is formed by a dowel pin and the opening by a dowel bore, wherein a fit between the dowel pin and the dowel bore is an interference fit, transition fit or preferably a clearance fit, wherein the clearance fit further preferably has at most a clearance of a clearance fit of type H7 / g6, particularly preferably at most the clearance of a clearance fit of type H7 / h6.Backplane system according to one of claims 1 to 3, characterised in that the housing rear wall has two pins, onto which the backplane board is plugged and by which a backplane board position of the backplane board is fixed relative to the housing rear wall and to the protrusion, and at least one positioning element with at least one positioning protrusion is arranged on the module rear wall, against which the module board abuts such that the positioning protrusion engages in a counterbore in the module board and that a module board position of the module board is fixed relative to the module rear wall and the opening.Backplane system according to any of claims 1 to 4, characterized in that the housing comprises two parallel housing side walls protruding in the insertion direction from the housing rear wall and between which the module is insertable in the insertion direction into the housing, the module comprising a module front wall connected to the module board on a side opposite the module rear wall and being screwable to the ends of the housing side walls opposite the housing rear wall when the module is in the final position, the module board preferably being oriented perpendicular to the housing rear wall and the housing side walls when the module is in the final position.Backplane system according to one of claims 1 to 5, characterized in that the module board is arranged perpendicular to the module rear wall and the protrusion is arranged centrally on the housing rear wall, wherein the protrusion is preferably arranged centrally between the housing side walls.Backplane system according to claim 6, characterized in that the module comprises two module side walls arranged between the module rear wall and the module front wall, wherein the housing side walls comprise a guiding protrusion along the insertion direction and module side walls comprise a guiding groove along the insertion direction, which engage with each other upon insertion of the module into the housing.The backplane system according to any of claims 1 to 7, characterized in that the protrusion forms a first stop adjacent to the end portion in the insertion direction, such that the module rear wall abuts the first stop when the module is in the end position.A backplane system according to claims 4 and 8, characterized in that the dowel pin forming the end portion is fixed in a bore in the first stop, preferably the protrusion other than the dowel pin being formed as part of the housing rear wall.Backplane system according to one of claims 1 to 9, characterized in that the housing rear wall forms a recess behind the backplane board, in which further plug connectors can be mounted on the backplane board, wherein preferably the protrusion is arranged in the recess and forms a second stop in the insertion direction, on which the backplane board rests.Backplane system according to claim 10, characterised in that the recess is accessible from outside the housing in a connection direction perpendicular to the insertion direction and perpendicular to a normal on the housing side walls and the further plug connectors have a connection direction in the connection direction.Backplane system according to any of claims 1 to 11, characterized in that at least one spring bolt is arranged on the housing rear wall such that it exerts a spring force against the module rear wall counter to the insertion direction when the module is in the end position, wherein the spring bolt is preferably designed such that it pushes the module out of the housing counter to the insertion direction when the module is not fastened to the housing such that the at least one plug connection is released and the module moves out of the end position, wherein the backplane system preferably comprises two spring bolts arranged symmetrically to the projection on the housing rear wall.The backplane system of claim 12, characterized in that the spring pin is mounted in a receptacle in the housing rear wall and extends through the backplane board.Backplane system according to one of claims 1 to 13, characterised in that the backplane system comprises at least one second module, wherein the second module can be inserted into the housing in an insertion direction and comprises a second module board which is connected to a second module rear wall which comprises at least one second plug contact, wherein the at least one second plug contact forms at least one second plug connection with a plug connector of the backplane board when the respective module is inserted into an end position in the insertion direction into the housing, wherein a second projection is fixedly arranged on the housing rear wall which extends through the backplane board and comprises a second end portion which is remote from the housing rear wall and can be inserted into a second opening in the second module rear wall in the insertion direction, when the second module is brought into the end position in the insertion direction, wherein the second end portion and the second opening are configured such that they limit a deflection of the second module rear wall with respect to the backplane board perpendicular to the insertion direction such that the at least one second plug connection is prevented.The backplane system of claim 14, characterized in that the end portion of the protrusion and the second end portion of the second protrusion are each formed as a dowel pin, and the protrusion and the second protrusion other than the dowel pin are formed as part of the housing back wall.

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