The present invention relates to a plastic housing having an integrated plug interface and a method relating thereto.
German patent document DE 197 31 420 A1 discusses a device for pressure measurement. The device described there is used to measure the pressure in the intake manifold of an internal combustion engine and has a carrier designed as a hybrid plate situated in a housing. A first housing space, provided as a pressure space, in which a sensor element situated on the carrier is located, is connectable via a pressure connection to the intake manifold and is sealed off from its surroundings which includes a second housing space using an adhesive. Bond wires, which electrically connect the carrier to a plug part, are situated in the second housing space, which is provided as a bond space.
German patent document DE 102 23 357 A1 discusses a device for pressure measurement. It has a housing in which a carrier provided with a sensor element and with electrical terminal elements is situated. The housing has a first housing space surrounding the sensor element and connected to a first pressure channel of a first pressure connection and has a second housing space, which surrounds at least the electrical terminal elements and is sealed with respect to the first housing space. The housing additionally has a third housing space, which is sealed with respect to the first housing space and the second housing space and is connected to a second pressure channel of a second pressure connection.
The pressure sensor housings used today such as sensor housings for pressure sensors are usually injection-molded plastic parts. This means that the sensor housing and a plug housing, together with plug pins, are injected into a plastic mold. The plug housings are high-precision parts, which make high demands on the precision of the pressure sensor housing to be injection molded in one operation, i.e., the sensor housing and the plug housing. As a result, the sensor housing is necessarily also manufactured with high standards regarding its tolerance, even though this is not required. Furthermore, in manufacturing pressure sensors, the finished housing, including the plug housing and sensor housing, passes through a curing oven. The plastics are cured inside the curing oven; this is associated with thermal deformation, which has a negative effect on the plug dimensions, which had previously been strictly accurate. This deformation necessarily occurs in passing through the curing oven and is difficult to prevent in the case of relatively large sensor housings having integrally molded plug housings in particular. Moreover, flexibility is also very limited because a separate sensor housing and a separate injection mold required for same must be manufactured and kept on hand for almost each customer's plug.
An object of the exemplary embodiments and/or exemplary methods of the present invention is to provide a housing having an integrated interface, which is manufactured by the plastic injection molding method and has a much greater flexibility with regard to customer's plug variants and makes lower demands regarding the precision of the mold in which the plastic housing is manufactured.
The plastic housing may be a housing in which a sensor is accommodated or a housing which holds an actuator for actuating a final controlling element, or the like.
It is proposed according to the exemplary embodiments and/or exemplary methods of the present invention that a plug interface for contacting a sensor or an actuator be manufactured separately from the plastic housing in which the sensor or actuator contacting the plug interface is accommodated. The plug interface may be welded to the plastic housing forming the base part in a subsequent operation, for example, by the plastic laser welding method. This allows the use of an injection mold having a simpler design for manufacturing the plastic housing and a mold of a simpler design for fabrication of the particular plug interface.
The approach proposed according to the exemplary embodiments and/or exemplary methods of the present invention increases flexibility due to the possibility of using the customer's particular plug interface variant, i.e., the injection mold required for manufacturing same, so that a shared mold may still be used for fabrication of the plastic housing. The plug pins may be replaced by replaceable inserts in the mold. With regard to the fabrication of the plastic housing and the plug interface, which is fabricated separately from the former, cost savings may be achieved due to the fact that it is not absolutely necessary to use a separate injection mold for each variant of a plastic housing.
The approach proposed according to the exemplary embodiments and/or exemplary methods of the present invention allows greater flexibility with regard to the variants of plug interfaces demanded by customers while retaining a housing mold for manufacturing a plastic housing for a sensor or an actuator which is usable for multiple variants. The mold for manufacturing the plug interfaces may have a simpler design, in particular without insertion parts which are usually fabricated from a metallic material and are used to manufacture the plug pins. In comparison with the precision requirements which are made for the plug interface, i.e., the housing, and are necessary to achieve dimensionally more stable plug interfaces, relatively low precision requirements may be made for the mold in comparison with that by fabricating the plastic housing to receive the sensor or the actuator. In addition, when using the approach proposed according to the present invention, redundancy is achieved in sealing the plug pins in the interior of the sensor housing.
Thus, following the approach proposed according to the exemplary embodiments and/or exemplary methods of the present invention, the plastic housing for holding a sensor or an actuator is manufactured in the housing mold using insert parts for fabrication of the plug pins by the plastic injection molding method. For each variant of a customer's plug interface, which is to be connected to the plastic housing, the customer's own plug pins are sheathed by using replaceable insertion parts. This is necessary because plug pins may have various thicknesses, shapes, patterns, surfaces, and materials, as a function of the customer's requirements.
Following the approach proposed according to the present invention, the plug interfaces are injected separately from the plastic housing and are manufactured with a high precision due to the simple mold shape. Due to the approach provided by the exemplary embodiments and/or exemplary methods of the present invention of the separate fabrication of the plastic housing to hold a sensor or an actuator and the plug housing, which is a customer-specific design of a plug interface, it is possible to achieve a simpler method of maintaining tolerances, in particular in the fabrication of the plug part, which is to be manufactured to a high precision, so that the plastic housing, which has lower tolerance requirements, may be fabricated to hold a sensor or an actuator of lower tolerance requirements and in particular one and the same injection mold may be used. The precision requirements made for the plug interface on the one hand and the plastic housing on the other hand may thus be uncoupled from one another with regard to the fabrication. Furthermore, the geometry in which the plastic housing is fabricated is simplified by separating the fabrication of the customer-specific design of the plug part forming the plug interface, so that smaller base bodies may be used and a fabrication that is more suitable for plastics is implementable.
The plug housing, which forms the plug interface and is fabricated separately, is attached to the plastic housing, which is fabricated separately and is pressed as far as a stop, for example. This means that the plug pins attached to the plastic housing are surrounded by the plug housing and may push through it. In assembly, the plug pins of the plastic housing for receiving a sensor or an actuator pass through the bottom face of the plug housing representing the plug interface. In pushing through the bottom surface of the plug housing, for example, the plug pins may be additionally sealed by displaced material at the particular passages. The plug housing may be bonded to the plastic housing on its lateral surface, for example, by laser welding along the circumference and thus joined mechanically to the plastic housing, which is manufactured separately and forms a basic module.
The plastic housing to receive a sensor or an actuator and the plug interface as proposed according to the present invention being designed as separate parts advantageously ensures that the plug pins embedded in the plastic housing, which forms a basic module, are sheathed in the plastic housing on the one hand while on the other hand they may be additionally sealed in the assembly of the plug housing by pushing through the bottom of the plug housing, so that there is redundant sealing of the plug pins.
The exemplary embodiments and/or exemplary methods of the present invention is described in greater detail below on the basis of the drawings on the example of a pressure sensor.
The diagram according to
As shown by the perspective diagram according to
The diagrams in FIGS. 3 and 3.1 show plastic housings fabricated separately from one another and then joined together for a sensor or an actuator or a plug housing in a first embodiment variant.
As also shown in the diagram according to
When plug pins 18 are optionally pushed through at least one opening 42 in bottom part 40 of plug housing 37 in the first specific embodiment, the plastic material bordering at least one opening 42 in bottom 40 is deformed and forms seal 44 around individual plug pins 18. The approach of manufacturing plastic housing 30 and plug housing 36 separately in different specific embodiments, as proposed according to the present invention and explained below, allows redundant sealing of plug pins 18, first in embedding 32 of plastic housing 30 and secondly in seal 44 in bottom part 40 of plug housing 36 in the first embodiment variant. The projecting portion by which the ends of plug pins 18 protrude above bottom part 40 through openings 42 may be adjusted through the design of the height of bottom part 40 of plastic housing 30 to receive an actuator or a sensor.
The sectional diagram in
The sequence of
Bottom part 40, which is inserted into receptacle opening 34 of sensor housing 30 shown in
Plastic housing 30 according to the diagrams in
The approach of manufacturing plug housing 36, 54, 72 independently of plastic housing 30 to receive a sensor or an actuator, as proposed according to the present invention, allows greater flexibility in customer variants, in particular in the case of plug geometries of various designs. Plastic housing 30 of the same design may ideally always be used. The approach proposed according to the present invention results in injection molds of a smaller and simpler design and a higher precision in manufacturing the plug interfaces formed by the various sensor housing variants.
Although the requirements of plastic housing 30, which always has essentially the same design, to receive a sensor or an actuator always remain the same, the more complex plug geometries for plug housings 36, 54, and 72 may be constructed in separate but smaller molds as a function of customer specifications. Much greater tolerance demands are made for these customer-specific designs for the injection molds for manufacturing plug housings 36, 54, and 72 in comparison with the requirements for the mold for manufacturing plastic housing 30 to receive the sensor or the actuator.
Number | Date | Country | Kind |
---|---|---|---|
10 2008 003 848.2 | Jan 2008 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/EP2008/066860 | 12/5/2008 | WO | 00 | 10/1/2010 |