DE102009021008A1 - Sensor i.e. pressure sensor, for measuring fluid pressure, has insertion receptacle placed in housing plate, and having peripheral sections that are deformed and sealingly lay at sealing surfaces of sealing thorn - Google Patents

Abstract

The sensor (1) has a sensor housing (2), a housing plate (4), and a sensor element e.g. resistance sensor element, placed in a sensory space of the housing. The housing and the plate are connected to each other in sealing manner. A sealing thorn at the housing is inserted into an insertion receptacle of the plate, where peripheral sections of the insertion receptacle are deformed and sealingly laid at sealing surfaces of the sealing thorn. The sealing thorn and the receptacle are made from plastic, polyamide and high-density polyethylene. An anti-twist plate (14) is provided in the housing.

Description

The The invention relates to a sensor according to the preamble of claim 1.

Such sensors are designed for example as a pressure sensor for measuring a fluid pressure and usually have a multi-part sensor housing, in which a sensor element, for example a capacitive, resistive or piezoelectric sensor element is added. This sensor element is acted upon on the one hand with the fluid to be measured, so that an absolute or relative pressure can be measured. Such a pressure sensor is for example in the DE 60 2005 001 715 T2 disclosed. In this known solution, the sensor housing is designed in several parts, wherein a membrane-bearing housing lower part is connected to a housing carrying the electronics upper part. The upper housing part dips into a receptacle of the lower housing part, wherein an O-ring is provided for sealing. The mechanical connection of the two housing parts takes place by crimping the housing upper part. The production of such a pressure sensor is very expensive, since on the one hand a separate O-ring must be used and on the other hand, the combination of materials of the housing with respect to the flange must be designed, in which case essentially metallic materials come into question.

It Solutions are also known in which the housing parts are made of plastic and then screwed together, plugged or welded - even with such Solutions are the sealing rings described above for warranty the tightness required.

In contrast, the object of the invention is to provide a sensor which ensures a sufficient tightness with a simple construction.

These Task is achieved by a sensor with the features of claim 1 solved. Advantageous developments of the invention are Subject of further subclaims.

Has according to the invention the sensor has two housing parts that form a sensor space, in which a sensor element is received. The two housing parts are sealingly connected together, with one on a housing part trained sealing mandrel into a corresponding plug-in receptacle of other housing part is used. This will be circumferential sections the plug-in receptacle elastically / plastically deformed, so that these sealing abut against sealing surfaces of the sealing mandrel. Such a connection over a mandrel profile is on the one hand very easy to manufacture and guaranteed on the other hand due to the plastic deformation of the plug-in receptacle a sufficient tightness.

These Tightness can be further improved when the sealing mandrel with a double cone, d. H. two axially offset conical surfaces is executed.

at An embodiment of the invention are the sealing mandrel and / or the plug-in receptacle made of plastic, for example PA, HDPE produced.

The Material selection is preferably made so that the material the sealing mandrel with higher rigidity than the material the plug-in receptacle is executed.

The Tightness can be further improved, if at least a sealing surface of the sealing mandrel executed burr-free is. When manufacturing by injection molding this sets advance that the tool division does not pass through this sealing surface passes through.

The Mounting the sensor is further simplified when the housing parts are executed with a rotation.

The Connection of the two housing parts is particularly reliable, if additional means to increase the holding power are provided.

at a particularly compact embodiment is a housing part about cup-shaped with a from the case back protruding sealing mandrel executed. This housing part is placed on a housing plate, on which the plug-in receptacle is trained.

These Housing plate can in turn be inserted into a mounting collar become. On the cup-shaped housing part are preferably the measuring or signal connections of the sensor educated.

According to the invention it is preferred if the sensor is designed as a pressure sensor is.

One preferred embodiment of the invention is hereinafter explained in more detail with reference to schematic drawings. Show it:

1 a three-dimensional schematic diagram of a pressure sensor according to the invention;

2 a section along the line AA in 1 and

3 a detailed view of the pressure sensor 2 ,

1 shows a pressure sensor for recording me the pressure of a fluid. The pressure sensor 1 consists essentially of a sensor housing 2 attached to a housing plate 4 is attached, which in turn is in a mounting frame 6 is used, at the two diametrically arranged mounting tabs 8th . 10 with mounting holes 12 are formed. The housing plate 4 and the sensor housing 2 are with a rotation lock 14 executed. To improve the cohesion of sensor housing 2 and sensor plate 4 are additional holding elements 16 intended. At the in 1 visible upper face of the sensor housing 2 is a connection socket 18 with measuring and electrical connections 20 . 22 executed, which is designed according to the task designed holding, mounting and connection geometries.

2 shows a section along the line AA in 1 , One recognizes the approximately cup-shaped sensor housing 2 that has a sensor room 24 at least partially encompasses. In this example, a capacitive, resistance or piezoelectric sensor element 26 taken on a bottom part 28 of the sensor housing 2 is supported. This sensor element 26 is with the aforementioned connections 20 . 22 connected via the connection socket 18 are accessible. The sensor room 24 is in the range of the connection socket 18 sealed to the outside. From the bottom part 28 of the sensor housing 2 a sealing pin protrudes 30 Out, sealing in a plug-in receptacle 32 the sensor plate 4 (Disk) dips. This sensor plate 4 is in turn in a ring recording 34 of the sensor plate 4 encompassing mounting frame 6 used. This mounting frame has an approximately cylindrical peripheral wall 36 covering the bottom area of the sensor housing 2 and the sensor plate 4 embraces. This connector is designed so that the sensor housing 2 with its bottom peripheral edge sealing the sensor plate 4 is applied.

3 shows the contact area between the sealing mandrel 30 and the plug-in receptacle 32 in an enlarged view. Accordingly, the sealing mandrel 30 with two in the presentation according to 3 to the right, ie to the end portion of the sealing mandrel 30 tapered, approximately conical sealing sections 38 . 40 executed, the radially out of the main body of the sealing mandrel 30 protrude. The inside width d of the plug-in receptacle 32 is less than the outer diameter of the two sealing sections 40 . 38 chosen so that when inserting the sealing mandrel 30 in the plug-in receptacle 32 whose peripheral wall is elastically and / or plastically deformed, so that peripheral wall sections sealingly against the sealing surfaces 40 . 38 invest. By this mandrel profiling thus a double sealing surface is designed, which ensures a reliable support, as an area 42 the Steckaufnahmenumfangswandung in the space between the two sealing surfaces 38 . 40 is deformed into it and thus the sealing mandrel 30 fixed in position in the axial direction.

According to the invention, it is provided that the components of the housing are made of plastic. When selecting the material, care is taken to ensure that the sealing mandrel 30 made of a material with a higher rigidity than the material of the sensor plate 4 is selected, so that the above-described seal is supported by deformation of the plug-in receptacle. The tightness is inventively further improved because in the manufacture of the sensor housing 2 and thus the plug 30 Care is taken that no tool division cut in the axial direction by the Dichtab 38 or 40 runs. The formation of this area is preferably carried out by a slide of the injection mold, through which the conical sealing surface is formed over the entire surface and free of burrs. This ensures that there is no burr in the sealing area, so that an optimal sealing of the sensor space 24 is guaranteed. In the illustrated embodiment, the sealing mandrel 30 integral with the sensor housing 2 executed - in principle, this could also be recognized as a separate component.

As already mentioned, can improve the holding force between the sensor housing 2 and sensor plate 4 additional holding elements 16 For example, brackets or the like may be provided. The anti-twist device 14 is in the illustrated embodiment by a projection 44 at the top of the sensor plate 4 formed in the correct mounting position between two centering projections 46 of the sensor housing 2 dips.

In the illustrated embodiment, a central sealing mandrel 30 intended. In principle, also several sealing mandrels 30 are provided, each of which a plug-in receptacle 32 assigned.

Disclosed is a sensor with a multi-part housing, wherein a sensor housing 2 via a mandrel profile with a sensor plate 4 connected is.

1

pressure sensor

2

sensor housing

4

sensor plate

6

mounting frame

8th

mounting tab

10

mounting tab

12

mounting hole

14

twist

16

retaining element

18

socket

20

measuring connection

22

electrical connection

24

sensor chamber

26

sensor element

28

the bottom part

30

sealing mandrel

32

plug-in receptacle

34

ring holder

36

peripheral

38

sealing portion

40

sealing portion

42

section

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 602005001715 T2 [0002]

Claims (11)

Sensor with one of at least two housing parts ( 2 . 4 ) executed housing, in the sensor space ( 24 ) a sensor element ( 26 ), wherein the housing parts are sealingly connected to each other, characterized by a sealing mandrel ( 30 ) on one of the housing parts ( 2 ), which fits into a plug-in receptacle ( 32 ) of the other housing part ( 4 ) is inserted, wherein peripheral portions of the plug receptacle ( 32 ) are deformed and sealing at sealing surfaces ( 38 . 40 ) of the sealing mandrel ( 30 ) issue. Sensor according to claim 1, wherein the sealing mandrel ( 30 ) with two sealing surfaces ( 38 . 40 ) is executed. Sensor according to claim 1 or 2, wherein the sealing mandrel ( 30 ) and / or the plug-in receptacle ( 32 ) made of plastic, preferably made of PA, HDPE. Sensor according to one of the preceding claims, wherein the sealing mandrel ( 30 ) of a stiffer material than the plug-in receptacle ( 32 ) is trained. Sensor according to claim 2 and 3 or 4, wherein a sealing surface ( 38 ) is executed burr-free. Sensor according to one of the preceding claims, with an anti-twist device ( 14 ) for the housing parts ( 2 . 4 ). Sensor according to one of the preceding claims, with means ( 16 ) to increase the holding force. Sensor according to one of the preceding claims, wherein an approximately cup-shaped sensor housing ( 2 ) on a sensor plate ( 4 ) is mounted, wherein the sensor plate ( 4 ) the plug-in receptacle ( 32 ) and the sensor housing ( 2 ) the sealing mandrel ( 30 ) wearing. Sensor according to claim 8, with a sensor plate ( 4 ) receiving mounting frame ( 6 ), on the laterally projecting mounting tabs ( 8th . 10 ) are formed. Sensor according to one of the preceding claims, with on the housing ( 2 . 4 ) measuring or supply connections ( 20 . 22 ). Sensor according to one of the preceding claims, this is designed as a pressure sensor.