GB2301155A

GB2301155A - Seal for a housing

Info

Publication number: GB2301155A
Application number: GB9610699A
Authority: GB
Inventors: Peter Zweigle
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1995-05-26
Filing date: 1996-05-22
Publication date: 1996-11-27
Anticipated expiration: 2016-05-22
Also published as: JPH0923073A; GB9610699D0; DE29508747U1; GB2301155B; FR2734687B3; FR2734687A3

Abstract

A seal (18) is for a housing of an electric sensor, the said seal consists of a plurality of parts (19, 20, 21 and 22) and is injected as one part into the housing in an injection moulding process. The parts (19, 20, 21 and 22) of the seal (18) are provided to seal electric line ducts (25, 26 and 27). The seal (18) consists of a collar-like part (19) and three O-ring-like parts (20, 21 and 22), and the collar-like part (19) is connected to the three O-ring-like parts (20, 21, 22) by means of cross-pieces (28, 29, 30) which lie inside the housing. The seal is intended for a sensor of an injection pump of motor vehicles.

Description

Seal for a housing Prior Art The invention relates to a seal for a housing according to the generic type of the main claim. Such a seal is known.

These known seals lie in a separation gap between the housing and a cover which shuts off from the outside an inner chamber surrounded by the housing. Inside the housing there are provided, for example, electric or electronic components which form a sensor for injection pumps of motor vehicles and which are disposed in the housing protected against dirt and moisture.

However, in such housings there exists not only the problem of sealing between the housing and the cover but the line ducts must also be sealed so that the housing inner chamber is protected. O-rings are normally used for this which surround the lines with their inner diameter and which are embedded with their outer diameter into the cover or into the housing. For three line ducts, therefore, at least three O-rings are required and for the cover seal a further sealing ring is required. From these four seals it is easy for a part to be lost or to be forgotten during assembly of the housing. Furthermore, in the region of the seals the housing must comprise a shape adapted to the stationing of the seals.

It is the object of the invention to overcome these disadvantages and to create a seal which causes no difficulties during assembly. Furthermore a large degree of freedom of formation should be provided in the construction of the housing.

This object is achieved in the seal named in the introduction by the characterising features of the main claim.

Advantageous developments of the subject matter of claim 1 emerge from the features of the sub claims and from the description and the drawing.

Drawing An embodiment of the invention is illustrated in the drawing and explained in more detail in the following description.

Figure 1 illustrates a cross-sectional view of the housing with the cover and seal, Figure 2 illustrates a cross-sectional view along the line II-II of Figure 1 but shows the housing only partially and without the cover, and Figure 3 illustrates an injection mould for producing the seal.

Description of the embodiment A housing 1 consisting of synthetic material, in particular of a thermoplastic, is closed by a metal cover 2 which in the middle comprises a threaded connection 3 and a hexagonal part 4 to screw the cover onto a component part of an injection pump, not illustrated.

The cover 2 has a flange edge 5 with which it engages an annular edge 6 of the housing 1 and thus holds the housing 1 and cover 2 firmly together. A central line connection 7 is inserted into the housing 1 and is anchored with a foot 8 in the housing 1. An outer surface of the foot 8 has the reference number 9.

Two eccentrically disposed electric lines 10 and 11 are also provided in the housing 1 and are formed in an L shape.

Between two limbs 12 and 13 of the L-shaped lines 10 and 11 an insulating material disc 14 is provided for electrical separation of the power supply. There is also a conductive plate 16 in the cover 2, which supports electronic components, not illustrated, of a sensor 17 disposed in the cover 2.

Between the housing 1 and cover 2 is disposed a seal 18 which consists of a collar-like sealing part 19 and, as shown in Figure 2, of three O-ring-like sealing parts 20, 21 and 22.

The collar-like sealing part 19 has a surrounding sealing lip 23 with which it lies in a sealing manner on a cylindrical inner surface 24 of the cover 2 and which constitutes a seal for the housing 1 and cover 2. The three other sealing parts 20, 21 and 22 are intended to ensure a reliable seal of the line ducts 25, 26 and 27 formed on the line connection 7 (outer surface 9) and on the two electric lines 10 and 11.

Figure 2 shows that the three O-ring-like sealing parts 20, 21 and 22 are connected by cross-pieces 28, 29 and 30 to the collar-like sealing part 19 so that a unitary seal 18 is created.

The seal 18 consists of a thermoplastic elastomer and is produced by an injection moulding process. For this purpose the prefabricated synthetic material housing 1 is inserted between two tool halves 31 and 32, and a free space 33 is sprayed with an elastomer injection medium via an injection duct 35 after positioning of a tool disc 34 (Figure 3).

It is clear from the description that the unitary seal 18 is easy to manufacture and that its individual parts 19 to 22 cannot be lost or forgotten. Furthermore, it should be noted that in an embodiment of the seal 18 in accordance with the invention the freedom of formation of the housing 1 is retained and that the housing 1 is freely accessible both on its inside and outside because the seal 18 does not prevent access.

Claims

CLAIMS 1. Seal for a housing which is intended to receive electric components and which is closed by a cover and the interposition of the seal, characterised in that a part of the seal is disposed between the housing and cover and that another part of the seal is provided on electric line ducts and that both parts the seal are installed into the housing together as one piece in an injection process. 2. Seal according to claim 1, characterised in that the part of the seal disposed between the housing and cover is formed in a collar-like manner. 3. Seal according to claim 1 or 2, characterised in that the part of the seal provided on the electric line ducts is formed as a multiple O-ring. 4. Seal according to claims 2 and 3, characterised in that the collar-like part of the seal is connected to the multiple O-ring-like part of the seal by means of cross-pieces lying inside the housing. 5. Seal according to claim 3 or 4, characterised in that the sealing part provided on the electric line ducts consists of two small O-rings and a large O-ring. 6. Seal according to claim 5, characterised in that the two small O-rings each surround a single-wire electric line in a sealing manner and that the large O-ring surrounds a central line connection in a sealing manner. 7. Seal constructed and adapted to operate substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings. Amendments to the claims have been filed as follows CLAIMS

1. A method of forming a seal in a housing, which housing is adapted to receive electrical components and which is closable by a cover with the interposition of the seal, wherein the seal is formed in the housing by an injectiOn process such that the seal is formed as a unitary piece with a part of the seal adapted to be disposed between the housing and cover and a further part of the seal adapted to be provided about electric line ducts which in use extend in the housing.

2. A method of forming a seal according to claim 1, wherein the part of the seal adapted to be disposed between the housing and cover is formed in a collar-like manner.

3. A method of forming a seal according to claim 2, wherein the part of the seal for the electric line ducts comprises a multiple O-ring.

4. A method of forming a seal according to claim 3, wherein the collar-like part of the seal is connected to the multiple O-ring-like part of the seal by means of cross-pieces lying inside the housing.

5. A method of forming a seal according to claim 3 or 4, wherein the multiple O-ring comprises two small O-rings and a large O-ring.

6. A method of forming a seal according to claim 5, wherein the two small O-rings are each intended to surround in use a respective single-wire electric line in a sealing manner and the large O-ring is intended to surround in use a central line connection in a sealing manner.

7. A method of forming a seal substantially as hereinbefore described.

8. Seal constructed and adapted to operate substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.