WO2000076741A1

WO2000076741A1 - Fabrication of articles

Info

Publication number: WO2000076741A1
Application number: PCT/GB2000/002278
Authority: WO
Inventors: Alan Henry Organ
Original assignee: Forsheda Ltd
Current assignee: Trelleborg Sealing Solutions UK Ltd
Priority date: 1999-06-11
Filing date: 2000-06-12
Publication date: 2000-12-21
Anticipated expiration: 2001-12-11
Also published as: GB9913648D0; AU5545000A

Abstract

An article is fabricated by forming a first component (22) with at least one retaining portion (15) and moulding a second component (24) about said retaining portion (15) so that the latter is deformed in the moulding process and thereby retains the components together. Preferably the first component (22) is moulded in a first tool (1, 3) and is transferred on a portion (1) of the first tool to a second tool (13) in which the second component (24) is moulded in contact with the first component (22) so that the two are combined, said portion (1) of the first tool having a moulding surface (23) which defines part of a second component. Preferably, the first component (22) is moulded from elastomeric material and comprises a sealing member, and the second component (24) is moulded from plastics material and may be the header tank of a vehicle engine cooling system incorporating the sealing member (22).

Description

FABRICATION OF ARTICLES

This application relates to fabricated articles and methods and apparatus for fabricating the same. In particular, this application relates to the fabrication of articles comprising moulded components.

When two members such as a header tank and a radiator in a vehicle cooling system are to be joined together in a substantially fluid-tight manner, a sealing member is provided at the interface between the two members. For convenience of assembly, the sealing member is preferably attached to one of the two members, for example, using adhesive. However, this adds an additional step to the assembly process, and may cause a problem in finding suitable adhesive for the elastomeric and plastics materials involved.

According to a first aspect, the invention consists in a method of creating an article comprising two components, the method including the steps of forming a first component with at least one retaining portion, and moulding a second component about said al least one retaining portion, so that the latter is deformed in the moulding process and thereby retains the components together.

Preferably, said at least one retaining portion is deformed either by the flow of material introduced into a mould to form the second component, or by the thermal energy of the fluid or semi-fluid material introduced into the mould to form the second component, or by chemical reaction between the substance of the first component and the material introduced into the mould to form the second component. Of course, the deformation of said at least one retaining portion can be a result of a combination of any of these causes.

In one embodiment, the first component may be a moulded elastomeric component, and the second component may be a moulded plastics component. The first component may be an elastomeric seal and the second component may be a plastics header tank of a vehicle engine cooling system. Us g this method, the seal is attached securely to the header tank during manufacture of the tank, and the cl lance of the seal becoming misaligned during mounting of the header tank to other parts o the cooling system is reduced.

According to a second aspect, the invention consists in a method of fabricating an article in which a first component of the article is moulded in a first tool and is transferred on a portion of the first tool to a second tool in which a second component of the article is moulded in contact with the first component so that the two are combined, said portion of the first tool having a moulding surface which defines part of the second component.

Preferably, the first component is moulded from elastomeric material and comprises a sealing member, and the second component is moulded from plastics material. For example, the second component may be the header tank of a vehicle engine cooling system incorporating an annular sealing member at its closing interface with another part of the system.

Some embodiments of the invention will now be described, by way of example only, and with reference to the accompanying figures, in which:-

Fieure 1 is a plan view of elastomeric moulding apparatus for manufacturing the sealing member of a header tank;

Figure ! is a cross-section of the moulding apparatus of Figure 1;

Figure 3 is a detail from Figure 2 to an enlarged scale;

Figure 4 is a cross-section of plastics moulding apparatus for manufacturing the body of a header tank;

Figure 5 is a longitudinal section of the moulding apparatus of Figure 4; and Fi^gure 6a and 6b are schematic illustrations of the plastics material as it flows into the mould of Figures 4 and 5 and contacts the pre-formed sealing member of Figures 1 and 3.

The moulding apparatus for manufacturing the sealing member consists of a moulding tool I defining an annular cavity 2 for forming a sealing body, and a cooperating moulding tool 3 that closes the open mouth of the cavity 2 and defines a series of elongated channels 4 to form tabs that project from the scaling body. The rectangular overall shape of the sealing body and arrangement of tabs is best seen in Figure 1.

The moulding tool 3 is mounted on a base plate 5, and the moulding tool 1 is mounted on a transfer plate 6 which is located between the base plate 5 and a clamp plate 7. Pins 8 guide relative movement of the base plate and clamp plate in opening and closing the mould. Guide pins 11 assist alignment of the transfer plate 6 with the moulding tool 3 when they engage one another. A punch 9 cooperates with a recess 10 in the rear of the transfer plate 6 and is formed with channels 12 to conduct elastomeric material to the mould cavity 2 during the seal moulding process.

Once a sealing member has been formed, the mould is opened and the transfer plate 6 and moulding tool 1 are disengaged from the moulding tool 3. In this process, the tabs formed on the sealing member are pulled free of the recesses 4 in which they are formed. The moulding tool 1, still with the sealing member contained within it, is removed to equipment for a secondary plastics moulding process. The moulding tool 1, either still attached to the transfer plate 6, or mounted on a separate back plate 12, is engaged with a moulding tool 13 having a moulding recess 14 into which the tabs 15 of the sealing member 22 project. The recess 14 has the external profile for the required shape of header tank seen in Figures 4 and 5, and the moulding tool 1 has a central projecting portion 23 wliich has the inner profile of the header tank and cooperates with the recess 1 to define a cavity 16 which forms U.e wall of the header tank. Plastics material 24 is injected through a passageway 17 that communicates with the cavity 16. The plastics flows into the extremities of the cavity in the region of the tabs 15 of the sealing member, and in the process, deflect the tabs laterally so that they are no longer completely upright within the cavity when the plastics sets. This process is illustrated in Figures 6a to 6c of the drawings. This process has the effec: of mechanically keying the tabs 15 within the rim of the header tank so as to hold the sealing member in place. At the same time, there may be a mechanical bonding process between compatible elastomeric and plastics materials, or by surface coating the tabs 15 before the plastics injection process.

Once the plastics moulding process is completed, the mould is opened and the moulding tool 13 separates from the moulded header tank which remains in place on the moulding tool 1 by virtue of the shape of the sealing member 22 which is held captive within the re-entrant cavity 2. However, the sealing member 22 is released by forcibly ejecting it from the tool 1 with the ejection pins IS. The body of the sealing member is thereby forcibly withdrawn from the cavity 2, but to aid this withdrawal process, the moulding tool 1 incorporates a release plate 19 around its periphery which defines the outer edge of the sealing member as shown in Figure 3. The release plate 19 is free to move relative to the base of the moulding tool 1 and is guided by pins 20 attached to the release plate and which have heads guided in recesses 21 in the base of the tool 1. The axial force exerted on the sealing member 22 to remove it from the cavity 2 is therefore transferred to the release plate 19, wliich moves with the sealing member, and thereby provides more space to accommodate distortion of the sealing member as it is further withdrawn through the opening of the cavity 2.

In an alternative embodiment of the invention, the tabs 15 may have a different profile and shape to that illustrated, and may be arranged other than in a straight line as shown in Figure 1.

Claims

1. A method of creating an article comprising two components (22,24), the method including the steps of forming a first component (22) with at least one retaining portion (15), and moulding _ second component (24) about said at least one retaining portion, characterised in that said at least one retaining portion (15) is deformed in the moulding process and thereby retains the components (22,24) together.

2. A method as claimed in claim 1 in which said at least one retaining portion is deformed by a flow of material introduced into a mould to form the second component.

3. A method as claimed in claims 1 or 2 in which said at least one retaining portion is deformed by the thermal energy of a fluid or semi-fluid material introduced into the mould to form the second component.

4. A method as claimed in any one of claims 1 to 3 in which said at least one retaining portion is deformed by a chemical reaction between the substance of the first component and the material introduced into the mould to form the second component.

5. A method as claimed in any one of the preceding claims in which the first component is a moulded elestomeric component, and the second component is a moulded plastics component.

6. A method as claimed in claim 5 in which the first component is an elastomeric seal and the second component is a plastics header tank of a vehicle engine cooling system.

7. A method of fabricating an article in which a first component (22) of the article is moulded in a first tool (1,3) and is transferred on a portion (1) of the first tool to a second tool (13) in which a second component (24) of the article is moulded in contact with the first component (22) so that the two are combined, said portion of the first tool (1) having a moulded surface (23) which defines part of the second component (24).

8. A method as claimed in claim 7 in which the first component is moulded from elastomeric material and comprises a sealing member, and the second component is moulded from plastics material

9. A method as claimed in claim 8 in which the second component is the header tank of a vehicle engine cooling system incorporating an annular seahng member at its closing interface with another part of the system

10. Apparatus for fabricating an article comprising two components comprising a first tool (1), a second tool (3) with which the first tool (1) cooperates to form a first component (22), means to engage the first tool (1) with the second tool (3) to form said first component (22) and to remove the first tool (1 ) with said first component (22) from the second tool (3), and a third tool (13) with which the first tool (1) and first component (22) cooperate to form a moulding cavity (16) which the second component (24) is moulded so as to contact at least a portion (15) of the first component (22).

11. Apparatus for manufacturing the article as claimed in any one of claims 1 to 9.

12. An article manufactured according to the method of any one of claims 1 to 9.