GB2165635A

GB2165635A - Electric starting aid

Info

Publication number: GB2165635A
Application number: GB08522562A
Authority: GB
Inventors: Brian John Chalke
Original assignee: Lucas Industries Ltd
Current assignee: ZF International UK Ltd
Priority date: 1984-10-16
Filing date: 1985-09-12
Publication date: 1986-04-16
Also published as: JPS6198966A; ES547574A0; JPS6198965A; ES8802082A1; IT1201469B; GB8426125D0; IT8522256A0; GB8522562D0

Abstract

An electric starting aid for an internal combustion engine includes a body 10 having reduced diameter integral end portions and a bore 13 extending therethrough. One end portion forms a fuel inlet 14 and the other end portion is closed off by a plug 16 but has a side aperture 17A through which fuel can flow. Surrounding the other end portion is a fuel pervious insulating sleeve 15 about which is wound an electric heating element 21 the ends of which are connected to insulated terminal posts 22, 23 which are connected to terminals 30, 32 respectively. The terminal posts 22, 23 extend in insulating relationship through drillings 25, 26 in the body. <IMAGE>

Description

SPECIFICATION Electric starting aids This invention relates to electric starting aids for internal combustion engines and of the kind in which liquid fuel is vaporized within the aid and is ignited, the fuel burning in the air inlet manifold of the engine to heat the air flowing to the engine.

Vehicles which carry flammable cargoes for example petrol tankers, have by law to have electrical systems of the insulated return type and therefore starting aids for use in such a vehicle must have two electric supply terminals connected to the ends respectively of the heating element of the aid.

The object of the present invention is to provide a starting aid of the kind specified and which is suitable for incorporation in an insulated return vehicle electrical system.

According to the invention an electric starting aid for the purpose specified comprises a unitary metal body adapted to be secured in use in the inlet manifold of the engine said body defining reduced end portions, a bore extending through the body and said end portions, one of said end portions defining a fuel inlet, means closing the end of the bore in the other end portion, an aperture formed in the wall of the portion of the bore in said other end portion, a sleeve of insulating material mounted about said other end portion, a heating element mounted about said sleeve, a pair of drillings extending through the body and electrical terminal posts extending in insulated relationship through said drillings respectively, the ends of said windings being connected to said terminal posts.

An example of a starting aid in accordance with the invention is illustrated in sectional side elevation in the accompanying drawing.

The starting aid comprises a metallic body generally indicated at 10 and which has a portion 11 of hexagonal profile. The body 10 is also provided with a threaded portion 12 whereby the aid can be secured in an air inlet manifold of the engine. The body has reduced end portions at its opposite ends respectively and extending through the body and end portions is a bore 13. At one end the reduced end portion defines a fuel inlet 14 for connection in use to a source of liquid fuel. The opposite end portion of the body is longer than the aforesaid end portion and is provided with an electrically insulating sleeve 15 surrounding its outer peripheral surface. The sleeve 15 conveniently is formed from woven glass fibre sold under the trade name "VIDAF LEX".Moreover, located within the aforesaid opposite end portion is a plug 16 having an integral part 17 which lies in spaced relationship with the surface of the bore 13.

Located within the bore at a position adjacent the inlet, is a filter 18 and downstream of the filter but immediately upstream of the part 17 is a cup-shaped member 19 in the base wall of which is formed a central orifice 20. Fuel supplied to the bore 13 through the inlet 14, passes through the orifice 20 and engages as a jet, the end surface of the part 17.

Surrounding the insulating sleeve 15 is an electric heating element in the form of a helically wound metal tape 21. The ends respectively of the tape are secured to terminal posts 22, 23 which extend alongside the sleeve but in spaced relationship thereto and these can be connected to a source of electric supply when the starting aid is required for use. A hollow thin walled shroud 24 is secured to the body and extends in spaced relationship about the terminal post and the aforesaid end portion of the body. In use, with the heating element energised and a fuel supply connected to the inlet 14, the fuel flowing through the orifice 20 will flow through an aperture or apertures 1 7A in the end portion of the body and will also pass through the sleeve 15. The fuel is vaporized by the heating element and mixes with air within the space defined by the shroud.The resulting air/fuel mixture is ignited by a portion of the heating element which is spaced from the insulating sleeve and therefore is at a temperature sufficient to cause ignition of the air/fuel mixture.

The terminal posts 22, 23 extend through respective drillings 25, 26 which extend axially within the main part of the body 10. The terminal post 22 is integral with an annular washer 27 which is supported relative to the body 10 by means of a moulded insulator 28, the insulator adjacent the post 22 including a portion 29 which extends partly within the bore 25. The washer is integral with a terminal 30. The terminal post 23 is integral with a washer 31 which in similar manner is integral with a terminal 32 and the washer 31 is spaced from the washer 27 by means of an insulator 33 which is provided with a portion 34 extending partly within the bore 26. The insulators and washers are held in assembled relationship on the body by means of an annular retaining member 35 which is engaged with the end portion of the body which defines the inlet 14.Insulating washers 36 are interposed between the retaining member 35 and the washer 31. The washers 36 may be formed from any suitable material such as leatheroid and the insulators 28 and 33 may be formed from "Victrex" manufactured by Imperial Chemical Industries.

When assembly of the parts as described has been completed, the drillings 25 and 26 are filled with a material capable of resisting the high temperatures encountered during the use of the starting aid conveniently, a high temperature epoxy casting resin.

A starting aid of the construction described has the body isolated from the terminals and heater and can therefore be screwed directly into a threaded aperture in the engine inlet manifold which aperture is the same size as that required for an aid which uses earth return. There is no need therefore as has been the case in the past, to provide a different manifold for an engine to be fitted in a vehicle not having earth return. In the past the manifold for use with an vehicle not having earth return was provided with an enlarged hole to receive an insulated bush in which the standard form of aid was mounted.

Claims

1. An electric starting aid for an internal combustion engine, the aid being of the type in which liquid fuel is vaporized within the aid and is ignited, the fuel burning in the air inlet manifold of the engine to heat the air flowing to the engine, the aid comprising a unitary metal body adapted to be secured in use in the inlet manifold of the engine said body defining reduced end portions, a bore extending through the body and said end portions, one of said end portions defining a fuel inlet, means closing the end of the bore in the other end portion, an aperture formed in the wall of the portion of the bore in said other end portion, a sleeve of insulating material mounted about said other end portion, a heating element mounted about said sleeve, a pair of driilings extending through the body and electrical terminal posts extending in insulated relationship through said drillings respectively, the ends of said windings being connected to said terminal posts.

2. A starting aid according to Claim 1 in which said sleeve of insulating material is constructed to allow flow of fuel from said aperture onto the surface of the sleeve.

3. A starting aid according to Claim 2 in which said sleeve of insulating material is formed from glass fibre.

4. A starting aid according to Claim 1 in which said terminal posts are integrally formed with a pair of washers respectively, said washers being mounted in insulating relationship about said one end portion of the body, said washers also carrying a pair of terminals respectively whereby electrical connections can be made to the heating element.

5. A starting aid according to Claim 1 in which said drillings are filled with a material capable of resisting high temperature such for example as a high temperature epoxy casting resin.

6. An electric starting aid for internal combustion engines comprising the combination and arrangement of parts substantially as hereinbefore described with reference to the accompanying drawings.