GB1593491A

GB1593491A - Fuel injection arrangements in an internal combustion engine cylinder head

Info

Publication number: GB1593491A
Application number: GB52938/76A
Authority: GB
Original assignee: Lucas Industries Ltd
Current assignee: ZF International UK Ltd
Priority date: 1976-12-17
Filing date: 1976-12-17
Publication date: 1981-07-15
Also published as: FR2374524A1; IN148276B; HU178043B; MX146483A; JPS6025627B2; JPS5376221A; PL115689B1; DD133986A5; IT1089636B; CA1074196A; ZA777159B; ES465069A1; AU3122277A; AR212491A1; DE2756257A1; BR7708316A; CS200534B2; SU797607A3; PL203034A1; FR2374524B1

Description

(54) FUEL INJECTION ARRANGEMENT IN AN INTERNAL COMBUSTION ENGINE CYLINDER HEAD (71) We, LUCAS INDUSTRIES LIMITED, A British Company of Great King Street, Birmingham B19 2XF, do hereby declare the invention for which we pray that a Patent may be granted to us and the method by which it is to be performed to be particularly described in and by the following statement: This invention relates to a fuel injection arrangement in an internal combustion engine, the engine preferably being of the compression ignition type.

According to the present invention, there is provided, in an internal combustion engine induding a cylinder head having a bore therethrough, a fuel injection arrangement comprising a fuel injection device located in said bore, the device including a housing having a seating thereon and a valve member slidable within the housing and co-operating with the seating to control the flow of fuel from the device in use; a fuel pipe in flow communication with the fuel injection device, means on the fuel pipe defining a portion of larger diameter than the pipe, a member defining an opening through which the pipe extends, said member being in screwthreaded engagement with the cylinder head, the member and the housing having respective abutments thereon which engage axially opposed parts d said portion so as to trap said portion therebetween, the force exerted by the sorew-threaded engagement of the member and the cylinder head forming the sole means of effecting a fuel tight seal between said portion and the housing and also serving to hold the fuel injection device in said bore.

Preferably, said bore is stepped and the fuel injection device is urged into engagement with the step in the bore by the member acting through the intermediary of said portion.

In one embodiment, the member includes a head portion and a screw-threaded shank portion which surrounds the fuel pipe with clearance, the abutment being provided on the head portion and an end of the fuel in jection device being accommodated within the shank portion.

In an alternative embodiment, the mem ber includes a head portion and a screw threaded shank portion, and the abutment is provided at or adjacent an end of the shank portion remote from the head portion.

Either or both of the abutments may be formed by a chamfered surface.

Embodiments of the present invention will now be described by way of example, with reference to the accompanying drawing, in which: Figure 1 is a sectional side view of a compression ignition engine provided with a first embodiment of a fuel injection arrange ment according to the present invention, Figure 2 is a sectional side view of a compression ignition engine provided with a second embodiment of a fuel injection ar rangement acording to the present invention, and Figure 3 is a sectional side view of a modification of the fuel injection arrangements shown in Figures l-and 2.

Referring to Figure 1 the fuel injection arrangement shown therein comprises a fuel injection device 10 located in a bore 11 in a cylinder head 12 of the engine and engaging a step 13 in the bore 11 through the intermediary of a seating washer 13a. The injection device 10 includes a housing 14 formed in two parts 15, 16 which are mutually sealingly engaged and which define a chamber in the housing 14. The housing part 15 has a fuel inlet opening 17 therein communicating with the chamber, and the housing part 16 has an axial bore therein in which a poppet valve member 18 is slidably housed. A head of the member 18 co-operates with a seating 19 on the housing part 16 to control the flow of fuel into a combustion chamber 20 of the engine into which the narrower end of the bore 11 opens.

A stem of member 18 is so sized relative to the bore in housing part 16 that an annular space is defined between the stem and the side wall of the bore, which space communicates with the chamber via openings 21 in the housing part 16. A collar 22 is provided on the stem and has helical grooves therein, the grooves acting to impart a swirling motion to the fuel as it is ejected from the injection device 10 to enhance atomisation of the fuel.

The operation of this form of injection device is well known, and will not be described further. An end of the valve member 18 remote from the head thereof has a spring abutment 23 mounted thereon, and a spring 24 is accommodated in the housing chamber between the spring abutment 23 and the housing part 16 the spring 24 acting to oppose lifting of the valve member 18 off the seating 19.

The fuel injection arrangement further comprises a fuel supply pipe 26 having a portion of larger diameter than the pipe and formed by means of an olive 27. A screw-threaded member 28 is provided having a central opening through which the pipe 26 passes. The member 28 includes a head portion 29 and a shank portion 30 integral therewith which is screw-threaded on its external surface and which engages corresponding screw-threading on the side wall of bore 11. An end of the shank portion 30 remote from the head portion 29 is chamfered so as to define an abutment 31. The housing 14 of the fuel injection device 10 is also chamfered in the region of the inlet opening 17 so as to define a further abutment 32.The abutments 31, 32 engage axially opposed parts of the olive 27, so that the end of the pipe 26 is trapped therebetween, the pipe 26 thereby being held in flow communication with the inlet opening 17. Liquid tight seals between the member 28 and the olive 27 on the one hand, and between the housing 14 and the olive 27 on the other hand are produced by deformation of the olive 27 by the force gencrated as the member 28 is screwed down.

From the above, it will be appreciated that the screw-threaded member 28 not only serves to connect the pipe 26 to the injection device 10, but also serves to hold the injection device 10 in position in the bore 11 by acting on the olive 27 and, through the intermediary of the latter, urging the device 10 into engagement with the step 13 i th.

bore 11.

The fuel injection arrangement shown in Figure 2 is similar to that described above in relation to Figure 1, similar parts being accorded the same reference numerals with 100 added. In this embodiment, however, the shank portion 130 of the screw-threaded member 128 surrounds the outer end of the fuel injection device 110 and the bore 111 is further stepped to accommodate the threaded member. The olive 127 is trapped between the abutment 132 on the housing 114 of the fuel injection device 110 and an abutment 131 on the head portion 129 of the screwthreaded member 128.

From a comparison of Figures 1 and 2 it will be appreciated that the arrangement of Figure 2 occupies less axial space in the cylinder head than that of Figure 1.

A modification of the above described ar rangement is illustrated in Figure 3. In the embodiments of Figures 1 and 2, sealing between an end of the housing part 15, 115 and the step 13, 113 in the bore 11, 111 is effected by means of the sealing washer 13a, 113a. However, this form of arrangement can be replaced by that shown in Figure 3, in which the end of the body part (referenced 150) is radiussed and engages the seat (referenced 151) directly. The seat itself is of spherical or substantially spherical form and its radius of curvature is greater than the radius of the end of the body part, so that the body part and the seat can be mutually sealingly engaged.

In a modified arrangement (not shown) the olive is omitted and a portion of larger diameter than the pipe is formed at the end of the fuel supply pipe 26, 126 by flaring the wall thereof outwardly.

The constructions described obviate the need to provide two separate arrangements for effecting a fuel tight connection of the pipe to the housing and for securing the device within the bore. As a result there is an economy of parts and the axial length of the injection device can be made smaller.

In the known constructions the housing is provided with a screw thread for engagement with the bore and a head to receive a spanner for tightening the housing within the bore to obtain the desired seal. The head must be accessible from the exterior of the cylinder head and on the end of the head is provided the attachment for the fuel supply pipe.

WHAT WE CLAIM IS: 1. A fuel injection arrangement in an internal combustion engine including a cylinder head having a bore therethrough comprising a fuel injection device located in said bore, the device including a housing having a seat in= thereon and a valve member slidable within the housing and co-operating with the seating to control the flow of fuel from the device in use; a fuel pipe in flow communication with the fuel injection device, means on the fuel pipe defining a portion of larger diameter than the pipe, a member defining an opening through which the pipe extends, said member being in screw-threaded engagement with the cylinder head the member and the housing having respective abutments thereon which engage axially opposed parts of said portion so as to trap said portion therebetween, the force exerted by the screwthreaded engagement of the member and the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. space is defined between the stem and the side wall of the bore, which space communicates with the chamber via openings 21 in the housing part 16. A collar 22 is provided on the stem and has helical grooves therein, the grooves acting to impart a swirling motion to the fuel as it is ejected from the injection device 10 to enhance atomisation of the fuel. The operation of this form of injection device is well known, and will not be described further. An end of the valve member 18 remote from the head thereof has a spring abutment 23 mounted thereon, and a spring 24 is accommodated in the housing chamber between the spring abutment 23 and the housing part 16 the spring 24 acting to oppose lifting of the valve member 18 off the seating 19. The fuel injection arrangement further comprises a fuel supply pipe 26 having a portion of larger diameter than the pipe and formed by means of an olive 27. A screw-threaded member 28 is provided having a central opening through which the pipe 26 passes. The member 28 includes a head portion 29 and a shank portion 30 integral therewith which is screw-threaded on its external surface and which engages corresponding screw-threading on the side wall of bore 11. An end of the shank portion 30 remote from the head portion 29 is chamfered so as to define an abutment 31. The housing 14 of the fuel injection device 10 is also chamfered in the region of the inlet opening 17 so as to define a further abutment 32.The abutments 31, 32 engage axially opposed parts of the olive 27, so that the end of the pipe 26 is trapped therebetween, the pipe 26 thereby being held in flow communication with the inlet opening 17. Liquid tight seals between the member 28 and the olive 27 on the one hand, and between the housing 14 and the olive 27 on the other hand are produced by deformation of the olive 27 by the force gencrated as the member 28 is screwed down. From the above, it will be appreciated that the screw-threaded member 28 not only serves to connect the pipe 26 to the injection device 10, but also serves to hold the injection device 10 in position in the bore 11 by acting on the olive 27 and, through the intermediary of the latter, urging the device 10 into engagement with the step 13 i th. bore 11. The fuel injection arrangement shown in Figure 2 is similar to that described above in relation to Figure 1, similar parts being accorded the same reference numerals with 100 added. In this embodiment, however, the shank portion 130 of the screw-threaded member 128 surrounds the outer end of the fuel injection device 110 and the bore 111 is further stepped to accommodate the threaded member. The olive 127 is trapped between the abutment 132 on the housing 114 of the fuel injection device 110 and an abutment 131 on the head portion 129 of the screwthreaded member 128. From a comparison of Figures 1 and 2 it will be appreciated that the arrangement of Figure 2 occupies less axial space in the cylinder head than that of Figure 1. A modification of the above described ar rangement is illustrated in Figure 3. In the embodiments of Figures 1 and 2, sealing between an end of the housing part 15, 115 and the step 13, 113 in the bore 11, 111 is effected by means of the sealing washer 13a, 113a. However, this form of arrangement can be replaced by that shown in Figure 3, in which the end of the body part (referenced 150) is radiussed and engages the seat (referenced 151) directly. The seat itself is of spherical or substantially spherical form and its radius of curvature is greater than the radius of the end of the body part, so that the body part and the seat can be mutually sealingly engaged. In a modified arrangement (not shown) the olive is omitted and a portion of larger diameter than the pipe is formed at the end of the fuel supply pipe 26, 126 by flaring the wall thereof outwardly. The constructions described obviate the need to provide two separate arrangements for effecting a fuel tight connection of the pipe to the housing and for securing the device within the bore. As a result there is an economy of parts and the axial length of the injection device can be made smaller. In the known constructions the housing is provided with a screw thread for engagement with the bore and a head to receive a spanner for tightening the housing within the bore to obtain the desired seal. The head must be accessible from the exterior of the cylinder head and on the end of the head is provided the attachment for the fuel supply pipe. WHAT WE CLAIM IS:

1. A fuel injection arrangement in an internal combustion engine including a cylinder head having a bore therethrough comprising a fuel injection device located in said bore, the device including a housing having a seat in= thereon and a valve member slidable within the housing and co-operating with the seating to control the flow of fuel from the device in use; a fuel pipe in flow communication with the fuel injection device, means on the fuel pipe defining a portion of larger diameter than the pipe, a member defining an opening through which the pipe extends, said member being in screw-threaded engagement with the cylinder head the member and the housing having respective abutments thereon which engage axially opposed parts of said portion so as to trap said portion therebetween, the force exerted by the screwthreaded engagement of the member and the

cylinder head forming the sole means of effecting a fuel tight seal between said portion and the housing and also serving to hold the fuel injection device in said bore.

2. An arrangement according to claim 1 in which the bore is provided with a step, the device being urged into engagement with said step by the member acting through the intermediary of the said portion.

3. An arrangement according to claim 2 in which said member is provided with a head portion and a screw threaded shank portion, the abutment being provided on the head portion and an end of the fuel injection device being acommedated within the shank portion.

4. An arrangement according to claim 2 in wrich said member is provided with a head portion and a screw threaded shank portion, th abutment being provided at or adjacent an end of the shank portion remote from the head portion.

5. An arrangement according to claims 3 or 4 in which either or both of said abutments are formed by a chamfered surface.

6. An arrangement according to any one of the preceding claims in which said portion of larger diameter than the fuel pipe is formed by flaring the end of the pipe outwardly.

7. An arrangement according to any one of claims 1 to 5 in which said portion of larger diameter than the fuel pipe is formed by an olive located on the pipe.

8. A fuel injection arrangement in an internal combustion engine comprising the combination and arrangement of parts substantially as hereinbefore described with reference to Figure 1 of the accompanying drawings.

9. A fuel injection arrangement in an internal combustion engine comprising the combination and arrangement of parts substantially as hereinbefore described with reference to Figure 2 of the accompanying drawings.

10. A fuel injection arrangement in an internal combustion engine comprising the combination and arrangement of parts substantiaily as hereinbefore described with reference to Figure 1 or 2 as modified by Figure 3 of the accomanying drawings.