Porting arrangement for direct injected engine

An improved porting and cylinder head arrangement for a multi-valve overhead valve internal combustion engine. The porting arrangement in the cylinder head permits the use of two separate and relatively large intake passages beneath which a fuel injector can be conveniently positioned without obstruction of the shape or configuration of these intake passages. A separate control valve body is fixed to the cylinder head for controlling the flow through the intake passages independently of each other while providing a common intake that can be valved by a single throttle valve.

BACKGROUND OF THE INVENTION
 This invention relates to a porting arrangement for a direct injected
 internal combustion engine and more particular to an improved cylinder
 head arrangement for such an engine.
 Many techniques are employed in order to improve the performance and also
 efficiency of internal combustion engines. A number of these techniques
 relate to the design of the cylinder head and particularly the porting and
 combustion chamber configuration therein. For example, it is becoming
 common practice to use multiple intake and multiple exhaust valves and one
 or twin overhead cam shafts for operating these valves. This obviously
 complicates the cylinder head construction.
 Furthermore, it has been proposed to utilize various tuning arrangements so
 that each intake passage can function independently of the others under
 some running conditions and/or so as to induce turbulence under one
 running condition without increasing flow resistance at high speed high
 load conditions. Finally, direct cylinder injection also can be employed
 in order to improve engine performance.
 However, if all of these features are used in combination, with prior
 cylinder head constructions some sacrifices had to be made. The sacrifices
 either involve putting the fuel injector at other than an optimum location
 and/or changing the configuration of the intake passages to accommodate
 the fuel injector and in some instances using Siamese rather than separate
 intake passages.
 It is, therefore, a principal object of this invention to provide an
 improved cylinder head and porting arrangement for an internal combustion
 engine wherein multiple valves, separate intake passage tuning and direct
 cylinder injection may all be employed without restricting the breathing
 capacity of the engine.
 It is a further object of this invention to provide an improved porting
 arrangement for an overhead cam multiple valve fuel injected internal
 combustion engine.
 SUMMARY OF THE INVENTION
 This invention is adapted to be embodied in a cylinder head for an internal
 combustion engine having a lower surface adapted to be affixed in
 engagement with a corresponding surface of a cylinder block. The cylinder
 head has a recessed area in its lower surface cooperating with a cylinder
 bore in the cylinder block to form, in part, a combustion chamber. A pair
 of valve seats are formed in the cylinder head recess on one side thereof.
 A pair of intake passages each extending from a respective one of the
 intake ports to a pair of spaced apart inlet openings formed in an outer
 surface of the cylinder head. A fuel injector is mounted in the cylinder
 head below the intake passages and disposed therebetween. The fuel
 injector is received in an opening formed in the cylinder head that is
 disposed between and below the intake passage openings for receiving a
 fuel injector for spraying directly into the cylinder head recess.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION
 Referring now in detail to the drawings and initially primarily to FIGS. 1
 and 2, an internal combustion engine constructed in accordance with an
 embodiment of the invention is shown partially and is identified generally
 by the reference numeral 11. The invention deals, as should be apparent
 from the foregoing description, primarily with the construction of the
 cylinder head assembly, indicated by the reference numeral 12 and the
 porting arrangement therefore. Therefore, where components of the engine
 are not necessary to illustrate this construction, nor permit those
 skilled in the art to practice the invention, they have not been
 illustrated nor will be they described except generally. Therefore, where
 any components of the engine 11 do not appear in the drawings or are not
 described herein, those skilled in the art may resort to any suitable
 constructions with which to practice the invention.
 The cylinder head assembly 12 is attached to a cylinder block 13 in any
 suitable manner. The cylinder block 13 is formed with one or more cylinder
 bores 14 which are closed by a main cylinder head member 15 of the
 cylinder head assembly 12. The construction shown in the figures
 represents a multiple cylinder, incline type engine. It should be readily
 apparent, however, to those skilled in the art how to practice the
 invention with engines having other cylinder numbers and other
 configurations.
 The cylinder head member 15 has recesses 16 in its lower surface which
 cooperate with the cylinder bores 14 and pistons 17 that reciprocate
 therein to form the variable volume chambers of the engine which will be
 at times referred to as the "combustion chambers". In fact, at top dead
 center position as shown in FIG. 2, the cylinder head recess 16 forms
 substantially the entire volume of the combustion chamber and at times
 this reference numeral will be used to designate the combustion chamber.
 In the illustrated embodiment, the engine 11 is of the multiple valve per
 cylinder type and includes at least two intake valves 18 which have stem
 portions 19 that are supported for reciprocation in valve guides 21 in the
 cylinder head member 15. These intake valves 18 control the opening and
 closing of intake ports 22 that are formed at the termination of a pair of
 side-by-side intake passages 23 which are formed the cylinder head member
 15 and which are totally separated from each other by a wall, shown in
 FIG. 5 and indicated by the reference numeral 24. This wall also appears
 in FIG. 3.
 It will be seen that the intake passages 23 extend outwardly and terminate
 in openings formed in an external surface 25 of the cylinder head member
 16. A control valve body, indicated generally by the reference numeral 26
 is affixed to this surface 25 and has branch passages 27 which are
 separated also from each other for a portion of their length by an
 integral wall 28 which forms an extension of the cylinder head wall 27.
 The control valve body 26 mates with a suitable intake manifold and air
 supply system which is not shown. This system may include one or more
 speed controlling throttle valves.
 The control valve body 26, on the other hand, includes a butterfly type
 control valve 29 which is mounted on a control valve shaft 31 in the body
 26 in only one of the two intake passages 27 thereof associated with each
 cylinder. Thus, by opening or closing the control valve 29, the flow
 through one of the intake valve seats 22 can be either opened or
 restricted.
 By restricting the flow through the passage in which the control valve 29
 is positioned, a swirl indicated by the arrow S in FIG. 5 can be
 generated. This can be used to promote turbulence under low and mid range
 operation so as to improve flame propagation and, at times, to control
 stratification within the combustion chamber 16. Rather than swirl, tumble
 can be created by utilizing a properly configured and located valve. In
 addition both swirl and tumble can be created either simultaneously or
 sequentially.
 The control valve 29 is operated by a servo motor 32 that is affixed to the
 control valve shaft 31 and which is controlled by a suitable EMU in
 connection with a desired control strategy.
 As may be seen best in FIG. 3 and FIGS. 6 and 7, the cylinder head intake
 passages 27 have a generally rectangular configuration that merges toward
 their discharge ends at the ports 22 in a circular or cylindrical
 configuration. By using this type of configuration, it is possible to
 obtain a larger flow area without making the cylinder head unduly large
 and also to provide a recessed area 33 (see FIG. 3) that extends beneath
 and between the two intake passages 23 for each cylinder.
 This recessed area 33 permits the formation of an opening 34 which receives
 a fuel injector 35 as best seen in FIG. 2. Thus, the fuel injector 35 can
 be positioned so as to have the optimum spray pattern within the
 combustion chamber. The control valve body 26 has like recesses 40 (FIG.
 4) for a similar purpose.
 Referring now primarily to FIG. 1, the intake valves 18 are urged to their
 closed positions by means of coil spring assemblies 36 which are loaded
 between a surface of the cylinder head member and a keeper retainer
 assembly which is not shown but which is affixed to the upper end of the
 stem portion 19 of the intake valves 18.
 Thimble tappets 37 are received in bosses 38 formed in the cylinder head
 member 15 and bear against these keeper retainer assemblies. The thimble
 tappets 37 are actuated by the lobes 39 of an intake cam shaft 41 that is
 journaled for rotation in a suitable manner within the cylinder head
 member 15. This intake cam shaft is driven at one half crankshaft speed by
 a suitable timing drive, as is well known in the art.
 As best seen in FIG. 2, the intake cam shaft 41 is journaled by bearing
 surfaces formed in the cylinder head member 15 and by bearing caps 42 that
 are affixed thereto by threaded fasteners 43.
 Centrally of the cylinder head member 15 there is provided a spark plug
 well 44 in which a spark plug 45 is received. The spark plug 45 is
 positioned so that its spark gap 46 lies substantially on the axis of the
 cylinder bore 14 and hence, generally at the center of the combustion
 chamber 16. This ensures equal flame propagation and complete combustion
 in the combustion chamber.
 The burnt charge is discharged from the combustion chamber 16 through
 exhaust ports 47 which are formed at the inlet ends of a Siamesed type
 exhaust passage, indicated generally by the reference numeral 48. This
 passage 48 has individual portions 49 that merge into a common discharge
 opening 51 formed in an outer surface 52 of the cylinder head member 15.
 An exhaust manifold, shown schematically at 53 is affixed to the surface
 52 and collects the exhaust gases for discharge to the atmosphere in a
 known manner.
 The exhaust ports 47 are valved by the heads of exhaust valves 54. Like the
 intake valves 18, the exhaust valves 54 have stem portions 55 that are
 supported within valve guides 56 in the cylinder head 15. Again, coil
 compression spring 57 act against the cylinder head member 15 and keep a
 retainer assembly affixed to the upper ends of the valve stems 55 for
 holding them in closed positions.
 Thimble tappets 58 are slidably supported in bores formed in bosses 59 of
 the cylinder head member 15 and engage these keeper retainer assemblies.
 The lobe 61 of an exhaust cam shaft 62 cooperate with the thimble tappets
 58 for opening exhaust valves 54 in a well known manner. the exhaust cam
 shaft 62 is, like the intake cam shaft 41, driven at one half crankshaft
 speed by any suitable drive.
 As seen in FIG. 2, the exhaust cam shaft 62 is also journaled in the
 cylinder head member 15 by integral bearing surfaces. Bearing caps 63 are
 affixed thereto by the threaded fasteners 43.
 It should be noted that the cam shafts 41 and 62 are journaled in a cam
 chamber 64 that is formed by the cylinder head member 15 and a cam cover
 65 which is affixed thereto also by the threaded fasteners 43. The cam
 cover 65 has a flange portion 66 which is grooved at 67 so as to receive a
 seal 68 that is sealingly engaged with the exterior surface of the
 cylinder head member 15 around this cam chamber 64.
 Thus, from the foregoing description it should be readily apparent to those
 skilled in the art that the described cylinder head and porting
 arrangement provides a very large effective flow area without interfering
 with the desired placement of the fuel injector. Also, the arrangement
 utilizing the control valve assembly 26 permits desired types of
 turbulence to be generated in one or if desired both of the intake passage
 but different from each other. This is done why still permitting the use
 of a common intake opening that can be controlled by a single throttle
 valve.
 Of course, the foregoing description is that of a preferred embodiment of
 the invention and various changes and modifications may be made without
 departing from the spirit and scope of the invention, as defined by the
 appended claims.