GB1565670A

GB1565670A - Internal combustion engines

Info

Publication number: GB1565670A
Application number: GB48044/76A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1975-12-12
Filing date: 1976-11-18
Publication date: 1980-04-23
Also published as: DK507976A; IN147061B; SE7613524L; PL108709B1; BE849263A; FR2334820B1; NO764211L; AU1969676A; CH600147A5; DD127279A5; ES453715A1; NL7613218A; DE2655497A1; FI763392A; IT1069714B; FR2334820A1; BR7608275A; JPS5272039A

Description

(54) IMPROVEMENTS IN OR RELATING TO INTERNAL COMBUSTION ENGINES (71) We, SOCIETE D'ETUDES DE MACHINES THERMIQUES - S.E.M.T. a French Body Corporate of 2, Quai de Seine, 93202 Saint Denis, France, 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: The present invention relates to an internal combustion engine and value system combination and particularly to a combination in which there is continuous circulation of a coolant liquid through a pair of poppet valves of the valve system.

The problem of continuous cooling of a poppet valve, comprising an inlet conduit and an outlet conduit machined in parallel relationship to one another in the valve stem and opening into an annular chamber machined in the valve head has already been solved in the prior art. To this end, a cooling liquid such as oil from the engine crank-case through the medium of a conduit machined in the cylinder head flows into an inlet orifice of the cooling inlet conduit of the valve stem and returns to the crankcase through a return conduit communicating with an outlet orifice of the outlet conduit of the valve stem.In order to ensure continuous cooling of the valve, the coolant intake communicates with the inlet orifice of the cooling inlet conduit of the valve through an annular chamber which is so dimensioned that during the reciprocating motion of the valve the inlet orifice of the valve inlet conduit always communicates with the said chamber.

In such a cooling system an intake conduit for the coolant has to be machined in the cylinder head, and the system allows only one valve to be cooled at a time, therefore as many intake conduits must be provided as there are valves.

According to the present invention there is provided an internal combustion engine and valve system combination comprising a pair of poppet valves each slidingly located in a bore in the cylinder head of the engine and each defining a passageway with an inlet and an outlet orifice through which a coolant fluid can flow, said inlet orifices of the valves being connected to a coolant fluid supply via an intermediate connecting element coupling the valves together and slidingly mounted on a pin projecting from the cylinder head whereby the connecting element reciprocates with the valves to ensure a continuous circulation of fluid throughout the period of reciprocation.

Hence, it can be seen that the present invention does not require a fluid intake conduit to be machined in the engine cylinder head as was required with previous arrangements.

Other advantages, features and details of the invention will appear more clearly from the following explanatory description made with reference to the appended drawing given solely by way of example and wherein: Figure 1 is a longitudinal sectional view of the cooling system of the invention; and Figure 2 is a sectional view upon II - II of Figure 1, showing the fluid intake device to an enlarged scale.

As shown in Figure 1, the cooling system according to the invention allows a cooling fluid to be continuously and simultaneously circulated in two valves actuated by a single rocker-arm through the medium of a tie piece or bridge member which in this case constitutes the afore-mentioned intermediate connecting element between the fluid intake and the valves.

Two valves 1, 2 are mounted, in a manner known per se, in the engine cylinder head 3 in two guides defined by two sheaths 4, 5, respectively, in which the two valve stems 6, 7, respectively, are adapted to slide. The valve heads 8,9 in one position of the valves bear through the medium of respective annular surfaces thereof upon their seats 10, 11 provided in the cylinder head 3.

The free end faces of the stems 6, 7 or the valves 1,2 bear upon a tie piece or bridge member 12 actuated by a rocker-arm 13.

The substantially symmetrical tie piece 12 comprises two arms 14, 15 associated with the two valves 1,2, respectively. The tie piece 12 is provided with a central bore 16, the longitudinal axis of which is parallel with the valve stems 6, 7, and is adapted to slide on a stationary pin 17 partially press-fitted at one end in the engine cylinder head 3 and protruding at its other end from the said cylinder head so as to allow the tie piece 12 to move up and down.

Each arm 14,15 of the tie piece 12 is provided on its surface opposite the end faces of the valve stems 6, 7 with a blind bore 18 constituted by three coaxial chambers with successively diminishing diameters defining two shoulders 19,20.

The free ends of the stems 6, 7 of the valves 1, 2, which are smaller in diameter than the bottom of the blind bores 18, abut against the said bottom. An annular sealing gasket 21 surrounding the valve stems 6, 7 is fitted on the shoulder 20. The sealing gaskets 21 are retained by circlips 22 applied on the shoulders 19, respectively, with an annular spacer 23 interposed therebetween if suitable. The valve stems 6, 7 are smaller in diameter than the bottoms of the bores 20, which allows an annular chamber 24 to be provided in each blind bore around each free end of the valve stems 6, 7.

Around the stems 6,7 of the valves 1,2, between the tie piece 12 and the cylinder head 3, are mounted two annular cup-shaped spring retainers, viz. an upper retainer 25 and a lower retainer 26, with two concentric return springs 27, 28 abutting therebetween. The upper spring retainer 25 is constituted, in a manner known per se, by two concentric portions, viz. an outer and an inner portion, the latter comprising an O-ring gasket 29 inserted in an annular groove of the associated valve so as to allow the upper spring retainer 25 to move jointly with the valve.

The arm 15 of the tie piece 12 associated with the valve 2 is also provided with a tapped bore 30 for an adjusting screw 31 one end of which presses on the free end face of the stem 7 of valve 2.

The free upper end of the central bore 16 of the tie piece 12 terminates with a protuberance 32 in which is press-fitted a plug 33 provided with an external collar 34 resting upon the annular end surface of the protuberance 32. The other end of the plug 33 contacts the rockerarm 13.

The simultaneous cooling system for the valves 1, 2 is constituted by a set of passages supplied from a fluid intake (which will be described with reference to Figure 2) through the medium of the tie piece 12. A blind bore 5Q is machined along the pin 17 serving as a sliding support for the tie piece 12. The bore 50 is closed at its free end by a plug 51 and forms a cooling-fluid inlet passage communicating with a fluid intake which will be described in more detail with reference to Figure 2. At the periphery of the stationary pin 17 on which the tie piece 12 slides is machined an annular chamber 52 which communicates with the central passage 50 through the medium of two radial passages 53.In each arm 14, 15 of the tie piece 12 is machined a passage 54 communicating at one end with the annular chamber 52 and whose other end is clr sed by a plug 55. Into the passage 54 opens tae end of a passage 56 whose other end opens no the annular chamber 24 defined by each end of the valve stems 6,7 and the bottom of the corresponding blind bore 18.

In each valve 1, 2 is provided a first longitudinal passage 57 machined within each valve stem 6,7 and opening through the medium of a radial passage 59 into an annular chamber 58 provided in the head 8, 9 of each valve. A second passage, or return passage, 60 machined in each valve stem 6, 7 also opens into the annular chamber 58 through the medium of a radial passage 61. Each inlet passage 57 communicates with the corresponding chamber 24 through an inlet orifice 62. Each return passage 60 opens out-side through the medium of an outlet orifice 63.

The intake of the cooling fluid proceeding, for example, from the engine crank case will now be described with reference to Figure 2.

To this end, a passage 64 machined in the cylinder head 3 communicates through a connecting member (not shown) directly with the crank-case, whereas its other end opens into an annular chamber 66 machined at the periphery of the stationary pin 17 towards its end fitted in the cylinder head 3. The annular chamber 66 communicates with the central passage 50 of the stationary pin 17 through two radial passages 67.

The operation of the cooling system according to the invention will now be described with reference to Figures 1 and 2. The paths followed by the fluid between the cooling-fluid intake 65 and the outlet orifice 63 of the valves 1 and 2 are as follows. The fluid proceeding from the crank-case passes through the inlet conduit 64 of the cylinder head 3, flows into the annular chamber 66 provided in the stationary pin 17 on which the tie piece 12 slides, and passes through the radial passages 67 into the central conduit 50 of the stationary pin 17. Thereafter, the fluid passes through the radial passages 53 into the annular chamber 52 and then through the passage 54 and the passage 56 provided in the tie piece 12 before reaching the annular chamber 54 provided around the free end of each valve stem 6, 7.The fluid flows from the chamber 24 through the inlet orifice 62 into the inlet cooling passage 57 of each valve and then into the annular chamber 58 provided in each valve head through the medium of the radial passage 59.

The fluid retums from the chamber 58 through the radial passage 61 into the return passage 60 of each valve stem and then flows outside through the outlet orifice 63.

The cooling system is symmetrical with respect to the stationary pin 17 and the distribution of fluid towards the valves 1 and 2 starts from the annular chamber 52 and the two conduits 54 of the tie piece 12. As appears from Figure 1, the height of the annular chamber 52 is such that during the reciprocating motion of the tie piece 12 along the stationary pin 17, the passages 54 move along the annular chamber 52 while at the same time remaining connected therewith.

Thus, with the cooling system just described, two valves 1,2 coupled together through the medium of the tie piece 12 can be cooled simultaneously from a fluid intake 64.

The lubricating system of the valve system uses a movable intermediate connecting element between the fluid intake and an inlet orifice of the valves and is advantageous in that the said element is not an additional element which may result in complicating the structure, but an element which is an integral part of the structure, i.e. the tie piece or bridge member 12.

WHAT WE CLAIM IS: 1. An internal combustion engine and valve system combination comprising a pair of poppet valves each slidingly located in a bore in the cylinder head of the engine and each defining a passageway with an inlet and an outlet orifice through which a coolant fluid can flow, said inlet orifices of the valves being connected to a coolant fluid supply via an intermediate connecting element coupling the valves together and slidingly mounted on a pin projecting from the cylinder head whereby the connecting element reciprocates with the valves to ensure a continuous circulation of fluid throughout the period of reciprocation.

2. A combination as claimed in Claim 1, in which the connecting element is associated with a single rocker arm.

3. A combination as claimed in Claim 1 or 2, in which the connecting element comprises a pair of arms each of which is connected respectively to one of the pair of valves.

4. A combination as claimed in Claim 3, in which the pin is provided with a central bore forming a passage communicating with the fluid supply via a passage formed in the cylinder head, the pin and the connecting element defining therebetween annular peripheral chamber around the pin, which chamber permanently communicates with two passages machined one in each arm respectively of the connecting element and ensuring the flow of fluid towards each valve.

5. A combination as claimed in Claim 4, in which the passages machined in the arms of the connecting element each communicate respectively with an inlet passage associated with one of the valve stems, which inlet passage communicates with an inlet passage machined in the said valve stem via an annular cham- ber formed in each arm of the connecting element.

6. An internal combustion engine and valve system combination substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawing.

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Claims

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52 and then through the passage 54 and the passage 56 provided in the tie piece 12 before reaching the annular chamber 54 provided around the free end of each valve stem 6, 7. The fluid flows from the chamber 24 through the inlet orifice 62 into the inlet cooling passage 57 of each valve and then into the annular chamber 58 provided in each valve head through the medium of the radial passage 59.

The fluid retums from the chamber 58 through the radial passage 61 into the return passage 60 of each valve stem and then flows outside through the outlet orifice 63.

The cooling system is symmetrical with respect to the stationary pin 17 and the distribution of fluid towards the valves 1 and 2 starts from the annular chamber 52 and the two conduits 54 of the tie piece 12. As appears from Figure 1, the height of the annular chamber 52 is such that during the reciprocating motion of the tie piece 12 along the stationary pin 17, the passages 54 move along the annular chamber 52 while at the same time remaining connected therewith.

Thus, with the cooling system just described, two valves 1,2 coupled together through the medium of the tie piece 12 can be cooled simultaneously from a fluid intake 64.

The lubricating system of the valve system uses a movable intermediate connecting element between the fluid intake and an inlet orifice of the valves and is advantageous in that the said element is not an additional element which may result in complicating the structure, but an element which is an integral part of the structure, i.e. the tie piece or bridge member 12.

WHAT WE CLAIM IS: 1. An internal combustion engine and valve system combination comprising a pair of poppet valves each slidingly located in a bore in the cylinder head of the engine and each defining a passageway with an inlet and an outlet orifice through which a coolant fluid can flow, said inlet orifices of the valves being connected to a coolant fluid supply via an intermediate connecting element coupling the valves together and slidingly mounted on a pin projecting from the cylinder head whereby the connecting element reciprocates with the valves to ensure a continuous circulation of fluid throughout the period of reciprocation.
2. A combination as claimed in Claim 1, in which the connecting element is associated with a single rocker arm.
3. A combination as claimed in Claim 1 or 2, in which the connecting element comprises a pair of arms each of which is connected respectively to one of the pair of valves.
4. A combination as claimed in Claim 3, in which the pin is provided with a central bore forming a passage communicating with the fluid supply via a passage formed in the cylinder head, the pin and the connecting element defining therebetween annular peripheral chamber around the pin, which chamber permanently communicates with two passages machined one in each arm respectively of the connecting element and ensuring the flow of fluid towards each valve.
5. A combination as claimed in Claim 4, in which the passages machined in the arms of the connecting element each communicate respectively with an inlet passage associated with one of the valve stems, which inlet passage communicates with an inlet passage machined in the said valve stem via an annular cham- ber formed in each arm of the connecting element.
6. An internal combustion engine and valve system combination substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawing.