Friction insert for directional valve

Abstract

The friction insert for an orientation valve (60) is intended for a valve-controlled ignition pre-chamber (1) and comprises an outer valve body guide cylindrical bearing surface (64) arranged on the periphery of the valve with guide pin (50) and sliding with a small clearance into a first valve body guide means (63), the insert (60) also comprising an outer pin guide cylindrical bearing surface (66) arranged on the outer periphery of the orientation pin (15) and sliding with a small clearance into a second orientation pin guide means (65), the two means (63, 65) being wear-resistant and fixedly attached to a non-magnetic pre-chamber tip (62) which guides and orients the valve with guide pin (50).

Description

[Technical Field]

[0001] The present invention relates to a friction insert for a directing valve, which constitutes an improvement on the valve-controlled ignition pre-chamber that is the subject of French patent no. 3061743, published on August 16, 2019, belonging to the Applicant. [Background technology]

[0002] The friction insert for the directing valve according to the invention is advantageously combined with the main improvements of the pre-chamber according to French patent no. 3061743, which improvements form the subject of several patent applications.

[0003] Among these improvements, attention should be paid to the "valve magnetic return device" subject of French patent application no. 3085718 published on March 13, 2020, or the "ignition insert with active prechamber" subject of French patent application no. 1904961 filed on May 13, 2019, or the "reverse combustion direction valve ignition prechamber" subject of French patent application no. 2001508 dated February 14, 2020, as well as the patent entitled "valve having a guide pin" published in WO 2022079367.

[0004] All these patents and patent applications have in common the fact that they have an ignition pre-chamber formed from a laminated cavity, arranged in the cylinder head of an internal combustion engine according to the prior art and directed to alternative internal combustion engines, as do the majority of torch ignition devices.

[0005] The strategy employed in the patents, patent applications, and devices is specifically known as "turbulent jet ignition."

[0006] According to the patent and patent application, the stack cavity is connected on the one hand to the combustion chamber of the internal combustion engine by a stack duct and, on the other hand, receives a stack injector capable of injecting into the cavity a pilot load pre-pressurized by a compression means, the pilot load consisting of an oxidizer / fuel mixture that can be easily ignited by a spark.

[0007] It should be noted that the combustion chamber itself receives the main load, which can either be undiluted or diluted with air or recirculated exhaust gases, this dilution making it possible, in particular, to maximize the energy efficiency of the internal combustion engine.

[0008] Applicant's patents and patent applications differ from the prior art in that the laminate duct includes a valve closure seat against which a laminate valve can seat to close the duct, thereby isolating the laminate cavity from the combustion chamber of an internal combustion engine.

[0009] However, as described in French Patent Application No. 3085718, when the valve leaves its seat and seats on a chamber-side valve stop either directly or via a damping chamber, the valve together with the stack duct forms a torch-ignited pre-combustion chamber which simultaneously communicates with the stack cavity on the one hand and with the combustion chamber via a gas discharge orifice on the other hand.

[0010] This particular configuration allows the introduction of a pilot load into the stack cavity that remains fully ignitable, whatever the nature and composition of the main load formed in the combustion chamber, and in fact the two loads are hermetically separated by the stack valve, so that the main load and the pilot load cannot mix any further.

[0011] This advantage is crucial since the composition, pressure, and temperature of the pilot load can be radically different from that of the main load.

[0012] The stacked valve therefore makes it possible to avoid one of the main drawbacks of torch-ignited pre-chambers that can be considered "open" - i.e. without a stacked valve - which is that, according to the prior art, if a gas mixture that is difficult to ignite forms the main load, this mixture will also - partly and with an inappropriate mixture - form the pilot load in the ignition pre-chamber.

[0013] In fact, in the case of an "open" pre-chamber, the mixing of the main load and the pilot load makes the pilot load less and less capable of providing high ignition power, the more high ignition power is required to ignite the main load.

[0014] Conversely, and always in the case of an "open" pre-chamber, when the main load is formed from a largely undiluted and very active mixture that requires only a low ignition power to avoid its combustion in the main chamber generating too high a pressure gradient and noise, the pilot load, which is formed partly from the mixture that makes up the main load and inherits its pressure and temperature, becomes too energetic.

[0015] In other words, without the presence of a stack valve according to French Patent No. 3061743 making it possible to close the stack duct, the pilot load would necessarily be formed partly from the mixture constituting the main load, and would therefore partly take over the ease of ignition and combustion of the main load, and its energy storage would be directly related to the pressure exerted on it by the main load, which is contrary to necessity.

[0016] In fact, the less reactive the main load, the more powerful the pilot load must be, and conversely, the more easily and rapidly the main load can burn, the lower the energy of the pilot load must be to avoid burning the main load too quickly.

[0017] The valve-controlled ignition pre-chamber of French Patent No. 3061743 therefore forms an autonomous torch ignition device whose ignition power can be freely adjusted, thereby achieving the best compromise between efficiency, polluting emissions and acoustic emissions of the internal combustion engine that receives the autonomous torch ignition device.

[0018] To illustrate this, it can be seen from the figures of WO2022079367 that advantageously an orientation pin protrudes from the axial opening face with the main valve body of the laminated valve, thereby forming a valve with a guide pin.

[0019] The orientation pin engages with an axial guide orifice housed with a small radial clearance and passing through the chamber-side valve stop, so that the pin can slide longitudinally within the orifice without completely exiting it, thereby orienting the valve with the guide pin within the stacked duct.

[0020] When reading WO2022079367, it should also be noted that the valve with the guide pin comprises a peripheral centering surface located on the periphery of its main valve body, which peripheral centering surface is capable of contacting the inner wall of the laminated duct to center the body within the duct.

[0021] In WO 2022079367, a valve damping chamber is formed by a laminated duct, an axial opening surface, and a chamber-side valve stopper, and the volume of the chamber is maximized when the axial closing surface of the valve with the guide pin is seated on the duct closing seat with the laminated duct, and is minimized when the axial opening surface is seated on the chamber-side valve stopper.

[0022] WO2022079367 also describes that the valve with the guide pin may advantageously be fully or partially coated with a wear-resistant, low friction coefficient material, such as a "diamond-like coating" or physical vapor deposition such as "Ionbond 90", while the inner surface of the laminated duct in contact with the valve is coated, for example, with chemical nickel with a low phosphorus content.

[0023] As can be seen in the figures of WO2022079367, the laminated duct comprises a non-magnetic pre-chamber tip made of copper or stainless steel, which may or may not be coated with a highly wear-resistant anti-friction material.

[0024] The magnetic valve return device, which is the subject of French patent application No. 3085718, requires the non-magnetic properties of the material that makes up the pre-chamber tip, without which the valve with the guide pin would not be able to close quickly enough, especially when the valve is applied to high-speed engines such as those found in automobiles.

[0025] It should be noted that in the figures of WO2022079367, a pre-chamber tip is attached by fret connection to both sides of the gas discharge pipe and the non-magnetic sleeve insert, and the tip receives the combustion chamber side valve stop and an axial guide orifice that accommodates the orientation pin with a small clearance.

[0026] It should be noted that the non-magnetic pre-chamber tip discussed is not only non-magnetic in order to be compatible with the magnetic valve return device that is the subject of French patent application No. 3085718, but also must be made of a material with high thermal conductivity, such as copper, to avoid the tip becoming too hot due to direct exposure to the hot gases present in the combustion chamber of the internal combustion engine.

[0027] In fact, if the non-magnetic pre-chamber tip becomes too hot, it can cause unintended self-ignition of the main load contained in the combustion chamber, which can lead to damage to the internal combustion engine.

[0028] The problem is that copper, from which the non-magnetic pre-chamber tip can be advantageously made, is a ductile and malleable material, and the tip must be coated with a hard coating so that it is resistant, on the one hand, to wear induced by friction with the peripheral centering surfaces of the valve with the guide pin, and, on the other hand, to wear induced by friction between the orientation pin and the axial guide orifice.

[0029] However, copper coatings are not suitable for the functional conditions of valves with guide pins when it comes to ensuring a long service life of pre-combustion chambers with valves with guide pins, which results from the combination of French patent no. 3061743 and international publication no. 2022079367.

[0030] Indeed, the torch ignition pre-chamber is subjected to a high thermal load of temperatures exceeding 2000 degrees Celsius when the ignition torch is ejected from said pre-chamber through the gas discharge orifice.

[0031] For example, although chemical nickel coatings are compatible with mechanically resistant copper alloys such as "C17500", the coatings do not have sufficient temperature and wear resistance to meet the operating specifications of pre-chambers equipped with valves having guide pins according to WO2022079367.

[0032] Indeed, the chemical nickel coating rapidly loses its mechanical properties due to temperature, is repelled by the laminated valve and is further deposited on said valve by a series of micro-melts.

[0033] The problem is that copper cannot accept coatings that are resistant to very high temperatures, which are typically applied at temperatures of 500-800 degrees Celsius.

[0034] One solution consists in replacing the copper with non-magnetic stainless steel, but said steel has poor thermal conductivity. Summary of the Invention

[0035] Therefore, in order to solve the various problems mentioned above and the dilemmas arising from them, according to the friction insert for an orientation valve according to the invention and according to a particular embodiment of said insert, the laminated valve forming the valve with the guide pin and the orientation pin are no longer guided directly by the material constituting the non-magnetic pre-chamber tip, but by guide means made of a hard material that is wear-resistant and compatible with the most effective anti-friction coatings, which are generally deposited at high temperatures.

[0036] In this regard, the present invention provides a valve-controlled ignition pre-chamber from the friction insert to the orientation valve. The non-magnetic pre-chamber tip can be made from a highly thermally conductive non-magnetic material such as copper without compromising the mechanical strength and service life of the tip. ●Its service life is compatible with that of mass-produced automotive engines, and its operation remains stable throughout that service life, ensuring optimal efficiency and operation throughout the service life of the internal combustion engine that receives it. • Its mass production does not pose any particular problems. • Its cost price is compatible with the economic constraints of the mass-produced automobile market.

[0037] It is understood that the friction insert for a directional valve according to the present invention can be applied not only to pre-chambers with valves having guide pins according to WO2022079367, but also to any other application close to its design and principle in which the features and functions of the insert can be advantageously utilized.

[0038] Friction insert for an orientation valve for a valve-controlled ignition pre-chamber arranged in a cylinder head of an internal combustion engine crowning a combustion chamber, the pre-chamber comprising a laminate cavity into which an ignition means and a laminate injector open, the cavity being connected to the combustion chamber by a laminate duct opening into the chamber in the form of a non-magnetic pre-chamber tip, the tip accommodating a laminate valve, the laminate being oriented by an orientation pin capable of closing the duct and capable of sliding in an axial guide orifice arranged in the tip, the valve and the pin together forming a valve with a guide pin, while the non-magnetic pre-chamber tip together with the valve forms a torch-ignition pre-chamber when not closing the laminate duct, the torch-ignition pre-chamber connecting the laminate cavity to the combustion chamber via at least one gas discharge orifice, At least one outer valve body guide cylindrical bearing surface disposed on the periphery of the valve having a guide pin; at least one first valve body guide means, which is wear-resistant and fixedly attached to the non-magnetic pre-chamber tip, and which has, at least locally, an inner diameter which is on the one hand smaller than the inner diameter of the tip and on the other hand substantially larger than the outer diameter of the outer valve body guide cylindrical bearing surface, the axial thickness of the first means and its axial position in the non-magnetic pre-chamber tip being such that the outer valve body guide cylindrical bearing surface can slide with a small clearance into the first means, thereby intended to radially guide the valve with the guide pin over all or part of its travel in the non-magnetic pre-chamber tip; at least one outer tip guide cylindrical bearing surface disposed on the outer periphery of the orientation pin; and at least one second orientation pin guide means, resistant to wear and fixedly attached to the axial guide orifice, which second means has, at least locally, an inner diameter which is, on the one hand, smaller than the inner diameter of the orifice and, on the other hand, substantially larger than the outer diameter of the outer pin guide cylindrical bearing surface, the axial thickness and axial position of which are intended to allow the outer pin guide cylindrical bearing surface to slide with a small clearance into the second means and to keep the longitudinal axis of the valve with the guide pin substantially parallel to the longitudinal axis of the non-magnetic pre-chamber tip over all or part of the valve stroke.

[0039] The friction insert for the orientation valve comprises a first valve body guide means and a second orientation pin guide means, which are made of a non-magnetic material having high thermal and mechanical resistance.

[0040] The friction insert for an orientation valve comprises a first valve body guide means and a second orientation pin guide means, which form part of the same multifunctional insert, whether assembled or not, which is fixedly attached on the one hand to a non-magnetic pre-chamber tip and, on the other hand, houses all or part of a valve with a guide tip, which multifunctional insert replaces the non-magnetic pre-chamber tip to house an axial guide orifice.

[0041] The friction insert for the aligning valve comprises a multifunctional insert which, on the one hand, together with the axial opening surface of the valve with the guide pin oriented towards the combustion chamber, and, on the other hand, together with the aligning pin, forms a valve damping chamber.

[0042] The friction insert for the orientation valve comprises at its end an axial guide orifice with a damping counterbore opening into the valve damping chamber, said counterbore engaging with a damping shoulder provided on the orientation pin.

[0043] The friction insert for the orientation valve comprises a damping counterbore connected directly or indirectly to the combustion chamber by at least one pressure reduction duct.

[0044] The friction insert for the aligning valve comprises a valve having a guide pin with a second sealing collar that extends the outer valve body guide cylindrical bearing surface in the direction of the stacked duct. [Brief explanation of the drawings]

[0045] The following description, with reference to the accompanying drawings, is given by way of non-limiting example and will enable a best understanding of the invention, the features it possesses and the advantages it can offer. [Figure 1] 1 is a schematic cross-sectional view of a friction insert for an orientation valve according to the present invention, in which a first valve body guide means and a second orientation pin guide means of the friction insert are fixedly attached to a non-magnetic pre-chamber tip independently of each other. [Figure 2] 1 is a schematic cross-sectional view of a friction insert for an orientation valve according to the invention, in which the first valve body guide means and the second orientation pin guide means form part of the same multi-function insert fixedly attached to a non-magnetic pre-chamber tip, held flat on the insert by a snap ring, a "Belleville" type disc spring and an axial insert bearing shoulder of the tip, the valve with the guide tip closed, i.e. closing off the stacked duct, but with the volume of the valve damping chamber at its maximum. [Figure 3] 3 is a schematic cross-sectional view of a friction insert for an orientation valve according to the present invention and the variant shown in FIG. 2, in which the valve with the guide pin is opened, the axial opening surface of the valve with the guide pin is seated on the combustion chamber side valve stopper, the valve forms a torch-ignited pre-combustion chamber together with the non-magnetic pre-combustion chamber tip, and the volume of the valve damping chamber is minimized while the stacked duct is in the combustion chamber and connected to it. [Figure 4]3 is a schematic cross-sectional view of a friction insert for a direction valve according to the present invention and according to the variant shown in FIG. 2, which differs slightly from FIG. 2 in that the multifunctional insert is held flat against the axial insert bearing shoulder by an expandable ring for the axial stop, which engages with a pressing cone located at the end of the non-magnetic pre-chamber tip. [Figure 5] 3 is a schematic cross-sectional view of a friction insert for a direction valve according to the invention and according to the variant shown in FIG. 2, in the environment of an internal combustion engine in which it is received, the insert being at the end of an active pre-chamber ignition insert such as that described in French patent application No. 1 904 961 belonging to the applicant, and engaging an ignition plug and an electromechanically controlled stack injector. [Figure 6] 3 is a three-dimensional view of a friction insert for an orienting valve according to the invention and according to the variant shown in FIG. 2. [Figure 7] 3 is an exploded three-dimensional view of a friction insert for a direction valve according to the invention and according to the variant shown in FIG. 2, without an internal combustion engine; DETAILED DESCRIPTION OF THE INVENTION

[0046] 1 to 7 show a friction insert 60 for a directing valve according to the invention, together with various details of its components, components, variants and accessories thereof.

[0047] As shown in Figures 1 to 7, the friction insert 60 for a direction valve is primarily intended for a valve-controlled ignition pre-chamber 1 arranged in an internal combustion engine cylinder head 2, which is crowned by a combustion chamber 3, the pre-chamber 1 comprising a stacked cavity 4 with ignition means 5 and a stacked injector 6 therein.

[0048] As can be clearly seen in FIGS. 1 to 6, the stack cavity 4 is connected to the combustion chamber 3 by a stack duct 7 which opens into said combustion chamber 3 in the form of a non-magnetic pre-chamber tip 62 .

[0049] It should be noted in FIGS. 1 to 7 that the non-magnetic pre-chamber tip 62 is capable of closing the stack duct 7 and houses a stack valve 61 oriented by the orientation pin 15 .

[0050] As shown successively in Figures 1 and 3, the orientation pin 15 can slide in an axial guide orifice 17 arranged in the non-magnetic pre-combustion chamber tip 62, and the stacked valve 61 and the pin 15 together form the valve with guide pin 50, while the non-magnetic pre-combustion chamber tip 62, together with the valve 50, forms the torch-ignited pre-combustion chamber 9 when not closing the stacked duct 7.

[0051] It should be noted in FIGS. 1, 3 and 4 that a torch-ignited pre-chamber 9 connects the stack cavity 6 to the combustion chamber 3 via at least one gas discharge orifice 16 .

[0052] In FIG. 2, a valve 50 having a guide pin is shown having an axial closing surface 10 that can seat on a duct closing seat 11 of the laminated duct to close the laminated duct 7.

[0053] In Figure 3, it is shown that the valve 50 with the guide pin also has an axial opening surface 13, and when the axial opening surface contacts the chamber-side valve stopper 14, the valve 50 with the guide pin is determined to be in a position furthest from the stack cavity 4, and when in this position, the valve 50 allows gas 19 to circulate freely between the stack cavity 4 and the combustion chamber 3.

[0054] In particular, Figures 1-4 and 7 illustrate a friction insert 60 for a directional valve according to the present invention, which comprises at least one outer valve body guide cylindrical bearing surface 64 disposed on the periphery of the valve 50 having a guide pin.

[0055] In a manner that can be seen in particular in FIG. 1, the friction insert 60 for a directional valve according to the invention is also shown to comprise at least one first valve body guide means 63, which may be, for example, a continuous ring or a split ring as shown in FIG. 1, and which first means 63 is fixedly attached to a wear-resistant and non-magnetic pre-chamber tip 62.

[0056] The first valve body guide means 63 has, at least locally, an inner diameter that is smaller than the inner diameter of the non-magnetic pre-chamber tip 62 and that is substantially larger than the outer diameter of the outer valve body guide cylindrical bearing surface 64.

[0057] As shown in Figures 2 and 3, the axial thickness of the first valve body guide means 63 and its axial position in the non-magnetic pre-chamber tip 62 are intended to allow the outer valve body guide cylindrical bearing surface 64 to slide with a small clearance into the first means 63, thereby radially guiding the valve with the guide pin 50 over all or part of its travel in the non-magnetic pre-chamber tip 62.

[0058] As can be seen in Figures 1-4, the inner surface of the first valve body guide means 63 can have a curved axial profile, which prevents the means 63 from exposing sharp edges to the outer valve body guide cylindrical bearing surface 64 when the means 63 contacts the outer valve body guide cylindrical bearing surface.

[0059] 1 to 7 also show that the friction insert 60 for the orienting valve according to the invention further comprises at least one cylindrical bearing surface 66 for the outer guide pin, which is arranged on the outer periphery of the orienting pin 15.

[0060] In particular, as can be seen in FIG. 1, the friction insert 60 for the orientation valve according to the invention is also shown to comprise at least one second orientation pin guide means 65, which may be, for example, a continuous ring or a split ring, as shown in FIG. 1, and which second means 65 is wear-resistant and fixedly attached to the axial guide orifice 17.

[0061] The second orientation pin guide means 65 has, at least locally, an inner diameter that is smaller than the inner diameter of the axial guide orifice 17 and that is substantially larger than the outer diameter of the outer pin guide cylindrical bearing surface 66 .

[0062] As shown in Figures 2 and 3, the axial thickness and axial position of the second orientation pin guide means 65 are intended to allow the outer pin guide cylindrical bearing surface 66 to slide with a small clearance into the second means 65 and to maintain the longitudinal axis of the valve 50 with the guide pin substantially parallel to the longitudinal axis of the non-magnetic pre-chamber tip 62 throughout all or part of the valve 50's travel.

[0063] As can be seen in Figures 1 to 4, the inner surface of the second orientation pin guide means 65 can have a curved axial profile, which prevents the second means 65 from exposing sharp edges to the outer pin guide cylindrical bearing surface 66 when the second means 65 contacts the outer pin guide cylindrical bearing surface.

[0064] It should be noted that according to one variant of the embodiment of the friction insert 60 for the orientation valve according to the invention, the first valve body guide means 63 and / or the second orientation pin guide means 65 can be made of a non-magnetic material with high thermal and mechanical resistance, such as "Inconel 718".

[0065] As a variant, and advantageously as illustrated in Figures 2 to 7, the first valve body guide means 63 and the second orientation pin guide means 65 can form part of the same multi-function insert 67, which, whether assembled or not, is fixedly attached to the non-magnetic pre-chamber tip 62.

[0066] In this case, a multi-function insert 67 can accommodate all or part of the valve 50 with a guide pin, and the insert 67 replaces the non-magnetic pre-chamber tip 62 to accommodate the axial guide orifice 17.

[0067] As shown in Figures 2 and 3, the axial position of the multi-function insert 67 in the non-magnetic pre-chamber tip 62 can be fixed by an axial insert bearing shoulder 72, a snap ring 68, and a disc spring 69, for example of the per se known "Belleville" type, which holds the insert 67 against the shoulder 72.

[0068] It should be noted that the multi-function insert 67, the snap ring 68 and the disc spring 69 can advantageously be made of a non-magnetic stainless metal, such as "Inconel", which maintains high mechanical resistance to high temperatures.

[0069] Note that in FIG. 4, alternatively, the multi-function insert 67 is held flat against the axial insert bearing shoulder 72 by an expandable axial stop ring 70 which engages a pressure cone 71 located at the end of the non-magnetic pre-chamber tip 62.

[0070] Additionally or alternatively to what has been described above, the multi-functional insert 67 may be clamped to the non-magnetic pre-chamber tip 62 to ensure maximum thermal coupling between the insert 67 and the tip 62, so that heat received by the insert 67 during combustion of the main load 27 in the combustion chamber 3 can be dissipated by conduction through the non-magnetic pre-chamber tip 62.

[0071] As clearly shown in Figures 2 to 4, the multifunctional insert 67 can form, on the one hand, an axial opening surface 13 oriented towards the combustion chamber 3, which the valve has with the guide pin 50, and, on the other hand, together with the orientation pin 15, a valve damping chamber 18.

[0072] In this case, when the valve with the guide pin 50 is opened and a torch-ignited pre-combustion chamber 9 is formed together with the non-magnetic pre-combustion chamber tip 62, the valve damping chamber 18 cushions any possible collision that may occur between the axial opening surface 13 and the chamber-side valve stopper 14 that stops the stroke of the valve 50 in the direction of the combustion chamber 3, the stopper 14 being located only other than at the bottom of the valve damping chamber 18.

[0073] As shown in Figures 1 to 4, the axial guide orifice 17 of the friction insert 60 for the orientation valve according to the invention can have at its end a damping counterbore 47 which opens into the valve damping chamber 18 and which engages with a damping shoulder 47 provided on the orientation pin 15.

[0074] It should be noted that the damping counterbore 47 and damping shoulder 46 are positioned so that the valve with the guide pin 50 can cover the first part of its stroke towards the combustion chamber side valve stop 14 with very little slowing down by the valve damping chamber 18.

[0075] In fact, when the damping shoulder 46 does not reach the damping counterbore 47, the gases 19 contained in the valve damping chamber 18 can freely leave the valve damping chamber in the direction of the combustion chamber 3 through the gap left between the shoulder 46 and the counterbore 47 and then through the pressure reduction duct 48 shown in Figures 2 to 4.

[0076] When the damping shoulder 46 reaches the damping counterbore 47, the restriction thus created causes the gas 19 to become highly stratified, which slows down the valve 50 with the guide pin during the second part of its stroke towards the combustion chamber side valve stopper 14, thus reducing any collision forces that may occur between the axial opening face 13 and the combustion chamber side valve stopper 14.

[0077] This particular configuration of the multi-function insert 67 and of the valve 50 with the guide pins provides the valve with a long service life.

[0078] 2 to 4 thus show in practice that the damping counterbore 47 can be connected directly or indirectly to the combustion chamber 3 by at least one decompression conduit 48.

[0079] As a variant of the embodiment of the friction insert 60 for the aligning valve according to the invention, FIGS. 1 and 4 show that the valve 50 with the guide pin can be provided with a second sealing collar 73 extending the outer valve body guide cylindrical bearing surface 64 in the direction of the stacked duct 7, said collar 73 forming a labyrinth seal or at least one baffle providing resistance to the gas passage 19 entering or leaving the valve damping chamber 18.

[0080] Operation of the invention The operation of the friction insert 60 for a directing valve according to the present invention can be easily understood in view of FIGS.

[0081] 5 to 7 show the environment of the invention, which consists of an internal combustion engine cylinder head 2 of an internal combustion engine 79, which comprises a piston 80 and a cylinder 81, which together with the cylinder head 2 form a combustion chamber 3.

[0082] 1 to 4 clearly show that the laminated duct 7 has a gas discharge pipe 25 made of stainless steel, which in this example has high magnetic permeability and low magnetic remanence, and that the duct 7 also has a non-magnetic sleeve insert 26 made of, for example, "Inconel 718", which is attached by fret connection to the gas discharge pipe 25 and receives the conduit closure seat 11.

[0083] 1 to 7, it will be noted that the laminated duct 7 opens into the combustion chamber 3 in the form of a non-magnetic pre-chamber tip 62 made of a copper alloy, for example copper-beryllium-cobalt of the "C17500" type, which tip 62 is attached by fretted joints to both sides of the gas discharge pipe 25 and the non-magnetic sleeve insert 26.

[0084] It should be noted in Figures 1-7 that the non-magnetic pre-chamber tip 62 receives a friction insert 60 for a directing valve according to the present invention, and that this comes in two main forms.

[0085] The first configuration shown in FIG. 1 comprises a first valve body guide means 63 and a second orienting tip guide means 65, which take the form of rings attached independently to the non-magnetic pre-chamber tip 62.

[0086] A second configuration, shown in Figures 2 to 7, contemplates that the first valve body guide means 63 and the second orienting tip guide means 65 form part of a single and identical multi-function insert 67 fixedly attached to the non-magnetic pre-chamber tip 62.

[0087] In this second form, and in particular in its variant of the embodiment shown in Figures 2, 3 and 5 to 7, the specific operation of the friction insert 60 for the orientation valve according to the invention is detailed in this case, in the context of which the operation of the valve 50 with guide pin is identical to that described in WO2022079367, bearing in mind that the purpose of the friction insert 60 for the orientation valve according to the invention is not to modify said operation but to ensure a high stability of said friction insert over time and a high durability for the valve-controlled ignition pre-chamber 1.

[0088] According to the variant of the friction insert 60 for the aligning valve according to the invention shown in Figures 2, 3, 5, 6 and 7, the multifunctional insert 67 is held axially flat on an axial insert bearing shoulder 72 arranged in the non-magnetic pre-chamber tip 62 by means of a snap ring 68 and a Belleville type disc spring 69, the insert 67, the snap ring 68 and the disc spring 69 being made of Inconel, a stainless steel, non-magnetic metal that maintains high mechanical resistance at high temperatures.

[0089] Advantageously, the multifunctional insert 67 is in this case clamped onto the non-magnetic pre-chamber tip 62 to ensure maximum thermal coupling between said insert 67 and said tip 62 .

[0090] Therefore, the heat received from the hot gases 19 in contact with the multifunctional insert 67 during combustion of the main load 27 in the combustion chamber 3 can be effectively dissipated by conduction through the non-magnetic pre-combustion chamber tip 62.

[0091] FIG. 2 shows that the valve 50 with the guide pin is in the "fully closed" position, i.e., its axial closing surface 10 is in contact with the conduit closing seat 11, thereby closing the stack duct 7 and preventing any gas 19 from circulating from the stack cavity 4 to the combustion chamber 3 or vice versa, and maximizing the volume of the valve damping chamber 18.

[0092] Figure 3 itself shows that the valve 50 with the guide pin is in the "fully open" position, i.e., the axial opening surface 13 is in contact with the combustion chamber side valve stopper 14, whereby the stack duct 7 is also fully open, and the valve 50, together with the non-magnetic pre-combustion chamber tip 62, forms the torch ignition pre-combustion chamber 9, while gas 19 can circulate from the stack cavity 4 to the combustion chamber 3, minimizing the volume of the valve damping chamber 18.

[0093] It will be noted in particular in Figures 2 and 3 that the orientation pin 15 is provided with a damping shoulder 46 which engages with a damping counterbore 47 located at the entrance of the axial guide orifice 17, said counterbore 47 opening into the valve damping chamber 18.

[0094] This particular configuration of the valve 50 with the multi-function insert 67 and the guide pin allows the valve to cover the first part of its stroke to the combustion chamber side valve stop 14 with almost no slowdown by the valve damping chamber 18.

[0095] In fact, when the damping shoulder 46 does not reach the damping counterbore 47, the gases 19 contained in the valve damping chamber 18 can freely leave the valve damping chamber in the direction of the combustion chamber 3 through the gap left between the shoulder 46 and the counterbore 47 and then through the pressure reduction duct 48.

[0096] When the damping shoulder 46 reaches the damping counterbore 47, the restriction thus created causes the gas 19 to become highly stratified, which slows down the valve with the guide pin 50 during the second part of its stroke towards the combustion chamber side valve stopper 14, thus reducing any collision forces that may occur between the axial opening face 13 and the combustion chamber side valve stopper 14.

[0097] This particular configuration of valve 50 with guide pins gives the valve a long service life.

[0098] In Figures 5 to 7, note the presence of a permanent return magnet 24 which forms a "magnetic valve return device" as described in French Patent No. 3085718.

[0099] The permanent return magnet 24 ensures that the guide pin valve 50 closes again after it has been opened by the increase in pressure of the gas 19 created in the stack cavity 4, after the pilot load 31 has been introduced into the cavity 4 by the electromechanically controlled stack injector 74 and ignited by the spark plug 33.

[0100] 5-7 show an electromechanically controlled stack injector 74 with an injector needle 75 which introduces a pilot load 31 into the stack cavity 4 when lifted from its seat under the action of an electromagnetic injector actuator 76.

[0101] When the electromagnetic injector actuator 76 is de-energized, the injector needle 75 is returned to its seat by a return needle spring 77 which is isolated from the gas 19 comprising the pilot load 31 by a spring isolation seal 78.

[0102] As shown in Figures 5-7, the position of the injector needle 75 is constantly returned to a computer (not shown) by an injector needle position sensor 82, which allows the computer to adjust the amount of pilot load 31 introduced into the stack cavity 4 by the electromechanically controlled stack injector 74.

[0103] To this end, the computer executes software that constantly determines the mass of the pilot load 31 to be introduced into the stack cavity 4 from the lift of the injector needle 75 read by the injector needle position sensor 82, and corrects this lift, if necessary, so that the mass of the pilot load 31 actually introduced into the stack cavity 4 corresponds to the mass required for optimal operation of the internal combustion engine 79.

[0104] It should be noted that in Figures 5 to 7 the stacked cavity 4 is arranged in an active pre-chamber ignition insert 42 similar to that described in French Patent Application No. 1904961 filed on May 13, 2019 belonging to the Applicant, which insert 42 is fixedly held in the cylinder head 2 of the internal combustion engine by an insert clamping means 43.

[0105] As can be seen, the operation of the valve 50 with guide pins in the context of the friction insert 60 for an orienting valve according to the invention is similar to that described in WO2022079367.

[0106] However, contrary to what is shown in WO 2022079367 and in the aforementioned French patent No. 3061743 with regard to the valve-ignited pre-chamber, and to the patents for improvements resulting from the aforementioned patent, the contact line, which was previously always in the same position on the stacked valve 61 and of variable height within the stacked duct 7, is now fixed to said duct 7, i.e. to the non-magnetic pre-chamber tip 62 in the manner in which said duct 7 terminates, and becomes variable in height above the valve 50 with its guide pin and in relation to said guide pin.

[0107] This novel configuration avoids the need to coat the interior of the non-magnetic pre-chamber tip 62 with any coating, although in practice it is widely known that coatings that retain hardness and wear resistance at high temperatures are not compatible with the copper alloy that makes up the non-magnetic pre-chamber tip 62 due to the high temperatures at which they are applied.

[0108] Further advantageously, the friction insert 60 for an orienting valve according to the present invention allows the first valve body guide means 63 and the second orienting pin guide means 65 to be made of a material such as "Inconel", which has a hard core and therefore forms a substrate more suitable for hard coatings, and which is resistant to high temperatures and can therefore accept a wide range of "DLC" type, "PVD" type, or any type of hard coating known to those skilled in the art.

[0109] Advantageously, the valve 50 with its guide pin is itself made of a material that maintains high mechanical resistance at high temperatures, and said valve 50 can also be covered with any type of wear-resistant coating.

[0110] From the above results, it can be seen that the friction insert 60 for the aligning valve according to the present invention allows for the selection of coatings that are compatible with each other, which coatings provide a long service life for both the first valve body guide means 63 and the second aligning pin guide means 65, as well as the valve 50 with the guide pin.

[0111] In order to provide high impact resistance to the combustion chamber side valve stopper 14, which forms the bottom of the valve damping chamber 18, said stopper 14 advantageously forms part of a multifunctional insert 67 as shown in Figures 2 to 7 and benefits from the same mechanical and wear resistance as any other part of said insert 67.

[0112] Thus, the first valve body guide means 63, the second orientation pin guide means 65, and the combustion chamber side valve stopper 14 do not constitute two or more single and identical parts in the form of a multi-functional insert 67, the high temperature core and surface mechanical characteristics of the material that constitutes said insert 67 benefiting all operating surfaces that engage with the valve 50 having the guide pin.

[0113] Knowing that the valve 50 with guide pins is in almost constant contact with the first valve body guide means 63 and the second aligning pin guide means 65 within the multi-function insert 67 and in periodic contact with the combustion chamber side valve stopper 14 without benefit of any lubrication, a person skilled in the art can only understand the fundamental advantages that the friction insert 60 for the aligning valve according to the present invention represents in the implementation and durable operation of the valve 50 with guide pins.

[0114] In fact, a valve with a guide pin 50 will be "dry" in the multi-function insert 67 and will be subject to a much greater abrasive attack than foreign matter such as minerals or carbon particles can have if inserted at high temperatures between the valve 50 and the first valve body guide means 63, the second aligning pin guide means 65 and the chamber-side valve stopper 14 with which it engages.

[0115] It should be noted that the above-described example embodiment of the friction insert 60 for the orientation valve according to the present invention is non-limiting.

[0116] In fact, the friction insert 60 for a directional valve according to the present invention can be applied in other fields, such as in a single internal combustion engine.

[0117] The insert 60 can be applied, for example, to a gas nailer, a firearm, or any appliance where ignition of a main load by a pilot load is required to have the best effect, as possible.

[0118] It must be understood that the choice of friction insert 60 for the orientation valve according to the present invention is not limited to the applications that have been described so far, and furthermore, the above description is given by way of example only and does not in any way limit the field of the invention, which cannot be deviated from by replacing the details of the implementation described with any other equivalents.

Claims

1. Friction insert for a directing valve (60) for a valve-controlled ignition pre-chamber (1) arranged in an internal combustion engine cylinder head (2) crowning a combustion chamber (3), said pre-chamber (1) comprising a laminate cavity (4) into which ignition means (5) and a laminate injector (6) open, said cavity (4) being connected to a combustion duct (3) by a laminate duct (7) opening into said chamber (3) in the form of a non-magnetic pre-chamber tip (62), said tip (62) containing a laminate valve (61) capable of closing a conduit (7), and the valve (61) is oriented by an orientation pin (15) that can slide into an axial guide orifice (17) arranged in the tip (62), the valve (61) and the pin (15) together forming a valve (50) with a guide pin, while the non-magnetic pre-chamber tip (62) together with the valve (50) forms a torch-ignited pre-chamber (9) when not closing the stack duct (7), the torch-ignited pre-chamber connecting the stack cavity (6) to the combustion chamber (3) via at least one gas discharge orifice (16); At least one outer valve body guide cylindrical bearing surface (64) disposed on the periphery of said valve (50) having a guide pin; at least one first valve body guide means (63) resistant to wear and fixedly attached to the non-magnetic pre-chamber tip (62), the first means (63) having, at least locally, an inner diameter which is, on the one hand, smaller than the inner diameter of the tip (62) and, on the other hand, substantially larger than the outer diameter of the outer valve body guide cylindrical bearing surface (64), the axial thickness of the first means (63) and the axial position of the non-magnetic pre-chamber tip (62) on the first means (63) being such that the outer valve body guide cylindrical bearing surface (64) can slide with a small clearance into the first means (63), thereby intended to radially guide the valve (50) with a guide pin through all or part of its travel in the non-magnetic pre-chamber tip (62); at least one outer pin guide cylindrical bearing surface (66) arranged around the periphery of said orientation pin (15); and at least one second orientation pin guide means (65) resistant to wear and fixedly attached to the axial guide orifice (17), the second means (65) having, at least locally, an inner diameter which is, on the one hand, smaller than the inner diameter of the orifice (17) and, on the other hand, substantially larger than the outer diameter of the outer pin guide cylindrical bearing surface (66), the axial thickness and axial position of the means (65) being intended to allow the outer pin guide cylindrical bearing surface (66) to slide with a small clearance into the second means (65) and to keep the longitudinal axis of the valve (50) with its guide pins substantially parallel to the longitudinal axis of the non-magnetic pre-chamber tip (62) over all or part of the stroke of the valve (50).

2. Friction insert according to claim 1, characterized in that the first valve body guide means (63) and the second orientation pin guide (65) are made of a non-magnetic material with high thermal and mechanical resistance.

3. 2. A friction insert according to claim 1, characterized in that the first valve body guide means (63) and the second orientation pin guide means (65) form part of one and the same multifunctional insert (67), which, whether assembled or not, is fixedly attached to the non-magnetic pre-chamber tip (62) and accommodates all or part of the valve (50) with its guide pin, and on the other hand, the multifunctional insert (67) replaces the non-magnetic pre-chamber tip (62) in order to accommodate the axial guide orifice (17).

4. 4. A friction insert according to claim 3, characterized in that the multifunctional insert (67) forms, on the one hand, together with the axial opening face (13) of the valve (50) with a guide pin, which is oriented towards the combustion chamber (3), and, on the other hand, together with the orientation pin (15), a valve damping chamber (18).

5. Friction insert according to claim 3, characterized in that the axial guide orifice (17) has at its end a damping counterbore (47) opening into the valve damping chamber (18), said counterbore (47) engaging a damping shoulder (46) provided on the orientation pin (15).

6. Friction insert according to claim 5, characterized in that the damping counterbore (47) is connected directly or indirectly to the combustion chamber (3) by at least one pressure reduction duct (48).

7. Friction insert according to claim 1, characterized in that the valve (50) with guide pin comprises a second sealing collar (73) which extends the outer valve body guide cylindrical bearing surface (64) in the direction of the stack duct (7).

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