EP4042001A1

EP4042001A1 - Compact piston valve

Info

Publication number: EP4042001A1
Application number: EP20861963.5A
Authority: EP
Inventors: Stéphane Pascal Perotto; Julien SIXT; Benoît Chenevard
Original assignee: Bontaz Centre R&D SAS
Current assignee: Bontaz Centre R&D SAS
Priority date: 2019-11-15
Filing date: 2020-11-13
Publication date: 2022-08-17
Also published as: CN114729590A; KR20220093361A; US20220389855A1; FR3103244B1; BR112022009049A2; WO2021094690A1; FR3103244A1

Abstract

Piston valve comprising a body (2), a valve seat (14), a shut-off member (4) in the form of a piston, and a return spring (5). The body (3) comprises a casing (3) provided with at least one pressurized-fluid outlet orifice (10), and an inner element (6) which is fitted into the casing (3). The inner body (6) bears the valve seat (14) and provides for the translational guidance of the shut-off member (4) in the body. In addition, the inner element (6) comprises at least one aperture (16) configured to guide the fluid from the valve seat towards the outlet orifice (10).

Description

COMPACT PISTON VALVE

DESCRIPTION

TECHNICAL FIELD AND STATE OF THE PRIOR ART

The present invention relates to a piston valve for controlling the circulation of a pressurized fluid, in particular in the automotive field.

In the automotive field, piston cooling jets for an internal combustion engine are used to project a cooling fluid such as oil against the piston base, that is to say against the piston face outside of the piston. the explosion chamber, or in a piston gallery specially designed for this purpose.

Commonly used piston cooling jets are attached parts, fixed to the crankcase and communicating with a coolant inlet port.

A nozzle comprises a body in which is mounted a valve, and at least one tube fixed to the body for directing the coolant.

The nozzle may be of the screw-valve type, i.e. it comprises a screw provided with a bore in which the valve is mounted, the screw being screwed directly into the engine block. In general, a sub-assembly carrying the tube or tubes is held between the head of the screw and the engine block. According to another type of nozzle, the nozzle comprises a fixing plate which is fixed to the engine block by means of an attached screw.

The valve controls the circulation of pressurized coolant to the piston. When the fluid pressure reaches a certain pressure level, the valve opens and allows fluid to pass through the valve, which is projected to the piston via the tube (s).

There are ball valves and piston valves. Piston valves generally exhibit better responsiveness than ball valves.

A piston valve comprises a body provided with a bore opening at the level of a first longitudinal end of the body and the second end of which longitudinal is closed, one or more lateral openings opening into the bore forming one or more oil outlet orifices. The emerging end of the bore is connected to a source of pressurized fluid and the side opening (s) are oriented towards the zone towards which it is desired to bring the fluid. A shutter of cylindrical shape of revolution, designated piston, is mounted in the bore and is movable between a rest position in which it prevents the flow of fluid from the bore and the outlet (s) and an open position. complete, in which traffic is permitted. The piston is returned to the rest position by a spring mounted in compression between the second closed end of the body and the piston. The nozzle comprising such a piston valve has a length beyond the relatively large oil outlet or ports to allow clearance of the piston from the valve seat and from the outlet or from the outlet ports, when opening the valve, which increases its size in the engine. DISCLOSURE OF THE INVENTION

It is consequently an object of the present invention to provide a piston valve for a pressurized fluid circuit having a reduced bulk.

The object stated above is achieved by a piston valve comprising a body, a valve seat, a piston-shaped shutter and a return spring. The body comprises an outer body, forming a casing, provided with at least one outlet for the pressurized fluid, and an inner body forming a jacket which is attached to the casing. The liner carries the valve seat and provides translational guidance of the shutter in the body. In addition, the liner has at least one window configured to guide fluid from the valve seat to the outlet port. Thanks to the implementation of this sleeve, it is possible to have the valve seat in an axial position very upstream with respect to the oil outlet orifice, which allows the piston to be released at least partly upstream of the outlet. The length of the valve, in particular of its part upstream of the outlet orifice can then be reduced. In addition, the body of the nozzle comprises, on the side of the outlet for the pressurized fluid, a bottom in one piece with the casing, and all the components of the nozzle, ie at least the shutter and the jacket, are introduced into the casing through an open end thereof opposite the bottom, and through which the pressurized fluid is delivered to the nozzle. This simplifies the nozzle and makes it more reliable.

Advantageously, the outer body is manufactured by cold heading and then re-machining, which makes it possible to reduce the quantity of material required and to increase the production rate, and the liner is made of plastic material directly by molding by injection. The cost of manufacturing the valve is therefore reduced. In addition, the mass of the valve can be reduced compared to the piston valve of the state of the art.

In other words, a piston valve is produced comprising a composite body in which the functions are distributed between an outer part and an inner part. The outer part ensures the function of fixing to the fluid circuit and the circulation of the fluid towards the outside of the valve, and the internal part ensures the function of valve seat, guide for the obturator and forms at least one fluidic channel for the valve. fluid from the valve seat to the valve outlet.

The present invention therefore relates to a piston valve for a hydraulic or pneumatic circuit comprising a hollow body with a longitudinal axis, a first longitudinal end of which is closed off by a bottom and a second longitudinal end is intended to be connected to a source of fluid under pressure, comprising at least one fluid outlet orifice, a valve seat between the second longitudinal end of the body and the outlet orifice, a shutter having a cylindrical shape of revolution, cooperating with the valve seat, and a valve spring return of the shutter to rest against the valve seat. The body comprises an envelope forming at least partially the exterior of the body and an interior element forming at least partially the interior of the body and mounted in the envelope in sealed contact with the envelope. The casing comprises the at least one outlet orifice and a vent, and G interior element comprises a bore, the interior face of which comprises a first part on the side of the second longitudinal end of the body and a second part of the body. side of the outlet port, the first part and the second part joining at the valve seat. The second part ensures the guiding in translation of the shutter along the longitudinal axis and comprises at least one window extending axially so as to provide a channel for the fluid between the casing and the shutter allowing the fluid to flow. flow from the first part to the outlet when the plug is released from the valve seat.

Advantageously, the interior element is made of plastic material.

For example, the body has a first sealed contact between a first longitudinal end of the inner member and the bottom of the casing, and a sealed contact between a second longitudinal end of the inner member and a second longitudinal end of the shell. envelope located at the second longitudinal end of the body.

In an exemplary embodiment, the first sealed contact is obtained by a cone on cone contact. In another exemplary embodiment, the first contact is a plane support orthogonal to the longitudinal axis.

According to an additional characteristic, the first longitudinal end of the inner element may include at least one annular bead in contact with the bottom of the casing.

The second contact may be a plane contact contact normal to the longitudinal axis.

The spring is a coil spring, and the shutter may include a hollow body closed at one end intended to come into contact with the valve seat. A longitudinal end of the spring is mounted in the shutter. Advantageously, the bottom has a recess housing another longitudinal end of the spring.

In an exemplary embodiment, each window has a zone facing an outlet orifice.

The piston valve may have n outlet ports and n windows, n being greater than or equal to 1. The n outlet ports may be bores and each window may have a cross section close to or equal to the diameter of an orifice of exit. In an advantageous example, the piston valve comprises means of angular orientation between the casing and the interior element, so that a zone of a window faces an outlet orifice. The orientation means may include shapes on the envelope and the interior element cooperating so as to impose a given angular position to the interior element with respect to the envelope.

The inner element can be held in the casing by crimping.

A subject of the present invention is also a pressurized fluid circuit comprising a source of pressurized fluid and at least one piston valve according to the invention connected by its first end to the source of fluid.

The circuit forms for example a hydraulic circuit of an internal combustion engine.

The present invention also relates to a nozzle for cooling the piston of an internal combustion engine comprising at least one piston valve according to the invention and at least one tube intended to guide the fluid from the outlet orifice towards the piston. The casing may have an external thread for mounting in an engine block.

The present invention also relates to a method of manufacturing a piston valve according to the invention, comprising:

-The manufacture of the envelope.

-The manufacture of the interior element.

-The introduction of the inner element into the casing from one end of the casing intended for the entry of the fluid.

-The immobilization of the interior element in the envelope.

The envelope is for example produced by cold heading and recovery by machining

The interior element is advantageously made by thermoplastic injection molding.

The immobilization of the interior element in the casing can be achieved by crimping. Advantageously, during crimping, the inner element is placed under axial stress in the casing. BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood on the basis of the description which follows and the appended drawings in which:

FIG. 1 is an exploded view of a piston valve according to an exemplary embodiment,

Figure 2A is a longitudinal sectional view of the valve of Figure 1 according to a first sectional plane, the valve being in a closed state,

FIG. 2B represents the view of FIG. 2A, the valve being in an open state,

FIG. 3 is a view in longitudinal section of the valve of FIG. 1 according to a second section plane orthogonal to the first section plane, the valve being in an open state,

Figure 4 is a perspective view of the inner element of Figure 1 shown on its own,

FIG. 5 is a view in longitudinal section of a piston valve according to another exemplary embodiment, the valve being in a closed state,

Figure 6 shows the piston valve of Figure 5 in an open state,

Figure 7 is a detail view of Figure 6,

FIG. 8 is a perspective view of the interior element of FIG. 5 shown on its own,

FIG. 9 is a view in longitudinal section of a piston valve according to another exemplary embodiment, the valve being in a closed state,

Figure 10 shows the piston valve of Figure 9 in an open state,

Figure 11 is a detail view of Figure 10,

FIG. 12 is a perspective view of the interior element of FIG. 9 shown on its own,

FIG. 13 is a view in longitudinal section of a piston valve according to another exemplary embodiment, the valve being in a closed state, Figure 14 shows the piston valve of Figure 13 in an open state,

Figure 15 is a detail view of Figure 14,

Figure 16 is a perspective view of the inner element of Figure 13 shown alone,

FIG. 17 is a view in longitudinal section of a piston valve according to another exemplary embodiment, the valve being in a closed state,

Figure 18 shows the piston valve of Figure 17 in an open state,

Figure 19 is a detail view of Figure 18,

Figure 20 is a perspective view of part of the inner member of Figure 18,

Figures 21A and 21B are perspective views of another part of the inner member of Figure 18,

FIG. 22A is a perspective view of an example of a nozzle comprising a piston valve according to the invention,

FIG. 22B is a view in longitudinal section of the nozzle of FIG.

22 A,

FIG. 23A is a perspective view of an example of a nozzle comprising a piston valve according to the invention,

Figure 23B is a longitudinal sectional view of the nozzle of Figure

23A,

FIG. 24A is a perspective view of an example of a nozzle comprising a piston valve according to the invention,

Figure 24B is a longitudinal sectional view of the nozzle of Figure

24 A.

DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS

The invention will be described more particularly in an application to the piston cooling of an internal combustion engine of a motor vehicle. by spraying coolant. It will be understood that the invention applies to any hydraulic circuit, and also to any pneumatic circuit in the automotive field and in other fields using fluids under pressure.

The invention relates to a piston valve, also referred to as a distributor, intended in particular to equip jets, for example jets of the screw-valve type, more particularly used in the field of internal combustion engine piston cooling.

In all the exemplary embodiments, the flow of the fluid is shown schematically by the arrows F.

In FIGS. 1 to 4, one can see a first example of a piston valve C1 comprising a body 2. The body may have an external thread then forming a screw, allowing it to be mounted directly in the device to be fitted, for example in the block. internal combustion engine engine.

The valve also comprises a shutter 4 cooperating with a valve seat, a return spring 5 mounted between the shutter 4 and the body 2 pushing the shutter towards the valve seat. The shutter 4 has a cylindrical shape of revolution and may be designated as a piston. It comprises at least one longitudinal end intended to cooperate in a sealed manner with the valve seat, and a side wall ensuring, during the sliding of the piston, a seal between the piston and the inner wall of the body 2.

The body 2 has a substantially tubular shape of revolution with a longitudinal axis X, comprising a first longitudinal end 2.1 and a second longitudinal end 2.2.

The body 2 comprises an outer body 3 or envelope and an inner body 6 designated in the remainder of the description "inner element".

The casing 3 has a bore 8 opening out at the level of the second longitudinal end 2.2 of the casing. The other longitudinal end of the casing is closed by a bottom 7. However, a vent 9 is formed in the bottom of the casing to allow the circulation of air when the shutter 4 moves. The first end 8.1 of the bore 8 is oriented towards the bottom side of the casing 3 and the second end 8.2 of the bore is oriented towards the side of the open end of the casing 3. The bottom 7 is made of 'one piece with the envelope.

The second end 8.2 of the bore 8 is intended to be connected to a source of pressurized fluid. The fluid flows from the second end 8.2 to the first end 8.1.

The casing 3 has at least one fluid outlet opening 10 passing through the side wall of the casing. In the example shown, two diametrically opposed outlet ports 10 are formed. The orifice or orifices open out into the bore 8. The casing is preferably made of a metallic material, advantageously by cold heading followed by resumption of machining to produce the bore 8 and the outlet orifices 10. It will be understood that the envelope may have more than two outlet openings distributed around the circumference of the envelope.

The inner element 6 is intended to form a longitudinal guiding surface for the piston as well as a valve seat.

The interior element 6 has a tubular shape substantially of revolution about an axis XI which is intended to be coaxial with the axis X when the interior element 6 is mounted in the casing 3. The interior element 6 comprises a first longitudinal end 6.1 and a second longitudinal end 6.2. The first longitudinal end 6.1 is intended to be inserted first into the bore 8 of the casing 3 so as to be facing the bottom of the casing 3. The second longitudinal end 6.2 is disposed on the side of the open end. of the envelope 3.

In Figures 3 and 4, one can see the inner element comprising, at its second longitudinal end 6.2, a shoulder 11 intended to come into contact with an annular bearing 13 located at the second end of the bore 8. The annular bearing surface 13 is for example produced by countersinking. The contact between the shoulder 11 and the annular surface 13 is such that it is fluid tight. As a variant, the shoulder 11 and the annular bearing form a cone on cone bearing. As a further variant, the element The interior does not have a shoulder 11 and the sealed contact between the interior element and the bore takes place at the level of the end 6.2.

Advantageously, the inner element 6 is guided in the bore 8. The guidance can be provided by the ring bearing the shoulder 11 in cooperation with the portion of the bore comprising the annular bearing surface 13, and / or by the ring. cooperation of the outer surface of the inner element 6 and the portion of the bore 8 upstream of the windows considering the section of Figure 3, or even by the cooperation of the entire outer surface of the inner element 6 and the 'bore 8.

The interior element 6 also comprises a bore 12 of axis XI and opening at the two longitudinal ends of the interior element 6.

In the example shown, the bore 12 comprises a portion of smaller diameter 12.1 and a portion of larger diameter 12.2 connected by an annular bearing surface forming a valve seat 14 for the shutter 4. The outer diameter of the shutter 4 is such that it can slide longitudinally in the portion of larger diameter 12.2 while being guided by the portion of larger diameter 12.2.

The interior element also comprises at least one side window 16, two windows in the example shown, opening into the portion of larger diameter 12.2 of the bore 12, i.e. downstream of the valve seat. The windows 16 are diametrically opposed and are positioned so that, when the interior element 6 is mounted in the casing 3, part of a window 16 is opposite an outlet orifice 10.

The windows 16 have a first longitudinal end 16.1 on the side of the first end 6.1 of the inner member 6, and a second longitudinal end 16.2 on the one side of the valve seat 14.

The first end 16.1 of each window facing substantially an outlet 10 and the second end of each window is located just downstream of the valve seat 14 in the flow direction F. As can be seen in the figure. FIG. 2A, each window 16 defines, between the surface of the bore 8 and the outer lateral surface of the shutter, a longitudinal channel which makes it possible to guide the pressurized fluid from the portion of smaller diameter 12.1 of the bore 12 at one hole outlet 10 via a passage between the casing 3 and the side wall of the shutter 4. The implementation of the internal element 6 therefore makes it possible to increase the axial distance between the valve seat 14 and the orifice (s) outlet 10. Thus the space required for the release of the shutter when opening the valve is located upstream of the outlet orifices 10 in the direction of flow. The length of the casing 3, in particular its axial extension downstream of the outlet ports 10, can be reduced while not modifying the position of the outlet ports. This reduction in length very advantageously makes it possible to reduce the bulk in the motor.

Advantageously, the transverse dimension of the windows is equal to the diameter of the outlet orifices 10, so as to maximize the flow of fluid through the valve and to reduce the pressure losses. The windows 16 being relatively narrow, there is enough material left for guiding the shutter 4.

Preferably, the interior element 6 has as many windows 16 as the casing 3 has outlet orifices 10.

In this example, the windows 16 are rectangular in shape but other shapes can be envisaged, for example a trapezoidal shape.

Preferably, the valve comprises orientation means 18 for angularly orienting the inner element 6 with respect to the casing 3 around the longitudinal axis X so that, during assembly, each window 16 is directly opposite d 'an outlet orifice 10, making it possible to optimize the flow rate through the valve.

In this example, the orientation means are formed both in the casing and in the interior element. The inner surface of the bore 8 comprises at its second end 8.2 two grooves 20 extending longitudinally over part of the surface. The inner element 6 comprises on its outer surface at its second longitudinal end 6.2 two ribs 22 extending longitudinally over a part of the length of the inner element and dimensioned to penetrate into the grooves 20. The ribs 22 are arranged. one with respect to the other in a manner corresponding to the relative arrangement of the two grooves 20. Thus, by orienting the inner element with respect to the casing so as to align the grooves 20 and the ribs 22, each window 16 is automatically aligned with an orifice of outlet 10. The length of the ribs is advantageously less than that of the grooves to ensure contact between the annular bearing surface 13 and the shoulder 11.

In this example, each rib 22 is aligned with a window 16, but this arrangement is not limiting, it is possible to envisage ribs offset angularly with respect to the windows, for example by an angle of 90 °.

The implementation of one groove and one rib or more than two grooves and two ribs does not depart from the scope of the present invention. As a variant, the rib (s) are carried by the casing and the groove (s) are carried by the interior element.

Other means such as visual markings on the envelope and the interior element can be envisaged to facilitate the orientation of the interior element relative to the envelope.

As a variant, the windows 16 are not oriented with respect to the outlet orifices and an annular channel in which the windows and the outlet orifices open out ensures the flow of the liquid from the interior of the interior element towards the orifice of. outlet regardless of the orientation of the windows in relation to the outlet orifice. The channel can be produced, for example, by making a bore portion 8 of larger diameter at the level of the outlet orifices 10 and / or a section of the internal element 6 at the level of the windows 16 of reduced diameter.

The first end 6.1 of the inner element 6 is such that its contact with the first end 8.1 of the bore 8 is substantially fluid-tight. Thus the outlet orifices 10 and the vent 9 are sealed from each other.

In this example, the first ends 6.1 and 8.1 are shaped to achieve a cone on cone contact, ensuring a tight tight assembly. As a variant, a tight fitting of two cylindrical surfaces does not depart from the scope of the present invention.

The return spring 5 is mounted in reaction between the shutter and the bottom of the bore 8 so as to bring the shutter back to bear against the valve seat 14. In the example shown and preferably, the spring is a helical spring.

Advantageously, the shutter 4 comprises a hollow body closed at a longitudinal end by a bottom 24 intended to cooperate with the valve seat, the spring 5 is mounted in the hollow body. The outside diameter of the spring 5 is smaller than the inside diameter of the hollow body. In addition, the bottom of the bore 8 also comprises a recess 26, the inside diameter of which corresponds to the outside diameter of the spring 5 and forms a housing for the other end of the spring 5. The bottom of the bore 8 surrounding the recess advantageously forms an axial stop for the valve, and preventing the spring from being compressed in a state where the turns are contiguous. The vent 9 preferably opens into the bottom of the recess 26.

Advantageously, the first end 12.3 of the bore 12 has a bearing surface that is clear with respect to the outer diameter of the shutter which extends, making it possible to ensure free sliding of the shutter in the interior element despite the mounting. tightness of the interior element in the casing.

The inner element 6 is immobilized longitudinally in the casing 3, so that its first longitudinal end 6.1 is in close contact with the first end 8.1 of the bore 8 of the casing, and the shoulder 11 is in abutment against the annular bearing surface 13. In the example shown and in a nonlimiting manner, the immobilization is carried out by crimping. For this, the casing comprises at its open end an annular projection 28 bordering the second end 8.2 of the bore 8 located upstream of the annular bearing surface 13, and which is intended to be folded over the inner element for the 'immobilize axially (in the figures the projection 28 is not folded down). Preferably, the crimping is such that it places the inner element 6 under axial stress to ensure tight contact between the conical surfaces of the casing and of the interior element, and between the shoulder 11 and the annular surface 13. In the case where the inner element does not have a shoulder, the axial stress is applied between the end 6.1 of the inner element and the first end 8.1 of the bore 8.

The inner element 6 is advantageously made of plastic material, preferably of thermoplastic material, preferably by molding, of preferably by injection molding. The part obtained directly by injection molding can be directly mounted in the casing 3. For example, the material of the interior element is chosen from PA6.6 (polyamide 66), PPA (Polyphthalamide), poly (phenylene sulfide) or PPS, PEEK (polyetheretherketone). Advantageously, an additive improving the slip, for example PTFE (polytetrafluoroethylene) or graphite, can be added.

The interior element 6 can be made of plastic material because it is not subjected to shocks or clamping forces liable to damage it.

The materials used to make the casing 3, the inner element 6 and the shutter 4 are chosen according to the specifications in terms of torque resistance, temperature, chemical resistance to the fluid circulating in the valve, in terms coefficient of friction, in particular between the shutter and the interior element, to prevent premature wear and the detachment of particles.

The casing can for example be made of hardened impact steel or not and the shutter can be made of steel, aluminum or plastic.

The longitudinal guide of the shutter is obtained by the interior element

An example of the process for manufacturing the valve C1 will now be described.

The envelope is produced by cold heading. Then the part is taken up by machining in particular to produce the bore 8 and the outlet orifices 10.

Furthermore, the interior element is made by injection molding.

The shutter is for example produced by cold heading, by plastic injection or by machining.

The shutter is housed in the portion of larger small diameter 12.2 of the bore 12 of the inner member 6 and the spring is introduced into the shutter through a longitudinal end.

The assembly thus formed is then introduced into the bore 8 by introducing the first end 6.1 of the internal element 6 into the bore 8. The first end 6.1 bears conically against the conical surface of the bottom of bore 8.

Crimping then takes place. This consists in deforming the annular projection 28 towards the interior element so as to maintain the conical support between the end 6.1 and the end 8.1 of the bore 8.

As a variant, the inner element 6 and the body 2 can be assembled by crimping at the end, ie by means of a punch which tears material in the bore 8 to hold the element 6, or by means of a punch. claw washer.

The implementation of a casing and a bottom in one piece and advantageously of a crimping on the side of the arrival of the pressurized fluid makes it possible, on the one hand, to reduce the number of components simplifying manufacture, and secondly to significantly improve the operating safety of the nozzle. Indeed, the bottom being in one piece with the casing there is no risk of failure of a crimping between the casing and the bottom. If the pressurized fluid inlet side crimping fails, the oil is still sent to the nozzle tube. Finally, the action of the pressurized fluid tends to maintain the components in the body of the nozzle and to keep them assembled, which allows them to continue to ensure degraded operation of the nozzle.

On the contrary in the nozzles of the state of the art, such a bottom is crimped on the body of the nozzle, in the event of failure, the components of the nozzle are then found in the engine ejected by the pressure of the fluid, which can damage engine, and fluid is no longer conducted to the nozzle tube, resulting in piston damage and engine failure. In addition, this results in a very large fluid leak, causing a drop in the general fluid pressure of the engine leading to serious malfunctions.

In FIGS. 22A, 23 and 24B one can see various examples of a nozzle comprising a piston valve according to the invention.

In Figures 22A and 22B, the nozzle G1 is of the screw-valve type comprises a piston valve C1 provided with an external thread 51 forming a screw, a body 52 mounted around the piston valve, a tube T1 mounted in a bore 54 of the body 52. The bore 54 opens out facing at least one outlet opening 10. The body is intended to be held by clamping between the head 55 of the screw and the engine block (not shown). Advantageously, the body 52 comprises means cooperating with means of the engine block to ensure the orientation of the tube. In this example, the body has a planar face 52.1 cooperating with a milling or counterbore made on the engine block.

In Figures 23A and 23B, the nozzle G2 is also of the screw-valve type comprises a piston valve C1 provided with an external bore 57 forming a screw, a body 58 in the form of a ring, a tube T2 mounted in a bore 60 of the body 58. The bore 60 opens out opposite at least one outlet opening 10. The body 58 is intended to be held by clamping between the head 59 of the screw and the engine block (not shown). The nozzle also has a mounting plate 62 and a pin 64 for orienting the nozzle. The pin is intended to enter a hole formed in the engine block.

In FIGS. 24A and 24B, the nozzle G3 comprises a piston valve of the monobloc type, the casing 3 'of which forms the body provided with a bore 66 extending forming the outlet orifice 10 and a tube T3 mounted in a bore 66. The nozzle also has a mounting plate 68. A lumen 70 is formed in the mounting plate 68 for receiving a screw for fixing to the engine block. The nozzle is for example formed by a mechanically welded assembly.

The nozzle may have several tubes.

The operation of a nozzle comprising a piston valve of FIG. 1 will now be described.

The nozzle is mounted in an engine crankcase of an internal combustion engine, the tube or tubes being oriented so that the oil jet is oriented towards the piston bases. The nozzle regulates the flow.

The pressure at which the valve opens depends on the load of the spring 5. As long as the force exerted by the pressurized oil on the shutter 4 is less than the load of the spring 5, the shutter 4 rests on the seat. valve 14 and the oil does not supply the outlet ports (figure 1). When the pressure is sufficient, the shutter is released from the valve seat 14 and the oil circulates in the windows 16 and reaches the outlets through which it is projected against the pistons of the engine.

When the pressure level increases, the shutter 4 comes into abutment against the bottom of the casing 3 before the spring 5 is in a configuration with contiguous turns, which reduces the risk of damage to the latter (figures 2 and 3).

When the pressure drops below the given pressure, the shutter 4 is pushed against the valve seat 14 by the return spring 5, the flow is interrupted.

In FIGS. 5 to 8, one can see another example of a piston valve C2.

The valve C2 is similar in structure to that of the valve C1.

However, the valve C2 comprises a shutter 104 whose cross section is of smaller section, which makes it possible to maximize the passage section of the oil and therefore the flow rate passing through the valve. In addition, the interior element 106 comprises a conical bearing surface at its first longitudinal end 106.1 provided with several annular beads 130 (FIG. 7) centered on the longitudinal axis and ensuring the seal. These beads form zones which will deform during assembly, in particular during crimping.

In addition the windows 116 have trapezoidal shapes with the larger base facing the upstream side (Figure 8). This shape also helps to maximize throughput.

The operation of the piston valve C2 is similar to that of the valve C1.

In FIGS. 9 to 12, one can see another embodiment of a piston valve C3.

The valve C3 is similar in structure to those of the valves C1 and C2.

However, the valve C3 comprises a shutter 204 whose bottom is provided with a protrusion 232 oriented upstream, ie towards the end of the valve connected to the pressure source. The protrusion 232 is of frustoconical shape whose smaller base is oriented upstream. This protrusion has the effect of deflecting the flow radially outwards, reducing the pressure drops.

In addition, the bore 212 of the interior member 206 includes a portion 234 upstream of the valve seat 214 having a biconical shape improving the dynamic flow of the fluid and minimizing the pressure drops of the system. The part 234 comprises a first zone 234.1 remote from the valve seat 214, the passage section of which decreases, a second zone 234.2 on the side of the valve seat whose passage section increases and a third zone 234.3 of constant passage section connecting the first zone 324.1 and the second zone 234.2. Alternatively, the constant section zone 234.3 can be omitted.

In addition, the first end 206.1 of the inner element 206 comprises an end face 236 perpendicular to the longitudinal axis and provided with an annular bead 238 in contact with the bottom of the casing 203. The bead 238 is crushed. during assembly of the interior element in the casing 203, in particular during crimping. The bead 238 provides the seal between the casing and the interior element. In FIG. 11, the bead 238 can be seen before crushing (in broken lines) and after crushing.

In this example, windows 216 are also trapezoidal in shape with the larger base facing the upstream side (Figure 12).

In figures 13 to 16, we can see another example of a piston valve

C4.

The valve C4 is similar in structure to those of the valves C1, C2 and C3.

The valve C4 differs from the valves C1, C2 and C3 in that the shutter 304 is a pin. The cost of the valve is reduced.

In addition, in this example, the interior element abuts against the bottom of the bore 308 without deformation. The first end 306.1 of the interior element 306 comprises a flat face 340 perpendicular to the X axis and bears flat against the bottom of the bore 308 ensuring the seal. For this, the positioning of the shoulder 311 is such that it does not come into contact with the annular bearing surface 313. The seal is produced between the side wall of the interior element and the casing 303. In this example, when the valve C4 is open, the axial stop of the shutter 304 is obtained when the turns of the spring 305 are contiguous (FIG. 14).

In Figures 17 to 21B, we can see another example of piston valve C5.

The C5 valve is similar in structure to those of the C4 valve.

The C5 valve differs from the C4 valve in that it protects the spring by preventing the turns from being contiguous when the valve is open.

The valve C5 has an interior element 406 comprising a first part 442.1 carrying the valve seat 414 and the windows 416 and a second part 442.2 forming the first end 406.1 of the interior element 406 configured to come into contact with the bottom of the valve. envelope 403.

In Figure 20, we can see the first part 442.1 shown alone, and in Figures 21A and 21B, we can see the second part 442.2 shown alone. It comprises an annular part 444 comprising a face 446 provided with an annular bead or protrusion intended to come into contact with the bottom of the bore, and a second face 448 opposite to the face 446, intended to bear against one end longitudinal section of the first part 442.1. The second face has fingers 450 extending axially and intended to penetrate into the bore 412 of the first part. The fingers 450 have an outer lateral face in the form of an arc of a circle with a radius of curvature corresponding substantially to the radius of curvature of the bore 412. The fingers 450 provide a clamping assembly of the second part 442.2 in the first part 442.1. Preferably the fingers 450 are preferably diametrically opposed.

The first and second parts are made of the same material or different materials, for example the second part is made of a softer material to confirm the seal.

The various examples of valve C1 to C4 are not mutually exclusive and can be combined, for example valve C1 can include a shutter formed by a pin. Furthermore, the interior element of the valve C3 can be made in two parts of different material, in a similar manner to the interior element of the valve C5. The part intended to ensure the sealing is made of a more flexible. It should be noted that in the valve C3 the second part does not provide the stopper function for the shutter. The second part is for example produced by coextrusion with the first part.

In the examples described the windows extend axially, as a variant the windows are portions of a helix.

The piston valve according to the invention is suitable for controlling the supply of pressurized fluid in any hydraulic or pneumatic circuit, in particular in the automotive field. The piston valve according to the invention is particularly suitable for producing cooling jets, in particular jets of the screw-valve type, for internal combustion engines, more particularly for piston cooling.

Claims

1. Piston valve for hydraulic or pneumatic circuit comprising a hollow body (2) with a longitudinal axis (X), a first longitudinal end of which is closed by a bottom (7) and a second longitudinal end is intended to be connected to the source. fluid under pressure, comprising at least one fluid outlet (10), a valve seat (14) between the second longitudinal end of the body and the outlet (10), a shutter (4) having a shape cylindrical of revolution, cooperating with the valve seat (14), and a return spring (5) of the shutter (4) bearing against the valve seat (14), characterized in that the body (2) comprises a casing (3) forming at least partially the exterior of the body and an interior element (6) forming at least partially the interior of the body and mounted in the casing (3) in sealed contact with the casing (3), in that the casing (3) has the at least one outlet (10) and one vent (9), and G inner element (6) has a bore (12) whose inner face comprises a first part (12.1) on the side of the second longitudinal end of the body and a second part (12.2) on the side of the outlet port (10) , the first part (12.1) and the second part (12.2) being connected at the level of the valve seat (14), in that the second part (12.2) ensures the guiding in translation of the shutter (4) along the longitudinal axis (X) and comprises at least one window (16) extending axially so as to provide a channel for the fluid between the casing (3) and the shutter (4) allowing the fluid to flow from the first part (12.1) to the outlet (10) when the shutter (4) is detached from the valve seat (14), and in that said bottom (7) is integrally with the envelope.

2. A piston valve according to claim 1, wherein the inner member (6) is made of thermoplastic material.

3. Piston valve according to claim 1 or 2, wherein the body (2) comprises a first sealed contact between a first longitudinal end of the inner member (6) and the bottom of the casing (3), and a second sealed contact between a second longitudinal end of the inner element (6) and a second longitudinal end of the casing (3) located at the second longitudinal end of the body.

4. Piston valve according to claim 3, wherein the first sealed contact is obtained by a cone on cone contact.

5. Piston valve according to claim 3, wherein the first contact is a plane support orthogonal to the longitudinal axis (X).

6. A piston valve according to claim 4 or 5, wherein the first longitudinal end of the inner member comprises at least one annular bead in contact with the bottom of the casing.

7. Piston valve according to one of claims 4 to 6, wherein the second contact is a contact support plane normal to the longitudinal axis.

8. Piston valve according to one of claims 1 to 7, wherein the spring (5) is a helical spring, and wherein the shutter (4) comprises a hollow body closed at one end intended to come into contact with the valve seat, and in which a longitudinal end of the spring is mounted in the shutter.

9. Piston valve according to one of claims 1 to 8, wherein the bottom (7) has a recess housing another longitudinal end of the spring.

10. Piston valve according to one of claims 1 to 9, wherein each window (16) comprises a zone facing an outlet orifice (10).

11. Piston valve according to one of claims 1 to 10, comprising n outlet orifices and n windows, n being greater than or equal to 1.

12. A piston valve according to claim 11, in which the n outlet orifices (10) are bores and in which each window (16) has a cross section close to or equal to the diameter of an outlet orifice.

13. Piston valve according to one of the preceding claims, comprising angular orientation means between the casing (3) and the inner element (6), so that an area of a window (16) is next to an outlet opening (10).

14. Piston valve according to the preceding claim, wherein said means comprise shapes on the casing (3) and the inner member (6) cooperating so as to impose an angular position given to the inner member (6) by compared to the envelope (3).

15. Piston valve according to one of the preceding claims, wherein the inner element (6) is held in the casing by crimping.

16. A pressurized fluid circuit comprising a source of pressurized fluid and at least one piston valve according to one of the preceding claims connected by its first end to the source of fluid.

17. Fluid circuit according to the preceding claim, said circuit forming a hydraulic circuit of an internal combustion engine.

18. Internal combustion engine piston cooling nozzle comprising at least one piston valve according to one of claims 1 to 15 and at least one tube intended to guide the fluid from the outlet to the piston.

19. A piston cooling nozzle according to the preceding claim, wherein the casing has an external thread for mounting in an engine block.

20. A method of manufacturing a piston valve according to one of claims 1 to 15, comprising:

-The manufacture of the envelope.

-The manufacture of the interior element.

-The immobilization of the interior element in the envelope.

21. The manufacturing method according to claim 20, wherein the casing is produced by cold heading and recovery by machining.

22. The manufacturing method according to claim 20 or 21, wherein the inner member is made by thermoplastic injection molding.

23. The manufacturing method according to claim 20, 21 or 22, wherein the immobilization of the inner element in the casing is achieved by crimping.

24. The manufacturing method according to claim 23, in combination with claim 3, wherein during crimping the inner element is placed under axial stress in the casing.