FR3040552A1 - ELECTRICAL CONNECTOR FOR AN ELECTROMAGNETIC ACTUATOR FOR A VALVE - Google Patents

Abstract

An electromagnetic actuator valve actuator (3) control assembly (8) comprising: - an electromagnetic actuator (9) comprising: • an armature (12); A crew (14) movable relative to the frame and comprising: a carcass (19); ○ a coil wound on the carcass, this coil having a primary end (23) and a secondary end (24); ○ a valve (3); an electrical circuit (10) including a primary terminal (25) and a secondary terminal (26); an electrical connector (11) comprising a primary conductor connecting the primary terminal to the primary end, and a secondary conductor connecting the secondary terminal to the secondary end; the primary and secondary conductors each being in the form of a flexible blade and being contiguous with the interposition of an insulating layer.

Description

ELECTRICAL CONNECTOR FOR AN ELECTROMAGNETIC ACTUATOR FOR A VALVE

The invention relates to the power supply of an electromagnetic actuator for a valve of an internal combustion engine.

Traditionally, the control of the valves in the internal combustion engines is carried out mechanically, by a distribution system comprising one or more camshaft (s) which drive the valves, either directly or indirectly via rocker arm . A camshaft is rotatably coupled to the crankshaft by a timing belt or chain.

An alternative valve control technique is electromagnetic actuation. In this technique, each valve is driven by means of an electromagnetic actuator. One or more magnets generate an electromagnetic field capable of moving, by the force of Laplace, a carcass on which is wound a coil traversed by an electric current and which is secured to the valve. The valve is thus able to move linearly in one direction, by Laplace force, when the coil is supplied with a positive current, and respectively in the opposite direction when it is supplied with a negative current.

An electrical control circuit controls each electromagnetic actuator and in other words each valve. The various control circuits associated with the engine valves are themselves under control of a computer (also called engine control). The computer is connected to different sensors that provide real-time data on the engine including data on the position of the crankshaft and the position of each valve relative to the cylinder head. The computer, via the electrical control circuits, makes it possible to synchronize the valves with the other elements of the engine such as the pistons.

Each electrical control circuit is for example fixed relative to the cylinder head and comprises two terminals adapted to be electrically connected to both ends of the coil. More specifically, each terminal is connected, via an electrically conductive path (for example in the form of a wire or a connector), to one end of the coil, which wiring makes it possible to form a closed electrical circuit capable of to control the coil electrically.

It is known to connect the terminals of the electrical control circuit and the ends of the coil via two standard electrical son, connected in parallel. In this arrangement, each wire is slightly stripped and soldered respectively to one of the terminals of the electrical control circuit and to one end of the coil. However, even if the electric wires have the advantage of having a small footprint and a low mass, the fact remains that they are unsuitable for the cyclic movements of the carcass on which the coil is wound, whose frequency can reach 3000 cycles per minute, a cycle being considered as a descent and a rise of the valve. Indeed, it is found in the short term, a break in the welded connection between the control circuit terminal and the wire and / or between the end of the coil and the wire.

It is also known to connect the terminals of the electrical control circuit and the ends of the coil via two standard electrical connectors, connected in parallel, each electrical connector defining an electrically conductive path. In this arrangement, each electrical connector comprises an electrically conductive flexible body (for example a braid or a superposition of thin strips) delimited by two rigid electrically conductive frames, the portion situated between the collars being covered with an insulating envelope. , a first armature being for example fixed on the cylinder head and the second opposite armature being fixed on the carcass. Each connector is electrically connected to the electrical control circuit and to the coil, via a first wire connecting a terminal and a first armature and a second wire connecting one end of the coil and the second armature.

[0008] Compared to a wiring only made with electrical wires mentioned above, the use of electrical connectors can increase reliability. However, the electrical connectors represent a significant bulk and mass. In addition, the assembly of connectors requires many operations, to the detriment of productivity.

A first objective is to provide a control assembly of an electromagnetic actuator for an internal combustion engine valve, this assembly comprising an electromagnetic actuator, an electrical control circuit and a connector electrically connecting the electromagnetic actuator and the circuit. electrical control, this electrical connector being flexible, compact, lightweight and reliable.

A second objective is to provide a motor comprising a control unit meeting the above stated objective.

A third objective is to provide a motor vehicle comprising a motor meeting the above stated objective.

For this purpose, it is proposed, firstly, a control assembly of an electromagnetic actuator for an internal combustion engine valve, which comprises: an electromagnetic actuator comprising: • an armature; A moving element relative to the reinforcement and comprising: a carcass provided with a tubular frame; a coil wound on the framework of the carcass, this coil having a primary end and a secondary end; a valve integral with the carcass; an electrical control circuit including a primary terminal and a secondary terminal, the primary and secondary terminals being fixed relative to the armature; an electrical connector comprising: a primary conductor connecting the primary terminal of the electrical control circuit to the primary end of the coil; A secondary conductor connecting the secondary terminal of the electrical control circuit to the secondary end of the coil; the primary and secondary conductors each being in the form of a flexible blade and being contiguous with the interposition of an insulating layer.

Various additional features may be provided, alone or in combination: the electrical connector is flexible so as to be deformable from a rest position in which the connector is flat to a mounted position in which the connector is on the one hand fixed on a contact surface of a base of the carcass and secondly on a support surface of a fixed support relative to the frame, the connector having in mounted position a curved body delimited by a primary sole and a secondary sole, the primary and secondary soles each representing an end portion of the electrical connector in contact respectively with the bearing surface and the contact surface; the bearing and contact surfaces are flat and positioned so that distances OS and OC are equal, where: • S is in section the embedding point located at a lower end of the bearing surface; • C is in section the embedding point located at a lower end of the contact surface; • O is the point of intersection of the normals to the bearing and contact surfaces passing respectively through the embedding point S and the embedding point C. The length L of the electrical connector is defined as: where:

• R is the radius of the center circle O passing respectively through the embedding point S and the embedding point C; • A is the angle, measured in degrees, defined between said normals; • Hs is the height of the bearing surface; • Hc is the height of the contact surface; the angle A is 180 ° and 225 ° and is avilately 215 °; the primary and secondary conductors are bonded to the insulating layer; the thickness Ec of the primary and secondary conductors is between 0.04 mm and 0.12 mm and is advantageously 0.08 mm; the primary and secondary conductors each comprising two protruding tongues, the primary end and the primary terminal being each fixed to one of the tongues of the primary conductor, the secondary end and the secondary terminal being each attached to one of the tongues secondary driver.

It is proposed, secondly, an internal combustion engine comprising a control assembly as presented above.

It is proposed, thirdly, a motor vehicle comprising a motor as previously described.

Other features and advantages of the invention will appear more clearly and concretely on reading the following description of embodiments, which is made with reference to the accompanying drawings, in which: FIG. perspective view of a motor vehicle (in broken lines) comprising a motor (in solid lines) comprising at least one control assembly of an electromagnetic actuator for a valve; Figure 2 is a perspective view of a control assembly comprising an electromagnetic actuator, an electrical control circuit and an electrical connector electrically connecting the electrical control circuit to the actuator; Figure 3 is a sectional view along the plane III-III of Figure 2 with two detail medallions on an enlarged scale; Figure 4 is a detailed perspective view of the attachment of a soleplate of the electrical connector on a carcass of the electromagnetic actuator; Figure 5 is a perspective view of detail of the attachment of a sole of the electrical connector on a support; Figure 6 is a detail sectional view along the plane III-III of Figure 2; Figure 7 is a detail sectional view along the plane III-III of Figure 2; Figure 8 is a front view of the electrical connector; Figure 9 is a bottom view of the electrical connector.

In Figure 1 is shown a vehicle 1 automobile - here a vehicle 1 particular but it could be any other type of vehicle: utility, truck, construction equipment.

The vehicle 1 is equipped with an internal combustion engine 2 provided with cylinders defining combustion chambers and in which pistons are slidably mounted, these pistons being connected, by connecting rods, to a crankshaft whose rotation causes the vehicle wheels 1, via a transmission.

The engine 2 comprises, for each cylinder, at least one intake valve and an exhaust valve.

In the figures and in the following description, for reasons of clarity, the term valve is generalized so that the valve 3 shown and described can be likened to either an intake valve or a valve of exhaust.

As illustrated in the figures and in particular Figures 2 and 3, each valve 3 comprises a rod 4 which extends along a central axis X which defines a vertical direction. At one end of the rod 4 is formed a head 5. Each valve 3 is movable in translation relative to a cylinder head 6 (partially shown) of the engine 2 between a closed position, in which the head 5 of the valve 3 is supported. against a seat 7 to close an intake duct (or, respectively, an exhaust duct) and an open position in which the head 5 is spaced from the seat 7 to put the combustion chamber in communication with the intake duct (or, respectively, with the exhaust duct).

By convention, one defines the positioning in height of an element relative to the axis X. By convention, the height is increasing from the head 5 of the valve 3 to the rod 4 of the valve 3. The terms "inferior (e)" and "superior (e)" associated with the different elements refer to this convention.

As illustrated in Figure 2, a control assembly 8 can control each valve 3 of the internal combustion engine 2. A control assembly 8 comprises an electromagnetic actuator 9 actuating the valve 3, an electric control circuit 10 controlling the actuator 9 and an electrical connector 11 electrically connecting the electromagnetic actuator 9 and the electrical control circuit 10. The various electrical control circuits associated with the various valves 3 of the engine 2 are themselves under control of a computer (also called engine control).

The computer is connected to different sensors that provide real-time data on the engine 2 and in particular on the position of the crankshaft and the position of each valve 3 relative to the cylinder head 6.

With this feedback, the computer independently controls each electromagnetic actuator 9 via the electrical control circuit 10 with which it is associated, in order to synchronize the valves 3 with the other elements of the engine 2, such as the pistons.

According to the embodiment illustrated in the figures, each actuator 9 comprises, on the one hand, an armature 12 fixed relative to the cylinder head 6 and defining a magnetic circuit 13, and on the other hand, a mobile crew 14 .

The magnetic circuit 13 includes on the one hand an annular magnet 15 which extends symmetrically about the central axis X, and on the other hand, an upper annular pole piece 16 and a lower annular pole piece 17. , these pole pieces 16, 17 being symmetrical about the central axis X and sandwiching the magnet 15. The magnetic circuit 13 further comprises a central core 18 which is in the form of a cylinder of revolution around the central X axis.

The core 18 is housed concentrically in a bore defined internally and jointly by the magnet 15 and the parts 16, 17 polar. In other words, the magnet 15 and the pole pieces 16, 17 extend annularly around the core 18. The outer diameter of the core 18 is smaller than the internal diameter of the bore, so that is defined a gap, between the core 18 and the parts 16, 17 polar, that is to say a space in which the magnetic field is directed substantially radially, and more specifically, an upper air gap between the core 18 and the pole piece 16 upper, and a lower air gap between the core 18 and the lower pole piece 17.

The magnetic circuit 13 generates a magnetic field whose field lines are toric around the central axis X.

The mobile equipment includes a carcass 19 which comprises a base 20 extending out of the frame 12 and a tubular frame 21 projecting vertically from the base 20. This carcass 19 is made in a non-electrically conductive material, for example in a polymeric material.

The frame 21 extends substantially over the entire height of the frame 12 between the core 18 and the magnet 15. The frame 21 has an upper section dipped in the upper air gap and a lower section dipped in the lower air gap.

The mobile equipment 14 further comprises a coil 22 made by helically winding a wire made of an electrically conductive material, this coil 22 comprising: an upper portion wound, in a primary direction, around the upper section frame 21 and plunged into the upper air gap; a lower portion wound, in a secondary direction opposite the primary direction, around the lower section of the frame 21 and immersed in the lower air gap.

The coil 22 further has a primary end 23 and a secondary end 24 through which the coil 22 is supplied with current, these ends 23, 24 primary and secondary projecting out of the carcass 19 near the base 20 as shown in Figure 4.

As shown in the figures and in particular Figures 2 and 3, the valve 3 is integrated with the moving crew 14 being secured to the carcass 19, for example by means of screws.

The circulation of a current in the coil 22 generates, by the interaction with the magnetic field, a force known as the Laplace force, which produces a displacement of the coil 22 driving with it the valve 3.

The Laplace force is proportional to the magnetic field, the intensity of the current and the length of the solenoid constituting the coil 22.

The supply of the coil 22 with a positive current allows the displacement of the valve 3 in one direction and respectively in a reverse direction when the coil 22 is supplied with a negative current.

The electrical control circuit 10 is fixed relative to the armature 12, and comprises a primary terminal 25 and a secondary terminal 26, the terminals 25, 26 primary and secondary being respectively able to be connected to the ends 23, 24 of the coil 22 via the flexible electrical connector 11. According to the example illustrated in the figures and in particular in FIGS. 2 and 5, each terminal 25, 26 has a flexible, electrically conductive extension 27, for example in the form of an electric cable, this flexible extension 27 allowing to adapt to the external environment between the electrical control circuit 10 and the electrical connector 11.

The electrical connector 11 comprises on the one hand a primary conductor 28 electrically connecting the primary terminal 25 of the electrical control circuit 10 to the primary end 23 of the coil 22, and on the other hand, a secondary conductor 29 connecting electrically the secondary terminal 26 of the electrical control circuit 10 at the secondary end 24 of the coil 22. The primary and secondary conductors 28, 29 are each in the form of a flexible blade and are contiguous with the interposition of a layer Insulation.

The electrical connector 11 is flexible, so that it can be deformed from a rest position (unassembled and unpowered current, see FIGS. 8 and 9) in which it is substantially flat, at a mounted position (not energized). in current, see Figures 2, 3, 4, 5 and 7) in which the connector 11 is firstly fixed on the base 20 of the frame 19 and secondly on a support 31 fixed relative to the frame 12.

The electrical connector 11, in the mounted position, has a curved body 32 (in particular circular or elliptical) delimited laterally by a primary sole 33 and a sole 34 secondary. The soles 33, 34 primary and secondary each represent an end portion of the electrical connector 11 in contact respectively with a bearing surface 35 of the support 31 and a contact surface 38 of the carcass 19.

According to the embodiment illustrated in the figures, the body 32 is circular, each sole 33, 34 being flat and tangential to the body 32.

According to the embodiment illustrated in the figures, more specifically, the primary sole 33 is fixed on the flat support surface 35 of the support 31, via a washer 36 shouldered and a screw 37. In the same way, the secondary sole 34 is fixed on the plane contact surface 38 of the carcass 19 via a washer 36 shouldered and a screw 37. The washers 36 shouldered and the screws 37 are made of a non-electrically conductive material, for example a polymer material .

The illustrated example is in no way limiting, the surfaces 35, 38 of support and contact could be of any other form.

As shown in Figure 6, for the purpose of determining the length L flat (in the rest position) of the electrical connector 11 necessary to obtain the desired profile thereof in the mounted position, it defines a point d mounting S of the electrical connector 11 on the support 31 and an embedding point C of the electrical connector 11 on the frame 19. In section, the embedding point S is located on the support surface 35, at a lower end of this bearing surface 35. In the same way, in section, the embedding point C is located on the contact surface 38, at a lower end of the base 20 of the carcass 19. The point O is defined as being the point of intersection of the normals 39 to the bearing and contact surfaces 35, 38 passing respectively through the points S and C, the distances OS and OC being equal. In addition, in dotted lines, the arc 40 of the circle of center O passing through the points S and C is shown.

arc 40 having a radius R (equal to the distances OS and OC) and an angle A (also angle between the normals 39). Hs and Hc, respectively, the height of the bearing surface and the height of the contact surface 38, measured in section, as shown in FIG.

Advantageously, the flat length L (in the rest position) of the connector 11 is expressed in the following manner (A being expressed in degrees):

This dimensional requirement associated with the electrical connector 11, defined above, allows the mobile crew 14 to achieve its predefined stroke (about 8 mm) at high frequencies while limiting the residual forces generated by the connector 11 on the carcass 19 for the benefit of the consumption of electricity and the control of the valve 3.

The angle A is between 180 ° and 225 °, and is preferably 215 °. The heights Hs and Hc are between 1 mm and 7 mm, and are advantageously 4 mm. The radius R is between 4 mm and 12 mm, and is advantageously 8.6 mm.

According to the embodiment shown in the figures and in particular Figure 2, in the mounted position, the soles 33, 34 primary and secondary respectively have a height equal to the heights Hs and Hc, and the body 32 of the electrical connector 11 is defined according to the geometric characteristics of the arc 40, namely an outside radius R and an angle A.

According to the embodiment illustrated in the figures, the primary conductor 28 (respectively the secondary conductor 29) comprises two tongues 41, each tongue 41 extending in axial projection at a sole 33, 34, both tongues 41 facing one another, each tongue 41 comprising a hole 42 adapted to receive either one of the ends 23, 24 of the coil 22 or the extension 27 of one of the terminals 25, 26 of the electrical control circuit 10. The tabs 41 of the primary conductor 28 are opposed to the tabs 41 of the secondary conductor 29. The primary end 23 of the coil 22 and the primary terminal 25 of the electrical control circuit 10 are electrically connected to the primary conductor 28 via the tongues 41. In the same way, the secondary end 24 of the coil 22 and the terminal 26 secondary of the electric control circuit 10 are electrically connected to the secondary conductor 29 via the tabs 41.

More specifically, each end 23, 24 of the coil 22 is first introduced into the hole 42 of the corresponding tongue 41, then in a second step, the end 23, 24 is for example welded to the tongue 41 so as to have electrical continuity. In the same way, each denuded extension 27 is first introduced into the hole 42 of the corresponding tongue 41, then in a second step, the stripped portion of the extension 27 is welded to the tongue 41, so as to have a electrical continuity.

The conductors 28, 29 primary and secondary are in the form of a flexible blade made of a conductive material having a high electrical conductivity, such as copper, these conductors 28, 29 having a thickness Ec and a width The (width measured at the body 32 of the connector 11 and in other words not taking into account the tongue 41), as illustrated in FIGS. 8 and 9.

The thickness Ec is for example between 0.04 mm and 0.12 mm, and is preferably 0.08 mm. The width Le is for example between 2 mm and 8 mm, and is advantageously 5 mm.

The insulating layer 30 is made of a non-electrically conductive material, such as cardboard or a polymeric material. The insulating layer 30 has the function of electrically isolating the conductors 28, 29 from each other.

The primary and secondary conductors 28, 29 and the insulating layer 30 are advantageously bonded together.

According to an embodiment not shown, the electrical connector 11 comprises an additional insulating layer 30 which is contiguous to the primary conductor 28, so that the primary conductor 28 is interposed between two insulating layers 30.

According to another embodiment not shown, the electrical connector 11 comprises two additional insulating layers 30 which are respectively contiguous to the primary conductor 28 and the secondary conductor 29, so that each conductor 28, 29 is interposed between two layers 30 insulating.

The control assembly 8 which has just been described offers the following advantages.

First, by its geometric and structural characteristics, the electrical connector 11 has a low mass and great flexibility, these properties to significantly reduce the residual forces generated by the connector 11 on the carcass 19 to the benefit of the consumption of electricity and control of the valve 3.

Secondly, the mounting of the electrical connector 11 is formed by means of two washers 36 stepped and two screws 37 for the benefit of productivity.

Third, given the large number of valves 3 in the engine 2, the low mass of the connector 11 can participate in the decrease in fuel consumption and pollutant emissions of the vehicle 1.

Fourthly, the electrical connector 11 is compact to the benefit of the overall size of the engine 2.

Claims (10)

An assembly (8) for controlling an electromagnetic actuator (9) for an internal combustion engine valve (3), which comprises: an electromagnetic actuator (9) comprising: • an armature (12); A crew (14) movable relative to the frame (12) and comprising: a carcass (19) provided with a tubular framework (21); a coil (22) wound on the framework (21) of the carcass (19), this coil (22) having a primary end (23) and a secondary end (24); a valve (3) integral with the carcass (19); an electric control circuit (10) including a primary terminal (25) and a secondary terminal (26), the primary and secondary terminals (25, 26) being fixed relative to the frame (12); an electrical connector (11) comprising: • a primary conductor (28) connecting the primary terminal (25) of the electrical control circuit (10) to the primary end (23) of the coil (22); A secondary conductor (29) connecting the secondary terminal (26) of the electrical control circuit (10) to the secondary end (24) of the coil (22); characterized in that the primary and secondary conductors (28, 29) are each in the form of a flexible blade and are contiguous with the interposition of an insulating layer (30). 2. Assembly (8) according to claim 1, characterized in that the connector (11) electrical is flexible so as to be deformed from a rest position in which the connector (11) is flat to a mounted position in which the connector (11) is firstly fixed on a contact surface (38) of a base (20) of the carcass (19) and secondly on a support surface (35) of a support ( 31) fixed relative to the frame (12), the connector (11) having in mounted position a curved body (32) delimited by a sole (33) primary and a sole (34) secondary, the soles (33, 34 ) primary and secondary each representing an end portion of the electrical connector (11) in contact respectively with the bearing surface (35) and the contact surface (38). 3. Assembly (8) according to claim 2, characterized in that the surfaces (35, 38) of support and contact are flat and positioned so that distances OS and OC are equal, where: S is in section the embedding point located at a lower end of the bearing surface (35); C is in section the embedding point located at a lower end of the contact surface (38); O is the point of intersection of the normals (39) with the bearing and contact surfaces (35, 38) passing respectively through the embedding point S and the embedding point C. 4. Assembly (8) according to claim 3, characterized in that the flat length L of the electrical connector (11) is defined as: where: R is the radius of the center circle O passing respectively through the embedding point S and the embedding point C; A is the angle, measured in degrees, defined between said normals (39); Hs is the height of the bearing surface (35); Hc is the height of the contact surface (38). 5. Assembly (8) according to claim 4, characterized in that the angle A is 180 ° and 225 ° and is preferably 215 °. 6. Assembly (8) according to any one of the preceding claims, characterized in that the conductors (28, 29) primary and secondary are bonded to the layer (30) insulating. 7. Assembly (8) according to any one of the preceding claims, characterized in that the thickness Ec of the conductors (28, 29) primary and secondary is between 0.04 mm and 0.12 mm and is preferably 0.08 mm. 8. Assembly (8) according to any one of the preceding claims, characterized in that the conductors (28, 29) primary and secondary each comprise two tabs (41) projecting, the end (23) primary and the terminal ( 25) each being fixed on one of the tongues (41) of the primary conductor (28), the secondary end (24) and the secondary terminal (26) being each fixed on one of the tongues (41) of the conductor (29) secondary. 9. Internal combustion engine (2) comprising a control assembly (8) according to one of the preceding claims. 10. Vehicle (1) automobile comprising a motor (2) according to claim 9.