FR2872248A1 - Solenoid valve for hydraulic brake system, has retention device that holds valve unit in position equivalent to open position of valve seat before control of unit by actuator and its operation is neutralized after control of unit - Google Patents

Abstract

The valve has a retention device (15) that cooperates with a valve unit (5) and holds the unit in a position equivalent to an open position of a valve seat (4) before control of the unit by an actuator. The actuator acts in closing direction of the seat and the operation of the retention device is neutralized after the control of the unit by the actuator. The unit is housed in a valve chamber (7) delimited by a valve insert (2).

Description

Field of the invention

  The present invention relates to a solenoid valve comprising a valve member guided in longitudinal movement in a valve insert and cooperating with a valve seat formed on the body of the valve, this element being subjected in the mounting position to an electromagnetic actuator acting in the closing direction of the valve seat, wherein at least a portion of the valve member is housed in a valve chamber defined by the valve insert at the valve seat.

  State of the art DE 100 36 576 A1 discloses a valve or a valve with electromagnetic control or solenoid valve installed in the hydraulic brake systems of motor vehicles. The valve comprises an insert provided with a longitudinal bore. The insert is connected to a valve cap receiving a movable armature in the longitudinal direction. The armature cooperates with a valve pusher or valve member longitudinally guided in the valve insert. The cooperation between the valve member and the armature is such that the movement of the armature in the closing direction of a valve seat is transmitted to the valve pusher provided with a closure member for the valve seat. .

  The valve pusher or valve member is guided with a small radial clearance over the entire length of the longitudinal bore of the valve insert and its casing has at least two channels separated from each other. A valve chamber at the valve seat or a valve chamber of the valve defined by the valve insert communicates through the channels with the cap, allowing the residual air of the cap to be forced through the channels.

  Disconnected from the current, the valve is held in the open position by a spring device or a return spring; this spring device in the form of a compression spring is housed in the valve chamber. The installation of the compression spring in this valve chamber simplifies the assembly of the valve.

  The spring device is, however, exposed to troublesome static and dynamic influences due to its installation in the valve chamber; these influences caused by the passage of fluid in the valve chamber deteriorate the operation of the valve. These influences, caused inter alia by the passage of fluid in the valve chamber and the fluid flow and fluid deflection forces on the turns of the compression spring, vary considerably throughout the operating range of the valve and being not predictable, can only be difficult to master.

  If the force developed by the spring device corresponds substantially to the forces applied by the passage of the fluid in the valve chamber to the turns of the spring in the direction of opening of the valve seat, it will have the negative influence described below. above on the operation of the spring device. In particularly unfavorable operating conditions of the valve, it will be possible, for example, to have the compression spring rise from its support against the valve body, so that a force component acting on the valve tappet in the direction of the valve Opening the valve seat will negatively influence the operation of the valve or valve.

  OBJECT OF THE INVENTION The present invention aims to develop a valve of the type defined above, having no spring device housed in the valve chamber as is known in the state of the art, to prevent that the passage of the fluid in the valve chamber deteriorates the operation of the valve.

  DESCRIPTION AND ADVANTAGES OF THE INVENTION For this purpose the invention relates to a valve of the type defined above, characterized by a holding device cooperating with the valve element and designed so that the valve element is held by the device. holding in a position equivalent to the open position of the valve seat before the first control of this element by the actuator, and to neutralize the operation of the holding device after the first control of the valve member by the actuator.

  Thus, before the first actuation by the actuator preferably during an evacuation and filling operation of a hydraulic system in which the valve is integrated, in all situations of the valve, the latter is maintained in a position in which valve seat is open; after the first electromagnetic actuation of the valve element, the operation of the restraint system is neutralized so that the mobility of the valve element will no longer or hardly be influenced by the holding device during operation of the valve.

  According to other advantageous features of the invention, the holding device comprises a pin which projects in the direction of the valve chamber from the supply zone of the valve chamber and comes to its end turned towards the valve chamber against the end of the valve member facing the valve seat so that the valve member is spaced from the valve seat; - the holding device comprises a holding member cooperating with the pin and realized so that the holding device, when closing the valve seat produced by the first control of the valve member by the actuator, under the effect of the axial stroke of the valve member necessary for closing of the valve seat, which is transmitted by the spindle to the holding member, changes from its equivalent stable state to the open state of the seat of the pope in a stable state equivalent to the state of closure of the valve seat, - the spindle is connected by the holding element which holds the spindle so that when the valve element is first actuated by the actuator, the spindle moves from its first equivalent position in the open state of the valve seat in its second position equivalent to the closed state of the valve seat, at least partially sliding relative to the holding member to be held by this holding member; pin is connected to the holding member so that from its first position equivalent to the open state of the valve seat, the pin passes into its second position equivalent to the closed state of the valve seat, at least partially in common with the holding member sliding relative to the valve seat to be held by the holding member, the holding member is flexible at least in zones, and at least a portion of the movement of the pin corres in the course of the stroke of the valve member is produced by deformation of the flexible zone of the holding member, - the holding device is in the form of a clamping element between the valve member and the valve insert so that the valve member is held in a position equivalent to the open state of the valve seat prior to its first actuator control, the holder is embodied as an annular member installed on the valve member, and whereby the force required to hold the valve member in its first equivalently open position of the valve seat is generated as a clamping force between the valve member valve insert and the holding device.

  Drawings The present invention will be described hereinafter in more detail with the aid of three embodiments of an electrovalve held open with its first actuation according to the invention, represented in the appended drawings in which: FIG. 1 is a diagrammatic longitudinal section of a valve according to the invention; FIG. 2 shows on an enlarged scale part II of FIG. 1; FIG. 3 shows the only holding device of FIG. Z direction of Figure 2, - Figure 4 is an enlarged view of an alternative embodiment of Part II of Figure 1, - Figure 5 shows the holding device shown alone and seen in the Y direction of FIG. 4 is a schematic longitudinal section of another embodiment of a valve according to the invention, FIG. 7 shows the holding device of FIG. 6 in plan view, the device being represented alone.

  Description of the embodiments

  FIG. 1 shows in longitudinal schematic section a part of a valve 1 with electromagnetic control. The valve 1 comprises a valve member 5 movable in the longitudinal direction in a valve insert 2 and cooperating with a valve seat 4 made in the valve body 3.

  The area of the valve member 5 facing the valve seat 4 is housed in the valve chamber 7 defined at the level of the valve seat 4 by the valve insert 2; the dimensions of the valve chamber are explained by the rectangle drawn in phantom in Figure 1; the area of the valve member 5 associated with the valve chamber 7 comprises a first cylindrical sector 5A continuing through a second cylindrical sector 5B of reduced diameter with respect to that of the first cylindrical sector 5A; a truncated cone sector 5C follows the second cylindrical sector 5B; a third cylindrical sector 5D continues the truncated cone sector 5C and finally a sector shaped spherical cap 5E ends the third cylindrical sector 5D. The spherical cap sector 5E of the valve member 5 cooperates with the conically shaped valve seat 4 so that when the valve member 5 is pressed against the valve seat 4, there will be a seal separating the area 8 of the valve chamber 7 of its outlet zone 9 when the valve seat 4 is closed.

  The valve 1 consists mainly of the hydraulic module 1A shown in Figure 1 and a not shown electrical module engaged on the hydraulic module 1A. The electrical module consists of a coil with an electric winding and a stirrup ring so that the armature of the hydraulic module 1A acting as an electromagnetic actuator acts in the closing direction of the valve seat 4 against the pressure prevailing in the zone d 8 and the valve chamber 7.

  The armature 10 is movably guided in the longitudinal direction in a valve cap 11 integrally connected to the valve insert 2; the armature delimits with the cap 11 several channels 12A communicating the dead volume 13 delimited between the cap 11 and the end of the armature 10 opposite that of the valve seat 4 by grooves 12B made in the valve element 5 for communicating with the valve chamber 7.

  When the valve 1 is not energized, the valve element 5 is moved away from the valve seat 4 towards the dead volume 13 by the hydraulic force applied to this valve element 5; the armature 10 is thus separated from the valve insert 2 by being pushed into the zone of the dead volume 13 against the cap 11 and applied against it. In this position of the valve member 5 and the armature 10, the valve member 5 or the spherical cap area 5E of the valve member 5 disengages the valve seat 4 and allows the feeding zone 8 to communicate with the exit zone 9.

  Moreover, in this state of the valve 1, the active fluid can pass through the valve 1, that is to say that starting from the supply zone 8 of the valve chamber 7 the fluid can pass through the seat of 4 and arrive in the exit zone 9 of the valve and then pass into the system connected to the exit zone 9 such as an ABS system (Antilock System), a TCS system (Traction Control System) or an ESP system (Electronic Stabilization Program).

  To close the valve seat 4, the electrical module of the valve 1 engaged on the cap 11 is fed to generate an electromagnetic force displacing the armature from its position shown in FIG. 1 towards the valve seat 4 and applying the spherical cap sector 5E of the valve member 5 sealingly against the valve seat 4 of the valve body 3 to close the valve 1. In this state of the valve 1, the supply zone 8 is separated from the outlet zone 9 and the active fluid can not pass through the valve 1 if between the supply zone 8 and the outlet zone 9, there is a positive pressure difference. Inside the valve, there will be a positive pressure difference if the pressure in the supply zone 8 is greater than that in the outlet zone 9 of the valve 1.

  This is because the supply zone 8 for a positive pressure difference with respect to the outlet zone 9 is separated from this outlet zone 9 by a shut-off valve 14; for a negative pressure difference that is to say if the pressure in the outlet zone 9 is greater than the pressure of the supply zone 8, the shut-off valve 14 is open.

  The side of the valve seat 4 not facing the valve chamber 7, inside the valve body 3 comprises a holding device 15. This device consists of a pin 16 and a holding member 17 to hold pin 16.

  The pin 16 of the holding device 15 cooperates at its end other than that of the holding member 17 with the spherical cap sector 5E of the valve member 5; this pin is made so that the holding device 15 holds the valve member 5 before the first actuation by the actuator in a position equivalent to the open state of the valve seat 4; this position is that shown in Figure 1; the operation of the holding device is neutralized after the first control of the valve member 5 by the actuator.

  In the position of the holding device 15 equivalent to the open state of the valve seat, the end of the rod 16 opposite that of the holding member 17 arrives in the feed zone 8 of the chamber valve 7 towards the valve seat 4 so that the valve member 5 is supported by its spherical cap sector 5E against the rod or pin 16 and moves the valve member 5 away from the valve seat 4 inside the valve 1.

  The holder 15 is supported in the axial direction against a plastic insert 18 by the holding member 17; this element is guided in the radial direction inside the valve body 3 by three guide zones 19 shown in more detail in FIGS. 2 and 3; Figure 2 shows on an enlarged scale Part II of Figure 1; FIG. 3 shows the holding device 17, shown alone in a view in the Z direction of FIG. 2.

  Between the three guide segments 19 of the holding member 17 there remain three clearances 20 allowing the active fluid to pass substantially without loss of load on the device hand-15 maintenance from the supply zone 8 in the direction of the valve chamber 7.

  The holding member 17 includes a first base sector 17A with the guide segments 19 and the recesses 20 and a substantially tubular or hollow cylindrical guide sleeve 17. The central bore of the guide sleeve 17B receives the pin or rod 16 longitudinally movable by its zone opposite to that of the valve member 5; the connection between the pin 16 and the guide sleeve 17B is such that the pin 16 is moved relative to the guide sleeve 17B only if a defined thrust is exerted on the pin 16 by the valve member.

  The clamping force between the pin 16 and the guide sleeve 17B of the holding element 17 to be overcome is sufficiently high for the valve element 5 to remain in the position shown in FIG. actuating the valve member 5 or the armature 10 by the actuator, so that the valve seat 4 remains held in the open position by the holding device 15.

  When the electromagnetic actuator is energized and the latter exerts a force on the armature 10 in the closing direction, a force transmitted to the valve member 5, the pin 16 will be pushed by the valve member 5 against the holding member 17 held axially to pass inside the guide sleeve 17B in the position shown in Figure 2. The valve seat 4 is then closed by the bearing of the valve member 5 against the valve body 3.

  This means that the control of the valve member 5 by the actuator causes the pin 16 to slide relative to the holding member 17 according to the maximum displacement travel of the valve member 5, in a limited manner because this stroke is limited by the valve seat 4. As the clamping force remains after the sliding of the pin 16 in the holding member 17, in the connection zone between the pin 16 and the guide sleeve 17B, the pin 16 remains in the position shown in Figure 2 throughout the life of the valve 1; thus, the operation of the holding device 15 after the first control of the valve member 5 by the actuator is neutralized and the holding device 15 will have no influence on the valve element or will no longer only a weak influence.

  Figure 4 shows Part II of Figure 1 shown on an enlarged scale according to an alternative embodiment with respect to that shown in Figures 1 to 3; in this embodiment, the holding device 15 or the pin 16 and the holding member 17 are made in one piece.

  The holding device 15 shown in FIG. 4 has substantially the same function as the holding device 15 shown in FIGS. 1 to 3. Indeed, the holding device 15 of FIG. 4, after its installation in the valve body 3 and before the first control of the valve member 5 by the actuator, is applied by its pin 16 against the spherical cap sector 5E of the valve member 5 to hold this valve member 5 in the position shown in Figure 1 and have a valve seat 4 or-green.

  The main difference between the holding device shown in FIG. 4 and the holding device represented in FIG. 1 is that the holding device 15 of FIG. 4 is held at the level of the holding element 17 by the insert plastic material 18 in the axial direction and in the radial direction the support is against the valve body 3; the holding device has two stable deformed positions and is integral with the pin 16. The first deformation position of the holding member 17 is shown in Figure 4; in this position the holding member 17 has a curved shape directed towards the valve member 5 so that the pin 16 moves the valve member 5 away from the valve seat 4.

  When the valve member 5 is controlled by the actuator, the pin 16 exerts a push on the holding member 17 towards the plastic insert 18 so that the elastic holding member 17 tilts its first stable end position shown in Figure 4 in its second stable end position shown in broken lines. In this second stable end position, the holding member 17 has a curved shape directed away from the valve member 5 as shown in FIG. 4. Thus, the end of the spindle 16 towards the valve member 5 is displaced from the stroke X shown in FIG. 4 with respect to the valve seat 4.

  This means that the holding member 17 is resilient so that upon the first control of the valve member 5 by the actuator, it moves from its first stable end position to its second end position. stable, click and thus discards the pin 16 of the valve member 5; during the entire life of the valve 1, the pin 16 remains in a position corresponding to the second end position of the holding member 17 in which the holding device 15 no longer influences the pumping element. -pape 5 or influence it only weakly.

  Both the embodiment of the valve 1 of Figure 1 and that of Figure 4 have the advantage that the operation of the valve can be first checked without the plastic insert 18 and the device of hold 15 and then be mounted simply after this check.

  FIG. 5 shows the holding device 15 of FIG. 4 according to the view in the Y direction of FIG. 4. This device comprises three guide segments 19 and three clearances 20. At the same time the holding element 17 of FIG. 3 and that of Figure 4 may be made with different shapes from those of the drawings; the holding device 15 can be positioned in the axial direction and in the radial direction inside the valve so that the fluid coming from the arrival zone of the valve chamber 7 can pass substantially without loss of pressure. the zone of the holding device 15 and this with the desired flow towards the valve chamber 7.

  Figures 6 and 7 show another alternative embodiment of the holding device 15. Figure 6 is a longitudinal section of a valve 1 provided with the holding device 15; FIG. 7 shows the holding device 15 of FIG. 6, shown alone, the device being seen in the direction W of FIG. 6.

  The holding device 15 is mainly made in the form of a circular part installed inside the valve insert 2 at the level of the second cylindrical sector 5b of the valve element 5. Its outer side turned towards the The valve insert 2 of the retaining device 15 has a plurality of longitudinal ribs 21 through which the retaining device 15 is clamped in the valve insert 2.

  Prior to the first control of the valve member 5 by the actuator, the holding device 15 functioning as a clamping member is placed in the valve insert 2 so that the valve member 5 is applied by its actuator. frontal surface facing the holding device 15 against the holding member 17; the valve element 5 is thus held by the holding device 15 in the position shown in Figure 6 in which the valve seat 4 is open.

  For actuation of the valve member 5 by the actuator, which closes the valve seat 4 by the axial displacement of the valve member 5 toward the seat 4, the hand-hold device 15 is pushed by the valve member 5 towards the valve seat 4.

  This means that due to the longitudinal ribs 21 of the holding device 15, the clamping force exerted between the valve insert 2 and the holding device 15 is exceeded by the force developed by the electromagnetic actuator; the holding device 15 is thus moved from its first stable position shown in Figure 6 in a second stable position for which the valve seat 4 is closed; the displacement is in the axial direction of the valve 1. This means that the clamping force between the holding device 15 and the valve insert 2 is defined so that it can be exceeded by the force developed by the electromagnetic actuator and that the holding device 15 remains in its second stable position after the first actuation of the valve member 5 by the actuator. Thus, within the valve 1, during the lifetime of the valve 1, the holding device 15 will no longer be subjected to a force that will exceed the clamping force between the holding device 15 and the insert valve 2 and could move the holding device 15 relative to the valve insert.

  At the same time, the holding device 15 made in the form of an annular element has an internal diameter such that the valve element 5 passes through the holding device 15 with a radial clearance such that the holding device 15 does not influence the axial movement of the valve member 5; the holding device 15 does not modify in these conditions the normal operation of the valve 1.

  The holding device 15 shown in FIGS. 6 and 7 has the advantage over the embodiments of the holding device represented in FIGS. 1 and 3 that that of FIG. 6 is not in the area of the valve seat 4 and is not exposed thereby to the passage of the active fluid in the supply zone 8 of the valve chamber 7.

  All the embodiments shown in the drawings have the advantage that the valve element is held in the open position before the first control of the valve element by the actuator especially during the evacuation phase and the reminder phase. -filling the valve and the system in which the valve is integrated, without having any subsequent negative influence on the characteristics of the valve.

  This means that the valve according to the invention makes it possible to eliminate the return spring installed in the valve chamber according to the state of the art and acting on the valve element in the direction of the opening of the valve seat and which This is a disadvantage because, moreover, this spring is exposed during operation of the valve to influences related to the passage of the fluid, strong and often troublesome.

  In addition, the holding device according to the invention may also have a combination of the different features of the embodiments shown in the drawings. Thus, it is possible to give the base area of the holding device an elastic structure like that of Figure 3 and to slide the pin relative to the base as shown in Figure 1 during the first order of the valve member 5 by the actuator. In addition, the holding device housed in the valve body 3 is displaced during the first actuator control of the valve member 5 as shown in FIG. 6 with respect to the valve body 3 and may have an elastic base member, its pin making a relative movement with respect to the base member or the guide sleeve to no longer maintain the valve member 5 in a position equivalent to the open position of the valve seat 4 and do not further influence this valve element during subsequent operation.

Claims (8)

  1) solenoid valve (1) comprising a valve element (5) guided in longitudinal movement in a valve insert (2) and cooperating with a valve seat (4) formed on the body (3) of the valve, this element being subjected in the mounting position to an electromagnetic actuator acting in the closing direction of the valve seat (4), at least a portion of the valve member (5) being housed in a valve chamber (7) delimited by the valve insert (2) at the valve seat (4), characterized by a holding device (15) cooperating with the valve element (5) and arranged so that the valve element (5) is held by the holding device (15) in a position equivalent to the open position of the valve seat (4) before the first control of this element by the actuator, and to neutralize the operation of the holding device (15) after the first command of the valve element (5) by the actuator.   2) solenoid valve according to claim 1, characterized in that the holding device (15) has a pin (16) projecting towards the valve chamber (7) from the feed zone (8). of the valve chamber (7) and at its end facing the valve chamber (7) against the end of the valve element (5) facing the valve seat (4) so that the valve member (5) is spaced from the valve seat (4).   3) solenoid valve according to claim 2, characterized in that the holding device (15) comprises a holding element (17) cooperating with the pin (16) and designed so that the holding device (15), when closing of the valve seat (4) produced by the first control of the valve member (5) by the actuator, due to the axial stroke of the valve member (5) necessary for the closing of the seat of valve (4), which is transmitted by the spindle (16) to the holding element (17), changes from its equivalent stable state to the open state of the valve seat (4) in a stable state equivalent to closing state of the valve seat (4).   4) solenoid valve according to any one of claims 2 or 3, characterized in that the pin (16) is connected by the holding member (17) which holds the pin so that at the first command of the element valve (5) through the actuator, the spindle (16) moves from its first equivalent position in the open state of the valve seat (4) to its second position equivalent to the closed state of the valve seat (4) at least partially sliding relative to the holding member (17) to be held by this holding member (17).   5) solenoid valve according to any one of claims 2 to 4, characterized in that the pin (16) is connected to the holding member (17) so that from its first position equivalent to the open state of the seat of valve (4), the pin passes into its second position equivalent to the closed state of the valve seat (4), at least partially in common with the holding member (17) sliding relative to the valve seat (4). ) to be held by the holding member (17).   6) solenoid valve according to any one of claims 2 to 5, characterized in that the holding element (17) is flexible at least in zones and at least a portion of the movement of the spindle (16) corresponding to the stroke of the valve element (5) is produced by deformation of the flexible zone of the holding element (17).   7) Solenoid valve according to claim 1, characterized in that the holding device (15) is designed as a clamping element between the valve element (5) and the valve insert (2) so that the valve member (5) is held in a position equivalent to the open state of the valve seat (4) prior to its first actuator control.   8) Solenoid valve according to claim 7, characterized in that the holding device (15) is in the form of an annular element installed on the valve element (5), and by which the force required to maintain the valve member (5) in its first position equivalent to the open state of the valve seat (4) is generated as a clamping force between the valve insert (2) and the device holding (15).