FR2483337A1 - VALVE OF LEVELING - Google Patents

Abstract

LEVELING VALVE FOR THE CONTROL OF REGULATION OF THE LEVEL OF PNEUMATIC SPRINGS DEPENDING ON THE LOAD. A BODY1, EQUIPPED WITH AN AIR TANK FITTING2 AND A PNEUMATIC SPRING FITTING, CONTAINS AN INLET VALVE 5, 6 CONNECTING FITTING2 TO FITTING3, AND AN OUTLET VALVE6, 8 CONNECTING FITTING3 TO THE FREE AIR PURGE PORT4. THE VALVES ARE MADE IN THE FORM OF FLAP VALVES, EACH CONSISTING OF A VALVE 5, 6 WITH A SPAN 5A, 6A AND A BORE 7, 8 OF THE BODY 1. MECHANICAL MEANS OF TRANSMISSION ARE PROVIDED FOR THE REGULATION OF THE LEVEL OF THE PNEUMNS DEPENDING ON THE LOAD.

Description

The present invention relates to a leveling valve for

  regulating the level of pneumatic springs according to the load, with a body provided with at least one air tank connection and at least one pneumatic spring connection and comprising an inlet valve, which connects the air tank connection to the fitting

  pneumatic spring, and an outlet valve, which connects the

  pneumatic spring rope to a vent hole in the open air, and with mechanical transmission means for regulating the

  level of the air springs according to the load.

  Such a leveling valve is described in the patent of the Federal Republic of Germany No. 19 06 062. The operation of this known leveling valve providing an adjustable push in

  height for valve control, mounting dimensions, and especially

  the height are relatively large, so that the mounting of

  the valve may cause problems when the mounting space is

  available is limited, as in the case of

pneumatic board.

  Leveling valves are usually subject to a load

  permanent continuously variable. This permanent charge is likely to

  failing because the mechanical transmission of forces in the aforementioned leveling valve is effected by means of several mechanical references between control levers, the eccentric and the

valve pushbutton.

  The subject of the invention is an economic leveling valve of the

  type, having a height as low as possible in accordance with

  compact truction and supporting extremely high permanent loads. According to an essential characteristic of the invention - the inlet valve and the outlet valve are made in the form of flap valves, each constituted by a valve with a bearing and a piercing of the body; - Valve springs act on the valves and are arranged so that the forces they exert on them close the valves; and - the mechanical transmission means are constituted by a valve control member, made in the form of a cam member

  which is connected to an adjustable angle lever and operates directly

  the valves of the inlet and outlet valves.

  The use of clamshell valves arranged side by side has resulted in a compact and economical leveling valve, whose control forces are low as a result of the more favorable transmission and which is suitable for extremely high permanent loads. The position of the flap valves and the lateral arrangement as well

  possible lever protrusions perpendicular to the direction of closing

  valves and their connection to the radial transmission profile.

  of a rotating shaft, which is adapted to the flap valves and connected directly to the hinge lever, are other advantages

  characteristics of a compact construction.

  According to another characteristic of the invention

  - a free operating throttle is arranged between the

  pope inlet and the outlet valve on the one hand and the pneumatic spring connection on the other hand; the free-running choke is actuated by the valve control member with a predetermined clearance; the clearance between the free-acting choke and the valve controller is dimensioned such that from a basic position the free-operation choke limits the supply and bleed of the pneumatic spring coupling for small deviations of the valve control member and the

  frees for large deviations, a strangulation being all-

  restored only after returning to the basic position from a large deviation; and - the free-operating-striker is protected against inadvertent operation, at least on the clearance range between said choke

  and the valve control member.

  According to another characteristic of the invention - the free operating choke is constituted by an element

  annular, housed in rotation in a recess of the compression member

  valve arrangement, adapted to the outer radius of said choke; a bore connected to the pneumatic spring connection terminates in the annular surface of the recess; - the free operating choke has on its radius

  exterior a first and a second recess which release the

  a surface located between the recesses constituting a throttling surface limited by two throttling edges and which reduces the flow of compressed air in the bore hole over a given range of displacement of the valve control member or free operation choke; - for the establishment of a frictional connection between the valve control member and the free-operation choke, a

  spring disposed in the center of the latter band against the recess-

  said choke made of elastic material and elastically deformable due to the realization of the second recess; and - a driver, made in the form of a stud fixed on the valve control member, penetrates into the second recess so that its application on surfaces of the latter, made in abutments, allows the translation of the choke Operating

  free from the frictional connection with the

valve.

  These last two characteristics correspond to an embodiment of a leveling valve that is particularly suitable for

  good for use in air suspension car seats.

  This embodiment of the valve includes a throttling device which keeps the car seat at a constant height during normal walking, even in case of oscillations, and when the driver sits, the seat moves quickly to the seat. adjusted height,

  corresponding to the weight of the driver.

  According to another characteristic of the invention, the leveling valve comprises a damping device which, on a fixed range corresponding to a fixed range of movement of the height-adjustable lever, delays the movement of the valve control member and as a result the operation of the inlet valve and the outlet valve. According to another characteristic of the invention,

  the damping device is constituted by a damping element

  mechanical element and a hydraulic damping element. According to another characteristic of the invention: the mechanical damping element is constituted by a piston housed

  in a barrel and subjected to the action of a spring, said barrel

  let being connected to the lever; - a control shaft engages on the rounded lower surface

  of the piston so that a movement of the lever can not be

  ti rotation of the control shaft only when the con-

  dragged by the spring is exceeded; and the other end of the control shaft is rotationally fast

  of the valve control member of the leveling valve.

  According to another characteristic of the invention: the hydraulic damping element is constituted by a piston housed in a barrel and two damping chambers filled with a liquid and opposing the movement of the piston in the two directions; - The tolerances of the piston and the barrel are dimensioned so that the slot between these two elements circulates with constriction the liquid discharged by a movement of the piston of a damping chamber in the other; - A wide slot is provided in the piston to allow a rapid flow of liquid from one damping chamber in the other during a return of the piston and the opening of a valve valve; and - a driving bolt, triggering the movement of the piston, establishes a connection between the latter and the control shaft of the

leveling valve.

  These last four features correspond to one embodiment of the leveling valve. A hydraulic damping device avoids in this case an instantaneous response of the level control, even in the case of oscillations of the seat during the walk.

of the car.

  Other features and advantages of the invention will be

  better understood using the following detailed description of

  Embodiments and accompanying drawings in which: Figure I shows a leveling valve, consisting of two poppet valves and a narrowing device shown in phantom; Figure 2 shows the dart throttling device in Figure 1; Figure 3 shows the leveling valve according to Figure 1 with a damping device; and

  FIG. 4 is the section A-A of the hydraulic damping element

  with a B-B cut of the leveling valve according to Figure 3.

  The leveling valve according to FIG. 1 is constituted by a body 1 provided with an air-tank connector 2, a connector 3 of

  pneumatic spring and a vent opening 4 in the open air. Two keys

  farts 5 and 6, arranged horizontally in a chamber IA of the body 1 form with their bearing 5a, 6a and holes 7 and 8 an inlet valve 5, 7, connected to the bore 7 by the tank connector 2, and a valve outlet 6, 8, connected by the bore 8 to the purge port 4. Springs 9 and 10 disposed above the valves 5 and 6

  hold the two valves 5, 7 and 6, 8 in the closed position.

  The valve 5, 6 is simply held by the spring 9, 10 on the valve bore 7, 8, without fixing. In another embodiment, the valve 5, 6 pivots on one end and is mounted

with transversal translation.

  A valve control member 12, made in the form of a cam disk integral in rotation with a lever 11, is arranged between the two valves 5, 7 and 6, 8 so that a first cam 13 engaging on the valve 5 opens the inlet valve 5, 7 during the rotation in one direction of the valve control member 12, produced by the lever 11. During the rotation of the member 12 in the other direction a second cam 14 engaging on the valve 6 opens

the outlet valve 6, 8.

  A free-running choke 16, rotating with respect to the valve control member 12, is housed in a recess 15 of said member 12. This choke, shown in solid lines in FIG. 2 and in broken form in FIG. said free operation, because it is movable radially in a determined free operation and its outer diameter 17 forms a throttling slot with the recess 15, which contains the choke 16.The throttling slot is formed by a surface 18 predetermined, limited by two throttling edges 19 and 20 on the outer radius 17 of the free-acting choke 16 which, upon a rotation of the valve control member 12 on this throttling surface 18, overlaps a bore 3a of the pneumatic spring coupling 3 opening into

the recess 15.

  The recesses 21 and 22 of the free-operation choke 16, which follow the throttling edges 19 and 20 following the

  circumference, disengage the bore 3a of the pneumatic spring coupling 3

  tick. The recess 22 is made to allow the penetration of a driver 23, made in the form of a stud fixed on the valve control member 12. The recess 22 imparts a certain elasticity to the free-running choke 16 made of an elastic material, so that a spring 24 disposed in the center of said

  choke 16, and whose force is oriented radially outwards

  the outer wall 17 of the choke 16 on the

  15 containing the latter. This application pressure immobilizes the choke 16 during a rotation of the valve control member 12, over a determined range of displacement of said member. The rotation of the valve control member 12 is transmitted to the choke 16 of free operation only when the driver 23 is applied to the surfaces of the recess 22 made abutments

and 26.

  The clearance between the free operating choke 16 and the organ

  12 valve control is thus dimensioned so that the foreign

  16 limits the supply and purge of the pneumatic spring connection 3 for small deviations of the member 12 and releases them

for large deviations.

  The operation of the leveling valve equipped with a

  Strangulation technique is as follows.

  When the load increases, the lever 11 moves downwards and the rotation transmitted to the valve control member 12 opens the inlet valve 5, 7 by the cam 13 engaging on the valve 5, so that a connection is established for the compressed air between the tank connection 2 and the pneumatic spring connection 3. This connection purges the air spring until the establishment of the pressure balance corresponding to the load and the return of the lever 11 in its normal position, with new closing of the inlet valve 5, 7. When the load decreases the lever 11 moves upwards and the rotation of the valve control member 12 engages the cam 14 on the valve 6, causing the outlet valve 6, 8 to open, so that a link is established for compressed air

  between the air spring connection 3 and the open air, through

mediate the orifice 4.

  This link purges the air spring until the lever Il returns to its normal position and closes again.

outlet valve 6, 8.

  The foregoing description of the operation of the leveling valve

  does not take into account the simultaneous action of the choke

free operation 16.

  When the leveling valve is used for example in an air-suspended car seat, the driver is seated

  when the free-operation choke 16 is in the position

  1 and 2. The bore 3a terminating in

  pneumatic spring connector 3 is covered by the surface of

  18. Where unevenness in the road causes the driver to oscillate upwards, the free-running choke 16

  does not follow the rotation of the valve control member 12, by the in-

  the intermediary of the coach 23 and stop 25, that after the

  play, but prohibits rapid escape of air

  awarded between the air spring and the open air, by the outlet valve 6, 8 open, because the throttling surface is dimensioned so that the throttling edge of the surface 18 is not exceeded in the case of normal seat oscillations produced by

the march of the vehicle.

  The seat moves upward, due to the pressure in the air spring, only after exceeding a certain amplitude, for example when the driver abandons the seat. The radius of movement of the valve control member 12 is so large that the throttle edge 20 of the surface 18 of the free-running choke 16 rotated moves on the bore 3a of the spring coupling 3 pneumatic and that the latter is purged quickly in the open air, by said hole now open and the outlet valve 6, 8 open, depending

  the sole weight of the driver's seat.

  When the driver sits down, the seat is lowered to a stop and the throttling surface 18 allows rapid feeding of the air spring after crossing the edge

Strangulation 19.

  The seat resumes its normal position and the driver then has a seat that does not strongly oscillate because of the throttle device, but ensures a normal suspension as a result of the

  purge and strangled food still possible.

  Details of a damping device of the valve of

  leveling are described below using Figures 3 and 4.

  The parts bearing the same references in FIGS.

  in Figure 1 assume the same function.

  When the air spring is unloaded, the lever Il and a barrel 30 to which it is connected move upwards. A control shaft 31, connected to the barrel, does not follow this movement first, because a piston 33, housed in the barrel 30 and subjected to the action of a compression spring 32, is first raised. The piston 33 bears on an edge 31a of a flat part of the control shaft 31,

  thereby amplifying the force exerted by the compression spring 32.

  A defined torque is then exerted on the control shaft 31 and by

  continued on the damping device.

  The control shaft 31 exerts a force on a hydraulic piston

  33 in a barrel 34 through a bolt

  36 and bolts 37 and 38.

  The piston 35 however opposes a resistance to this force, since damping chambers 39, 40 located behind said piston are filled with a liquid. This liquid flows through a slot between the piston 35 and the barrel 34 to push the piston of a

  sinking chamber in the other.

  The movement of the piston 35 and the transmission of the rotation of the control shaft 31 to the valve control disc 12 raise

  the valve 6 and the compressed air escapes from the tire spring coupling 3

  in the open air, through the outlet valve 6, 8 open.

  A load of the air spring produces the phenomenon previously

  described, but with a displacement of the piston 35 in the opposite direction. The air spring is then purged by the connection 2 of the

  tank, inlet valve 5, 7 open and fitting 3.

  When the piston returns from its considered limit position in the middle position, one of the pilot edges 41 or 42 of the piston 35 is in the zone of one of the two damping chambers 39 or 40. The liquid can thus be flow quickly through a large slot a or 35b and valve valve 43 or 44 which then opens. The

  piston 35 follows the movement of the lever 11.

  The hydraulic damping device described establishes in the damping zone of the hydraulic piston 35 a state which does not allow any supply or purge of the air spring, or only

  a delayed supply or purge in the case of weak oscilla-

headquarters.

  In a modified embodiment, the choke device

  described may also be placed upstream of the

  and / or upstream or downstream of the outlet valve; an assembly outside had the body of the leveling valve or in the body

  is then possible in both cases.

  The slot between the cams 13, 14 and the valves 5, 6 fix the

  response stroke of the poppet valves 5, 7; 6, 8 and must be

  kept within specified tolerances. The valves are applied at rest on bosses 50 in order to avoid excessive tolerances of this response stroke, as in the case of a free pivoting

valves.

  In order to ensure good seating, the point of application of the force of the springs 9, 10 can be provided between the holes 7, 8 of

  valve and bosses 50. This provision does not permit a pivot

  indefinitely the valves and an inadmissible increase in

  tolerance of the response run.

  Of course, various modifications can be made by those skilled in the art to the principles and devices that have just been described by way of non-limiting examples, without departing from the scope of the invention.

Claims (11)

claims   1. Leveling valve for controlling the regulation of the level of pneumatic springs according to the load, with a body <1) provided with at least one connection (2) of the air tank and at least one connection (3) of an air spring and comprising an inlet valve (5, 7), which connects the air tank connection (2) to the air spring connection (3), and an outlet valve (6, 8), which connects the connection (3) to an air purge port (4), and with mechanical transmission means for regulating the level of the air springs as a function of the load, said valve being characterized in that: a) the inlet valve (5, 7) and the outlet valve (6, 8) are in the form of flap valves each consisting of a valve (5, 6) with a bearing surface (5a, 6a) and piercing (7, 8) of the body (1); b) valve springs (9, 10) act on the valves (5, 6) and are arranged in such a way that the forces they exert on the latter close the valves (5, 7, 6, 8) and c) the mechanical transmission means are constituted by a valve control member (12) in the form of a cam member which is connected to an adjustable angle lever and directly actuates the valves (5, 6) of the valves entry and exit (5, 7, 6, 8).   2. Leveling valve according to claim 1, characterized in that the valves (5, 6) are arranged in a common chamber (la) of the body, parallel to the surface of the member (12) for controlling the valves.   Leveling valve according to claims 1 and 2, characterized in   a) a free-running choke (16) is arranged between the inlet valve (5, 7) and the outlet valve (6, 8) on the one hand and the pneumatic spring connection (3) of somewhere else; b) the free-operation choke (16) is actuated by the valve-controlling member (12) with a predetermined clearance; c) the clearance between the free-acting choke (16) and the valve-controlling member (12) is dimensioned so that from a basic position the free-running choke (16) limits supplying and bleeding the pneumatic spring connection (3) for small deflections of the valve actuating member (12) and releasing them for large deviations, although a throttling is restored only after return at the base position from a large deviation; and d) the free-acting choke (16) is protected against inadvertent operation, at least over the clearance range between said   choke (16) and the valve actuator (12).   4. Leveling valve according to claim 3, characterized in that: a) the free operating choke (16) is constituted by an annular element, housed in rotation in a recess (15) of the control member (12) valves, adapted to the outer radius (17) of said choke (16); = b) a bore (3a) connected to the pneumatic spring connection (3) terminates in the annular surface of the recess (15); c) the free-acting choke (16) has on its outer radius (17) a first (21) and a second recess (22) which disengages the bore (3a), a surface located between the recesses (21 and 22) forming a throttling surface (18) bounded by two throttling edges (19, 20) and reducing the flow rate   compressed air in the bore (3a) on a given range of displacement.   of the valve actuating member (12) or   free operating glide (16); d) for establishing a frictional connection between the valve control member (12) and the free operating choke (16) -, a spring (24) disposed in the center of the latter against the recess (15) said choke (16) made of elastic material and elastically deformable as a result of making the second recess (22); and   e) a trainer (23) in the form of a stud fixed to the   valve control valve (12) enters the second recess.   (22) so that its application on surfaces of the latter, made in abutments (25, 26), allows the translation of   the free-running choke (16) relative to the link   its friction with the member (12) for controlling the valves.   Leveling valve according to claims 1 and 2, characterized   by a damping device (30, 31, 32, 33, 34, 35, 39, 40) which, on a fixed range corresponding to a fixed range of movement of the height-adjustable lever (11), delays the movement of the valve control member (12) and consequently the operation   of the inlet valve (5, 7) and the outlet valve (6, 8).   Leveling valve according to claim 5, characterized in that the damping device (30, 31, 32, 33, 34, 35, 39, 40) is   constituted by a mechanical damping element (30, 31, 32) and an element   hydraulic damper (34, 35, 39, 40).   7. Leveling valve according to claim 6, characterized in that a) the mechanical damping element (30, 31, 32) is constituted by a piston (33) housed in a barrel (30) and subjected to the action of a spring (32), the barrel (30) being connected to the lever (11);   b) one end of a control shaft (31) engages the sur-   rounded lower face of the piston (33) so that a movement of the lever (11) can be converted into a rotation of the control shaft (31) only when the stress exerted by the spring (32) is exceeded; and c) the other end of the control shaft (31) is integral in rotation with the valve control member (12) of the valve leveling.   8. leveling valve according to claim 6, characterized in that: a) the hydraulic damping element (34, 35, 39, 40) is constituted by a piston (35) housed in a barrel (34) and two chambers of damping (39, 40) filled with a liquid and opposing the movement of the piston (35) in both directions;   b) the tolerances of the piston (35) and the barrel (34) are   the slot between these two elements (34, 35) circulates the liquid discharged by a movement of the piston (35) of a damping chamber (39 or 40) in the other (40 or 39); c) a wide slot (35a or 35b) is provided in the piston (35) to allow rapid flow of the liquid from one damping chamber 39 or 40) into the other (40 or 39) in a return of the piston (35) and the opening of a valve flap (43 or 44); and   d) a drive bolt (36), triggering the movement of the piston   tone (35), establishes a connection between the latter and the   control (31) of the leveling valve.   9. Leveling valve according to any one of claims 1 to   8, characterized in that: a) the free-acting choke (16) is arranged so that its choke function acts only on the inlet valve (5, 7) within the chamber (la) of the body; b) the free-acting choke (16) is arranged so that its choke function acts only on the outlet valve (6, 8) within the chamber (la) of the body; c) the inlet valve (5, 7) and the outlet valve (6, 8 ') are arranged inside the chamber (la) of the body, d) the free operating choke (16) is arranged upstream of the inlet valve (5, 7); e) the free-operation choke (16) is arranged downstream of the outlet valve (6, 8); f) the free operating choke (16) is disposed outside the body (1); and g) the inlet valve (5, 7) and the outlet valve (6, 8) are   disposed outside the chamber (1a) of the body.   Leveling valve according to any one of claims 1 to   9, characterized in that the valve (5, 6) is held without fixing on the valve bore (7, 8) by the sole action of the spring (9, 10).   Leveling valve according to any one of claims 1 to , characterized in that:   a) one end of the valve (5, 6) pivots with transverse translation   dirty; b) the valve (5, 6) resting on a stop (50); and - c) the point of application of the spring force (9, 10) is between the stop (50) and the bore (7) of the inlet valve (5,   7 or the bore (8) of the outlet valve (6, 8).