Base valve assembly for damper

A damper includes a pressure tube, a piston assembly, a piston rod, a reserve tube, and a reserve chamber. The damper also includes a base valve assembly having a valve body and a compression disc assembly. The compression disc assembly engages a first end face of the valve body to restrict flow through at least one compression passage. The base valve assembly also includes a rebound disc assembly. The rebound disc assembly engages a second end face of the valve body to restrict flow through at least one rebound passage. The rebound disc assembly includes at least one rebound bending disc that directly engages the second end face to close the at least one rebound passage. The rebound bending disc bends in response to pressure within the at least one rebound passage to permit flow through the at least one rebound passage.

TECHNICAL FIELD

The present disclosure relates to a damper for a vehicle and, more particularly, to a base valve assembly for the damper.

BACKGROUND

A damper associated with a suspension system typically includes a pressure tube having a movable piston assembly therein and a reserve tube surrounding the pressure tube. During operation of the damper, the piston assembly slides within the pressure tube and displaces a working fluid within the pressure tube, and between the pressure tube and the reserve tube. Accordingly, a base valve assembly is provided between the pressure tube and the reserve tube in order to control fluid flow between the pressure tube and the reserve tube and tune compression and rebound characteristics of the damper as per user requirements.

However, in many situations, the base valve assembly may be tunable for a required compression characteristic of the damper whereas a rebound characteristic of the damper may be a constant ratio of the compression characteristic. As such, a rebound damping may always be dependent on a preselected compression damping, in turn, limiting independent tuning of the rebound characteristics relative to the compression characteristics of the damper. Also, the rebound damping may depend on a rod to bore ratio of the piston assembly and the pressure tube, in turn, limiting the rebound damping to be constant for a given size of the piston assembly and the pressure tube.

SUMMARY

In an aspect of the present disclosure, a damper is provided. The damper includes a pressure tube forming a working chamber. The damper includes a piston assembly disposed within the working chamber. The piston assembly divides the working chamber into an upper working chamber and a lower working chamber. The damper includes a piston rod attached to the piston assembly. The damper also includes a reserve tube disposed around the pressure tube. The reserve tube defines a reserve chamber between the pressure tube and the reserve tube. The damper further includes a base valve assembly fluidly disposed between the lower working chamber and the reserve chamber. The base valve assembly includes a valve body. The valve body defines at least one compression passage and at least one rebound passage. The base valve assembly also includes a compression disc assembly. The compression disc assembly engages a first end face of the valve body to restrict flow through the at least one compression passage. The base valve assembly further includes a rebound disc assembly. The rebound disc assembly engages a second end face of the valve body to restrict flow through the at least one rebound passage. The rebound disc assembly includes at least one rebound bending disc that directly engages the second end face to close the at least one rebound passage. The rebound bending disc bends in response to pressure within the at least one rebound passage to permit flow through the at least one rebound passage.

In another aspect of the present disclosure, a damper is provided. The damper includes a pressure tube forming a working chamber. The damper includes a piston assembly disposed within the working chamber. The piston assembly divides the working chamber into an upper working chamber and a lower working chamber. The damper includes a piston rod attached to the piston assembly. The damper includes a reserve tube disposed around the pressure tube. The reserve tube defines a reserve chamber between the pressure tube and the reserve tube. The damper includes an intermediate tube disposed between the pressure tube and the reserve tube. An intermediate chamber is defined between the intermediate tube and the pressure tube. The damper also includes an electronic valve fluidly coupled to the intermediate chamber and the reserve chamber. The electronic valve is adapted to control fluid flow between the intermediate chamber and the reserve chamber. The damper further includes a base valve assembly fluidly disposed between the lower working chamber and the reserve chamber. The base valve assembly includes a valve body. The valve body defines at least one compression passage and at least one rebound passage. The base valve assembly also includes a compression disc assembly. The compression disc assembly engages a first end face of the valve body to restrict flow through the at least one compression passage. The base valve assembly further includes a rebound disc assembly. The rebound disc assembly engages a second end face of the valve body to restrict flow through the at least one rebound passage. The rebound disc assembly includes at least one rebound bending disc that directly engages the second end face to close the at least one rebound passage. The rebound bending disc bends in response to pressure within the at least one rebound passage to permit flow through the at least one rebound passage.

In another aspect of the present disclosure, a damper is provided. The damper includes a pressure tube forming a working chamber. The damper includes a piston assembly disposed within the working chamber. The piston assembly divides the working chamber into an upper working chamber and a lower working chamber. The damper includes a piston rod attached to the piston assembly. The damper also includes a reserve tube disposed around the pressure tube. The reserve tube defines a reserve chamber between the pressure tube and the reserve tube. The damper further includes a base valve assembly fluidly disposed between the lower working chamber and the reserve chamber. The base valve assembly includes an elongate member having a first end and a second end opposite to the first end. The elongate member includes a head at the first end. The base valve assembly includes a nut threadably engaged with the elongate member proximate the second end. The base valve assembly includes a valve body disposed around the elongate member. The valve body defines at least one compression passage and at least one rebound passage. The base valve assembly also includes a compression disc assembly disposed around the elongate member. The compression disc assembly engages a first end face of the valve body to restrict flow through the at least one compression passage. The base valve assembly further includes a rebound disc assembly disposed around the elongate member. The rebound disc assembly engages a second end face of the valve body to restrict flow through the at least one rebound passage. The rebound disc assembly includes at least one rebound bending disc that directly engages the second end face to close the at least one rebound passage. The rebound bending disc bends in response to pressure within the at least one rebound passage to permit flow through the at least one rebound passage. The valve body, the compression disc assembly and the rebound disc assembly are clamped between the head and the nut.

DETAILED DESCRIPTION

Wherever possible, the same reference numbers will be used throughout the drawings to refer to same or like parts. Referring toFIG. 1, a perspective view of an exemplary vehicle100is illustrated. In the illustrated embodiment, the vehicle100is a passenger car. In other embodiments, the vehicle100may be any other vehicle, such as a Sports Utility Vehicle (SUV), a Multi Utility Vehicle (MUV), a truck, a bus, and so on, based on application requirements, having a front suspension system and/or a rear suspension system. Also, the vehicle100may be associated with any industry including, but not limited to, transportation, agriculture, construction, mining, material handling, and so on, based on application requirements.

The vehicle100includes a front suspension system102, a rear suspension system104, and a body106. The front suspension system102includes a transversely extending front axle assembly (not shown) adapted to operatively support a pair of front wheels108of the vehicle100. The front axle assembly is operatively connected to the body106by means of a pair of dampers110and a pair of helical coil springs112. The rear suspension system104includes a transversely extending rear axle assembly (not shown) adapted to operatively support a pair of rear wheels114of the vehicle100. The rear axle assembly is operatively connected to the body106by means of a pair of dampers116and a pair of helical coil springs118. The dampers110,116are adapted to dampen relative motion of an unsprung mass, i.e., the front suspension system102and the rear suspension system104, of the vehicle100, and a sprung mass, i.e., the body106of the vehicle100.

The dampers110,116will now be explained with reference to the damper110associated with the front suspension system102. It should be noted that the damper116associated with the rear suspension system104may have a configuration, structure, construction, and operation similar to that of the damper110. Referring toFIGS. 2A and 2B, a schematic representation of the damper110is illustrated. The damper110includes a pressure tube202. The pressure tube202is adapted to be operatively coupled to the unsprung mass of the vehicle100, such as the front suspension system102, via a connector204. The pressure tube202has a substantially hollow and elongate configuration defining a working chamber206therein. The pressure tube202is adapted to receive a fluid in the working chamber206. The fluid may be any working fluid, such as hydraulic oil.

The damper110also includes a piston assembly208. The piston assembly208is disposed slidably in the working chamber206of the pressure tube202. Accordingly, the piston assembly208divides the working chamber206in an upper working chamber210and a lower working chamber212. The upper working chamber210and the lower working chamber212are disposed on opposite sides of the piston assembly208. The piston assembly208is adapted to slide within the working chamber206in a direction “D1” during a compression stroke of the damper110, and in a direction “D2” during a rebound stroke of the damper110.

The piston assembly208includes at least one piston compression passage214. The piston compression passage214is fluidly coupled to each of the upper working chamber210and the lower working chamber212. Additionally, the piston assembly208includes a piston compression valve216disposed in the piston compression passage214. The piston compression valve216is adapted to selectively allow flow of fluid from the lower working chamber212to the upper working chamber210through the piston compression passage214during the compression stroke of the damper110, as shown by an arrow222. The piston compression valve216may be any valve assembly, such as a check valve assembly, a diaphragm valve assembly, a disc valve assembly, and so on, based on application requirements.

The piston assembly208also includes at least one piston rebound passage218. The piston rebound passage218is fluidly coupled to each of the upper working chamber210and the lower working chamber212. Additionally, the piston assembly208includes a piston rebound valve220disposed in the piston rebound passage218. The piston rebound valve220is adapted to selectively allow flow of fluid from the upper working chamber210to the lower working chamber212through the piston rebound passage218during the rebound stroke of the damper110, as shown by an arrow224. The piston rebound valve220may be any valve assembly, such as a check valve assembly, a diaphragm valve assembly, a disc valve assembly, and so on, based on application requirements. It should be noted that the piston assembly208may include additional components not described herein, such as one or more sealing elements, spring elements, conduits, couplers, fasteners, and so on, based on application requirements.

The damper110also includes a piston rod226attached to the piston assembly208. The piston rod226extends through the upper working chamber210of the pressure tube202and out of an upper end228of the damper110. The piston rod226is adapted to be operatively coupled to the sprung mass of the vehicle100, such as the body106, via a connector230. The damper110also includes a reserve tube232. The reserve tube232is disposed around the pressure tube202and defines a reserve chamber234between the pressure tube202and the reserve tube232. The reserve chamber234is fluidly coupled to the lower working chamber212of the pressure tube202via a base valve assembly236. Accordingly, the base valve assembly236allows flow of fluid from the lower working chamber212to the reserve chamber234during the compression stroke of the damper110, as shown by an arrow238. Also, the base valve assembly236allows flow of fluid from the reserve chamber234into the lower working chamber212during the rebound stroke of the damper110, as shown by an arrow240. The base valve assembly236will be explained in more detail later.

The damper110also includes an intermediate tube242. The intermediate tube242is disposed between the pressure tube202and the reserve tube232. Accordingly, the intermediate tube242defines an intermediate chamber244disposed between the intermediate tube242and the pressure tube202. The damper110also includes an electronic valve246fluidly coupled to the intermediate chamber244and the reserve chamber234. The electronic valve246is adapted to control flow of fluid between the intermediate chamber244and the reserve chamber234. More specifically, the electronic valve246is adapted to selectively allow flow of fluid from the intermediate chamber244to the reserve chamber234therethrough during the rebound stroke of the damper110, as shown by an arrow258. The electronic valve246may be any electronically operated fluid control valve, such as a solenoid valve. In some embodiments, the electronic valve246is a variable flow control valve.

Additionally, the damper110also includes an upper cap248disposed at the upper end228of the damper110. The upper cap248is adapted to seal each of the pressure tube202, the upper working chamber210, the reserve tube232, the reserve chamber234, and the intermediate chamber244at the upper end228. The upper cap248is also adapted to slidably receive the piston rod226therethrough. The damper110also includes a lower cap250disposed at a lower end252of the damper110. The lower cap250is adapted to seal each of the reserve tube232and the reserve chamber234at the lower end252.

The base valve assembly236is also adapted to seal the intermediate chamber244at the lower end252. More specifically, a portion of the base valve assembly236extends laterally in order to couple with each of the pressure tube202and the intermediate tube242and, thus, seal the intermediate chamber244at the lower end252. It should be noted that the configuration of the damper110, as shown inFIGS. 2A and 2B, is exemplary in nature and alternative configurations may be possible within the scope of the present disclosure.

The damper110also includes the base valve assembly236. The base valve assembly236will be hereinafter interchangeably referred to as the “assembly236”. The assembly236is disposed within the pressure tube202and adjacent to the lower end252of the damper110. The assembly236is fluidly disposed between the lower working chamber212and the reserve chamber234. Accordingly, the assembly236is adapted to selectively allow flow of fluid from the lower working chamber212to the reserve chamber234during the compression stroke of the damper110, as shown by the arrow238. Also, the assembly236is adapted to selectively allow flow of fluid from the reserve chamber234to the lower working chamber212during the rebound stroke of the damper110, as shown by the arrow240.

It should be noted that the damper110, as shown inFIGS. 2A and 2B, is exemplary in nature, and the damper110may have alternative configurations within the scope of the present disclosure. For example, the damper110may include a hydraulic compression stop assembly (not shown). Further, the damper110may include a rod guide assembly (not shown) disposed near the upper end228of the damper110. As such, the damper110may have any configuration and may include additional components not described herein, based on application requirements.

Referring toFIG. 3, a cross-sectional view of the assembly236is illustrated. The assembly236includes an elongate member302defining a longitudinal axis X-X′ of the assembly236. The elongate member302includes a first end304and a second end306. The second end306is disposed opposite to the first end304along the longitudinal axis X-X′. In the illustrated embodiment, the elongate member302is a machine bolt. Accordingly, the elongate member302includes a head308disposed on the first end304, and a nut310threadably engaged with the elongate member302proximate the second end306. In other embodiments, the elongate member302may be any other fastener, such as a stud bolt. In such a situation, the elongate member302may include a nut (not shown) disposed threadably proximate the first end304of the elongate member302, and the nut310disposed threadably proximate the second end306.

The assembly236also includes a valve body312. The valve body312will be hereinafter interchangeably referred to as the “body312”. The body312is disposed around the elongate member302and attached to the pressure tube202. More specifically, in the illustrated embodiment, the body312includes a lower valve body314and an upper valve body316. The lower valve body314is disposed proximate the first end304of the elongate member302. The upper valve body316is disposed adjacent to the lower valve body314and proximate the second end306of the elongate member302. Accordingly, the upper valve body316is disposed in the lower working chamber212of the pressure tube202(shown inFIGS. 2A and 2B). The lower and upper valve bodies314,316includes axially aligned bores (not shown) to receive the elongate member302therethrough.

The assembly236also includes at least one compression passage318. The compression passage318is defined by and extends through each of the lower valve body314and the upper valve body316. More specifically, the compression passage318includes a first section320and a second section322. The first section320is defined by the lower valve body314, while the second section322is defined by the upper valve body316. The first section320is disposed in the lower valve body314and defines a compression passage outlet324on a first end face326of the lower valve body314. The compression passage outlet324will be hereinafter interchangeably referred to as the “compression outlet324”. In the illustrated embodiment, an outlet axis A-A′ defined by the compression outlet324is substantially parallel to the longitudinal axis X-X′. In other embodiments, the outlet axis A-A′ may be inclined at any other angle relative to the longitudinal axis X-X′.

The second section322is disposed in the upper valve body316of the body312and defines a compression passage inlet328on a side surface330of the upper valve body316. The compression passage inlet328will be hereinafter interchangeably referred to as the “compression inlet328”. In the illustrated embodiment, an inlet axis B-B′ defined by the compression inlet328is substantially perpendicular to the longitudinal axis X-X′ and the outlet axis A-A′. Accordingly, the compression inlet328is orientated at approximately 90 degrees to the compression outlet324. The compression passage318may therefore be substantially L-shaped and may change a flow direction of the fluid. In other embodiments, the inlet axis B-B′ may be inclined at any other angle relative to the longitudinal axis X-X′ and the outlet axis A-A′.

The compression inlet328is fluidly coupled to the lower working chamber212of the pressure tube202. Accordingly, the compression inlet328is adapted to receive flow of fluid from the lower working chamber212into the second section322and the first section320of the compression passage318. The compression outlet324is fluidly coupled to the reserve chamber234of the damper110(shown inFIGS. 2A and 2B). Accordingly, the compression outlet324is adapted to allow flow of fluid from the first section320to the reserve chamber234. It should be noted that in the accompanying figure although only one compression passage318is illustrated, the body312may include multiple compression passages. In such a situation, each of the multiple compression passages may be disposed angularly spaced from each other and radially around the elongate member302. Accordingly, the first end face326of the lower valve body314may include multiple compression outlets, such that each of the multiple compression outlets may be disposed angularly spaced from each other and radially around the elongate member302. Also, the side surface330of the upper valve body316may include multiple compression inlets, such that each of the multiple compression inlets may be disposed angularly spaced from each other and radially around the elongate member302.

The assembly236also includes a compression disc assembly332. The compression disc assembly332is adapted to engage with the first end face326of the body312to restrict flow through the compression passage318and will be explained in more detail later. The compression disc assembly332is disposed around the elongate member302and between the lower valve body314and the first end304of the elongate member302. The compression disc assembly332includes at least one compression fulcrum disc334disposed between the lower valve body314and the first end304of the elongate member302. More specifically, the compression fulcrum disc334is disposed adjacent to the first end304of the elongate member302. In the illustrated embodiment, the compression disc assembly332includes a single compression fulcrum disc334. In other embodiments, the compression disc assembly332may include multiple compression fulcrum discs. In such a situation, each of the multiple compression fulcrum discs may be disposed adjacent to one another in a stacked configuration. The compression fulcrum disc334defines a diameter “CD1” and a thickness “CT1” thereof.

The compression disc assembly332also includes at least one compression preload disc336disposed between the lower valve body314and the first end304of the elongate member302. More specifically, the compression preload discs336are disposed adjacent to the lower valve body314. In the illustrated embodiment, the compression disc assembly332includes two compression preload discs336disposed adjacent to one another in a stacked configuration. In other embodiments, the compression disc assembly332may include single or multiple compression preload discs. Each of the compression preload discs336defines a diameter “CD2” and a thickness “CT2” thereof. In the illustrated embodiment, the diameter “CD2” is approximately equal to the diameter “CD1” of the compression fulcrum disc334. In other embodiments, the diameter “CD2” may be greater or smaller than the diameter “CD1”. Also, in the illustrated embodiment, the thickness “CT2” is smaller than the thickness “CT1” of the compression fulcrum disc334. In other embodiments, the thickness “CT2” may be equal to or greater than the thickness “CT1”.

The compression disc assembly332also includes a compression bending disc338. The compression bending disc338is disposed between the compression fulcrum disc334and the compression preload disc336. The compression bending disc338extends laterally relative to the longitudinal axis X-X′ in order to extend over the compression outlet324disposed on the lower valve body314. The compression bending disc338directly engages with the lower valve body314to close the compression outlet324of the compression passage318. The compression bending disc338is adapted to bend in a direction “D3” in order to open the compression passage318and will be explained in more detail later. The compression bending disc338defines a diameter “CD3” and a thickness “CT3” thereof. The diameter “CD3” is greater than the diameter “CD1” of the compression fulcrum disc334and the diameter “CD2” of the compression preload disc336. Also, the thickness “CT3” is smaller than the thickness “CT1” of the compression fulcrum disc334and the thickness “CT2” of the compression preload disc336.

The compression disc assembly332further includes one or more additional bending discs340. The additional bending discs340are disposed between the compression bending disc338and the compression fulcrum disc334. In the illustrated embodiment, the compression disc assembly332includes three additional bending discs340. In other embodiments, the compression disc assembly332may include single or multiple additional bending discs, based on application requirements. In yet some embodiments, the additional bending disc340may be omitted, such that the compression bending disc338may be disposed between and adjacent to each of the compression fulcrum disc334and the compression preload disc336. Each of the additional bending discs340defines a diameter “CD4” and a thickness “CT4”.

In the illustrated embodiment, the diameter “CD4” of each of the additional bending discs340is equal to one another. Further, each of the additional bending discs340may be identical to the compression bending disc338. In other embodiments, the diameter “CD4” of one or more of the additional bending discs340may be different from one another. Also, in the illustrated embodiment, the diameter “CD4” is approximately equal to the diameter “CD3” of the compression bending disc338. In other embodiments, the diameter “CD4” may be greater or smaller than the diameter “CD3”. In the illustrated embodiment, the thickness “CT4” of each of the additional bending discs340is equal to one another. In other embodiments, the thickness “CT4” of one or more of the additional bending discs340may be different from one another. Also, in the illustrated embodiment, the thickness “CT4” is approximately equal to the thickness “CT3” of the compression bending disc338. In other embodiments, the thickness “CT4” may be greater or smaller than the thickness “CT3”.

The assembly236also includes a compression land342disposed on the lower valve body314. More specifically, the compression land342is disposed on the first end face326of the lower valve body314. The compression land342extends away from the first end face326substantially parallel to the longitudinal axis X-X′. Also, the compression land342is disposed on the first end face326adjacent to the compression outlet324. Further, the compression land342is disposed radially around the elongate member302on the first end face326of the lower valve body314. The compression bending disc338is adapted to directly engage with the compression land342in order to close the compression outlet324of the compression passage318.

The assembly236also includes at least one rebound passage344. The rebound passage344is spaced from the at least one compression passage318. The rebound passage344is defined by and extends through each of the lower valve body314and the upper valve body316of the body312. More specifically, the rebound passage344includes a first section346and a second section348. The first section346is disposed in the lower valve body314and defines a rebound passage inlet350on the first end face326of the lower valve body314. The rebound passage inlet350will be hereinafter interchangeably referred to as the “rebound inlet350”.

In the illustrated embodiment, an inlet axis C-C′ defined by the rebound inlet350is substantially parallel to the longitudinal axis X-X′. In other embodiments, the inlet axis C-C′ may be inclined at any other angle relative to the longitudinal axis X-X′. The second section348is disposed in the upper valve body316and defines a rebound passage outlet352on a second end face354of the upper valve body316. The rebound passage outlet352will be hereinafter interchangeably referred to as the “rebound outlet352”. In the illustrated embodiment, an outlet axis D-D′ defined by the rebound outlet352is substantially parallel to the longitudinal axis X-X′ and the inlet axis C-C′. Accordingly, the rebound inlet350is orientated at approximately 180 degrees to the rebound outlet352. In other embodiments, the outlet axis D-D′ may be inclined at any other angle relative to the longitudinal axis X-X′ and the inlet axis C-C′. Also, in the illustrated embodiment, the outlet axis D-D′ is offset relative to the inlet axis C-C′. In other embodiments, the outlet axis D-D′ may be linearly aligned with the inlet axis C-C′.

The rebound inlet350is fluidly coupled to the reserve chamber234of the damper110. Accordingly, the rebound inlet350is adapted to receive flow of fluid from the reserve chamber234into the first section346and the second section348of the rebound passage344. The rebound outlet352is fluidly coupled to the lower working chamber212of the pressure tube202. Accordingly, the rebound outlet352is adapted to allow flow of fluid from the second section348to the lower working chamber212. It should be noted that in the accompanying figure although only one rebound passage344is illustrated, the body312may include multiple rebound passages. In such a situation, each of the multiple rebound passages may be disposed angularly spaced from each other and radially around the elongate member302. Accordingly, the first end face326of the lower valve body314may include multiple rebound inlets, such that each of the multiple rebound inlets may be disposed angularly spaced from each other and radially around the elongate member302. Also, the second end face354of the upper valve body316may include multiple rebound outlets, such that each of the multiple rebound outlets may be disposed angularly spaced from each other and radially around the elongate member302.

Additionally, the assembly236also includes a number of legs370(only two legs shown inFIG. 3). The legs370are disposed on the side surface330of the lower valve body314and extend parallel to the longitudinal axis X-X′. The legs370are disposed circumferentially spaced apart on the side surface330of the lower valve body314. As such, a number of notches (not shown) are formed between each of the legs370. The notches are fluidly coupled to the compression outlet324and the rebound inlet350. Accordingly, the notches provide fluid communication between the compression passage318and the reserve chamber234via the compression outlet324, and the rebound passage344and the reserve chamber234via the rebound inlet350. The legs370are adapted to be coupled to each of the pressure tube202and the intermediate tube242adjacent to the lower end252.

The assembly236also includes a rebound disc assembly356. The rebound disc assembly356is adapted to engage the second end face354of the body312to restrict flow through the rebound passage344and will be explained in more detail later. The rebound disc assembly356is disposed around the elongate member302and between the upper valve body316and the second end306of the elongate member302. The rebound disc assembly356includes at least one rebound fulcrum disc358disposed between the upper valve body316and the second end306of the elongate member302. More specifically, the rebound fulcrum disc358is disposed adjacent to the second end306of the elongate member302. In the illustrated embodiment, the rebound disc assembly356includes a single rebound fulcrum disc358. In other embodiments, the rebound disc assembly356may include multiple rebound fulcrum discs. In such a situation, each of the multiple rebound fulcrum discs may be disposed adjacent to one another in a stacked configuration. The rebound fulcrum disc358defines a diameter “RD1” and a thickness “RT1” thereof.

The rebound disc assembly356also includes at least one rebound preload disc360disposed between the upper valve body316and the second end306of the elongate member302. More specifically, the rebound preload disc360is disposed adjacent to the upper valve body316. In the illustrated embodiment, the rebound disc assembly356includes a single rebound preload disc360. In other embodiments, the rebound disc assembly356may include multiple rebound preload discs. In such a situation, each of the multiple rebound preload discs may be disposed adjacent to one another in a stacked configuration. The rebound preload disc360defines a diameter “RD2” and thickness “RT2” thereof. In the illustrated embodiment, the diameter “RD2” is approximately equal to the diameter “RD1” of the rebound fulcrum disc358. In other embodiments, the diameter “RD2” may be greater or smaller than the diameter “RD1”. Also, in the illustrated embodiment, the thickness “RT2” is smaller than the thickness “RT1” of the rebound fulcrum disc358. In other embodiments, the thickness “RT2” may be equal to or greater than the thickness “RT1”.

The rebound disc assembly356also includes a rebound bending disc362. The rebound bending disc362directly engages the second end face354to close the rebound passage344and will be explained in more detail later. The rebound bending disc362is disposed between the rebound fulcrum disc358and the rebound preload disc360. The rebound bending disc362extends laterally relative to the longitudinal axis X-X′ in order to extend over the rebound outlet352disposed on the upper valve body316. The rebound bending disc362directly engages with the upper valve body316to close the rebound outlet352of the rebound passage344. The rebound bending disc362is adapted to bend in a direction “D4” in response to pressure within the rebound passage344to permit flow through the rebound passage344and will be explained in more detail later. The rebound bending disc362defines a diameter “RD3” and a thickness “RT3” thereof. The diameter “RD3” is greater than the diameter “RD1” of the rebound fulcrum disc358and the diameter “RD2” of the rebound preload disc360. Also, the thickness “RT3” is smaller than the thickness “RT1” of the rebound fulcrum disc358and the thickness “RT2” of the rebound preload disc360.

The rebound disc assembly356further includes one or more additional bending discs364. The additional bending discs364are disposed between the rebound bending disc362and the rebound fulcrum disc358. In the illustrated embodiment, the rebound disc assembly356includes two additional bending discs364. In other embodiments, the rebound disc assembly356may include single or multiple additional bending discs, based on application requirements. In yet some embodiments, the additional bending disc364may be omitted, such that the rebound bending disc362may be disposed between and adjacent to each of the rebound fulcrum disc358and the rebound preload disc360. Each of the additional bending discs364defines a diameter “RD4” and a thickness “RT4”.

In the illustrated embodiment, the diameter “RD4” of each of the additional bending discs364is equal to one another. Further, each of the additional bending discs364may be identical to the rebound bending disc362. In other embodiments, the diameter “RD4” of one or more of the additional bending discs364may be different from one another. Also, in the illustrated embodiment, the diameter “RD4” is approximately equal to the diameter “RD3” of the rebound bending disc362. In other embodiments, the diameter “RD4” may be greater or smaller than the diameter “RD3”. In the illustrated embodiment, the thickness “RT4” of each of the additional bending discs364is equal to one another. In other embodiments, the thickness “RT4” of one or more of the additional bending discs364may be different from one another. Also, in the illustrated embodiment, the thickness “RT4” is approximately equal to the thickness “RT3” of the rebound bending disc362. In other embodiments, the thickness “RT4” may be greater or smaller than the thickness “RT3”.

The assembly236also includes a rebound land366disposed on the upper valve body316. More specifically, the rebound land366is disposed on the second end face354of the upper valve body316. The rebound land366extends away from the second end face354substantially parallel to the longitudinal axis X-X′. Also, the rebound land366is disposed on the second end face354adjacent to the rebound outlet352. Further, the rebound land366is disposed radially around the elongate member302on the second end face354of the upper valve body316. The rebound bending disc362is adapted to directly engage with the rebound land366in order to close the rebound outlet352of the rebound passage344.

The assembly236also includes a washer element368. The washer element368is disposed around the elongate member302and between the nut310and the rebound disc assembly356. More specifically, the washer element368is disposed adjacent to each of the nut310and the rebound fulcrum disc358. The washer element368may be any washer or spacer, such as a rubber washer, a metallic washer, and so on, based on application requirements. In an embodiment, each of the body312, the compression disc assembly332, and the rebound disc assembly356is press-fitted to the elongate member302. Further, each of the body312, the compression disc assembly332, and the rebound disc assembly356is clamped between the head308and the nut310of the elongate member302.

A combination of the washer element368, the press-fitting and the clamping provides a secure and stiff coupling of elements of the assembly236around the elongate member302and between the first end304and the second end306of the elongate member302. For example, the lower valve body314, the upper valve body316, the compression fulcrum disc334, the compression preload disc336, the compression bending disc338, the additional bending discs340, the rebound fulcrum disc358, the rebound preload disc360, the rebound bending disc362, and the additional bending discs364are clamped together around the elongate member302and between the first end304and the second end306of the elongate member302.

In an assembled position of the assembly236, as shown in the accompanying figure, the compression bending disc338engages and rests against the compression land342. Accordingly, the compression outlet324is closed by the compression bending disc338. During the compression stroke of the damper110, as the piston assembly208travels in the direction “D1”, the fluid flows from the lower working chamber212into the compression passage318through the compression inlet328. Due to the compression stroke, a pressure of fluid within the compression passage318may increase above a threshold bending load of the compression bending disc338. As such, the compression bending disc338and/or the additional bending discs340may bend in the direction “D3”. Accordingly, the compression outlet324may open in order to allow flow of fluid from the compression passage318into the reserve chamber234.

Also, in the assembled position of the assembly236, as shown in the accompanying figure, the rebound bending disc362engages and rests against the rebound land366. Accordingly, the rebound outlet352is closed by the rebound bending disc362. During the rebound stroke of the damper110, as the piston assembly208travels in the direction “D2”, the fluid flows from the reserve chamber234into the rebound passage344through the rebound inlet350. Due to the rebound stroke, a pressure of fluid within the rebound passage344may increase above a threshold bending load of the rebound bending disc362. As such, the rebound bending disc362and/or the additional bending discs364may bend in the direction “D4”. Accordingly, the rebound outlet352may open in order to allow flow of fluid from the rebound passage344into the lower working chamber212.

The threshold bending load of the rebound bending disc362may be tuned in multiple ways. In one embodiment, parameters of the rebound fulcrum disc358may be adjusted in order to vary the threshold bending load of the rebound bending disc362. For example, in one situation, the diameter “RD1” of the rebound fulcrum disc358may be relatively increased in order to provide a relatively higher bending diameter of the rebound bending disc362and a relatively higher threshold bending load of the rebound bending disc362. In another situation, the diameter “RD1” of the rebound fulcrum disc358may be relatively decreased in order to provide a relatively lower bending diameter of the rebound bending disc362and a relatively lower threshold bending load of the rebound bending disc362.

In another embodiment, parameters of the rebound preload disc360may be adjusted in order to vary the threshold bending load of the rebound bending disc362. For example, in one situation, the thickness “RT2” of the rebound preload disc360may be relatively increased in order to provide a relatively higher preload on the rebound bending disc362and a relatively higher threshold bending load of the rebound bending disc362. In another situation, the thickness “RT2” of the rebound preload disc360may be relatively decreased in order to provide a relatively lower preload on the rebound bending disc362and a relatively lower threshold bending load of the rebound bending disc362. In another situation, the number of the rebound preload discs360may be increased in order to provide a relatively higher preload on the rebound bending disc362and a relatively higher threshold bending load of the rebound bending disc362. In yet another situation, the number of the rebound preload discs360may be decreased in order to provide a relatively lower preload on the rebound bending disc362and a relatively lower threshold bending load of the rebound bending disc362.

In another embodiment, parameters of the rebound bending disc362may be adjusted in order to vary the threshold bending load of the rebound bending disc362. For example, in one situation, the thickness “RT3” of the rebound bending disc362may be relatively increased in order to provide a relatively higher threshold bending load of the rebound bending disc362. In another situation, the thickness “RT3” of the rebound bending disc362may be relatively decreased in order to provide a relatively lower threshold bending load of the rebound bending disc362.

In yet another embodiment, parameters of the additional bending discs364may be adjusted in order to vary the threshold bending load of the rebound bending disc362. For example, the thickness “RT4” of the one or more additional bending discs364may be relatively increased in order to provide a relatively higher threshold bending load of the rebound bending disc362. In another situation, the thickness “RT4” of the one or more additional bending discs364may be relatively decreased in order to provide a relatively lower threshold bending load of the rebound bending disc362. In another situation, the number of the additional bending discs364may be increased in order to provide a relatively higher threshold bending load of the rebound bending disc362. In yet another situation, the number of the additional bending discs364may be decreased in order to provide a relatively lower threshold bending load of the rebound bending disc362.

The assembly236provides a simple, effective, and cost-efficient method to provide independent tuning of the damping characteristics of the rebound stroke relative to the damping characteristics of the compression stroke of the base valve assembly236. More specifically, parameters of each of the rebound fulcrum disc358, the rebound preload disc360, the rebound bending disc362, and the additional bending discs364may be varied in order to tune the damping characteristics of the assembly236for the rebound stroke independently of that of the compression stroke for a desired soft or firm setup of the damper110. Also, the damping characteristics of the rebound stroke of the damper110may be tuned independently of a rod to bore ratio of the piston rod226and the pressure tube202. Accordingly, the assembly236provides independent comfort tuning for semi-active dampers, such as the damper110employing the electronic valve246.

For example, the rebound disc assembly356of the assembly236may provide independent tuning of soft damping characteristics of the damper110for the rebound stroke. The piston assembly208may provide independent tuning of soft damping characteristics of the damper110in the compression stroke. Also, the piston assembly208may provide independent tuning of firm damping characteristics of the damper110in the rebound stroke. Further, the compression disc assembly332of the assembly236may provide independent tuning of firm damping characteristics of the damper110for the compression stroke. Additionally, the electronic valve246may provide tuning of soft damping characteristics of the damper110in both the compression stroke and the rebound stroke.

Also, the assembly236includes the rebound land366that engages radially with the rebound bending disc362. As such, the rebound land366provides a gradual and smooth opening of the rebound outlet352during bending of the rebound bending disc362and/or the additional bending discs364, in turn, providing improved tuning of the damping characteristics of the rebound stroke of the assembly236. Additionally, the assembly236may provide an improved and direct response of the damper110relative to a stroke input, in turn, providing improved performance. In some cases, the assembly236may also enable usage of a simple on/off valve as an alternative to the electronic valve246, in turn, reducing system complexity and costs.

Further, the clamped and press-fitted configuration of the body312, the compression disc assembly332, and the rebound disc assembly356between the head308and the nut310of the elongate member302provides a substantially reduced operational noise compared to a conventional valve assembly having spring biased valving elements. The assembly236may be retrofitted in any damper with little or no modification to existing system, in turn, providing improved usability, flexibility, and compatibility. Also, the assembly236includes simple and readily available components, such as the elongate member302, components of each of the compression disc assembly332and the rebound disc assembly356, and so on, in turn, reducing complexity and costs.