Patent Description:
Vehicles, such as automobiles, typically have a suspension system that includes absorber units that are mounted between wheels of the vehicle and a vehicle body or substructure. The suspension system is generally configured based on vehicle integration to keep wheels in contact with a driving surface by absorbing energy from forces on the wheels or other portions of the vehicle. As technology continues to evolve, various types of absorber units have been developed. One particularly popular type of absorber unit is configured to be operable in one of two different stiffness settings. The two different stiffness settings may also be known as "comfort mode" and "sport mode," respectfully.

One such prior art absorber unit is disclosed in <CIT>. The absorber unit includes a piston assembly disposed on a center axis. The piston assembly includes a piston rod disposed on the center axis and attached to a piston head. A regulator is attached to the piston rod and defines a compartment to receive the piston head. The regulator has a first aperture and a second aperture. A restrictor divides the compartment into a first and second portion. An actuator is disposed in the compartment and movable between an opened and a closed position. A coil is disposed about a core for generating an electromagnetic field to switch between the operational stiffness settings. When switching between stiffness settings, instability and system behavior deviates from either comfort or sport modes as a result of a magnetic force ripple reacting to a varying input frequency to the coil.

Accordingly, there is a continuing desire to improve upon the operational framework and efficiency of suspension systems that offer switchable modes of stiffness with a reduction in force ripple reaction. Document <CIT> discloses a piston valve device of damper using magneto-rheological fluid. A piston valve apparatus comprises a core having a through hole including the threaded part, a flange, and a fitting sill; a bobbin installed around the core; a solenoid installed in the bobbin to form the magnetic field in applying current; a pole piece fitted from the lower part of the core to the fitting sill to support the lower part of the bobbin and to control damping force by forming the magnetic path flowing the magnetic field from the solenoid; a piston rod combined with the threaded part of the through hole of the core, and composed of a cable passage; a cable electrically connected to the solenoid via the through hole of the core from the cable passage of the piston rod; an upper plate having plural oil pass holes, and keeping the concentricity of the piston rod and the piston valve with fitting to the upper flange of the core; a supporter fitted to the lower part of the core to support the core and the pole piece; an inverse U-shaped flux ring composed of plural oil pass holes, and combined with the upper part of the upper plate to keep the closed loop of the magnetic field from the solenoid; an upper seal fitted to the upper plate to prevent outflow of magneto-rheological fluid; a cap nut thread-connected to the lower part of the core to combine the piston valve; and a piston band combined with the upper edge of the flux ring. Document <CIT> discloses a dual ride damper assembly. A piston assembly for a damper includes a main piston disposed on a center axis. A piston rod is attached to the main piston. A regulator extends between the piston rod and the main piston defining a compartment. The regulator has at least one first aperture and at least one second aperture. A restrictor divides the compartment into a first and second portion. An actuator having a core is disposed in the first portion movable between an opened and a closed position. The restrictor includes a sleeve disposed in the compartment and attached to the regulator. The sleeve defines a hole in fluid communication with the first and second portions and flares outwardly in the first portion toward the regulator to define a slanted edge extending at an oblique angle relative to the center axis to allow the working fluid to flow smoothly thereby limiting noises generated.

The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter that form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other embodiments for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such embodiments do not depart from the invention as set forth in the appended claims. This section provides a general summary of the disclosure and is not to be interpreted as a complete and comprehensive listing of all of the objects, aspects, features and advantages associated with the present disclosure.

The invention provides for suspension system with a solenoid assembly that improves upon the operational framework and efficiency of suspension systems that offer switchable modes of stiffness by providing an induction plate that reduces or eliminates magnetic force ripple caused by a varying input frequency to a coil.

It is one unclaimed aspect of the present invention to provide a solenoid assembly of a suspension system of an associated vehicle. The solenoid assembly comprises a core including a core head and a core body. A spool extends about the core body and defines a space. A coil is wrapped around the spool within the space and an induction plate is at least partially located between the spool and the core head.

It is another aspect of the present invention to provide a suspension system of an associated vehicle. The suspension system comprises an outer reservoir tube extending along an axis between a first end and a second end and defining a chamber. A piston assembly is at least partially located in the chamber. The piston assembly includes a piston rod and a piston head. A solenoid assembly is connected to the piston rod and includes a body defining a compartment. The solenoid assembly comprises a core including a core head and a core body, and located in the compartment. A spool extends about the core body and defines a space. A coil is wrapped around the spool within the space. An induction plate is at least partially located between the spool and the core head. An actuator is at least partially located in the compartment adjacent to the core and movable between a closed position and an open position, wherein the body defines at least one first aperture and at least one second aperture axially spaced from the at least one first aperture, wherein in the closed position, the actuator restricts a fluid flow from at least one of the first aperture and the second aperture to provide a stiffer damping property, and in the open position, permits the fluid flow through the at least one first aperture and the at least one second aperture to provide a less-stiff damping property.

In general, the subject embodiments are directed to a suspension system of an associated vehicle and in particular to the solenoid assembly thereof.

However, the example embodiments are only provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art.

Referring to the drawing, wherein like numerals indicate corresponding parts throughout the several views, a suspension system including a solenoid assembly is provided. The solenoid assembly improves upon the operational framework and efficiency of suspension systems that offer switchable modes of stiffness by providing an induction plate that reduces or eliminates magnetic force ripple that is caused by a varying input frequency to a coil.

With initial reference to <FIG>, the suspension system <NUM> includes an outer reservoir tube <NUM> defining a chamber <NUM>, <NUM>. The outer reservoir tube <NUM> extends along an axis A between a first end <NUM> and a second end <NUM>. The suspension system <NUM> includes a piston assembly <NUM> located in the chamber <NUM>, <NUM> and extending along the axis A. The piston assembly <NUM> includes a piston rod <NUM> extending to a piston head <NUM> that is sized similar to an inner diameter of the reservoir tube <NUM>. The piston head <NUM> divides the chamber <NUM>, <NUM> into a compression chamber <NUM> and a rebound chamber <NUM>. The compression chamber <NUM> is located between the second end <NUM> and the piston head <NUM> and the rebound chamber <NUM> is located between the first end <NUM> and the piston head <NUM>. In operation, the piston head <NUM> travels from the first end <NUM> towards the second end <NUM> during compression (i.e., in a compression direction) and from the second end <NUM> towards the first end <NUM> during rebound (i.e., in a rebound direction). An attachment ring <NUM> may be located on the second end <NUM> to connect the suspension system <NUM> to an associated vehicle. A rod guide sleeve <NUM> may be located on the first end <NUM>. The rod guide sleeve <NUM> includes an axially extending portion <NUM> that hugs an outer surface reservoir tube <NUM> and a radially extending portion <NUM> that covers the first end <NUM>. The radially extending portion <NUM> defines an opening for slideably accommodating and guiding the piston rod <NUM>.

A solenoid assembly <NUM> extends between a distal end of the piston rod <NUM> and the piston head <NUM> connecting the piston head <NUM> with the piston rod <NUM> facilitating the piston rod <NUM> to move the piston head <NUM> between a compression stroke and a rebound stroke. A cable <NUM> is electrically connected to the solenoid assembly <NUM> through a channel <NUM> (cf. <FIG> and <FIG>) defined by the piston rod <NUM> for providing an electric current to the solenoid assembly <NUM> to generate an electromagnetic field.

<FIG> is a perspective view of the piston assembly <NUM> including a portion of the piston head <NUM> and solenoid assembly <NUM> cutout to show internal components therein. <FIG> is an enlarged view of the piston head <NUM> and solenoid assembly <NUM> from <FIG>. The solenoid assembly <NUM> includes a body <NUM>, having a generally cylindrical shape, and having a top portion <NUM>, also having a generally circular shape, disposed adjacent to the distal end of the piston rod <NUM>. The top portion <NUM> extends annularly about the center axis A and radially outwardly from the center axis A. The body <NUM> further includes a bottom portion <NUM> extending radially outwardly from the top portion <NUM>, annularly about the center axis A, to a proximal end <NUM>. The body <NUM> defines a compartment <NUM> extending between the top portion <NUM> and the proximal end <NUM> to receive the piston head <NUM>. Stated another way, the bottom portion <NUM> extends between the piston head <NUM> and the piston rod <NUM> connecting the piston head <NUM> and the piston rod <NUM>. In some embodiments, the body <NUM> may further include a collar portion <NUM>, having a generally cylindrical shape, disposed in the channel <NUM> of the piston rod <NUM> and extending along the axis A to connect the body <NUM> to the piston rod <NUM>. The collar portion <NUM> may further define a collar channel <NUM> extending along center axis A for receiving the cable <NUM> and connecting the cable <NUM> to the solenoid assembly <NUM>. In some embodiments, the body <NUM> defines at least one first aperture <NUM> and at least one second aperture <NUM> axially spaced from the at least one first aperture <NUM>. In some embodiments, the at least one first aperture <NUM> includes a plurality of axially aligned and circumferentially arrayed first apertures <NUM>. In some embodiments, the at least one second aperture <NUM> includes a plurality of axially aligned and circumferentially arrayed second apertures <NUM>. A bearing ring <NUM> may be located between an outer surface of the top portion <NUM> and the piston rod <NUM>.

An actuator <NUM> is at least partially located in the compartment <NUM>. The actuator <NUM> is movable between a closed position and an open position. In the closed position, the actuator <NUM> restricts a fluid flow from at least one of the first apertures <NUM> and the second apertures <NUM> for providing a stiffer absorption property. In the open position, the fluid flow through the first apertures <NUM> and the second apertures <NUM> is unrestricted for providing a less-stiff absorption property.

The solenoid assembly <NUM> includes a core <NUM> located in the compartment <NUM> adjacent to the actuator <NUM>. The core <NUM> may define a core body <NUM> that extends towards the piston head <NUM> to a core head <NUM> extending radially outwardly from the core body <NUM>. A protrusion <NUM> may extend axially from the core head <NUM> opposite the core body <NUM>. A spool <NUM> extends about the core body <NUM> and defines a space <NUM> for locating a coil <NUM> that is wrapped therearound to define ring-shaped winding having an inner diameter and an outer diameter. The cable <NUM> electrically connects to the coil <NUM> to generate an electromagnetic field. The actuator <NUM> includes a plunger <NUM> abutting the core head <NUM> opposite the core body <NUM>. In some embodiments, the plunger <NUM> defines and outer diameter that is equal to an outer diameter of the core head <NUM>. The plunger <NUM> extends from the core head <NUM> towards the second end <NUM>. A plunger guide <NUM> extends about the plunger <NUM> in hugging engagement therewith. In some embodiments, the plunger <NUM> may be formed of a magnetic material such that the plunger <NUM> is moved between an open position and a closed position based on the presence of an electromagnetic field. In some embodiments, the plunger guide <NUM> may guide a magnetic flux to the plunger <NUM>. More particularly, in the closed position, the plunger <NUM> is moved towards the core <NUM> to restrict fluid flow through at least one of the first apertures <NUM> and the second apertures <NUM> to provide stiffer damping properties. In the open position, the plunger <NUM> is moved away from the core <NUM> to permit fluid flow through the first apertures <NUM> and the second apertures <NUM> to provide less-stiff or softer damping properties.

With reference now to <FIG> and <FIG>, further details of the solenoid assembly <NUM> will be further described. The solenoid assembly <NUM> includes an induction plate <NUM> located under the coil <NUM>. The induction plate <NUM> may be annularly shaped and located in abutment with the spool <NUM>. The induction plate <NUM> may be formed of stainless steel, steel alloy, Aluminum, Aluminum alloy, Copper, or Copper Alloy. In some embodiments, the induction plate <NUM> is formed of a material with a conductivity of at least <NUM>,<NUM>,<NUM> Siemens/m, a steel material with a conductivity of <NUM>,<NUM>,<NUM> Siemens/m, Aluminum material with a conductivity of <NUM>,<NUM>,<NUM> Siemens/m, a Copper material with a conductivity of <NUM>,<NUM>,<NUM> Siemens/m, or a combination thereof. The induction plate <NUM> includes a top ring portion <NUM> that is sandwiched between the spool <NUM> and the core head <NUM>. The top ring portion <NUM> may include an inner diameter that is located radially inwardly from the inner diameter of the wrapping of the coil <NUM>. The top ring portion <NUM> may further include an outer diameter that is located radially outwardly from the outer diameter of the wrapping of the coil <NUM>. In some embodiments, the outer diameter of the top ring portion <NUM> abuts the bottom portion <NUM> of the body <NUM> and the inner diameter of the top ring portion <NUM> abuts outer diameter of the core body <NUM>. The induction plate <NUM> may further include a bridge portion <NUM> extending axially towards the second end <NUM> and away from the coil <NUM>. The bridge portion <NUM> may be in hugging engagement with an outer diameter of the core head <NUM> and spaced from the bottom portion <NUM> of the body <NUM>. A hook portion <NUM> extends radially outwardly from the bridge portion <NUM> and into abutment with the bottom portion <NUM> of the body <NUM>. An O-ring ring <NUM> is located in a space defined by the top ring portion <NUM>, the bridge portion <NUM>, the hook portion <NUM>, and the bottom portion <NUM> of the body <NUM>. In some embodiments, at least one first weld interface <NUM> may be located between the induction plate <NUM> and the core <NUM>. In some embodiments, at least one second weld interface <NUM> may be located between the induction plate <NUM> and the body <NUM>. Therefore, the induction plate <NUM> may hermetically seal portions of the solenoid assembly <NUM> from fluid.

In operation, an associated controller dictates current supply to the coil <NUM>. In some embodiments, this current supply is approximately <NUM> frequency. As current is supplied to the coil <NUM>, a magnetic field buildup and decay occurs as the current is modulated. This magnetic field buildup and decay results in the induction of eddy currents throughout the solenoid assembly <NUM>. The eddy current induces an opposing magnetic field in the induction plate <NUM> attenuating the force ripples of the magnetic field buildup and decay.

Claim 1:
A suspension system (<NUM>) of an associated vehicle, the suspension system (<NUM>) comprising:
an outer reservoir tube (<NUM>) extending along an axis (A) between a first end (<NUM>) and a second end (<NUM>) and defining a chamber (<NUM>, <NUM>); and
a piston assembly (<NUM>) at least partially located in the chamber (<NUM>, <NUM>), the piston assembly (<NUM>) including a piston rod (<NUM>) and a piston head (<NUM>);
characterized in that the suspension system (<NUM>) further comprises a solenoid assembly (<NUM>) connected to the piston rod (<NUM>) and including a body (<NUM>) having a generally cylindrical shape, and having a top portion (<NUM>), also having a generally circular shape, disposed adjacent to the distal end of the piston rod (<NUM>), the top portion (<NUM>) extending annularly about the axis (A) and radially outwardly from the axis (A), the body (<NUM>) further including a bottom portion (<NUM>) extending radially outwardly from the top portion (<NUM>), annularly about the axis (A), to a proximal end (<NUM>), the body (<NUM>) defining a compartment (<NUM>) extending between the top portion (<NUM>) and the proximal end (<NUM>) to receive the piston head (<NUM>),
wherein the solenoid assembly (<NUM>) comprises:
a core (<NUM>) including a core head (<NUM>) and a core body (<NUM>) and located in the compartment (<NUM>);
a spool (<NUM>) extending about the core body (<NUM>) and defining a space (<NUM>);
a coil (<NUM>) wrapped around the spool (<NUM>) within the space (<NUM>); and
an induction plate (<NUM>) at least partially located between the spool (<NUM>) and the core head (<NUM>),
wherein an actuator (<NUM>) is at least partially located in the compartment (<NUM>) adjacent to the core (<NUM>) and movable between a closed position and an open position, wherein the body (<NUM>) defines at least one first aperture (<NUM>) and at least one second aperture (<NUM>) axially spaced from the at least one first aperture (<NUM>), wherein in the closed position, the actuator (<NUM>) restricts a fluid flow from at least one of the first aperture (<NUM>) and the second aperture (<NUM>) to provide a stiffer damping property, and in the open position, permits the fluid flow through the at least one first aperture (<NUM>) and the at least one second aperture (<NUM>) to provide a less-stiff damping property.