FIELD

This application provides hardware for enabling variable valve actuation (“VVA”) techniques on one or two valves of a cylinder. The VVA techniques can comprise one or a combination of cylinder deactivation, hydraulic lash adjustment and engine braking. Additional functions such as late intake valve closing, early exhaust valve opening and internal exhaust gas recirculation or reverse intake can be combined also.

BACKGROUND

Type II, end pivot, type engines comprise an overhead rotating cam to actuate a rocker arm. The prior art lacks options to provision more than one variable valve actuation technique on a cylinder of an engine.

Prior art valve bridges can be as shown in U.S. D839,310, WO 2019/040733, WO 2019/036272 or US 2017/0276034. The valve bridge can transfer a first valve lift profile to both valves on the valve bridge. A movable cleat that passes through the valve bridge can permit an additional VVA valve lift profile to be applied to one of the valves.

SUMMARY

It is desired to expand the valve bridge concept to a type II valvetrain so that a first valve lift profile can be applied to both valves of the valve bridge and a VVA valve lift profile can be selectively applied to a first valve. Additionally, a second VVA valve lift profile can be selectively applied to the second valve. When applying all options disclosed herein, a pair of valves connected to the valvetrain can selectively offer more than one VVA valve lift profile such as cylinder deactivation (“CDA”) and engine braking (“EB”) with hydraulic lash adjustment (“HLA”) to both valves. Additional functions such as late intake valve closing (“LIVC”), early exhaust valve opening (“EEVO”) and internal exhaust gas recirculation (“iEGR”) or reverse intake (“RI”) can be combined with the CDA, HLA, & EB functionality.

The systems and methods disclosed herein overcome the above disadvantages and improves the art by way of a valvetrain for a type II engine comprising a valve bridge, a switching rocker arm, a center capsule, first auxiliary rocker arm, and first auxiliary capsule. The valve bridge comprises a center point, a first valve mounting area, and a second valve mounting area. The valve bridge is configured to transfer force from the center point to the first valve mounting area and to the second valve mounting area. The selectively switching rocker arm is configured to transfer a first valve actuation profile from a first overhead cam lobe to the center point when the switching rocker arm is selected to switch to a first configuration and is configured to transfer a second valve actuation profile from a second overhead cam lobe to the center point when the switching rocker arm is selected to switch to a second configuration. The switching rocker arm comprises a valve end and a pivot end. The center capsule is connected to either the valve end or to the pivot end. The center capsule is configured to switch between an active state and a lost motion state. The active state is configured to transfer the selected first valve actuation profile or the selected second valve actuation profile, and the lost motion state is configured to absorb the selected first valve actuation profile or the selected second valve actuation profile. The first auxiliary rocker arm is configured to transfer a first auxiliary valve actuation profile from a third overhead cam lobe to the first valve mounting area. The first auxiliary rocker arm comprises a first auxiliary valve end and a first auxiliary pivot end. The first auxiliary capsule is connected to either the first auxiliary valve end or the second auxiliary pivot end. The first auxiliary capsule is configured to switch between a first auxiliary active state and a first auxiliary lost motion state. The first auxiliary active state is configured to transfer the first auxiliary valve actuation profile and the first auxiliary lost motion state is configured to absorb the first auxiliary valve actuation profile.

The valvetrain can further comprise a second auxiliary rocker arm and a second auxiliary capsule. The second auxiliary rocker arm is configured to transfer a second auxiliary valve actuation profile from a fourth overhead cam lobe to the second valve mounting area. The second auxiliary rocker arm comprises a second auxiliary valve end and a second auxiliary pivot end. The second auxiliary capsule is connected to either the second auxiliary valve end or the second auxiliary pivot end. The second auxiliary capsule is configured to switch between a second auxiliary active state and a second auxiliary lost motion state. The second auxiliary active state is configured to transfer the second auxiliary valve actuation profile and the second auxiliary lost motion state is configured to absorb the second auxiliary valve actuation profile.

Additional objects and advantages will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the disclosure. The objects and advantages will also be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the claimed invention.

