Switching rocker arm for internal exhaust gas recirculation with simple latch control

Abstract

A switching rocker arm constructed in accordance to one example of the present disclosure includes an outer arm, an inner arm, a latch, a roller, a first lost motion spring and a second lost motion spring. The outer arm has a first outer side arm, a second outer side arm, an outer arm first end and an outer arm second end. The first outer side arm has a first leg retaining tab. The second outer side arm has a second leg retaining tab. The inner arm is pivotally secured to the outer arm and has a latch bore, a first inner side arm, a second inner side arm, an inner arm first end and an inner arm second end. The inner arm first end has a first finger, a second finer, a first hub and a second hub.

What is claimed is: 
     
         1 . A switching rocker arm comprising:
 an outer arm having a first outer side arm, a second outer side arm, an outer arm first end and an outer arm second end, the first outer side arm having a first leg retaining tab, the second outer side arm having a second leg retaining tab;   an inner arm pivotally secured to the outer arm and having a latch bore, the inner arm having a first inner side arm, a second inner side arm, an inner arm first end and an inner arm second end, the inner arm first end having a first finger, a second finger, a first hub and a second hub;   a latch slidably connected to the inner arm at the latch bore and configured to selectively extend to engage the outer arm;   a roller and bearing configured on the inner arm;   a first and second lost motion torsion spring mounted on the respective first and second hubs and configured to bias the inner arm, the first and second lost motion torsion springs each having a first leg and a second leg, wherein (i) the first leg of the first lost motion spring engages the second leg retaining tab and the second leg of the first lost motion spring engages the second finger, and (ii) the first leg of the second lost motion spring engages the first leg retaining tab and the second leg of the second lost motion torsion spring engages the first finger; and   wherein the first and second fingers of the inner arm and the first and second leg retaining tabs are all positioned intermediate (i) the first and second hubs and (ii) the bearing.   
     
     
         2 . The switching rocker arm of  claim 1 , further comprising slider pads configured on the outer arm, wherein the roller and bearing cooperate to accommodate a main lift and the slider pads are configured to accommodate a secondary lift. 
     
     
         3 . The switching rocker arm of  claim 1  wherein the latch and the first and second torsion springs are positioned at the inner arm first end. 
     
     
         4 . The switching rocker arm of  claim 3  wherein the inner arm further includes a socket arranged at the inner arm first end and a valve pad positioned at the inner arm second end. 
     
     
         5 . The switching rocker arm of  claim 4 , further comprising a pivot axle that rotatably couples the inner arm and the outer arm, wherein the outer arm second end extends generally above the pivot axle in a direction generally opposite the valve pad. 
     
     
         6 . The switching rocker arm of  claim 5  wherein the socket is configured to receive a ball plunger end of a dual feed hydraulic lash adjuster. 
     
     
         7 . The switching rocker arm of  claim 1  wherein the inner arm further comprises a rear stopper that is configured to selectively engage the outer arm. 
     
     
         8 . The switching rocker arm of  claim 1  wherein the first and second ends of both of the first and second lost motion torsion springs are free from engagement with the outer arm first end. 
     
     
         9 . The switching rocker arm of  claim 1  wherein the first and second lost motion torsion springs have respective coil portions that are mounted on the respective first and second hubs. 
     
     
         10 . The switching rocker arm of  claim 1  wherein the first and second leg retaining tabs are each generally in the shape of a hook having a respective extension. 
     
     
         11 . The switching rocker arm of  claim 10  wherein the first leg of the first lost motion spring is positioned between the first outer side arm and the extension of the first leg retaining tab while the second leg of the second lost motion spring is positioned between the second outer side arm and the extension of the second leg retaining tab. 
     
     
         12 . A switching rocker arm comprising:
 an outer arm having a first outer side arm, a second outer side arm, an outer arm first end and an outer arm second end, the first outer side arm having a first leg retaining tab, the second outer side arm having a second leg retaining tab;   an inner arm pivotally secured to the outer arm and having a latch bore, the inner arm having a first inner side arm, a second inner side arm, an inner arm first end having a socket and an inner arm second end having a valve pad, the inner arm first end having a first finger, a second finger, a first hub and a second hub;   a latch slidably connected to the inner arm at the latch bore and configured to selectively extend to engage the outer arm;   a roller and bearing configured on the inner arm;   a first and second lost motion torsion spring mounted on the respective first and second hubs and configured to bias the inner arm, the first and second lost motion torsion springs each having a first leg and a second leg, wherein (i) the first leg of the first lost motion spring engages the second leg retaining tab and the second leg of the first lost motion spring engages the second finger, and (ii) the first leg of the second lost motion spring engages the first leg retaining tab and the second leg of the second lost motion torsion spring engages the first finger; and   a pivot axle that rotatably couples the inner arm and the outer arm, wherein the outer arm second end extends generally above the pivot axle in a direction generally opposite the valve pad.   
     
     
         13 . The switching rocker arm of  claim 12  wherein the first and second fingers of the inner arm and the first and second leg retaining tabs are all positioned intermediate (i) the first and second hubs and (ii) the bearing. 
     
     
         14 . The switching rocker arm of  claim 12 , further comprising slider pads configured on the outer arm, wherein the roller and bearing cooperate to accommodate a main lift and the slider pads are configured to accommodate a secondary lift. 
     
     
         15 . The switching rocker arm of  claim 12  wherein the latch and the first and second torsion springs are positioned at the inner arm first end. 
     
     
         16 . The switching rocker arm of  claim 12  wherein the socket is configured to receive a ball plunger end of a dual feed hydraulic lash adjuster. 
     
     
         17 . The switching rocker arm of  claim 12  wherein the inner arm further comprises a rear stopper that is configured to selectively engage the outer arm. 
     
     
         18 . The switching rocker arm of  claim 12  wherein the first and second ends of both of the first and second lost motion torsion springs are free from engagement with the outer arm first end. 
     
     
         19 . The switching rocker arm of  claim 12  wherein the first and second lost motion torsion springs have respective coil portions that are mounted on the respective first and second hubs. 
     
     
         20 . The switching rocker arm of  claim 12  wherein the first and second leg retaining tabs are each generally in the shape of a hook having a respective extension. 
     
     
         21 . The switching rocker arm of  claim 20  wherein the first leg of the first lost motion spring is positioned between the first outer side arm and the extension of the first leg retaining tab while the second leg of the second lost motion spring is positioned between the second outer side arm and the extension of the second leg retaining tab.