Method for optimizing response time of hydraulic latch-pin in cylinder deactivation rocker arm

Abstract

A method for optimizing response time of a latch in a cylinder deactivation rocker arm assembly is provided. The latch is configured to move between an engaged position with an inner arm of the rocker arm assembly and a retracted position. A major outer diameter (L 1 ) of the latch is determined. An installed length (L 2 ) of a spring biasing the latch is determined. A clearance (L 3 ) between L 1 and a major inner diameter of an outer arm of the rocker arm assembly is determined. A radial clearance (L 4 ) between a cage coupled to the outer arm and a major inner diameter of the latch is determined. A minor diameter (L 5 ) of the latch is determined. A relationship between the response time of the latch and L 1, L 2, L 3, L 4 and L 5 is established. Components of the cylinder deactivation rocker arm assembly are selected based on the relationship.

What is claimed is: 
     
         1 . A method for optimizing response time of a latch in a cylinder deactivation rocker arm assembly, the latch moving between an engaged position with an inner arm of the rocker arm assembly and a retracted position, the method comprising:
 determining a major outer diameter (L 1 ) of the latch;   determining an installed length (L 2 ) of a spring biasing the latch;   determining a clearance (L 3 ) between L 1  and a major inner diameter of an outer arm of the rocker arm assembly;   determining a radial clearance (L 4 ) between a cage coupled to the outer arm and a major inner diameter of the latch;   determining a minor diameter (L 5 ) of the latch;   establishing a relationship between the response time of the latch and, L 1 , L 2 , L 3 , L 4  and L 5 , wherein at least one of the L 1 , L 2 , L 3 , L 4  and L 5  impacts the response time more than a remainder of the L 1 , L 2 , L 3 , L 4  and L 5 ; and   selecting components of the cylinder deactivation rocker arm assembly based on the relationship.   
     
     
         2 . The method of  claim 1  wherein the response time is an ON response time required for the latch to move from the inner arm and enable switching to a cylinder deactivation mode. 
     
     
         3 . The method of  claim 2  wherein L 4  has a greater impact on response time than L 1 , L 2  and L 3 . 
     
     
         4 . The method of  claim 3  wherein L 5  has a greater impact on response time than L 1 , L 2  and L 3 . 
     
     
         5 . The method of  claim 4  wherein the relationship comprises:
   ON Response time (ms)=22.1431+1.2675* L 1−1.28* L 2−0.2625* L 3−8.8762* L 4+8.1951* L 5+0.55* L 1* L 2−2.825* L 1* L 4−2.77* L 1* L 5+0.655* L 2 *L 4−0.6050* L 2* L 5−0.4875* L 3* L 4−4.035* L 4* L 5.
 
 
     
     
         6 . The method of  claim 1  wherein the response time is an OFF response time required for the latch to move from the retracted position to the engaged position. 
     
     
         7 . The method of  claim 6  wherein L 1  has a greater impact on response time than L 2 , L 3 , L 4  and L 5 . 
     
     
         8 . The method of  claim 7  wherein L 4  has a greater impact on response time than L 2 , L 3  and L 5 . 
     
     
         9 . The method of  claim 8  wherein L 5  has a greater impact on response time than L 2  and L 3 . 
     
     
         10 . The method of  claim 9  wherein the relationship comprises:
   OFF Response time (ms)=19.731+15.8987* L 1+1.17163* L 2−1.53* L 3−7.6401* L 4−4.405* L 5+1.3375* L 1* L 2−10.265* L 1* L 4−1.837* L 1* L 5−1.005 *L 2* L 5+1.7875* L 4* L 5.
 
 
     
     
         11 . A method for optimizing ON and OFF response times of a latch in a cylinder deactivation rocker arm assembly, the latch moving between an engaged position with an inner arm of the rocker arm assembly and a retracted position, the method comprising:
 determining a major outer diameter (L 1 ) of the latch;   determining an installed length (L 2 ) of a spring biasing the latch;   determining a clearance (L 3 ) between L 1  and a major inner diameter of an outer arm of the rocker arm assembly;   determining a radial clearance (L 4 ) between a cage coupled to the outer arm and a major inner diameter of the latch;   determining a minor diameter (L 5 ) of the latch;   establishing a relationship between the response time of the latch and, L 1 , L 2 , L 3 , L 4  and L 5 , wherein each of L 1 , L 2  and L 5  have inverse relationships with respect to ON response time and OFF response time; and   selecting components of the cylinder deactivation rocker arm assembly based on the established relationship.   
     
     
         12 . The method of  claim 11  wherein the ON response time is required for the latch to move from the inner arm and enable switching to a cylinder deactivation mode. 
     
     
         13 . The method of  claim 12  wherein L 4  has a greater impact on response time than L 1 , L 2  and L 3 . 
     
     
         14 . The method of  claim 13  wherein L 5  has a greater impact on response time than L 1 , L 2  and L 3 . 
     
     
         15 . The method of  claim 14  wherein the ON response time comprises:
   ON Response time (ms)=22.1431+1.2675* L 1−1.28* L 2−0.2625* L 3−8.8762* L 4+8.1951* L 5+0.55* L 1* L 2−2.825* L 1* L 4−2.77* L 1* L 5+0.655* L 2 *L 4−0.6050* L 2* L 5−0.4875* L 3* L 4−4.035* L 4* L 5.
 
 
     
     
         16 . The method of  claim 11  wherein the OFF response time is required for the latch to move from the retracted position to the engaged position. 
     
     
         17 . The method of  claim 16  wherein L 1  has a greater impact on response time than L 2 , L 3 , L 4  and L 5 . 
     
     
         18 . The method of  claim 17  wherein L 4  has a greater impact on response time than L 2 , L 3  and L 5 . 
     
     
         19 . The method of  claim 18  wherein L 5  has a greater impact on response time than L 2  and L 3 . 
     
     
         20 . The method of  claim 19  wherein the OFF response time comprises:
   OFF Response time (ms)=19.731+15.8987* L 1+1.17163* L 2−1.53* L 3−7.6401* L 4−4.405* L 5+1.3375* L 1* L 2−10.265* L 1* L 4−1.837* L 1* L 5−1.005 *L 2* L 5+1.7875* L 4* L 5.