Method and apparatus for measuring engine compression ratio, clearance volume and related cylinder parameters

Claim 1

A method of measuring clearance volume V TDC wi the cylinder of an internal combustion engine having a piston disposed to reciprocate in said cylinder and a crankshaft coupled to said piston, said method comprising the steps of: (a) monitoring angular rotation of said crankshaft, (b) identifying an angular position θ TDC of said crankshaft corresponding to top dead center of said piston within said cylinder, (c) measuring cylinder pressures P a , P b , P c at angularly spaced positions θ a , θ b , θ c of said crankshaft different from said top dead center position θ TDC , (d) identifying volumes V a-b , V b-c and V a-TDC of piston displacement between crankshaft positions θ a , θ b , θ c and θ a , θ TDC respectively, and (e) determining at least clearance volume V TDC as a function of the following four equations involving the four unknowns V a , V TDC , γ and k: P.sub.a V.sub.a.sup.γ =k P.sub.b (V.sub.a +V.sub.a-b).sup.γ =k P.sub.c (V.sub.a +V.sub.a-b +V.sub.b-c).sup.γ =k (f) determining said clearance volume as a function V.sub.TDC =V.sub.a -V.sub.a-TDC.

Claim 2

A method of measuring clearance volume V TDC wi the cylinder of an internal combustion engine having a piston disposed to reciprocate in said cylinder and a crankshaft coupled to said piston, said method comprising the steps of: (a) monitoring angular rotation of said crankshaft, (b) identifying an angular position θ TDC of said crankshaft corresponding to top dead center of said piston within said cylinder, (c) measuring cylinder pressures P a , P b , P c at angularly spaced positions θ a , θ b , θ c of said crankshaft different from said top dead center position θ TDC , (d) identifying volumes V a-b , V b-c and V a-TDC of piston displacement between crankshaft positions θ a , θ b , θ c and θ a , θ TDC respectively, and (e) determining at least clearance volume V TDC as a function of the following four equations involving the four unknowns V a , V TDC , γ and k: P.sub.a V.sub.a.sup.γ =k P.sub.b (V.sub.a +V.sub.a-b).sup.γ =k P.sub.c (V.sub.a +V.sub.a-b +V.sub.b-c).sup.γ =k (f) determining said clearance volume as a function V.sub.TDC =V.sub.a -V.sub.a-TDC.

Claim 4

A method of measuring angle of valve operation within the cylinder of an internal combustion engine having a piston disposed to reciprocate within said cylinder and a crankshaft rotatably coupled to said piston, cylinder pressure and volume being related to each other with all valves closed by the equation PV.sup.γ =k wherein P is pressure, V is volume and γ and k are constants, said method comprising the steps of: (a) monitoring angular rotation of said crankshaft, (b) identifying an angular position θ TDC of said crankshaft corresponding to top dead center of said piston within said cylinder, (c) measuring pressure within said cylinder at a multiplicity of angularly spaced positions of said crankshaft while said crankshaft is rotating and said piston is reciprocating within said cylinder, (d) identifying displacement volumes of said piston within said cylinder between at least some of said angularly spaced positions at which said valve is known to be closed, (e) determining said constants γ and k as a function of said displacement volumes and said measured pressures, (f) comparing said measured pressures at the remainder of said angularly spaced positions to pressures P predicted by said equation, and (g) identifying angle θ V of valve operation with respect to θ TDC as a function of a difference between said predicted pressure and said measured pressure for each said angularly spaced position.

Claim 5

A method of measuring angle of valve operation within the cylinder of an internal combustion engine having a piston disposed to reciprocate within said cylinder and a crankshaft rotatably coupled to said piston, cylinder pressure and volume being related to each other with all valves closed by the equation PV.sup.γ =k wherein P is pressure, V is volume and γ and k are constants, said method comprising the steps of: (a) monitoring angular rotation of said crankshaft, (b) identifying an angular position θ TDC of said crankshaft corresponding to top dead center of said piston within said cylinder, (c) measuring pressure within said cylinder at a multiplicity of angularly spaced positions of said crankshaft while said crankshaft is rotating and said piston is reciprocating within said cylinder, (d) identifying displacement volumes of said piston within said cylinder between at least some of said angularly spaced positions at which said valve is known to be closed, (e) determining said constants γ and k as a function of said displacement volumes and said measured pressures, (f) comparing said measured pressures at the remainder of said angularly spaced positions to pressures P predicted by said equation, and (g) identifying angle θ V of valve operation with respect to θ TDC as a function of a difference between said predicted pressure and said measured pressure for each said angularly spaced position.

Claim 14

A method of quantifying leakage within the cylinder of an internal combustion engine having a piston disposed to reciprocate in said cylinder and a crankshaft coupled to said piston, said method comprising the steps of: (a) monitoring angular rotation of said crankshaft, (b) identifying an angular positio θ TDC of said crankshaft corresponding to top dead center of said piston within said cylinder, (c) measuring during the compression/power stroke of said piston cylinder pressures P a , P b , P c at angularly spaced positions θ a , θ b , θ c of said crankshaft different from said top dead center position θ TDC , (d) measuring cylinder pressure P d at angular position θ d at preselected relationship to said angular position θ TDC , (e) identifying volumes V a-b , V b-c and V a-d of piston displacement between crankshaft positions θ a , θ b , θ c and θ d respectively, (f) determining the four unknowns V a , V d , γ and k as a function of the following four equations: P.sub.a V.sub.a.sup.Γ =k P.sub.b (V.sub.a +V.sub.a-b).sup.γ =k P.sub.c (V.sub.a +V.sub.a-b +V.sub.b-c).sup.γ =k V.sub.d =V.sub.a-d (g) identifying a predicted pressure P' d at said crankshaft position θ d as a function of the equation: ##EQU15## and then (h) quantifying cylinder leakage during said compression/power stroke as a function of a difference between P' d and P d .

Claim 15

A method of quantifying leakage within the cylinder of an internal combustion engine having a piston disposed to reciprocate in said cylinder and a crankshaft coupled to said piston, said method comprising the steps of: (a) monitoring angular rotation of said crankshaft, (b) identifying an angular positio θ TDC of said crankshaft corresponding to top dead center of said piston within said cylinder, (c) measuring during the compression/power stroke of said piston cylinder pressures P a , P b , P c at angularly spaced positions θ a , θ b , θ c of said crankshaft different from said top dead center position θ TDC , (d) measuring cylinder pressure P d at angular position θ d at preselected relationship to said angular position θ TDC , (e) identifying volumes V a-b , V b-c and V a-d of piston displacement between crankshaft positions θ a , θ b , θ c and θ d respectively, (f) determining the four unknowns V a , V d , γ and k as a function of the following four equations: P.sub.a V.sub.a.sup.Γ =k P.sub.b (V.sub.a +V.sub.a-b).sup.γ =k P.sub.c (V.sub.a +V.sub.a-b +V.sub.b-c).sup.γ =k V.sub.d =V.sub.a-d (g) identifying a predicted pressure P' d at said crankshaft position θ d as a function of the equation: ##EQU15## and then (h) quantifying cylinder leakage during said compression/power stroke as a function of a difference between P' d and P d .

Claim 16

A method of measuring angle of valve operation within the cylinder of an internal combustion engine having a piston disposed to reciprocate within said cylinder and a crankshaft rotatably coupled to said piston, cylinder pressure and volume being related to each other with all valves closed by the equation PV.sup.γ =k wherein P is pressure, V is volume and γ and k are constants, said method comprising the steps of: (a) monitoring angular rotation of said crankshaft, (b) identifying an angular position θ TDC of said crankshaft corresponding to top dead center of said piston within said cylinder, (c) measuring pressure within said cylinder at a multiplicity of angularly spaced positions of said crankshaft while said crankshaft is rotating and said piston is reciprocating within said cylinder, (d) identifying displacement volumes of said piston within said cylinder between at least some of said angularly spaced positions at which all said valves are known to be closed, (e) determining a volume V 1 for at least one of said angularly spaced positions and said constants γ and k as a function of said displacement volumes and said measured pressures, (f) determining said volume V for each of the remainder of said angularly spaced positions as a function of said volume V 1 and engine design parameters, (g) comparing said measured pressures at said remainder of said angularly spaced positions to pressures P predicted by said equation, and (h) identifying angle θ V of valve operation with respect to θ TDC as a function of a difference between said predicted pressure and said measured pressure for each said angularly spaced position.

Claim 17

A method of measuring angle of valve operation within the cylinder of an internal combustion engine having a piston disposed to reciprocate within said cylinder and a crankshaft rotatably coupled to said piston, cylinder pressure and volume being related to each other with all valves closed by the equation PV.sup.γ =k wherein P is pressure, V is volume and γ and k are constants, said method comprising the steps of: (a) monitoring angular rotation of said crankshaft, (b) identifying an angular position θ TDC of said crankshaft corresponding to top dead center of said piston within said cylinder, (c) measuring pressure within said cylinder at a multiplicity of angularly spaced positions of said crankshaft while said crankshaft is rotating and said piston is reciprocating within said cylinder, (d) identifying displacement volumes of said piston within said cylinder between at least some of said angularly spaced positions at which all said valves are known to be closed, (e) determining a volume V 1 for at least one of said angularly spaced positions and said constants γ and k as a function of said displacement volumes and said measured pressures, (f) determining said volume V for each of the remainder of said angularly spaced positions as a function of said volume V 1 and engine design parameters, (g) comparing said measured pressures at said remainder of said angularly spaced positions to pressures P predicted by said equation, and (h) identifying angle θ V of valve operation with respect to θ TDC as a function of a difference between said predicted pressure and said measured pressure for each said angularly spaced position.

Claim 19

A method of measuring intake pressure P.sub.θ.sbsb.V within the cylinder of an internal combustion engi.ne having a piston disposed to reciprocate in said cylinder and a crankshaft coupled to said piston, said method comprising the steps of: (a) monitoring angular rotation of said crankshaft, (b) identifying an angular position θ TDC of said crankshaft corresponding to top dead center of said piston within said cylinder, (c) measuring cylinder pressure P a , P b , P c , P TDC at angularly spaced positions θ a , θ b , θ c , θ TDC of said crankshaft, (d) identifying volumes V a-b and V b-c of piston displacement between crankshaft positions θ a , θ b , θ c , (e) determining at least cylinder parameter γ as a function of the following three equations involving the three unknowns V a , γ and k: P.sub.a, γ=k P.sub.b (V.sub.a +V.sub.a-b).sup.γ =k P.sub.c (V.sub.a +V.sub.a-b +V.sub.b-c).sup. =k (f) identifying engine cylinder compression ratio C/R, and (g) determining cylinder intake pressure P.sub.θ.sbsb.V as a function of the equation: ##EQU17##

Claim 20

A method of measuring intake pressure P.sub.θ.sbsb.V within the cylinder of an internal combustion engi.ne having a piston disposed to reciprocate in said cylinder and a crankshaft coupled to said piston, said method comprising the steps of: (a) monitoring angular rotation of said crankshaft, (b) identifying an angular position θ TDC of said crankshaft corresponding to top dead center of said piston within said cylinder, (c) measuring cylinder pressure P a , P b , P c , P TDC at angularly spaced positions θ a , θ b , θ c , θ TDC of said crankshaft, (d) identifying volumes V a-b and V b-c of piston displacement between crankshaft positions θ a , θ b , θ c , (e) determining at least cylinder parameter γ as a function of the following three equations involving the three unknowns V a , γ and k: P.sub.a, γ=k P.sub.b (V.sub.a +V.sub.a-b).sup.γ =k P.sub.c (V.sub.a +V.sub.a-b +V.sub.b-c).sup. =k (f) identifying engine cylinder compression ratio C/R, and (g) determining cylinder intake pressure P.sub.θ.sbsb.V as a function of the equation: ##EQU17##

Claim 21

A method of measuring intake pressure P.sub.θ.sbsb.V within the cylinder of an internal combustion engine having a piston disposed to reciprocate in said cylinder and a crankshaft coupled to said piston, said method comprising the steps of: (a) monitoring angular rotation of said crankshaft, (b) measuring cylinder pressure P a , P b , P c at angularly spaced positions θ a , θ b , θ c of said crankshaft, (c) identifying volumes V a-b and V b-c of piston displacement between crankshaft positions θ a , θ b , θ c , (d) determining at least volume V a and cylinder parameter γ as a function of the following three equations involving the three unknowns V a , γ and k: P.sub.a V.sub.a.sup.γ =k P.sub.b (V.sub.a +V.sub.a-b).sup.γ =k P.sub.c (V.sub.a +V.sub.a-b +V.sub.b-c).sup.γ =k (e) identifying a volume V.sub.θ.sbsb.V of said cylinder corresponding to intake valve closure, and (f) determining cylinder intake pressure P.sub.θ.sbsb.V as a function of the equation: ##STR1##

Claim 22

A method of measuring intake pressure P.sub.θ.sbsb.V within the cylinder of an internal combustion engine having a piston disposed to reciprocate in said cylinder and a crankshaft coupled to said piston, said method comprising the steps of: (a) monitoring angular rotation of said crankshaft, (b) measuring cylinder pressure P a , P b , P c at angularly spaced positions θ a , θ b , θ c of said crankshaft, (c) identifying volumes V a-b and V b-c of piston displacement between crankshaft positions θ a , θ b , θ c , (d) determining at least volume V a and cylinder parameter γ as a function of the following three equations involving the three unknowns V a , γ and k: P.sub.a V.sub.a.sup.γ =k P.sub.b (V.sub.a +V.sub.a-b).sup.γ =k P.sub.c (V.sub.a +V.sub.a-b +V.sub.b-c).sup.γ =k (e) identifying a volume V.sub.θ.sbsb.V of said cylinder corresponding to intake valve closure, and (f) determining cylinder intake pressure P.sub.θ.sbsb.V as a function of the equation: ##STR1##

Claim 23

A method of quantifying leakage from a cylinder of an internal combustion engine having a piston disposed to reciprocate within said cylinder and a crankshaft rotatably coupled to said piston, said method comprising the steps of: (a) monitoring rotation of said crankshaft, (b) monitoring pressure within said cylinder while said crankshaft is rotating and said piston is reciprocating within said cylinder, (c) identifying displacement volumes of said piston within said cylinder as a function of rotation of said crankshaft, and (d) quantifying leakage from said cylinder as a function of monitored pressure and identified displacement volumes.

Claim 24

A method of quantifying leakage from a cylinder of an internal combustion engine having a piston disposed to reciprocate within said cylinder and a crankshaft rotatably coupled to said piston, said method comprising the steps of: (a) monitoring rotation of said crankshaft, (b) monitoring pressure within said cylinder while said crankshaft is rotating and said piston is reciprocating within said cylinder, (c) identifying displacement volumes of said piston within said cylinder as a function of rotation of said crankshaft, and (d) quantifying leakage from said cylinder as a function of monitored pressure and identified displacement volumes.