# US 10,480,357 B2 · Variable valve train > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,480,357 B2 - Document ID: US10480357B2 - Status: Granted - Kind: B2 - Application number: 16/089,900 - Filed: 2017-03-30 - Published: 2019-04-25 - Granted: 2019-11-19 - Earliest claimed: 2016-03-31 - Assignees: Honda Motor Co., Ltd. - Applicants: Honda Motor Co., Ltd. - Inventors: Yoshihiro Takada; Dai Kataoka; Kazunori Kikuchi - Web page: https://patentgrep.com/patent/US10480357B2 ## CPC - F01L 1/053: overhead type - F01L 1/047: Camshafts - F01L 1/08: Shape of cams - F01L 1/267: {with means for varying the timing or the lift of the valves} - F01L 13/00: Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations - F01L 13/0036: {the valves being driven by two or more cams with different shape, size or timing or a single cam profiled in axial and radial direction} - F01L 2001/0473: {Composite camshafts, e.g. with cams or cam sleeve being able to move relative to the inner camshaft or a cam adjusting rod} - F01L 2001/0476: {Camshaft bearings} - F01L 2013/0052: {with cams provided on an axially slidable sleeve} - F01L: CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES ## Abstract A variable valve train is provided with cylindrical cam carriers axially slidably and co-rotatably supported on camshafts. The cam carriers have thereon, respectively, plural cam lobes different in cam profile and axially adjacent to each other. Cam changeover mechanisms are provided for axially shifting the cam carriers and for changing over the cam lobes for operating on engine valves. At least one of the cam changeover mechanisms is disposed between axes of the two camshafts and on the side of an engine crankshaft relative to the axes. ## Claims ### Claim 1 A variable valve train of an internal combustion engine, comprising: two camshafts rotatably supported in a cylinder head of the internal combustion engine; a crankshaft for the engine; cylindrical cam carriers coaxially surrounding the camshafts, respectively, to be rotatable with and axially slidable relative to the camshafts, the cam carriers having thereon a plurality of cam lobes for operating engine valves and being different in cam profile and axially adjacent to each other; and cam changeover mechanisms for axially shifting the cam carriers to change over the cam lobes for operating the engine valves, wherein the cam changeover mechanisms include respectively: changeover pins provided for advancing and retracting movements for fitting engagement with and disengagement from lead grooves formed around the cam carriers; and changeover driving shafts provided with cam mechanisms for operating the changeover pins to advance and retract for fitting engagement with and disengagement from the lead grooves, wherein the cam lobes are operable to act on the engine valves by way of rocker arms, and wherein the rocker arms are rockably supported on the changeover driving shafts. ### Claim 2 (depends on 1) The variable valve train according to claim 1, wherein the lead grooves and the changeover driving shafts for operating the changeover pins are so related as to change over the cam lobes for operating the engine valves. ### Claim 3 (depends on 2) The variable valve train according to claim 2, wherein the changeover driving shafts are arranged in parallel with the camshafts. ### Claim 4 (depends on 2) The variable valve train according to claim 2, wherein: the cam carriers include an intake side cam carrier for operating the intake valves and an exhaust side cam carrier for operating the exhaust valves; the camshafts include an intake side camshaft for supporting therearound the intake side cam carrier and an exhaust side camshaft for supporting therearound the exhaust side cam carrier; the cam changeover mechanisms include an intake side cam changeover mechanism for axially shifting the intake side cam carrier and an exhaust side cam changeover mechanism for axially shifting the exhaust side cam carrier; and at least one of the intake side cam changeover mechanism and the exhaust side cam changeover mechanism is arranged between an intake side plane and an exhaust side plane, the intake side plane including the axis of the intake side camshaft and being parallel to a cylinder axis of the engine, the exhaust side plane including the axis of the exhaust side camshaft and being parallel to the cylinder axis. ### Claim 5 (depends on 2) The variable valve train according to claim 2, wherein: the changeover driving shafts are formed with elongated shift regulation holes having a predetermined axial length, respectively; and shift regulation pins pass through the shift regulation holes, respectively. ### Claim 6 (depends on 2) The variable valve train according to claim 2, wherein the cylinder head is formed with cylindrical portions receiving therein the changeover driving shafts, respectively, and having respective portions for restricting movement of the rocker arms in the axial directions of the changeover driving shafts. ### Claim 7 (depends on 1) The variable valve train according to claim 1, wherein the changeover driving shafts are arranged in parallel with the camshafts. ### Claim 8 (depends on 7) The variable valve train according to claim 7, wherein: the cam carriers include an intake side cam carrier for operating the intake valves and an exhaust side cam carrier for operating the exhaust valves; the camshafts include an intake side camshaft for supporting therearound the intake side cam carrier and an exhaust side camshaft for supporting therearound the exhaust side cam carrier; the cam changeover mechanisms include an intake side cam changeover mechanism for axially shifting the intake side cam carrier and an exhaust side cam changeover mechanism for axially shifting the exhaust side cam carrier; and at least one of the intake side cam changeover mechanism and the exhaust side cam changeover mechanism is arranged between an intake side plane and an exhaust side plane, the intake side plane including the axis of the intake side camshaft and being parallel to a cylinder axis of the engine, the exhaust side plane including the axis of the exhaust side camshaft and being parallel to the cylinder axis. ### Claim 9 (depends on 7) The variable valve train according to claim 7, wherein: the changeover driving shafts are formed with elongated shift regulation holes having a predetermined axial length, respectively; and shift regulation pins pass through the shift regulation holes, respectively. ### Claim 10 (depends on 7) The variable valve train according to claim 7, wherein the cylinder head is formed with cylindrical portions receiving therein the changeover driving shafts, respectively, and having respective portions for restricting movement of the rocker arms in the axial directions of the changeover driving shafts. ### Claim 11 (depends on 1) The variable valve train according to claim 1, wherein: the cam carriers include an intake side cam carrier for operating the intake valves and an exhaust side cam carrier for operating the exhaust valves; the camshafts include an intake side camshaft for supporting therearound the intake side cam carrier and an exhaust side camshaft for supporting therearound the exhaust side cam carrier; the cam changeover mechanisms include an intake side cam changeover mechanism for axially shifting the intake side cam carrier and an exhaust side cam changeover mechanism for axially shifting the exhaust side cam carrier; and at least one of the intake side cam changeover mechanism and the exhaust side cam changeover mechanism is arranged between an intake side plane and an exhaust side plane, the intake side plane including the axis of the intake side camshaft and being parallel to a cylinder axis of the engine, the exhaust side plane including the axis of the exhaust side camshaft and being parallel to the cylinder axis. ### Claim 12 (depends on 11) The variable valve train according to claim 11, wherein: the changeover driving shafts are formed with elongated shift regulation holes having a predetermined axial length, respectively; and shift regulation pins pass through the shift regulation holes, respectively. ### Claim 13 (depends on 11) The variable valve train according to claim 11, wherein the cylinder head is formed with cylindrical portions receiving therein the changeover driving shafts, respectively, and having respective portions for restricting movement of the rocker arms in the axial directions of the changeover driving shafts. ### Claim 14 (depends on 1) The variable valve train according to claim 1, wherein: the changeover driving shafts are formed with elongated shift regulation holes having a predetermined axial length, respectively; and shift regulation pins pass through the shift regulation holes, respectively. ### Claim 15 (depends on 14) The variable valve train according to claim 14, wherein the cylinder head is formed with cylindrical portions receiving therein the changeover driving shafts, respectively, and having respective portions for restricting movement of the rocker arms in the axial directions of the changeover driving shafts. ### Claim 16 (depends on 1) The variable valve train according to claim 1, wherein the cylinder head is formed with cylindrical portions receiving therein the changeover driving shafts, respectively, and having respective portions for restricting movement of the rocker arms in the axial directions of the changeover driving shafts.