Abstract: The present invention provides a production method of a multifunctional acrylate with a reduced tin content which includes adding an acid to a mixture containing an organotin compound and a multifunctional acrylate and distilling the mixture containing the acid.

Abstract: The present invention provides a production method of a multifunctional acrylate with a reduced tin content which includes adding an acid to a mixture containing an organotin compound and a multifunctional acrylate and distilling the mixture containing the acid.

Abstract: An internal combustion engine includes: a crankcase that supports a crankshaft rotatably about a rotational axis; a cylinder block connected with the crankcase and including at least one pair of cylinders that sandwich a valve chamber therebetween in an axial direction of the crankshaft, the valve chamber housing therein a valve actuating mechanism that connects a camshaft to the crankshaft; a detected member disposed between crank pins corresponding to the pair of cylinders, the detected member rotating integrally with the crankshaft; and a detection sensor disposed to face a trajectory of the detected member and generating a pulse signal in accordance with movement of the detected member. Accordingly, the internal combustion engine can avoid displacement of a nearby part and enlargement of the crankcase as much as possible, while allowing the detected member to be increased in size.

Abstract: A breather chamber structure for an internal combustion engine wherein the breather chamber can be disposed compactly and the degree of freedom in the layout of the parts of the internal combustion engine can be raised. The breather chamber structure includes a crankcase, a cylinder body provided upwardly on the crankcase, and a breather chamber configured to separate oil from oil mist in the crankcase. The breather chamber includes a crankcase side breather chamber provided in the crankcase and open to a joining plane between the crankcase and the cylinder body, and a cylinder side breather chamber provided in the cylinder body and open to the joining plane.

Abstract: An internal combustion engine includes: a crankcase that supports a crankshaft rotatably about a rotational axis; a cylinder block connected with the crankcase and including at least one pair of cylinders that sandwich a valve chamber therebetween in an axial direction of the crankshaft, the valve chamber housing therein a valve actuating mechanism that connects a camshaft to the crankshaft; a detected member disposed between crank pins corresponding to the pair of cylinders, the detected member rotating integrally with the crankshaft; and a detection sensor disposed to face a trajectory of the detected member and generating a pulse signal in accordance with movement of the detected member. Accordingly, the internal combustion engine can avoid displacement of a nearby part and enlargement of the crankcase as much as possible, while allowing the detected member to be increased in size.

Abstract: A compact power unit with a sufficient clearance between a stud bolt and a fixing shaft of a cam chain tensioner pivot mechanism for supporting a cam chain tensioner guide. The power unit including a crankshaft, a stud bolt configured to fix a crankcase and a cylinder body to each other, a cam chain, a cam chain tensioner mechanism including a cam chain tensioner guide, and a cam chain tensioner pivot mechanism including a pivot plate, a fixing shaft, and a swinging shaft, the fixing shaft and the swinging shaft are arranged so as to straddle the axis of the stud bolt as viewed in the axial direction of the crankshaft.

Abstract: A compact power unit with a sufficient clearance between a stud bolt and a fixing shaft of a cam chain tensioner pivot mechanism for supporting a cam chain tensioner guide. The power unit including a crankshaft, a stud bolt configured to fix a crankcase and a cylinder body to each other, a cam chain, a cam chain tensioner mechanism including a cam chain tensioner guide, and a cam chain tensioner pivot mechanism including a pivot plate, a fixing shaft, and a swinging shaft, the fixing shaft and the swinging shaft are arranged so as to straddle the axis of the stud bolt as viewed in the axial direction of the crankshaft.

Abstract: A breather chamber structure for an internal combustion engine wherein the breather chamber can be disposed compactly and the degree of freedom in the layout of the parts of the internal combustion engine can be raised. The breather chamber structure includes a crankcase, a cylinder body provided upwardly on the crankcase, and a breather chamber configured to separate oil from oil mist in the crankcase. The breather chamber includes a crankcase side breather chamber provided in the crankcase and open to a joining plane between the crankcase and the cylinder body, and a cylinder side breather chamber provided in the cylinder body and open to the joining plane.