Abstract: The invention prevents reverse rotation of a diesel engine which is possible to occur when the engine is started. A camshaft 13 is driven by a crankshaft 5 through power transmission means, and cams 14, 21 and 22 are provided on camshaft 13 so as to drive a fuel injection pump 12, an intake valve and an exhaust valve, respectively. In fuel injection pump cam 14, middle stage portion 53 is radially larger than minimum radius portion 51 and is disposed at a predetermined angle R3 on the back side in the rotation direction of the fuel injection pump cam from maximum radius portion 52.

Abstract: The purpose of the present invention is to improve cooling efficiency of a cylinder head of an air-cooled engine. With regard to the construction that a cooling fan is provided at one of ends of a crankshaft, and cooling air from the cooling fan is guided to a cylinder head 4 so as to cool the cylinder head 4, an intake manifold 8 is arranged above the cooling fan, a duct 51 is provided at the lateral center of the intake manifold 8 so as to suck air from an air cleaner, cooling air is sent from both sides of the duct 51 to an intake valve, an exhaust valve and an injection nozzle arranged in the cylinder head 4, and a shielding plate 55 is provided at one of lateral sides of the duct 51.

Abstract: The invention prevents reverse rotation of a diesel engine which is possible to occur when the engine is started. A camshaft 13 is driven by a crankshaft 5 through power transmission means, and cams 14, 21 and 22 are provided on camshaft 13 so as to drive a fuel injection pump 12, an intake vale and an exhaust valve, respectively. In fuel injection pump cam 14, middle stage portion 53 is radially larger than minimum radius portion 51 and disposed at a predetermined angle R3 on the back side in the rotation direction from maximum radius portion 52.

Abstract: A diesel engine 1 of the present invention comprises: a camshaft 13 with a cam 21; a fuel injection pump 12 having a plunger 84; a tappet for driving the plunger 84; and a slide portion 2b. The tappet includes a roller 80 and a roller tappet 82. The roller 80 serves as a rotor which abuts against the cam 21 so as to drive the fuel injection pump 12, and a roller tappet 82 serves as a support portion for supporting the rotor. The slide portion 2b slidably fits to the support portion. The roller tappet 82 has a tappet guide serving as a projection for restriction of rotation, and the slide portion 2b has a guide groove 92 into which the projection is fitted. Therefore, the rotor and the cam abutting against the rotor can be prevented from abrasion so as to maintain high accuracy in controlling slide stroke of the plunger.

Abstract: With regard to a construction that a fan 41 is provided at one side of an engine 1 and covered by a fan casing 45, and an air cleaner 30 is arranged near the fan casing 45 and at a side of a cylinder head 5 on which an intake port 5a is disposed, a suction port 31a communicated with the inside of the fan casing 45 is provided in a main body 31 of the air cleaner 30. A barrier 46 is provided at a position facing to the suction port 31a in the air cleaner 30. A wall standing toward the fan casing 45 and the cylinder head 5 is formed on the outer surface of the main body 31 of the air cleaner 30. An air intake part is provided on one of side surfaces of a cover body 32 of the air cleaner 30 and the cover body 32 is constructed to be an equilateral polygon. An intake pipe 31k communicating the air cleaner 30 with the intake port 5a of the cylinder head 5 is constructed integrally with a main body 31 of the air cleaner 30.

Abstract: With regard to a construction that a fan 41 is provided at one side of an engine 1 and covered by a fan casing 45, and an air cleaner 30 is arranged near the fan casing 45 and at a side of a cylinder head 5 on which an intake port 5a is disposed, a suction port 31a communicated with the inside of the fan casing 45 is provided in a main body 31 of the air cleaner 30. A barrier 46 is provided at a position facing to the suction port 31a in the air cleaner 30. A wall standing toward the fan casing 45 and the cylinder head 5 is formed on the outer surface of the main body 31 of the air cleaner 30. An air intake part is provided on one of side surfaces of a cover body 32 of the air cleaner 30 and the cover body 32 is constructed to be an equilateral polygon. An intake pipe 31k communicating the air cleaner 30 with the intake port 5a of the cylinder head 5 is constructed integrally with a main body 31 of the air cleaner 30.

Abstract: A diesel engine 1 of the present invention comprises: a camshaft 13 with a cam 21; a fuel injection pump 12 having a plunger 84; a tappet for driving the plunger 84; and a slide portion 2b. The tappet includes a roller 80 and a roller tappet 82. The roller 80 serves as a rotor which abuts against the cam 21 so as to drive the fuel injection pump 12, and a roller tappet 82 serves as a support portion for supporting the rotor. The slide portion 2b slidably fits to the support portion. The roller tappet 82 has a tappet guide serving as a projection for restriction of rotation, and the slide portion 2b has a guide groove 92 into which the projection is fitted. Therefore, the rotor and the cam abutting against the rotor can be prevented from abrasion so as to maintain high accuracy in controlling slide stroke of the plunger.

Abstract: A method for producing 2-cyclopentenones represented by the formula, ##STR1## wherein R represents an alkyl, alkenyl, cycloalkyl, substituted or non-substituted aryl or aralkyl group, which comprises heating 4-cyclopentenones represented by the formula, ##STR2## wherein R has the same meaning as above, in the presence of 1,8-diaza-bicyclo[5,4,0]undecene or its organic acid salt.The 2-cyclopentenones are useful as an intermediate for perfumes, medicines and agricultural chemicals.

Abstract: Acetone having a markedly low content of aldehydes is recovered from an aqueous rectification residue brought about by rectification of crude acetone carried out after one crude acetone having been alkali-treated or while an alkali or an aqueous solution thereof being added to the crude acetone, by mixing the aqueous rectification residue with an alkali, neutralizing the mixture to a pH of 4 to 9, and then subjecting the resulting mixture to distillation to obtain acetone as a distillate.

Abstract: Highly decolorized, purified hydroquinone and resorcinol can be separated from each other from a mixture containing hydroquinone and resorcinol and recovered by continuously rectifying the mixture, thereby obtaining rectification bottoms containing resorcinol and hydroquinone in a ratio by weight of resorcinol to hydroquinone of 0.1-1:1 while obtaining resorcinol as a distillate, redistilling the rectification bottoms, contacting hydroquinone vapor with water vapor, condensing the hydroquinone vapor in the presence of the water vapor, thereby recovering hydroquinone as an aqueous hydroquinone solution, and then recrystallizing the aqueous hydroquinone solution, if necessary, in the presence of an organic solvent, thereby separating hydroquinone from the aqueous solution.

Abstract: An organic quaternary ammonium salt used as a catalyst in a reaction between a benzylnitrile and a halide in the presence of an alkali to obtain an .alpha.-alkyl- or .alpha.-phenyl-benzylnitrile, is recovered effectively from the reaction solution containing the .alpha.-alkyl- or .alpha.-phenyl-benzylnitrile, the alkali and the catalyst, by adding water to the reaction solution to make the alkali concentration of the water layer 10% by weight or below, and then separating the water layer containing the organic quaternary ammonium salt from the oil layer containing the .alpha.-alkyl- or .alpha.-phenyl-benzylnitrile.