Improvements in or relating to a method and apparatus for reversing the direction ofrotation of internal-combustion engines, more particularly of two-stroke internal-combustion engines with fuel injection

摘要

732,611. Starting; reversing fuel pumps ; valves. LIST, H. June 8, 1953 [June 10, 1952], No. 15763/53. Classes 7(3), 7(5) and 7(6). [Also in Group XXVIII] In a method of reversing the direction of rotation of a two-stroke fuel injection engine by means of couplings 12, 121 which are arranged in the drive of the fuel injection pump 43 and/ or the rotary exhaust valve 38, the couplings each comprising a rotary piston which has two operative positions and which during operation is retained in the desired position by pressure oil, each piston and hence the engine, is reversed by forcing the pistons to one of their two positions by compressed air and retaining them therein by oil from the engine lubricating system. (see also Group XXVIII). Stop position. In this position of a control cam shaft 44 a controlling air valve 48 is closed, an air space 59 is vented and slide valves 56, one for each engine cylinder, are lifted from an axially displaceable camshaft 53 on a shaft 2 connected to the engine crankshaft 33 ; the shaft 2 is coupled to the shaft 1 of the fuel pump 43 and the rotary-valve shaft 42 by couplings 12, 12SP1/SP the pistons of which are capable of turning through less than one revolution in order to change the relationship of shafts 1 and 42 with regard to shaft 2 for ahead or astern operation. One set of cams is arranged on shaft 53 for each direction of rotation. A line 64 is vented through an opening 71 and a starting valve 65 is closed whilst both sides of the pistons of couplings 12, 121 are vented through lines 27, 28, shaft 44 and a line 72 ; the control rod 46 of the pump 43 is forced by a cam 68 on shaft 44 to zero delivery position. Ahead starting. In this position of shaft 44 the cam 47 opens valve 48 thereby placing space 59 under air pressure so opening valve 60 and forcing valves 57 to engage the camshaft 53 whereby air is alternately directed into the engine cylinder 30 through valves 65 and to atmosphere via opening 71 as the camshaft 53 is rotated. One side of the pistons of couplings 12, 121 are supplied with air from space 59, air flowing through line 27 and line 73 in shaft 44 to retain the pistons in the ahead position shown; the other sides of the pistons are vented by lines 28 and 72. Ahead running. With the shaft 44 in this position the valves 48, 60 and 65 are closed, valves 56 are lifted away from the camshaft 53 and the sides of the rotary pistons previously subjected to air pressure now communicate with the engine lubricating system through a line 70 and another passage in shaft 44. The control rod 46 is released from the zero position by cam 68. Reversed starting. The corresponding position of shaft 44 causes cam 50 to displace the camshaft 53 to the right through lever 52 so that valves 56 engage the reverse cams on shaft 53. Space 59 connects, by a bore in the shaft 44, with the line 28 to reverse the coupling pistons, the other sides of which are vented via lines 27 and 72. The operation is otherwise the same as for ahead starting. Reverse running. This position of the apparatus differs from ahead running only in that the camshaft 53 is in the opposite position in respect thereto whilst the line 27 carries the oil and line 28 is vented.