Patent GB-885616-A (GB)
Title: Improvements in or relating to diesel engines
IPC: F01L13/00
Filed: 1960-03-30
Abstract: 885,616. Starting; stopping; reversing. MOTOREN - WERKE MANNHEIM A.G. March 30, 1960 [April 16, 1959], No. 11265/60. Class 7(5). In a safety device for preventing the starting of a reversible diesel engine in the wrong direction of rotation after a reversing operation, the reversal of the diesel engine being arranged to be brought about by means of reversing valves and there being a shut off member for controlling the supply of starting air to the engine cylinders, the flow of starting air to the engine cylinders via the shut off member being controlled by a starting valve and on the initiation of a reversing operation the fuel injection pump of the engine being arranged to be locked in the zero delivery position by the operation of one of the reversing valves, a speed dependent control member is arranged to open a path for the starting air to the engine cylinders and to release the locking of the injection pump only in the case of the engine being stopped or in the case of the engine speed being reduced to a value which is safe for the reversing operation, the shut off member being locked in the open position so that starting air passes to the engine cylinders as long as the starting valve is operated. In Fig. 2 the camshaft 20 is shown in the ahead position. If the push button 1c is pressed compressed air is admitted to the space 12 of the operating cylinder 8 and the lever 16 moves to the Z position. The lever 16 can also be moved by hand to this position. The multiple cam 18 is thereby rotated in the anti-clockwise direction and the individual cam 18b opens the reversing valve 25 whereby compressed air is admitted to the oil container 35b by way of lines 34 and 34a. At the same time compressed air passes through the line 34b to the port 40b of the double non-return valve 40 forcing the valve piston 40a to the right to close the orifice 40c. Compressed air passes via the line 41 to the port 39c of the double non-return valve 39 where it presses the valve piston downwardly. Compressed air thus acts via the line 42 on the side 46f of the piston 46a. The piston 46a moves into its upper position and by means of the piston rod 46b and the bell crank 47 moves the control rod 45 into the stop position, i.e. the position in which the fuel injection pump of the engine gives zero delivery. The roller 48a engages the catch 47b so that the control rod 45 is locked in the stop position. The engine speed therefore falls. In the meantime the air admitted to the container 35b has brought about movement of the cam-shaft to the left (Fig. 2). The cam 18b comes out of engagement with the valve 25a shortly before the left hand end position is reached, while the individual cam 18d opens the valve 26. It will be assumed that due to the turbine effect of the ship's propeller the engine speed is still so high that reliable reversal is impossible. In this case the centrifugal weights 52b press the shoulder 55b on to the rubber ring 56a so that communication is cut off between the lines 32, 32a and 32d. The piston 46a remains in its upper position and the shut off member 50 remains closed. When the speed drops to a value which is safe for reversal the force of the spring 57 overcomes the force exerted by the centrifugal weights and lifts the shoulder 55b off the rubber ring 56a. The pressure of the starting air now bears on the plunger 55 and presses its shoulder against the rubber ring 56b thereby shutting the bore 55f off from atmosphere. The side 46e of the piston 46a is put under pressure, the piston rod 46b moves downwardly and the valve 50 is opened. The roller 48a disengages the catch 47b and the control rod 45 is left to the influence of the speed governor (not shown) which brings it to the position for full injection quantity. High pressure compressed air passes from the opened valve 26 through the valve 50 and the lines 32, 32b, 32c to the main starting valve 30 and opens the latter thereby admitting compressed air to the engine cylinders. The engine is thereby braked and started in the astern direction of rotation. Upon the pushbutton lc or the lever 16 being released the latter returns to the central position. Cam 18d is thereby brought out of engagement with the valve 26 and the latter and the main starting valve 30 close. Reversing from astern to ahead is controlled by the valve 2. When the button 3c is pressed, compressed air passes via the valve 3 through the line 38 to the double non-return valve 39 where it presses the valve piston 39a upwardly. Compressed air passes to the cylinder 46 and the control rod 45 is brought to the stop position.