Patent GB-532323-A (GB)
Title: Improvements in or relating to speed regulation for internal combustion engines of the injected fuel type
IPC: F02M59/36
Filed: 1939-07-19
Abstract: 532,323. Fuel injection pumps. SOC. ANON A. SAURER. July 19, 1939, No. 20948. Convention date, July 20, 1938. [Class 102 (i)] In a method of regulating the speed of internal combustion engines of the injected fuel type, a reciprocating control element such as the piston 11 is driven positively in one direction and impositively in the other direction to control an opening leading from the pump delivery space to a space of lower pressure, thus determining the amount of fuel injected in accordance with the speed of the impositive movement. The cam 1, Fig. 1, acts through a roller 4 to reciprocate a pump plunger 3. One arm of a bell crank lever 15 engages a slot 16 in the roller carrier and the other arm operates the control piston 11, the motion to the left being effected positively and the motion to the right by a spring 20 or by magnetic, hydraulic, or other non-positive means. Fuel is supplied from a line 6 leading to a suction valve 21 and adjustable throttle valve 23. During upward plunger movement, control piston moves positively to the left and draws a constant amount of fuel into space 12. On the downward stroke some of this fuel flows through passages 13, 29, to the plunger space 7 and is subsequently pumped along passage 8 to the nozzle. The non positive motion of the control piston which has a greater displacement than the pump plunger is determined partly by the filling of the space 7 and partly by the adjusted setting of the needle valve 25 leading to space 22. If for instance the setting of valve 25 corresponds to a medium speed of revolution and the actual speed is lower than this then on upward movement of the pump from the Fig. 1 position the passage 29 is first covered and then delivery occurs along passage 8 until the control piston has uncovered passage 13 which stops delivery after which continued movement of the control piston opens valve 21. On downward movement of the plunger the control piston moves impositively to the right and if the speed is too low the passage 13 will be closed before the next delivery stroke commences and a full injection will be made. As the speed increases a point is reached where the bore 13 is not closed at the beginning of the Injection stroke and a reduced charge is injected. At still higher speeds the bore 13 is not closed at all and no fuel is injected. By opening the needle valve 25 the impositive movement is accelerated and the engine will run at higher speed. If the needle valve is closed the impositive movement is so retarded that the passage 13 will not be closed and the engine will stop. The bell crank 15 is concentrically pivoted and may be adjusted to vary the maximum injection of fuel. In a modification the passage 29 may have a non- return valve so that delivery commences immediately the plunger starts the upward movement. In another modification, Fig. 3, the control piston is located in the axis of the plunger and the spring 20 is sufficiently strong to prevent the piston from rising during the delivery stroke. The control piston is stepped, the lower part carrying the control edge.