Electromagnetically actuated pumps

Claim 2

In an automotive power plant, the combination of: an internal combustion engine having an intake manifold; a fuel injection system comprising at least two positive displacement pumps and a common actuator for said pumps, said common actuator being in the form of a plate-like armature, electromagnetic drive means for shuttling said armature back and forth sequentially to actuate said pumps, pulse generator means for periodically energizing said electromagnetic drive means, and first and second stop means for positively and substantially instantaneously terminating the movements of said armature to delinete the end points of its back and forth movements, said stop means being constituted by a pair of rigid members disposed in spaced relation so that the spacing fixes said end points of armature movements correspondingly to fix the strokes of said pumps, at least said first stop means being movable to change said spacing and thereby alter the strokes of said pumps; and control means connected to said intake manifold and responsive to pressure variations therein for moving said first stop means to vary said spacing and the strokes of said pumps.

Claim 3

In an automotive power plant as defined in claim 1 wherein said first stop means is in the for of a wedge member and said control means shifts said wedge member along its length.

Claim 4

In an automotive power plant as defined in claim 2 including switch means responsive to predetermined low pressure condition in said intake manifold for disabling said pulse generator means.

Claim 5

In an automotive power plant as defined in claim 3 wherein said switch means is actuated by said control means.

Claim 6

In an automotive power plant as defined in claim 4 wherein said control means is in the form of a piston-cylinder assembly in which one side of said piston is subjected to intake manifold pressure while the other side thereof is subjected to ambient pressure.

Claim 7

In an automotive power plant as defined in claim 5 wherein said wedge member is lengthwise aligned with said piston.

Claim 8

In an automotive power plant as defined in claim 1 wherein said fuel injection system includes a pair of cylinder blocks each having a chamber corresponding to one of said pumps, said cylinder blocks being spaced apart and said chambers being aligned along a common axis bridging between the cylinder blocks, said armature having an end portion disposed between said cylinder blocks, said wedge member being disposed adjacent one of said cylinder blocks and positioned with its axis essentially orthogonal with respect to said common axis and presenting an inclined ramp facing said end portion of the armature.

Claim 9

In an automotive power plant as defined in claim 7 wherein the slope of said ramp is not greater than 1:10.

Claim 10

In a fuel injection system for internal combustion engines, the combination of: electrically actuated pump means for discharging fuel at intermittent intervals and at increasing volumetric rate during each such interval, said pump means including a pumping member, an armature connected to said pumping member and a pair of electromagnets closely spaced on opposite sides of said armature for attracting said armature, and pulse generating means intermittently and alternately energizing said electromagnets to pump fuel; stop means for substantially instantaneously terminating pump stroke motion of said pumping member and comprising a pair of rigid stop members disposed in spaced relation in the path of movement of said pumping member so that the spacing fixes the end points of movements of said pumping member, at least one of said stop members being movable to alter said spacing and thereby change the pump stroke imparted to said pumping member by said armature; and control means adapted to sense engine operating conditions for producing low energy force input to said movable stop member, which force input is effective accurately to position said movable stop member, in the absence of pump means-induced forces acting against said movable stop member, in accord with instantaneous demand of the associated engine; said pulse generating means producing pulses having sufficiently short time durations of electromagnet energization as to permit a high frequency of pumping strokes, the proximity of said electromagnets to and the mass of said armature being such as to cause said armature to execute a pump stroke within a time period which is a fraction of and occurs at least near the end of an energizing time duration whereby there is at least an initial period of the energizing time duration in which the low energy force input of said control means is effective to allow said movable stop member to be moved and thereby cause the output of said pump means closely to follow the instantaneous demand of the associated engine.

Claim 11

In a fuel injection system for internal combustion engines, the combination of: electrically actuated pump means for discharging fuel at intermittent intervals and at increasing volumetric rate during each such interval, said pump means including a pumping member, an armature connected to said pumping member and a pair of electromagnets closely spaced on opposite sides of said armature for attracting said armature, and pulse generating means intermittently and alternately energizing said electromagnets to pump fuel; stop means for substantially instantaneously terminating pump stroke motion of said pumping member and comprising a pair of rigid stop members disposed in spaced relation in the path of movement of said pumping member so that the spacing fixes the end points of movements of said pumping member, at least one of said stop members being movable to alter said spacing and thereby change the pump stroke imparted to said pumping member by said armature; and control means adapted to sense engine operating conditions for producing low energy force input to said movable stop member, which force input is effective accurately to position said movable stop member, in the absence of pump means-induced forces acting against said movable stop member, in accord with instantaneous demand of the associated engine; said pulse generating means producing pulses having sufficiently short time durations of electromagnet energization as to permit a high frequency of pumping strokes, the proximity of said electromagnets to and the mass of said armature being such as to cause said armature to execute a pump stroke within a time period which is a fraction of and occurs at least near the end of an energizing time duration whereby there is at least an initial period of the energizing time duration in which the low energy force input of said control means is effective to allow said movable stop member to be moved and thereby cause the output of said pump means closely to follow the instantaneous demand of the associated engine.

Claim 12

In a fuel injection system as defined in claim 9 wherein said time durations are in the order of not more than about 10 milliseconds.

Claim 13

In a fuel injection system as defined in claim 10 wherein said control means is in the form of a pressure sensor adapted to be connected to the intake manifold of the associated engine.

Claim 14

In a fuel distribution system as defined in claim 11 including switch means actuated by said pressure sensor for disabling said pump means in response to detection of a numerically large value of negative pressure sensed by said pressure sensor.

Claim 15

In a fuel injection system as defined in claim 9 wherein said control means is in the form of a pressure sensor adapted to be connected to the intake manifold of the associated engine.

Claim 16

In a fuel distribution system as defined in claim 13 including switch means actuated by said pressure sensor for disabling said pump means in response to detection of a numerically large value of negative pressure sensed by said pressure sensor.

Claim 17

In a fuel injection system as defined in claim 9 wherein said movable stop member is in the form of a wedge.

Claim 18

In a fuel injection system as defined in claim 9 wherein said control means is in the form of a cylinder and a piston slidable in said cylinder, said piston being connected to said movable stop member and said cylinder on one side of said piston being adapted for connection to the intake manifold of an associated engine.

Claim 19

In a fuel injection system as defined in claim 16 wherein said piston is barrel shaped.

Claim 20

In a fuel injection system as defined in claim 16 including a spring acting against said piston via a central ball.

Claim 21

In the combination as defined in claim 9 wherein said pulse generating means comprises a monostable multivibrator circuit.

Claim 22

In the combination as defined in claim 19 including switch means actuated by said control means, said switch means disabling said pump means when said internal pressure in the intake manifold indicates a condition in which the engine is being driven.