Fuel injection arrangement for internal combustion engines

Claim 2

A fuel injection arrangement for an air-compressing, spontaneous ignition, internal combustion engine; said arrangement includes at least one electromagnetic control valve, via which a high-pressure channel associated with a fuel injection pump, which is provided with an intake line, can be connected with a low-pressure channel; said control valve includes a valve body which is in the form of a piston valve and is spring-loaded; said piston valve has a high-pressure end and a low-pressure end, and two end faces; said piston valve is axially movable in a first chamber which includes at least one high-pressure connection associated with said high-pressure channel and said high-pressure end of said piston valve, and at least one low-pressure connection associated with said low-pressure channel and said low-pressure end of said piston valve; said piston valve is in operative connection with an electromagnetic adjusting device; the improvement comprises the provisioning of said piston valve with a valve seat for delimiting that piston valve region on said high-pressure end of said piston valve; said last-mentioned region has a fixed diameter which corresponds to the diameter of said valve seat, and that piston valve region on said low-pressure end of said piston valve has a diameter which is less than said fixed diameter; said first chamber including a second chamber, which is associated with said high-pressure end of said piston valve and one of said end faces thereof, and a third chamber, which is associated with said low-pressure end of said piston valve and the other one of said end faces thereof; at least one line for connecting said high-pressure second chamber and said low-pressure third chamber; that piston valve region on said low-pressure end of said piston valve being provided with a fourth chamber which begins at said valve seat, and cooperates with said low-pressure connection of said first chamber.

Claim 3

A fuel injection arrangement according to claim 1, in which said spring-loading of said piston valve, and the connection of the latter to said adjusting device, are such that that end face region of said piston valve which is subjected to pressure from said high-pressure second chamber is greater than that end face region of said piston valve which is subjected to pressure from said low-pressure third chamber.

Claim 4

A fuel injection arrangement for an air-compressing, spontaneous ignition, internal combustion engine; said arrangement includes at least one electromagnetic control valve, via which a high-pressure channel associated with a fuel injection pump, which is provided with an intake line, can be connected with a low-pressure channel; said control valve includes a valve body which is in the form of a piston valve and is spring-loaded; said piston valve has a high-pressure end and a low-pressure end, and two end faces; said piston valve is axially movable in a first chamber which includes at least one high-pressure connection associated with said high-pressure channel and said high-pressure end of said piston valve, and at least one low-pressure connection associated with said low-pressure channel and said low-pressure end of said piston valve; said piston valve is in operative connection with an electromagnetic adjusting device; the improvement comprises the provisioning of said piston valve with a valve seat for delimiting that piston valve region on said high-pressure end of said piston valve; said last-mentioned region has a fixed diameter which corresponds to the diameter of said valve seat, and that piston valve region on said low-pressure end of said piston valve has a diameter which is less than said fixed diameter; said first chamber including a second chamber, which is associated with said high-pressure end of said piston valve and one of said end faces thereof, and a third chamber, which is associated with said low-pressure end of said piston valve and the other one of said end faces thereof; at least one line for connecting said high-pressure second chamber and said low-pressure third chamber; said spring-loading of said piston valve being effected by a spring which is provided at that end face of said piston valve at said high-pressure end thereof, and which acts upon said piston valve for closing same.

Claim 5

A fuel injection arrangement for an air-compressing, spontaneous ignition, internal combustion engine; said arrangement includes at least one electromagnetic control valve, via which a high-pressure channel associated with a fuel injection pump, which is provided with an intake line, can be connected with a low-pressure channel; said control valve includes a valve body which is in the form of a piston valve and is spring-loaded; said piston valve has a high-pressure end and a low-pressure end, and two end faces; said piston valve is axially movable in a first chamber which includes at least one high-pressure connection associated with said high-pressure channel and said high-pressure end of said piston valve, and at least one low-pressure connection associated with said low-pressure channel and said low-pressure end of said piston valve; said piston valve is in operative connection with an electromagnetic adjusting device; the improvement comprises the provisioning of said piston valve with a valve seat for delimiting that piston valve region on said high-pressure end of said piston valve; said last-mentioned region has a fixed diameter which corresponds to the diameter of said valve seat, and that piston valve region on said low-pressure end of said piston valve has a diameter which is less than said fixed diameter; said first chamber including a second chamber, which is associated with said high-pressure end of said piston valve and one of said end faces thereof, and a third chamber, which is associated with said low-pressure end of said piston valve and the other one of said end faces thereof; at least one line for connecting said high-pressure second chamber and said low-pressure third chamber; said spring-loading of said piston valve being effected by a spring which is provided at that end face of said piston valve at said high-pressure end thereof, and which acts upon said piston valve for closing same.

Claim 6

A fuel injection arrangement according to claim 3, in which said electromagnetic adjusting device is provided at that end face of said piston valve at said low-pressure end thereof, and acts upon said piston valve for opening same.

Claim 7

A fuel injection arrangement according to claim 4, in which said adjusting device is designed in such a way that it can actuate said piston valve for opening same after a prestroke travel of said adjusting device.

Claim 8

A fuel injection arrangement according to claim 5, in which said adjusting device comprises a first switching coil and a second switching coil, each of which includes an iron core and an armature.

Claim 9

A fuel injection arrangement according to claim 6, in which said piston valve is adapted to be actuated in the opening direction by said first switching coil.

Claim 10

A fuel injection arrangement according to claim 7, in which said piston valve is adapted to be held in the open position by means of said first switching coil.

Claim 11

A fuel injection arrangement according to claim 6, which includes a spring element which is attached to said armature of said first switching coil, and which can be prestressed by energization of said first switching coil.

Claim 12

A fuel injection arrangement according to claim 9, which includes a spacer provided on said armature of said first switching coil for delimiting the prestress travel of said spring element.

Claim 13

A fuel injection arrangement according to claim 6, in which during operation of said adjusting device, said first switching coil is adapted to be deenergized for actuating said piston valve in the opening direction.

Claim 14

A fuel injection arrangement according to claim 10, in which said armature of said second switching coil comprises two pieces, namely an inner armature part, and an outer armature part; said inner armature part is axially movable relative to said outer armature part.

Claim 15

A fuel injection arrangement according to claim 12, in which said inner and outer armature parts of said second switching coil can be coupled together for an axial movement.

Claim 16

A fuel injection arrangement according to claim 12, in which said piston valve is adapted to be actuated in the closing direction by deenergization of said second switching coil.

Claim 17

A fuel injection arrangement according to claim 12, in which said first and second switching coils, along with their associated armatures and iron cores, are associated with said low-pressure end of said piston valve; said inner armature part of said second switching coil is in direct operative connection with said piston valve, and said armature of said first switching coil is in direct operative connection with said inner armature part.

Claim 18

A fuel injection arrangement according to claim 15, which includes a stop element disposed between said armature of said first coil and said outer armature part for delimiting the axial stroke movement of the latter.

Claim 19

A fuel injection arrangement according to claim 16, in which said stop element, and said spacer of said armature of said first switching coil, are designed in such a way that at maximum prestress of said spring element, a pre-stroke space exists, in the closure position of said piston valve, between said inner armature part of said second switching coil, and said armature of said first switching coil.

Claim 20

A fuel injection arrangement according to claim 16, which includes a further spacer which is provided between said outer armature part and said iron core of said second switching coil for delimiting the axial movement of said outer armature part.

Claim 21

A fuel injection arrangement according to claim 18, in which a stop element is associated with that end face of said piston valve on said high-pressure end thereof.

Claim 22

A fuel injection arrangement according to claim 12, in which said fuel injection pump includes a pump element which can be rotated about an axis which extends in the longitudinal direction of said pump element; the latter is provided with a longitudinal groove.

Claim 23

A fuel injection arrangement according to claim 20, in which said longitudinal groove is provided in the surface of said pump element, and can be connected with a pump chamber.

Claim 24

A fuel injection arrangement according to claim 20, in which, for rotation thereof, said pump element can be actuated by a mechanical regulating device which is influenced by the speed of said internal combustion engine; said longitudinal groove can be made to overlap said intake line.

Claim 25

A fuel injection arrangement according to claim 20, in which a sensor is provided in the movement region of one of said armatures and said end faces of said piston valve; said sensor comprises a permanent magnet, pole pieces, and an induction coil, and, as a function of one of movement of said piston valve and an air gap at one of said end faces of said piston valve, generates a pulse-like signal of said control valve for beginning of closure and/or opening of said valve.

Claim 26

A fuel injection arrangement according to claim 12, which includes a holding element which can be connected to said fuel injection pump; said control valve is associated with said holding element, and can be held on said piston valve by means of a holding force applied in the longitudinal direction of the latter.