WO2019025063A1 - ELECTROMAGNETIC ACTUATING VALVE AND FUEL HIGH PRESSURE PUMP - Google Patents

Abstract

The invention relates to an electromagnetically operable valve (1), in particular a suction valve for a high pressure fuel pump (2), comprising an annular solenoid (3) and an armature (6) liftable between two end stops (4, 5), wherein the armature (6 ) is penetrated by at least one compensating bore (7), which defines a first outlet opening (8) in a first end face (9) of the armature (6) and a second outlet opening (10) in a second end face (11) of the armature (6) , According to the invention, the compensation bore (7) extends obliquely, rising and / or coiled at least in sections, so that when the second end face (11) projects onto the first end face (9) the second exit opening (10) is offset in the projection plane from the first exit opening (8th) ) is arranged. Furthermore, the invention relates to a high-pressure fuel pump (2) with such a valve (1).

Description

 Description title

 Electromagnetically operated valve and high-pressure fuel pump

The invention relates to an electromagnetically operable valve, in particular a suction valve for a high-pressure fuel pump, with the features of

The preamble of claim 1. Furthermore, the invention relates to a high-pressure fuel pump with such a valve.

State of the art

A fuel high-pressure pump of the aforementioned type is used to promote fuel to high pressure. For this purpose, fuel is in one

Element space of the high pressure pump sucked, compressed and against the pressure in a high-pressure accumulator, the so-called rail promoted. When using an electromagnetically actuated suction valve to fill the

Element space with fuel will this depending on the stroke of a

Pump piston of the high-pressure pump driven to a defined

Metering amount of fuel. Thus, only the current

Operating state actually required amount of fuel compressed. If a solenoid of the suction valve remains de-energized, a strong compression spring holds the suction valve open indirectly via an armature cooperating with the magnetic coil. Upon energization of the magnetic coil, a magnetic field is formed, as a result of which the armature moves relative to the magnetic coil in order to close a working air gap. As a result of the armature movement, a valve tappet of the suction valve loses the frictional contact with the armature and thus with the strong compression spring, so that a weaker valve spring is able to close the suction valve. After completion of the energization of the solenoid, the strong compression spring returns the armature to its original position, the armature again comes into contact with the valve stem and the suction valve opens again. As the armature moves, one volume is increased on one side of the armature and one volume on the other side of the armature. Thus, this does not affect the movement of the armature, this usually has at least one balance hole to create a pressure equalization.

Moreover, the movement of the armature may be affected by magnetic forces that cause the armature to move in a preferred direction. This may be due to eddy currents. These are undirected currents that lead to the formation of magnetic fields that do not act in the direction of movement of the armature. The armature is thus deflected radially, which has an increased friction and thus increased wear in the field of leadership of the anchor result.

The object of the present invention is to minimize the wear in the region of the armature guide of an electromagnetically actuated valve, in particular a suction valve. In this way, the life of the valve should be increased.

To solve the problem, the electromagnetically actuated valve with the features of claim 1 is proposed. Advantageous developments of the invention can be found in the dependent claims. Furthermore, a high-pressure fuel pump with such a valve is given as the preferred application of the valve.

Disclosure of the invention

The proposed electromagnetically operable valve, in particular suction valve, comprises an annular solenoid and a liftable between two end stops armature. The armature is penetrated by at least one compensating bore, which defines a first outlet opening in a first end face of the armature and a second outlet opening in a second end face of the armature. According to the invention runs the

Balancing hole at least partially oblique, rising and / or coiled, so that in a projection of the second end face on the first End face, the second outlet opening in the projection plane offset from the first outlet opening is arranged.

This means that the at least one compensating bore of the armature has, at least in sections, a course deviating from an axial course. The compensation hole is thus not or not continuously flowed through axially during operation of the valve. This has the consequence that flow forces act on the anchor, by means of which an undesirable deflection of the armature can be counteracted. The armature is thus less stressed on wear, which increases the life of the armature or the valve.

The course of the at least one compensation bore is preferably selected such that the armature is set into a rotational movement via the flow forces. This is especially the case when the course of the

Compensation bore is at least partially rising and / or coiled. In an at least partially oblique course, the compensation bore is preferably at least partially tilted with respect to a plane which runs parallel to the longitudinal axis of the armature. In this case, an oblique hole course leads to a rotational movement of the armature.

Does the anchor not only one when opening and closing the valve

Lifting movement, but also a rotational movement, constantly changes the angular position of the armature with respect to the guide. This means that at a possible deflection of the armature always other areas or contact points are claimed for friction and thus wear. This also contributes to an increase in the life of the valve.

Further preferably, the outlet openings of the compensation bore are each arranged eccentrically with respect to the respective end face. The radial distance of the outlet openings to the center of the respective end face promotes flow forces that set the armature in a rotation.

Furthermore, the second outlet opening is preferably arranged in the projection at an angular distance α from the first outlet opening. The distance between the two outlet openings to the center of the respective end face can be chosen to be the same size or different sizes. In the latter case, the second outlet opening is additionally arranged in the projection at a radial distance a from the first outlet opening.

Advantageously, the armature is penetrated by a plurality of compensation bores, which are arranged in the plan view of the armature at the same angular distance ß to each other. For example, two, three or four

Be provided compensation holes. The angular distance ß in this case is 180 °, 120 ° or 90 °. Due to the plurality of equiangularly spaced equalization holes ensures that the flow forces in the circumferential direction uniformly act on the anchor, so that any deflection of the armature is not enhanced by the flow forces. At the same time can be offset in this way, the anchor in a uniform rotational movement.

In a further development of the invention, it is proposed that the armature has a central recess. Through the central recess, the mass of the armature is further reduced, which has a favorable effect on the dynamics of the armature movement. Furthermore, the recess of the connection of the armature can serve with an anchor bolt, so that preferably an anchor bolt is received in the central recess. Furthermore preferably protrudes beyond

Anchor bolt the anchor to form a stop surface for contacting a valve stem of the valve. The stop surface of the anchor bolt is therefore claimed during operation of the valve also to wear. If the anchor rotates, the contact points of the anchor bolt also change with the valve lifter, so that the wear is reduced.

Alternatively or additionally, it is proposed that the anchor is stepped. In the stepped version of the anchor itself can form a stop surface for contacting a valve stem, which in the case of

Rotational movement of the anchor also a lesser

Wear stress is exposed.

Preferably, the end faces of the armature are circular. This means that the armature is at least partially cylindrical. The outer peripheral surface forms a cooperating with the armature guide guide surface. Preferably, therefore, the diameters of the circular end faces are the same size.

Furthermore, a high-pressure fuel pump for a

Fuel injection system proposed with a valve according to the invention.

Preferably, the valve is a suction valve, which is integrated in a housing part of the high-pressure fuel pump. In that the valve is special

is wear-resistant, the life of the high-pressure fuel pump is increased.

Preferred embodiments of the invention are explained below with reference to the accompanying drawings. These show:

1 shows a schematic longitudinal section through an inventive valve in the form of a suction valve, which is integrated in a high-pressure fuel pump,

2 an enlarged detail of FIG. 1 in the region of the armature, FIG.

3 shows a schematic cross section through the armature of the valve of FIG. 1,

4 shows a schematic longitudinal section through an armature of a valve according to a second preferred embodiment of the invention and FIG. 5 shows a schematic longitudinal section through an armature of a valve according to a third preferred embodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS The electromagnetically operable valve 1 illustrated in FIG. 1, which is a suction valve, serves to fill an element space 21 of a high-pressure fuel pump 2 with fuel. The valve 1 is for this purpose in a

Housing part 20 of the high-pressure fuel pump 2 is integrated, in such a way that a valve stem 17 of the valve 1 opens into the element space 21. The reaching over the valve 1 in the element space 21 fuel is on the Stroke movement of a pump piston 22 compressed and then fed via an outlet valve 24 a high-pressure accumulator (not shown).

The valve stem 17 of the valve 1 is acted upon in the closing direction by the spring force of a valve spring 18, on the one hand on the valve stem 17, on the other hand

Housing part 20 is supported. At the same time, the spring force of a spring 16 on the valve stem 17, which is supported on the one hand to an armature 6, on the other hand to a pole core 15, which limits together with the armature 6 a working air gap. The spring force of the spring 16 is greater than that of the valve spring 18, so that the spring 16 keeps the valve 1 open as long as the armature 6 and the

Polkern 15 partially surrounding magnet coil 3 remains energized. If the magnetic coil 3 is energized, forms a magnetic field whose magnetic force moves the armature 6 in the direction of the pole core 15 to close the working air gap. The valve stem 17 is relieved in this way, so that the valve spring 18 is able to close the valve 1. Is the current of the

Magnetic coil 3 ends, the spring 16, the armature 6 in his

Starting position back. In this case, an anchor bolt 13, which is received in a central recess 12 of the armature 6, comes into contact with the valve stem 17, so that the valve 1 opens again.

In the open position of the valve 1, the element space 21 is filled via an annular low pressure chamber 19 with fuel. The fuel is the

Low-pressure chamber 19 is supplied via an inlet bore 23 formed in the housing part 20.

When opening and closing the valve 1, the armature 6 moves between two end stops 4, 5 back and forth. The end stop 4 is presently formed by the pole core 15. The end stop 5 is formed by a valve body 14 or a stop disc supported thereon, the valve body 14 guiding the armature 6. The valve body 14 and the armature 6 are therefore claimed during operation of the valve 1 for wear.

2, the armature 6 is penetrated by a plurality of compensating holes 7, each extending from one end face 9 to the other end face 1 of the armature 6 and via discharge openings 8, 10 open into the pressure chambers formed on both sides of the armature 6 , In operation of the Valve 1 is thus flows through the armature 6 of fuel, whereby a pressure compensation can be effected.

The Fig. 3 it can be seen that the armature 6 a total of four

Equalizing holes 7, wherein the number may vary. The four compensating holes 7 are each arranged at the same angular distance ß to each other, so that the angular distance ß in the present case is 90 °. As can also be seen from FIG. 3, the compensation bores 7 are not axially guided by the armature 6, but have a rising or coiled course. That is, the compensating holes 7 are made warped in the circumferential direction. If the end face 9 is projected onto the end face 11, as indicated in FIG. 3, then the two outlet openings 8, 10 are one

Balancing bore 7 at an angular distance α to each other, wherein the

Angular distance α in this case is 45 °. The angular distance α can also be chosen larger or smaller. The chosen course of the

Compensation holes 7 has the consequence that act on the armature 6 in the operation of the valve 1 flow forces that put the armature 6 in a rotational movement (see arrows). The rotational movement of the armature 6 ensures a uniform wear stress in the region of its outer peripheral side guide surface, so that the life of the armature 6 and thus of the valve 7 increases.

A further preferred embodiment is shown in FIG. 4. Here, the outlet openings 8, 10 of the compensation holes 7 in the projection at a radial distance a to each other. At the same time they run obliquely with respect to a plane which is arranged parallel to a longitudinal axis A of the armature 6 and in the present case corresponds to the plane of the drawing.

As shown by way of example in FIG. 5, the compensating bores 7 can also have only an oblique, rising and / or coiled course in sections. This means that there are a large number of possible variations with regard to the specific embodiment of the armature 6.

Claims

claims 1. Electromagnetically actuated valve (1), in particular suction valve for a high-pressure fuel pump (2), comprising an annular solenoid (3) and between two end stops (4, 5) liftable anchor (6), wherein the armature (6) of at least one compensating bore (7) is interspersed, the one first outlet opening (8) in a first end face (9) of the armature (6) and a second outlet opening (10) in a second  Defined end face (11) of the armature (6),  characterized in that the compensating bore (7) extends at least partially obliquely, rising and / or coiled, so that in a projection of the second end face (11) on the first end face (9), the second outlet opening (10) offset in the projection plane to the first Outlet opening (8) is arranged. 2. Valve (1) according to claim 1,  characterized in that the outlet openings (8, 10) are each arranged eccentrically with respect to the respective end face (9, 11). 3. Valve (1) according to claim 1 or 2,  characterized in that the second outlet opening (10) in the projection at an angular distance (a) to the first outlet opening (8) is arranged. 4. Valve (1) according to one of the preceding claims, characterized in that the second outlet opening (10) in the projection at a radial distance (a) to the first outlet opening (8) is arranged. 5. Valve (1) according to one of the preceding claims, characterized in that the armature (6) of several  Equalizing holes (7) is interspersed, which are arranged in the plan view of the armature (6) at the same angular distance (ß) to each other. 6. Valve (1) according to one of the preceding claims,  characterized in that the armature (6) has a central  Recess (12), in which an anchor bolt (13) is preferably received. 7. Valve (1) according to one of the preceding claims,  characterized in that the armature (6) is stepped. 8. Valve (1) according to one of the preceding claims,  characterized in that the end faces (9, 11) of the armature (6) are circular, wherein preferably the diameters of the circular end faces (9, 11) are equal. 9. High-pressure fuel pump (2) for a fuel injection system with a valve (1) according to one of the preceding claims, wherein preferably the valve (1) is a suction valve, which in a housing part (20) of the high-pressure fuel pump (2) is integrated ,