DE102016218846A1 - Electromagnetically actuated inlet valve and high-pressure fuel pump - Google Patents

Abstract

The invention relates to an electromagnetically controllable inlet valve (18) for a high-pressure fuel pump, comprising an annular solenoid (38) for acting on a between two end stops (44, 46) liftable and with a valve member (22) coupled magnet armature (36) at least partially received in a receptacle (54) of a valve body (50). An end stop (44) is formed by a pole core (40) which defines a working air gap (42) together with the magnet armature (36) and at least one through hole (60) extending in the longitudinal direction of the magnet armature (36) is formed in the magnet armature (36) , The at least one through-bore (60) in the magnet armature (36) is permanently hydraulically in its end region facing the pole core (40) with an outer space (62) surrounding the magnet armature (36) and / or with an inner core located inside the magnet armature (36) Room (58) connected. Furthermore, the invention relates to a high-pressure fuel pump with such an inlet valve (18).

Description

The invention relates to an electromagnetically actuated inlet valve for a high-pressure fuel pump with the features of the preamble of claim 1. The inlet valve is used to supply the fuel high-pressure pump with fuel. Furthermore, the invention relates to a high-pressure fuel pump with such an inlet valve.

State of the art

From the DE 10 2014 200 339 A1 is an electromagnetically controllable inlet valve for a high pressure pump of a fuel injection system, in particular a common rail injection system, known, comprising an annular solenoid for acting on a lifting magnet armature and a pole core, which defines a working air gap together with the armature. The armature is at least partially surrounded by a valve body, which is designed as a screw plug and the attachment of the inlet valve to the high-pressure pump is used. The pole core and the valve body are connected by means of a sleeve, wherein the connection of the sleeve with the pole core via a weld. The armature has in its longitudinal direction extending through holes to allow a hydraulic compensation between the arranged on both sides of the armature spaces. To open the inlet valve, the solenoid is energized and the armature comes to the pole core to the plant. When the inlet valve is to close, the energization of the solenoid is stopped and the armature moves away from the pole core again. The opening and closing of the inlet valve and accordingly the movement of the armature must be done with high dynamics. When the magnet armature bears against the pole core, the through bores are at least partially covered, whereby a so-called hydraulic bonding is effected and a release of the magnet armature is hindered by the pole core. As a result, the dynamics of the movement of the armature is deteriorated.

Disclosure of the invention

The intake valve according to the invention with the features of claim 1 has the advantage that the dynamics of the movement of the magnet armature is improved because its at least one through hole is constantly connected hydraulically to the inner space of the armature and / or the outer space and thus the effect of hydraulic bonding is at least mitigated.

In the dependent claims advantageous refinements and developments of the inlet valve according to the invention are given. Due to the construction according to one of claims 2 to 4, the permanent connection of the through hole with the inner and / or outer space is made possible in a simple manner. The embodiment of claim 5 has the advantage that despite the hydraulic connection, the end face of the armature is not reduced and thus its capacity is not reduced. The embodiment of claim 6 has the advantage that no additional holes or depressions on the armature are required for the preparation of the hydraulic connection and thus this is particularly easy to manufacture.

Furthermore, a high-pressure fuel pump for a fuel injection system with an inlet valve according to the invention is proposed according to claim 8. The inlet valve is preferably integrated in a housing part of the high-pressure fuel pump. This means that the valve stem of the intake valve is guided over a bore of the housing part of the high-pressure fuel pump and / or cooperates with a valve seat formed in the housing part of the high-pressure fuel pump. By integrating the inlet valve in the high-pressure fuel pump, a particularly compact design can be created.

drawing

Several embodiments of the invention are illustrated in the drawing and are explained in more detail below. Show it 1 a section of a fuel high-pressure pump in a longitudinal section, 2a in an enlarged view a section II of 1 according to a first embodiment of an inlet valve, 2 B the first embodiment in a section along line II-II in 2a . 3a a variant of the first embodiment of the inlet valve, 3b the variant in a section along line III-III in 3a . 4 a further variant of the inlet valve according to the first embodiment in section along line II-II in 2a . 5 the inlet valve according to a second embodiment in a perspective view, 6 the inlet valve according to a third embodiment and 7 the inlet valve according to a fourth embodiment.

Description of the embodiments

In 1 is a detail of a high-pressure fuel pump shown, which promotes fuel in a high-pressure accumulator. The high-pressure fuel pump is supplied by a prefeed pump under Vorförderdruck standing fuel. The high-pressure fuel pump has a housing part 10 in the form of a cylinder head, in which in a cylinder bore 12 a pump piston 14 is guided, in the cylinder bore 12 a pump workroom 16 limited. The pump piston 14 is driven in a lifting movement, for example by a drive shaft having a cam on which the pump piston 14 for example, via a plunger, which may be designed as a roller tappet is supported. During the suction stroke of the pump piston 14 becomes the pump work space 16 via an inlet valve 18 filled with fuel and the delivery stroke of the pump piston 14 will fuel through an exhaust valve 20 displaced into the high pressure accumulator when the inlet valve 18 closed is.

The inlet valve 18 is electromagnetically actuated and is in the housing part 10 integrated in such a way that a piston-shaped valve member 22 of the inlet valve 18 in one in the housing part 10 trained hole 24 Hubbeweglich is guided. The valve member 22 of the inlet valve 18 opens into the pump workroom 16 , When the inlet valve is open 18 can fuel from one in the housing part 10 formed low pressure space 26 via inlet bores 28 into the pump workroom 16 to stream. In the closing direction is the valve member 22 from the spring force of a valve spring 30 acted upon, so that the spring force of the valve spring 30 the valve member 22 in the direction of a valve seat 32 draws. To the inlet valve 18 against the spring force of the valve spring 30 to hold open or open is another feather 34 provided, whose spring force is greater than that of the valve spring 30 is. For the operation of the inlet valve 18 an electromagnetic actuator is provided, which is a magnet armature 36 , a magnetic coil surrounding this ring 38 and a pole core 40 includes. The other spring 34 is on the one hand on the armature 36 and on the other hand at the pole core 40 supported. When the solenoid 38 is de-energized, so presses the spring 34 the magnet armature 36 to the valve member 22 out, so that the magnet armature 36 for contact with the valve member 22 passes and the inlet valve 22 opens or keeps open. Will the solenoid coil 38 energized, forms a magnetic field whose magnetic force the armature 36 in the direction of the pole core 40 moves one between the pole core 40 and the armature 36 trained working air gap 42 close. The valve member 22 is relieved in this way, so that the valve spring 30 the valve member 22 in the valve seat 32 to draw.

The working air gap 20 limiting pole core 40 forms an end stop 44 for the lifting magnet armature 36 out. Another end stop 46 for the magnet armature 36 is by a ring collar 48 in a valve body 50 or one on the ring collar 48 supported stop plate 52 educated. The valve body 50 has a hole 54 on, which is a receptacle for the magnet armature 36 forms and in which the magnet armature 36 over its outer jacket in the direction of its longitudinal axis 37 Hubbeweglich is guided. The stop plate 52 causes a magnetic separation between the armature 36 and the valve body 50 because it is made of a non-magnetic material. It also reduces wear, since the material is also particularly resistant to wear. The axial distance between the pole core 40 and the stop plate 52 determines the stroke of the armature 36 , To the location of the pole core 40 to fix, is the Polkern 40 by means of a sleeve 56 with the valve body 50 firmly connected. The sleeve 56 is preferred for this purpose both with the pole core 40 as well as with the valve body 50 welded.

The magnet armature 36 has an approximately cylindrical shape and in this is the pole core 40 towards a recess 58 formed, for example in the form of a blind bore. In the recess 58 sticks out the spring 34 into it, located at the bottom of the recess 58 supported. The magnet armature 36 also has at least one in the direction of its longitudinal axis 37 running through hole 60 on, preferably several over the circumference of the armature 36 distributed through holes 60 are provided. Through the through holes 60 becomes a connection through the armature 36 on the one hand to the pole core 40 towards the valve member 22 made limited spaces and thus the lifting movement of the surrounded by fuel magnet armature 36 allows. The recess 58 in the magnet armature 36 forms an inner space and on its outer jacket is the magnet armature 36 in his pole core 40 facing end portion of an outer space 62 surrounded by the sleeve 56 is limited.

According to the invention it is provided that the through holes 60 of the magnet armature 36 constantly with the in the recess 58 formed inner space of the magnet armature 36 and / or with the outer space 62 hydraulically connected. This means that the hydraulic connection of the through holes 60 even then are open when the armature 36 at the pole core 40 as the first stop 44 is applied.

In the 2a and 2 B is the inlet valve 18 illustrated according to a first embodiment, wherein the hydraulic connection of the through holes 60 with the inner space 58 and / or the outer space 62 through in the pole core 40 facing end face 35 of the magnet armature 36 trained wells 64 is formed. The wells 64 are designed as grooves and these extend approximately radially to the longitudinal axis 37 of the magnet armature 36 starting from the through holes 60 inside and out. Every through hole 60 is thus over the radially inwardly extending portion of a recess 64 with the inner space 58 and over the radially outwardly extending portion of a recess 64 with the outer space 62 connected. The hydraulic connection of the through holes 60 allows pressure equalization in the radial direction, so that hydraulic adhesive effects is counteracted when the armature 36 a lifting movement from the pole core 40 executes away.

In the 3a and 3b is a variant of the intake valve 18 illustrated in the first embodiment, in which the training is substantially the same as in the first embodiment, however, the wells 66 not in the magnet armature 36 but in the magnet armature 36 facing, the end stop 44 forming end face of the pole core 40 are formed. The wells 66 extend at least approximately radially to the longitudinal axis 37 of the magnet armature 36 and in the circumferential direction of the armature 36 so that these are with its through holes 60 cover.

In 4 is another variant of the intake valve 18 illustrated, in which the training is substantially the same as in the first embodiment and thus the wells 64 exist in the form of radially extending grooves. In addition, in the variant according to 4 further wells 68 provided in the form of radially extending grooves in the peripheral areas between the through holes 60 of the magnet armature 36 are arranged. Through these further wells 68 be hydraulic connections between the inner space 58 and the outer space 62 produced. Alternatively or in addition to the further recesses formed in the form of radially extending grooves 68 can also do more wells 69 in the form of circumferentially about the longitudinal axis 37 of the magnet armature 36 be provided circumferential grooves. Through the other wells 69 in the form of circumferential grooves are the through holes 60 of the magnet armature 36 hydraulically connected to each other and, if present, the other wells 68 in the form of radially extending grooves. The other wells 68 . 69 can in the face of the magnet armature 36 and / or the pole core 40 be educated.

In 5 is the inlet valve 18 according to a second embodiment illustrated in which the hydraulic connection of the through holes 60 of the magnet armature 36 with the inner space 58 and / or outer space 62 this causes the pole core 40 facing end face of the armature 36 and / or the armature 36 facing Sitrnfläche the pole core 40 with a structured surface 70 is provided, which has a variety of wells 71 having. The wells 71 the structured surface 70 may form a lattice-shaped pattern, wherein the intersecting groove-shaped depressions 71 extending from radially outside to radially inside and thus the through holes 60 with the inner space 58 and / or outer space 62 connect. The depth of the groove-shaped depressions 71 is preferably at least 0.05 mm.

In 6 is the inlet valve 18 according to a third embodiment illustrated in which the hydraulic connection of the through holes 60 of the magnet armature 36 with the inner space 58 and / or outer space 62 caused by that in the armature 36 near the pole core 40 facing end at each through hole 60 an opening into this transverse bore 72 is provided in the inner space 58 or in the outer space 62 empties.

In 7 is the inlet valve 18 according to a fourth embodiment illustrated in which the hydraulic connection of the through holes 60 of the magnet armature 36 with the inner space 58 and / outer space 62 This causes the cross section of the through holes 60 in their end areas 61 to the pole core 40 enlarged. The mouths of the end areas 61 the through holes 60 are then not completely through the the end stop 44 forming end face of the pole core 40 covered but protrude beyond this radially out into the inner space 58 and / or outer space 62 , The end areas 61 the through holes 60 For example, they may be designed conically or rounded for increasing the cross-section.

The above-described embodiments of the magnet armature 36 and the polkernel 40 can be combined with each other in any way.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102014200339 A1 [0002]

Claims (8)

Electromagnetically actuated inlet valve ( 18 ) for a high-pressure fuel pump, comprising an annular magnet coil ( 38 ) affecting one between two end-stops ( 44 . 46 ) liftable and with a valve member ( 22 ) coupled magnet armature ( 36 ), at least in sections in a picture ( 54 ) of a valve body ( 50 ), wherein an end stop ( 44 ) from a pole core ( 40 ) is formed, which together with the armature ( 36 ) a working air gap ( 42 ) and wherein in the magnet armature ( 36 ) at least one in the longitudinal direction of the armature ( 36 ) running through bore ( 60 ), characterized in that the at least one through-bore ( 60 ) in the magnet armature ( 36 ) in her the Polkern ( 40 ) end region constantly hydraulically with a magnet armature ( 36 ) in which the pole core ( 40 ) facing the outer end region ( 62 ) and / or within the magnet armature ( 36 ) lying inner space ( 58 ) connected is. Inlet valve according to claim 1, characterized in that the pole core ( 40 ) a the magnet armature ( 36 ) facing stop surface ( 44 ), that the magnet armature ( 36 ) one of the stop surface ( 44 ) of the pole core ( 40 ) facing end face ( 35 ) and that the stop surface ( 44 ) of the pole core ( 40 ) and / or the end face ( 35 ) of the magnet armature ( 36 ) for the hydraulic connection of the at least one through-bore ( 60 ) of the magnet armature ( 36 ) with the outer space ( 62 ) and / or inner space ( 58 ) at least one depression ( 64 . 66 . 68 . 69 ) having. Inlet valve according to claim 2, characterized in that the at least one recess in the form of a groove ( 64 . 66 . 68 . 69 ) is formed, which in particular approximately radially with respect to the longitudinal axis ( 37 ) of the magnet armature ( 36 ) or in the circumferential direction about the longitudinal axis ( 37 ) of the magnet armature ( 36 ) runs. Inlet valve according to claim 1, characterized in that the pole core ( 40 ) a the magnet armature ( 36 ) facing stop surface ( 44 ), that the magnet armature ( 36 ) one of the stop surface ( 44 ) of the pole core ( 40 ) facing end face ( 35 ) and that the stop surface ( 44 ) of the pole core ( 40 ) and / or the end face ( 35 ) of the magnet armature ( 36 ) for the hydraulic connection of the at least one through-bore ( 60 ) of the magnet armature ( 36 ) with the outer space ( 62 ) and / or inner space ( 58 ) a structured surface ( 70 ) with several groove-shaped depressions ( 71 ), which preferably extend in a lattice-like manner. Intake valve according to one of the preceding claims, characterized in that the magnet armature ( 36 ) near the pole core ( 40 ) facing end at least one in the at least one through hole ( 60 ) transverse bore ( 72 ), through which the through-bore ( 60 ) with the outer space ( 62 ) and / or inner space ( 58 ) is hydraulically connected. Inlet valve according to one of the preceding claims, characterized in that the cross section of the at least one through-bore ( 60 ) in the magnet armature ( 36 ) in which the pole core ( 40 ) facing end region ( 61 ) such that the at least one through-bore ( 60 ) at the pole core ( 40 ) applied magnet armature ( 36 ) with the outer space ( 62 ) and / or inner space ( 58 ) is hydraulically connected. Inlet valve according to one of the preceding claims, characterized in that the pole core ( 40 ) via a sleeve ( 56 ) with the valve body ( 50 ), wherein preferably the sleeve ( 56 ) with the pole core ( 40 ) and / or the valve body ( 50 ) and that the outer space ( 62 ) through the sleeve ( 56 ) is limited. High-pressure fuel pump for a fuel injection system with an inlet valve ( 18 ) according to one of the preceding claims, wherein the inlet valve ( 18 ) preferably in a housing part ( 10 ) of the high-pressure fuel pump is integrated.

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