DE102009001706A1 - Residual air gap disc - Google Patents

Abstract

The invention relates to a magnetic assembly (10) for actuating a fuel injector. The magnet assembly (10) comprises a magnetic core (22) and a magnetic sleeve (32) receiving it. An end face (26) of the magnetic core (22) has an armature (14, 16). A residual air gap disc (44) is inserted between the magnetic core (22) and the magnet sleeve (32).

Description

State of the art

DE 196 50 865 A1 describes a solenoid valve for controlling the fuel pressure in a control chamber of an injection valve, such. B. a common rail high-pressure accumulator injection system. About the fuel pressure in the control chamber, a lifting movement of a valve piston is controlled, with which an injection port of the injection valve can be opened or closed. The solenoid valve comprises an electromagnet, a movable armature and a valve member moved with the armature and acted upon by a valve closing spring in the closing direction, which valve member cooperates with the valve seat of the solenoid valve and thus controls the fuel drain from the control chamber.

In known solenoid valves, the swing occurring during operation of the armature and / or bouncing of the valve member has a disadvantageous effect. According to the solutions out DE 196 50 865 A1 and DE 195 08 104 A1 the armature of the solenoid valve is designed as a two-part armature, so as to reduce the moving mass of the armature / valve member assembly and thus the bouncing kinetic energy. The two-piece armature includes an anchor bolt and an armature plate slidably received on the armature bolt against the force of a return spring in the closing direction of the valve member under the action of its inertial mass. This is secured by means of a locking washer and a surrounding locking sleeve on the anchor bolt.

additional Damping devices are used, comprising a moved with the anchor plate and a fixed part. The one with the armature plate movable part comprises a fixed part facing approach to damping the ringing to cause the anchor plate with dynamic displacement of the same. The other part of the damping device is arranged at a fixed location Part of the solenoid valve designed as a Überhubanschlag. This limits the maximum path length around which the Anchor plate on the anchor bolt can move in the axial direction. The Überhubanschlag can by a front side of a Anchor bolt leading, fixed in the solenoid valve arranged Slider or by an upstream of the slider Part, such. As a disc may be formed. When approaching the moving with the anchor plate approach to this Überhubanschlag arises between the facing surfaces hydraulic damping chamber. The one in the hydraulic damping chamber Existing fuel generates a drag, that of movement counteracts the anchor plate, so that a ringing of the anchor plate is strongly attenuated.

at Solenoid valves for actuating fuel injectors In fuel injection systems, the residual air gap by means of a Residual air gap disc made of non-magnetic metal foil. The residual air disc made of non-magnetic metal foil is placed on the armature during assembly of the armature assembly and held down by a spring plate with the solenoid valve spring. Thereby It is ensured that the thin metal foil, which is the Represents residual air gap disc, always occupies a defined position or the movement of the armature follows. When designing the residual air gap disc is always a compromise between strength and stability and meet the hydraulic requirements. Because the residual air disc is fixed in the center of the anchor, is a connection to Magnetinnenpol manufacture, which extends over the spring chamber. This however, it provides the drain for the repatriated return flow Because of this conflict, the outflow of tax or Leakage amount can not be optimally designed so that the adjusting Anchor movement is not optimal. This means that the anchor is short before the upper stop, d. H. at this assigning end face of the magnetic core, is strongly attenuated and not reached or only after the liquid, d. H. the discarded fuel, from the gap completely is displaced.

Disclosure of the invention

Of the present invention is based on the object, a residual air gap disc to provide that can be used on solenoid valves, without the outflow of the return flow is hindered.

Of the proposed solution according to the invention following, the geometry of z. B. non-magnetic metal foil producible residual air gap significantly simplified. These is not according to the invention, as in previous Variants, on the spring plate on fixed to the anchor. This results in a simplification of the assembly process. The inventively proposed residual air gap disc no longer conceals, even partially, the spring space and thus obstructs not the outflow of the tax or leakage quantity in Direction of the low-pressure side return. The cross section the return geometry in the armature and magnet is independent from the position of the residual air gap disk.

The inventively proposed residual air gap disc is designed as a simple disc with a slit, which serves to avoid deformation executed. Optionally, a plurality of radial slots may be formed with a slot length which is smaller than the width of the annular-shaped residual air gap disc. Instead of on the Anchor or the magnetic core facing planar surface of the armature, the inventively proposed residual air gap disc is inserted between the magnetic core and the magnet sleeve and fixed by the magnetic core. The inner diameter of the inventively proposed residual air gap disc is chosen to be as large as possible, so that the inner pole of the magnetic coil, which is embedded in the magnetic core, is not covered, whereas the outer pole of the magnetic core is covered by the annular-shaped residual air gap disc.

The According to the invention proposed residual air gap disc Can be very easy between the assembly of the anchor assembly Magnetic core and a circular-shaped attack inserted at the bottom of the magnet sleeve and during assembly be fixed very easy and captive.

Brief description of the drawings

Based In the drawings, the invention will be described below in more detail.

It shows:

1 the annular-shaped residual air gap disc, arranged between the magnetic core and the magnetic sleeve,

2 a first embodiment of the present invention proposed residual air gap disc and

3 a further embodiment of the inventively proposed residual air gap disc.

embodiments

The representation according to 1 is to take a schematic representation of a magnetic group of a fuel injector.

A magnet assembly 10 associated with actuation of a fuel injector, e.g. B. a fuel injector for a high-pressure accumulator injection system (common rail) is in an injector body 12 admitted the fuel injector. The magnet assembly 10 opposite there is an anchor 14 whose plan page 16 through a solenoid valve spring 18 is charged. With reference number 20 is an adjustment ring designated, which serves to adjust the solenoid valve. The adjusting ring 20 lies in the injector body 12 on and serves as a support for a magnet sleeve 32 , The magnet sleeve 32 serves to accommodate a magnetic core 22 , The magnetic core 22 in turn, encloses a magnetic coil 24 , The magnetic core 22 is on a front side 26 that's the plan page 16 of the anchor 14 Opposite, open and by the location of the coil 24 in an inner pole 28 and a pole 30 divided.

From the illustration according to 1 it turns out that the magnet sleeve 32 with her inside 36 the magnetic core 22 encloses. The magnet sleeve 32 will be with an in 1 Not shown clamping nut on the injector body 12 attached to the fuel injector. The magnetic core 22 is fixed within the magnet assembly, for example via a flange or a welded joint.

The magnetic core 22 the magnet group 10 comprises a passage opening in which on the one hand the solenoid valve spring 18 that the anchor 14 on the plan page 16 charged, arranged, and on the other hand as a return 40 serves, on the actuated by the solenoid valve from a control chamber of the fuel injector controlled control amount or leakage in the low-pressure side return of a fuel injection system, for example, flows back.

From the illustration according to 1 shows that a residual air gap disc 44 at a clamping point 42 between the front side 26 of the magnetic core 22 and the top of the encroachment 34 the magnet sleeve 32 is clamped. Before mounting the magnet sleeve 32 and the magnetic core 22 is the z. B. as a thin metal foil made of non-magnetic material, eg. B. circular residual air gap disc 44 on the attack 34 in the magnet sleeve 32 inserted, and then the magnetic core 22 with the magnetic coil 24 assembled. When a clamping nut with a defined tightening torque is applied, the magnet assembly becomes in the injector body 12 attached.

Thus, in departure from previously common principles, the residual air gap disc 44 not on the plan page anymore 16 of the anchor 14 z. B. attached by a spring plate or the like, but in departure from the previous practice of the front page 26 of the magnetic core 22 the magnet assembly 10 assigned.

From the illustration according to 1 it turns out that in one embodiment of the residual air gap disc 44 in the form of a circular ring, see illustration according to the 2 and 3 , the indoor pole 28 of the magnetic core 22 remains free while the outer pole 30 of the magnetic core 22 from the residual air gap disk 44 is covered. The residual air gap disk 44 no longer conceals, even partially, the spring space, ie the passage opening in the low-pressure side return 40 and thus no longer obstructs the outflow of the control or leakage amount in the low-pressure side return 40 , The cross cut the return geometry, ie the low-pressure side return 40 in the magnet assembly 10 is independent of the position of the inventively proposed residual air gap disc 44 , With reference number 38 Anchor slots are designated by which the Absteuer of leakage or control amount is improved in the low-pressure side return. About the anchor slots 38 can the control amount or the leakage amount of the through hole of the magnetic core 22 flow, in which the solenoid valve spring 18 located.

From the illustration according to 2 is a first embodiment of the inventively proposed residual air gap disc can be seen.

2 shows that the residual air disc shown there 44 as a circular ring 48 is trained. A circular ring width of the circular ring 58 is by reference numerals 54 indicated. An inner diameter 50 the as a circular ring 48 trained residual air gap disc 44 is sized so that this is the outer diameter of the inner pole 28 of the magnetic core 22 the magnet assembly 10 exceeds, furthermore, the inner diameter 50 of the annulus 48 designed so that even the magnetic coil 24 essentially not made by the non-magnetic material, as a metal foil z. B. trained residual air gap disc 44 is covered. The inner diameter of the bore of the annular-shaped residual air gap disk is preferred 44 maximum as large as the inner diameter of the outer pole 30 or the outer diameter of the coil space in which the magnetic coil 24 is included.

The representation according to 2 is also to be seen that the as a circular ring 48 trained residual air gap disc 44 a continuous single slot 46 includes. The slot is used to prevent deformation during assembly of the non-magnetic metallic foil material manufactured residual air gap disc 44 in the clamping position 42 between the front side 26 of the magnetic core 22 and the attack 34 the magnet sleeve 32 ,

The representation according to 3 is a further embodiment of a trained as a circular ring residual air disc to remove.

In contrast to the representation according to 2 in which the as a circular ring 48 trained residual air gap disc 44 with a single slot 46 is attached to the in 3 shown further embodiment of the as a circular ring 48 trained residual air gap disc an inside slit 56 educated.

Starting from the inside diameter 50 of the annulus 48 extends a number of slots 60 in the radial direction. As shown in the illustration 3 shows that the slits are lost 60 not continuous, but have a slot length 58 on, which is smaller than the circular ring width 54 , The circular ring width 54 represents the difference between the outside diameter 52 and the inside diameter 50 of the annulus 48 between the end of the slot 60 and the outside diameter 52 of the annulus 48 accordingly remains a web width 62 , so that according to the illustration in 1 a circumferentially continuous fixation of the inventively proposed residual air gap disc 44 at the clamping point 42 between the attack 34 the magnet sleeve 32 and the front side 26 of the magnetic core 22 can achieve.

Although not shown in the drawing, so is a combination of in 2 and 3 illustrated embodiments of the as a circular ring 48 trained residual air gap disc 44 conceivable. So instead of a multitude of non-continuous slots 60 in accordance with the embodiment in 3 in this embodiment of the annulus 48 also a continuous single slot 46 be provided to compensate for deformations, so that a combination of the slot pattern of the embodiments according to the 2 and 3 results.

Remains as in 3 shown at the end of the non-continuous slots 60 a bridge width 62 the residual air gap disk material, this can be much easier to handle, in particular much easier before mounting the magnetic core 22 in the magnet sleeve 32 position.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 19650865 A1 [0001, 0002]
• DE 19508104 A1 [0002]

Claims (10)

Magnetic assembly ( 10 ) with a magnetic core ( 22 ) and a magnetic sleeve ( 32 ), one end face ( 26 ) of the magnetic core ( 22 ) an anchor ( 14 . 16 ), characterized in that a residual air gap disc ( 44 ) between the magnetic core ( 22 ) and the magnetic sleeve { 32 ) is inserted. Magnetic assembly ( 10 ) according to claim 1, characterized in that the residual air gap disc ( 44 ) at a clamping point ( 42 ) through the magnetic core ( 22 ) in the magnetic sleeve ( 32 ) is fixed. Magnetic assembly ( 10 ) according to claim 1, characterized in that the magnetic sleeve ( 32 ) one the front side ( 26 ) of the magnetic core ( 22 ) intervening ( 34 ) having. Magnetic assembly ( 10 ) according to claim 1, characterized in that the residual air gap disc ( 44 ) is made as a metallic foil of non-magnetic material. Magnetic assembly ( 10 ) according to claim 1, characterized in that the residual air gap disc ( 44 ) as a circular ring ( 48 ) is executed. Magnetic assembly ( 10 ) according to claim 1, characterized in that an inner diameter ( 50 ) of the residual air disc ( 44 ) is greater than an outer diameter of an inner pole ( 28 ) of the magnetic core ( 22 ). Magnetic assembly ( 10 ) according to claim 1, characterized in that the residual air gap disc ( 44 ) a continuous slot ( 46 ) having. Magnetic assembly ( 10 ) according to claim 1, characterized in that the residual air gap disc ( 44 ) one of the inner diameter ( 50 ) outgoing internal slit ( 56 ) from a number of slots ( 60 ). Magnetic assembly ( 10 ) according to claim 8, characterized in that the slots ( 60 ) in one length ( 58 ), which is smaller than the difference between outer diameter ( 52 ) and inner diameter ( 50 ) of the residual air disc ( 44 ). Use of the magnet assembly ( 10 ) according to one or more of claims 1 to 9 in a fuel injector of a fuel injection system.