DE102010061793A1 - Electromagnetically actuated switching valve, in particular quantity control valve in particular for controlling the delivery rate of a high-pressure fuel pump - Google Patents

Abstract

An electromagnetically actuated quantity control valve, in particular for controlling the delivery rate of a high pressure pump, is described. The high-pressure pump has a movement space (28) which can be filled with a fluid (30), a movement part (22) of an electromagnetic actuating device arranged in this and a stop (26). A disk-like intermediate element (50) is preferably arranged between the moving part (22) and the stop (26).

Description

State of the art

The invention relates to an electromagnetically actuated switching valve according to the preamble of claim 1.

Switching valves, in particular quantity control valves, which have an electromagnetically actuated valve element are known from the market. Thus, the amount of fuel supplied to a high-pressure pump can be influenced in the fuel injection system of an internal combustion engine.

It is also known to provide abutment surfaces on a valve element coupled to an armature, which interact with associated abutment surfaces on a valve housing. As a result, the movement of the armature or of the valve element can be defined defined.

It is also known to provide an armature of the electromagnet, for example, with longitudinal bores in order to adjust the damping occurring during the movement of the armature can. Through such axial bores in the armature fluid, so fuel, transported from one axial side of the armature to the other side. As an alternative to an axial bore in the armature, it is also known to provide axial grooves on a peripheral wall of the armature, which also allow a fluid exchange between the two sides of the armature.

Disclosure of the invention

The invention provides an electromagnetically operated switching valve according to claim 1 is provided. Advantageous developments are specified in subclaims. Features which are important for the invention can also be found in the following description and in the drawings, wherein the features, both alone and in different combinations, can be important for the invention, without being explicitly referred to again.

The switching valve according to the invention has a movable in a housing portion in two directions moving part, wherein a direction of movement is limited by a stop. The housing section can be filled with fluid. Between the moving part and the stop an intermediate element is arranged. This is preferably, but not necessarily disc-like, so with a relatively large ratio between diameter and thickness. In many actual implementations, the intermediate element has the function of a known as residual air gap disc part, so there is also referred to as residual air gap disc. Such a residual air gap disc ensures that there is always a distance between the armature and magnetic pole, regardless of whether the space between the armature and magnetic pole is actually filled with air or another substance, for example the material of the residual air gap disc.

In the following, the "movement part" is referred to concretely as a magnetically actuated "armature".

An advantage of the invention is that during a tightening movement, i. H. a movement of the armature on the stop, in the region of two contact surfaces before the impact of the armature on the stop with the intermediate intermediate element in conjunction with the fluid at least one pressure cushion is formed, which reduces the speed of movement of the armature. This effect is called squeezing effect.

Another advantage of the invention is evident in a peel-off movement, i. H. a movement of the armature away from the stop, starting from a concern of the armature to the intermediate element and a simultaneous abutment of the intermediate element to the stop. In the region of the two contact surfaces arise one or two volumes which are filled with the fluid: one between the intermediate element and the stopper and - in the majority of embodiments - another between the armature and the intermediate element. The inserted between the armature and the stopper intermediate element makes it possible to reduce a so-called hydraulic bonding of the armature, and thus reduce switching times.

Impact deceleration and reduced hydraulic sticking will increase the NVH (Noise, Vibration & Harshness) characteristics of the switching valve, i. H. the properties regarding noise, vibration and roughness, influenced in a positive way.

The impact delay reduces the pulsation of the pressure during the tightening movement. Also Preller, d. H. a multiple impact during the tightening movement by resilient properties of the components involved are minimized. A reduction in the tendency to cavitation is achieved by the time-damped pressure curve and thus a slight tendency to locally sudden pressure differences.

With the preceding advantages is also achieved that a low strength-critical load and low erosion and thus increased life of the components involved such as welds, sleeves, o. Ä. Is reached. Also, it will allow an accurate Flow rate over the lifetime as well as short operating times can be guaranteed.

In an advantageous embodiment of the electromagnetically actuated switching valve, the intermediate element is made of a non-magnetic material, for example as austenitic alloy. This results in the advantage of a magnetic separation of armature and stop. In contrast to a version made of magnetic material, in this case no great force has to be expended for the separation of the armature from the intermediate element and the intermediate element from the stop.

The fact that the non-magnetic intermediate element is arranged between the armature and the stop, no direct contact between the armature and the stop is possible. As a result, the surfaces of the armature and the stop must not be provided with a non-magnetic coating, since the magnetic separation is done by the intermediate element.

In an advantageous development of the invention, in which the armature rests against the intermediate element and the intermediate element against the stop, there are two contact surfaces which are determined by surfaces of the three contact elements, the armature, the intermediate element and the stop. The surfaces are smaller than the total area of the anchor, the intermediate element or the stop.

Advantageously, the residual air gap disc defines the contact surfaces between the contact elements. As a result, in many, but not all, embodiments of the invention, neither the armature nor the stop must have a special shape on the respective end face. This can reduce the complexity of the shape of the surfaces of the armature and the stop.

The design of the respective surfaces of the armature, the intermediate element and the stop especially with regard to the size and shape of the contact surfaces, a compromise between the impact attenuation and the hydraulic bonding is achieved.

In an advantageous embodiment of the electromagnetically operable switching valve, axial channels within the armature cause a rapid filling of the volumes arising in the region of the contact surfaces to be achieved during the drawing off movement. The axial channels are also advantageous in the tightening movement, since the fluid, which is located in the region of the contact surfaces, can flow off quickly.

In an advantageous embodiment of the electromagnetically operable switching valve, the intermediate element has an annular plan view. This offers the advantage that, in the case of the contact partners, a gap remains free radially within the intermediate element. This gap facilitates the filling of the volumes resulting from the removal movement in the area of the contact surfaces.

An advantageous embodiment of the electromagnetically actuated switching valve provides that the intermediate element conceals an opening of the axial channel and does not obscure a further opening. Due to the strong compression of the fluid at the covered mouth, the armature movement is slowed down and, due to the high pressure drop between the two sides of the intermediate element, a braking pressure cushion is created. When concerns the intermediate element closes the covered mouths. In the subsequent removal movement, the uncovered mouth offers the advantage that fluid can flow without resistance. As a result, a cushioning is achieved and allows easy removal of the armature and the intermediate element by reduced hydraulic bonding.

In a further advantageous development of the electromagnetically actuated switching valve, the intermediate element has a width jump in one area. The width jump is matched to the mouths of the axial channels, that the intermediate element in the concern of the contact partners in any position, for example by rotation, can be located and always covers an opening of one of the axial channels.

In an advantageous embodiment of the electromagnetically operable switching valve, the intermediate element has one or more openings, which need not necessarily be carried out centrally. An opening can be made by drilling or punching the intermediate element. This simplifies the ventilation of the two sides. In particular, the hydraulic bonding in the peeling movement is reduced, so that a simple detachment of the intermediate element is possible.

In a further advantageous embodiment of the electromagnetically actuated switching valve, the intermediate element is designed such that the cross section has two substantially non-parallel surfaces. In case of a concern of the contact partners, this leaves a gap and it is easier to fill the volume, which is released during the peeling movement between the contact partners. This shape thus reduces the effect of hydraulic bonding.

In a particularly advantageous embodiment of the electromagnetically operable switching valve, at least one surface has a profiling. The profiling obstructs or favors the construction of the pressure pad and the hydraulic bonding. The profiling allows the behavior with regard to impact damping and hydraulic bonding to be precisely adjusted.

Particularly advantageous is an embodiment of the electromagnetically operable switching valve having an intermediate element which has a bending flexibility and is changed in the concerns of the contact partners in their shape. Starting from a concern of the armature to the intermediate element and the intermediate element to the stop at the peeling minimal gaps form, which prevent hydraulic sticking and facilitate removal of the armature and the intermediate element.

In a particularly advantageous embodiment of the electromagnetically operable switching valve, the intermediate element is made of a metal sheet. This offers advantages in the production of the intermediate element, which can be punched in a simple manner from a raw sheet.

An embodiment of the electromagnetically actuated switching valve provides that the intermediate element is at least partially clamped edge. As a result, the rigidity of the intermediate element can be increased (it thus acts as a stop spring) and at the same time the intermediate element can be held in a defined position.

A further embodiment of the invention provides that the stop limits the elastic deformation of the intermediate element. As a result, overloading of the intermediate element can be prevented simply and reliably even with large forces acting on the intermediate element, and a defined path of the armature is predetermined.

Furthermore, it is provided that the intermediate element is arranged directly adjacent to the stop and the stop has a concave recess towards the intermediate element. For example, the concave recess has the geometry of a spherical cap. This results in between the intermediate element and the stopper filled with fluid volume. On the one hand, a finite distance for braking the movement part or of the armature is created, and on the other hand, when it hits the intermediate element, the fluid present in the volume is at least partially pressed out of the volume, resulting in an additional damping effect.

The invention is particularly useful when the moving part towards the intermediate element has an at least partially convex end face. Thereby, the hydraulic sticking can be particularly effectively mitigated or even prevented when lifting the moving part of the intermediate element, whereby the switching speed of the switching valve can be increased.

Furthermore, it is provided that the curvature of the convex end face differs from the curvature of the concave recess, preferably being larger. This makes it possible that the convex end face of the moving part to bend the intermediate element in the manner of a plate spring and so at least partially in the concave recess of the stop - under displacement of fluid - can dive. In this way, the damping effect is improved.

Furthermore, it is achieved that on the one hand, the armature during the tightening can fit snugly enough with the convex end face of the concave recess, and on the other - during the stripping movement of the armature of the stop - sufficiently fast fuel between the convex end face and the intermediate element can flow in. As a result, a hydraulic bonding can be avoided and the switching speed of the switching valve can be increased. During the stripping movement of the armature, the elastically deformed intermediate element can assume its original shape, or return to the starting position.

Hereinafter, exemplary embodiments of the invention will be explained with reference to the drawings. In the drawing show:

1 a simplified diagram of a fuel injection system of an internal combustion engine;

2a a sectional view of a simplified schematic of an electromagnet (without coil) of a quantity control valve in a tightening movement;

2 B a sectional view according to 2a the quantity control valve in a pull-off movement;

3a a sectional view according to 2a with a residual air gap disc as an intermediate element;

3b a sectional view according to 3a ;

4 a sectional view according to 2a with a circular residual air gap disc as an intermediate element;

5a - 5d in each case an axial plan view of a residual air gap disk according to a direction III of 3a ;

6a - 6e each a cross section of a residual air gap disk along the line IV-IV of 5a ;

7a a sectional view according to 2a with a residual air gap disc as an intermediate element;

7b + 7c each an axial plan view of the device according to 7a according to a direction III;

8th an axial plan view corresponding to a direction III of a device according to 7a with a residual air gap disc as an intermediate element;

9 a sectional view according to 2a with a residual air gap disc as an intermediate element and a stop body; and

10 a sectional view of a further modified embodiment.

The same reference numerals are used for functionally equivalent elements and sizes in all figures.

1 shows a fuel injection system 1 an internal combustion engine in a much simplified representation. A fuel tank 9 is via a suction line 4 , a prefeed pump 5 and a low pressure line 7 with a (not explained in detail) high-pressure pump 3 connected. To the high pressure pump 3 is via a high pressure line 11 a high-pressure accumulator 13 ("Common rail") connected. An electromagnetically actuated switching valve 14 - in the following specifically as a quantity control valve 14 referred to - with an electromagnetic actuator 15 - hereinafter as an electromagnet 15 designated - is hydraulic in the course of the low pressure line 7 between the pre-feed pump 5 and the high pressure pump 3 arranged. Other elements, such as high-pressure pump valves 3 , are in the 1 not drawn. It is understood that the quantity control valve 14 as a unit with the high-pressure pump 3 can be trained. For example, by the quantity control valve 14 an inlet valve of the high pressure pump 3 be forced open.

When operating the fuel injection system 1 promotes the pre-feed pump 5 Fuel from the fuel tank 9 in the low pressure line 7 , The quantity control valve determines 14 the high pressure pump 3 amount of fuel supplied.

2a shows in a simplified representation of a section of the quantity control valve 14 , or the electromagnet 15 , The in the 2a shown elements have substantially a rotational symmetry about a central longitudinal axis of a housing portion 20 on.

Shown is the substantially hollow cylindrical housing portion 20 , and in this a generally markable as a movement part, displaceable in the direction of the longitudinal axis anchor 22 and one with the anchor 22 firmly connected valve element 24 , The housing section 20 is limited in the right part of the drawing by a stop 26 , In one in the housing section 20 formed and generally markable as a movement space anchor space 28 located on both sides of the anchor 22 a fluid not visible in the drawing 30 , Between an inner peripheral wall 32 of the housing section 20 and an outer peripheral wall 34 of the anchor 22 there is a circumferential annular gap 36 which is exaggeratedly large.

The anchor 22 has four axial channels in the present case 38 of which two in the sectional view of 2a are visible. In other embodiments, any number of channels 38 be present (ie at least one channel 38 ). The channels 38 can either be as holes in the anchor as shown 22 or as a groove on the peripheral wall 34 of the anchor 22 be executed.

In an end position in the direction of the arrow 42 lies the front side of the anchor 22 on the stop 26 in the area of a contact surface directly on. The contact surface is in the device after 2a through the frontal surface of the anchor 22 defined and only through the mouths of the channels 38 interrupted.

The contact surface generally consists of the overlapping surfaces of anchors 22 and stop 26 together. The individual surfaces can be unlike those in 2a Also shown in approximately plane-parallel surfaces also have a different surface shape, such as a convex, concave or wave-like surface shape, so that they form the contact surface upon contact by a mating fit.

In the in 2a illustrated operating situation of the electromagnet 15 becomes the anchor 22 together with the valve element 24 moved in the drawing to the right, which corresponds to the tightening movement. This is indicated by an arrow 42 symbolizes. The tightening movement is characterized in that the moving part, here the anchor 22 , on a non-moving part, here the stop 26 , too moved. After the concern of the anchor 22 on the stop 26 becomes the anchor 22 from the stop 26 off or pulled away. This is the stripping movement. An opening or closing of the valve is not meant with the tightening or Abziehbewegung.

The total area of the anchor 22 on the front side, so at the stop 26 facing side, corresponds to the plan view surface from the direction IIIa. The plan view surface does not take into account the mouths of the axial channels 38 still the annular gap 36 , For the stop 26 There is another plan view surface from the direction IIIb and thus also a further total area. The total area is thus by a plan view surface from the direction of the opposite contact partner, here the anchor 22 or the stop 26 , Are defined.

When tightening, the volume of a subsection 44 the anchor room 28 steadily reduced. This will do that in the subsection 44 existing fluid 30 repressed. The fluid 30 flows according to the arrows 46 from this subsection 44 out.

By a viscosity of the fluid 30 as well as the movement of the anchor 22 in the direction of the attack 26 a so-called squeezing effect occurs. The squeezing effect means a hindrance to the displacement of the fluid 30 , This is in the 2a by double arrows 48 indicated. With the crushing effect is an impact absorption of the anchor 22 allows. Ie. the anchor 22 can hit the stop at high speed 26 and the impact of the anchor 22 on the stop 26 is damped by the squeezing effect and a resulting pressure pad.

The crushing effect depends on the contact area between anchors 22 and stop 26 , The pressure pad runs at the in 2a illustrated quantity control valve 14 according to the illustrated double arrows 48 between the overlapping surfaces of the anchor 22 and the stop 26 , As shown, the surfaces of the anchor overlap 22 and the stop 26 in 2a except for the annular gap 36 and the mouths of the axial channels 38 , Completely.

The operating situation in 2 B corresponds to the pull-off movement according to the arrow 43 against the tightening movement in 2a , Between the operating situations in 2a and 2 B An impact of the anchor happens 22 on the stop 26 , According to the operating situation in 2 B arises after the impact again a volume in the region of the contact surface between the anchor 22 and the stop 26 , The volume becomes with the fluid 30 over the axial channels 38 according to the arrows 47 filled. Depending on the viscosity of the fluid 30 and the profile of the anchor 22 and the stop 26 may occur a so-called hydraulic bonding, which makes the peeling movement difficult.

In the following figures, usually only the tightening movement is shown.

3a shows a section of the quantity control valve 14 according to the 2a with one in the subsection 44 inserted annular intermediate element 50 , In the present case, this is functionally a residual air gap disk 50 and is therefore referred to as simplifying in the following. However, all embodiments shown below can also be realized in the same way if the intermediate element does not have the function of a residual air gap disk. The residual air gap disk 50 has one in comparison to the peripheral wall 32 the anchor room 28 smaller extent. The residual air gap disk 50 is located in a non-centered to the longitudinal axis position according to the 3a , The residual air gap disk 50 is exaggerated in the direction of the longitudinal axis.

As a contact partner are the anchor 22 with the residual air gap disc 50 and the residual air gap disk 50 with the stop 26 to understand.

The surfaces of the contact partners determine the contact surfaces. The residual air gap disk 50 determines the contact surfaces by their two-sided surfaces. The surfaces of the anchor 22 or the stop 26 are almost flat in the embodiments. In a manner not shown may also be relevant to the contact surfaces surfaces of the armature 22 and the stop 26 have a non-planar profile with, for example, projections and recesses.

For a damped impact and a stripping with a reduced hydraulic gluing, the contact surfaces passing through the residual air gap disk 50 are formed, smaller than the total area of the anchor 22 or the stop 26 , The total area is determined by the plan view surface on the anchor 22 or the stop 26 from the side of the residual air gap disk 50 out.

The operating situation in 3a shows the tightening movement before the concerns of the contact partners. By the movement of the anchor 22 in the direction of the arrow 42 becomes the fluid 30 within the subsection 44 according to the arrows 46 through the axial channels 38 in the anchor room 28 on the opposite side of the anchor 22 dissipated.

The operating situation in 3b shows in comparison with the operating situation in 3a the tightening movement just before the concerns of the contact partners. The residual air gap disk 50 is in contrast to the situation in 3a through the Flow conditions that prevail during the tightening movement, in an anchor 22 centered position. The reason for this is that radially outside the residual air gap disc 50 a pressure pad between anchor 22 and stop 26 forms, which concentrically spreads and thereby the residual air gap disc 50 forces into the central position.

The overlapping surfaces of the contact partners define the two annular contact surfaces on both sides of the residual air gap disk 50 , According to the two contact surfaces form before the impact of the anchor 22 on the residual air gap disc 50 and the impact of the residual air gap disc 50 on the stop 26 annular pressure pad according to the double arrows 48 on both sides of the residual air gap disc 50 out.

A pull-off movement, not shown, against the direction of the arrow 42 causes the resulting in the region of the two contact surfaces volumes with the fluid 30 be filled. The filling takes place, starting from a concern of the contact partners in that the fluid 30 , which is located radially outside the contact surfaces, a connection to the axial channels 38 Has.

4 shows a section of the quantity control valve 14 after 2a , In contrast to 2a is the anchor 22 in 4 formed such that it has a central axial channel 38 having. The circular residual air gap disk 50 is in a section 44 the anchor room 28 arranged.

The operating situation in 4 shows a tightening movement of the anchor 22 in the direction of arrows 42 , A fluid 30 in the subsection 44 flows according to an arrow 46 in the central axial channel 38 , Pressure pads build up before the impact of the anchor 22 circular around the canal 38 between the anchor 22 and the residual air gap disk 50 as well as circular between the residual air gap disc 50 and the stop 26 on.

Furthermore, between the inner peripheral wall 32 of the housing section 20 and the residual air gap disk 50 an outer annular gap 37 provided an exchange of fluid 30 between both sides of the residual air gap disc 50 permit.

In the withdrawal movement of the armature, not shown 22 is over the channel 38 the fluid 30 refilled. First, the area between anchor 22 and residual air gap disk 50 filled, then the area between the residual air gap disk 50 and stop 26 , Thus, first a release of the anchor happens 22 from the residual air gap disk 50 and then releasing the residual air gap disc 50 from the stop 26 ,

5a shows a circular residual air gap disc 50 in a plan view corresponding to a direction III of 3a , Such a residual air gap disk 50 is z. B. in the 4 available.

The residual air gap disk 50 can be designed with one or more openings. In one embodiment according to 4 For example, an opening in the middle of the residual air gap disc 50 be provided. The opening can also be performed off-center. This will provide ventilation of the area between the residual air gap disk 50 and stop 26 facilitated.

The residual air gap disk 50 can be made or stamped from a sheet, such as steel.

The residual air gap disk 50 is made such that it has a certain elasticity or bending flexibility. Indicates the residual air gap disk 50 In addition, in its cross-section on a shape that is changed when concerns the contact partners, so the residual air gap disc 50 during the tightening movement by the acting forces and their elasticity between anchors 22 and stop 26 be pressed flat. During the following stripping movement the residual air gap disc strives 50 back to their original shape, thereby releasing gaps that facilitate filling with fuel. This reduces hydraulic sticking.

5b shows the residual air gap disc 50 with an annular shape in a plan view corresponding to a direction III of 3a , Such a residual air gap disk 50 is in the 3a to see.

5c shows the residual air gap disc 50 with an annular shape with a break in a plan view according to a direction III of 3a ,

5d shows the residual air gap disc 50 with an annular shape with inner cross-shaped connecting webs in a plan view corresponding to a direction III of 3a , The connecting webs serve to reinforce the residual air gap disc 50 ,

6a shows a cross section of the residual air gap disc 50 along the line VI-VI of 5a , The residual air gap disk 50 has two nearly parallel, opposing surfaces. The residual air gap disk 50 is thus rotationally symmetric to a central axis 54 ,

6b shows a cross section of the residual air gap disc 50 along the line VI-VI of 5a wherein the cross-section is vertical with respect to the figure Has rejuvenation. The rejuvenation is triangular.

6c shows a cross section of the residual air gap disc 50 along the line VI-IVI the 5a wherein the section has a convex shape: starting from an outer circumference 56 The depth of the cut widens towards the central axis 54 ,

6d shows a cross section of the residual air gap disc 50 along the line VI-VI of 5a wherein the cut has a concave shape. Starting from an outer circumference 56 the depth of the cut decreases towards the central axis 54 ,

6e shows a cross section of the residual air gap disc 50 along the line VI-VI of 5a wherein the cross section has a wave-shaped profile.

7a shows a section of the quantity control valve 14 according to the 3b with the in the subsection 44 inserted annular residual air gap disc 50 that in contrast to 3b at the request of the contact partners the axial channels 38 closes.

The operating situation in 7a shows the tightening movement of the anchor 22 in the direction of the arrow 42 , The fluid 30 in the subsection 44 flows according to the arrows 46 in the axial channels 38 from. Pressure pads build between the residual air gap disc 50 and the stop 26 according to the double arrows 48 and in a manner not shown between the anchor 22 and the residual air gap disk 50 on.

In the withdrawal movement of the armature, not shown 22 is via the axial channels 38 the fluid 30 tracked. First, the area between anchor 22 and residual air gap disk 50 filled, then only the area between the residual air gap disc 50 and stop 26 ,

7b shows the axial top view 7a according to the direction III, wherein the residual air gap disc 50 in the to the valve element 24 centered position. For better visibility hatching was off 7a accepted. The residual air gap disk 50 covers the anchor 22 such that the axial channels 38 are completely covered. The mouths of the axial channels 38 are dashed behind the residual air gap disc 50 shown. This in 7a not shown pressure pad between the residual air gap disc 50 and anchor 22 is in 7b through the dashed double arrows 48 shown.

7c shows the axial top view of the device 7a according to the direction III, wherein the residual air gap disc 50 in a to the valve element 24 not centered position. Although the residual air gap disc 50 is in the non-centered position, it covers as in 7b still all axial channels 38 ,

8th shows the axial plan view of an anchor 22 according to the 7a and the residual air gap disk 50 according to the direction III of 7a , The residual air gap disk 50 is annular and has a radially inwardly pointing width jump 58 , By the broad jump 58 becomes a mouth of the axial channels 38 covered. The remaining three mouths of the axial channels 38 stay through the residual air gap disk 50 essentially free.

In a tightening movement of the anchor, not shown 22 can the fluid 30 through those axial channels 38 drain, not through the residual air gap disc 50 are covered.

In a pull-off movement of the armature, not shown 22 can through the uncovered channels 38 the fluid 30 in column between the anchor 22 and the stop, not shown 26 subsequently, the resulting volumes in the region of the contact surfaces between the armature also flow and fill 22 , the residual air gap disk 50 and the stop 26 ,

9 shows in a simplified representation of a section of the quantity control valve 14 , Shown is the housing section 20 , and in this the anchor 22 connected to the valve element 24 out 2a , Furthermore, a stopper body 73 with a stop 27 shown. Between the stop 27 and the anchor 22 is the annular residual air gap disc 50 arranged. The stopper body 73 , the residual air gap disk 50 and the anchor 22 with the axial channels 38 let through a common volume 80 to that between the sections 44 and 45 the anchor room 28 at any time the fluid 30 can move.

The illustrated removal movement of the valve element 24 with the anchor 22 is characterized in that the anchor 22 in a direction of the arrow 43 on the stop 27 too moved. Between the stop 27 and the residual air gap disk 50 and between the residual air gap disc 50 and the anchor 22 build shortly before the concern two pressure pads according to the double arrows 48 on. A fluid 30 can in this case about the volume 80 into the sections 44 and 45 flow away.

In the tightening movement of the anchor, not shown 22 be the annular contact surfaces between the stop 27 and the residual air gap disk 50 and between the residual air gap disc 50 and the anchor 22 through the volume 80 from the subsections 44 and 45 with the fluid 30 filled.

10 shows a partial view of a further modified embodiment of the electromagnetic switching valve 14 or the quantity control valve 14 in a sectional view. Between a top in the drawing housing section 20a and a lower housing portion 20b is the - in this case made of an austenitic spring steel - residual air gap disc 50 arranged, which is clamped at least in the area shown at the edge. The residual air gap disk 50 is to the stop 26 arranged immediately adjacent. Furthermore, the residual air gap disc comprises 50 a circular centric opening 82 , The upper housing section 20a has a concave recess 83 on which in the drawing of the 10 only open downwards, and its boundary surface the stop 26 forms.

In the lower part of the drawing of 10 is the anchor 22 arranged. In the present case is the anchor 22 on the valve element 24 pressed. An armature spring designed as a compression spring 86 is between an end face of the valve element 24 and a cylindrical recess 88 in the upper housing section 20a arranged, with the anchor spring 86 the centric opening 82 penetrates. The anchor 22 has a convex end face 90 on, and includes axial channels 38 two of which are visible in the drawing. The in the 10 shown elements are substantially rotationally symmetrical about a longitudinal axis 92 executed. A volume area between the upper housing section 20a and the convex end face 90 of the anchor 22 is with fuel or fluid 30 filled. In the present case, the curvature of the convex end face 90 greater than the curvature of the concave recess 83 ,

The anchors 22 is together with the valve element 24 vertically movable in the drawing. When the electromagnet 15 is energized, then the anchor 22 by magnetic force in the direction of the upper housing section 20a - Which in this case is a magnetic pole - moves. He displaces in a first phase, a portion of the fuel located in the volume range, which thereby passes through the axial channels 38 as well as through the annular gap 36 can drain away. In the 10 is the annular gap 36 shown exaggeratedly big.

In a second phase, the anchor beats 22 initially with an approximately annular sealing portion 94 at the residual air gap disc 50 on, causing the centric opening 82 is essentially closed.

In a third phase, the residual air gap disc 50 through the convex end face 90 of the anchor 22 - Comparable a diaphragm spring - elastically deformed, in particular the central region of the residual air gap disc 50 in the concave recess 83 is pressed into it. The one in the concave recess 83 existing fuel is at least partially through the central opening 82 and one between the residual air gap disk 50 and the sealing section 94 pressed out as a result of the high pressure forming gap. This will be the movement of the anchor 22 particularly slowed down. In addition, it is possible that fuel also on other, due to the design of the electromagnetic switching valve column from the concave recess 83 can escape. These columns are in the 10 but not shown.

Provided the kinetic energy of the anchor 22 while the previous phases have not been completely dismantled, then the anchor can 22 in a fourth phase, the residual air gap disk 50 continue to deform until this stop 26 strikes. The stop 26 So limits the elastic deformation of the residual air gap disc 50 , The one between the anchor 22 and the stop 26 or magnetic pole formed gap ("working air gap") has in this phase a minimum and almost vanishing size - namely, the thickness of the residual air gap disc 50 ,

When - starting from the reached state - the electromagnet 15 is turned off and the anchor 22 by the force of the anchor spring 86 is moved vertically downwards in the drawing, so there is a negative pressure in the concave recess 83 , This will cause the pull-off movement (downward movement) of the anchor 22 initially inhibited. Because the convex face 90 however, compared to the attack 26 or the concave recess 83 has a larger curvature, has the sealing portion 94 a correspondingly small area. Therefore, early fuel between the sealing section 94 and the residual air gap disk 50 inflow and the negative pressure in the concave recess 83 compensate quickly, so that the withdrawal movement of the anchor 22 Relatively little hydraulic resistance experiences (low "sticking"). In this way, resulting in the tightening movement and the peel-off movement of the armature 22 each different hydraulic forces. The tightening movement of the anchor 22 Thus, in the third and fourth phase is comparatively strongly attenuated and the stripping movement of the anchor 22 is damped comparatively weak.

It is understood that the representation of the 10 is only an example. In particular, the convex recess can 83 and the frontal area 90 characterizing radii be greater than shown in the drawing, that is, the curvatures of the convex recess 83 and the face 90 are in the 10 shown in an exaggerated manner for better illustration.

Claims (18)

Electromagnetically actuated switching valve ( 14 ), in particular quantity control valve for controlling the flow rate of a high-pressure pump ( 3 ), with one with a fluid ( 30 ) fillable movement space ( 28 ), a moving part arranged therein ( 22 ) an electromagnetic actuator ( 15 ), and a stop ( 26 . 27 ), characterized in that between the moving part ( 22 ) and the attack ( 26 ) a preferably disc-like intermediate element ( 50 ) is arranged. Electromagnetically operated switching valve ( 14 ) according to claim 1, characterized in that the intermediate element ( 50 ) consists of non-magnetic material. Electromagnetically operated switching valve ( 14 ) according to any one of the preceding claims, characterized in that when a movement of the moving part ( 22 ) on the intermediate element ( 50 ) or a concern of the intermediate element ( 50 ) at the stop ( 26 . 27 ) in each case a contact surface is present, wherein the contact surfaces either by a surface of the moving part ( 22 ) and the intermediate element ( 50 ) or a surface of the intermediate element ( 50 ) and the stop ( 26 . 27 ) are determined, and wherein the contact surfaces smaller than the total area of the moving part ( 22 ) or the stop ( 26 . 27 ) are. Electromagnetically operated switching valve ( 14 ) according to one of the preceding claims with at least one channel ( 38 ), which on both sides of the moving part ( 22 ) lying areas of the movement space ( 28 ) connects to each other. Electromagnetically operated switching valve ( 14 ) according to claim 4, characterized in that the intermediate element ( 50 ) the mouth of the axial channel ( 38 ) at the concern of the moving part ( 22 ) on the intermediate element ( 50 ) not covered. Electromagnetically operated switching valve ( 14 ) according to claim 4, characterized in that by the intermediate element ( 50 ) at least one of the mouths of the axial channels ( 38 ) and at least one of the mouths of the axial channels ( 38 ) is not obscured. Electromagnetically operated switching valve ( 14 ) according to claim 6, characterized in that the intermediate element ( 50 ) has an annular plan view with a width jump in a region, wherein the width jump is an opening of an axial channel ( 38 ) at the concern of the moving part ( 22 ) on the intermediate element ( 50 ) obscured. Electromagnetically operated switching valve ( 14 ) according to one of the preceding claims, characterized in that the intermediate element ( 50 ) has an opening, wherein the opening may also be arranged off-center. Electromagnetically operated switching valve ( 14 ) according to one of the preceding claims, characterized in that the intermediate element ( 50 ) has in a cross-section two substantially non-parallel surfaces. Electromagnetically operated switching valve ( 14 ) according to one of the preceding claims, characterized in that the surface of the moving part ( 22 ), the intermediate element ( 50 ) and / or the stop ( 26 . 27 ) has a profiling. Electromagnetically operated switching valve ( 14 ) according to one of the preceding claims, characterized in that the intermediate element ( 50 ) has a bending flexibility, wherein when a concern of the moving part ( 22 ) on the intermediate element ( 50 ) and / or a concern of the intermediate element ( 50 ) at the stop ( 26 . 27 ) the shape of the intermediate element ( 50 ) is changed. Electromagnetically operated switching valve ( 14 ) according to one of the preceding claims, wherein the intermediate element ( 50 ) is made of a sheet metal. Electromagnetically operated switching valve ( 14 ) according to one of claims 11 or 12, characterized in that the intermediate element ( 50 ) is at least partially clamped edge. Electromagnetically operated switching valve ( 14 ) according to claim 13, characterized in that the stop ( 26 ) the elastic deformation of the intermediate element ( 50 ) limited. Electromagnetically operated switching valve ( 14 ) according to claim 14, characterized in that the intermediate element ( 50 ) to the stop ( 26 ) is located immediately adjacent and the stop ( 26 ) to the intermediate element ( 50 ) a concave recess ( 83 ) having. Electromagnetically operated switching valve ( 14 ) according to claim 15, characterized in that the movement part ( 22 ) to the intermediate element ( 50 ) an at least partially convex end face ( 90 ) having. Electromagnetically operated switching valve ( 14 ) according to claim 16, characterized in that the curvature of the convex end face ( 90 ) of the curvature of the concave recess ( 83 ), preferably larger. Fuel high pressure pump ( 3 ) comprising a switching valve ( 14 ) or quantity control valve according to one of the preceding claims.

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