WO2008122452A1

WO2008122452A1 - Magnetic valve

Info

Publication number: WO2008122452A1
Application number: PCT/EP2008/051338
Authority: WO
Inventors: Bernd Streicher; Rudolf Heinz; Susanne Spindler; Stefan Haug; Holger Rapp; Wolfgang Stoecklein; Christian Faltin
Original assignee: Robert Bosch Gmbh
Priority date: 2007-04-04
Filing date: 2008-02-04
Publication date: 2008-10-16
Also published as: EP2145100B1; CN101802385A; CN101802385B; DE502008001902D1; DE102007016252A1; EP2145100A1; ATE489553T1; WO2008122452A8

Abstract

The invention relates to an injection valve (10), particularly for the injection of fuel into the combustion spaces of internal combustion engines. The injection valve (10) comprises an anchor assembly which, in turn, has an anchor plate (20) and an anchor bolt (18). A seat (30) of the injection valve (10) is unblocked or closed off by the anchor assembly. The anchor plate (20) of the anchor assembly comprises a number of anchor wings (22), pairs of which have different inherent frequencies.

Description

description

Title solenoid valve

State of the art

DE 100 08 554 A1 relates to a fuel injection valve for internal combustion engines. It is disclosed a fuel injection valve having at least two valve body parts, which rest against each other on a contact surface and are clamped by a clamping device against each other perpendicular to the contact surface. In both valve body parts, an inlet channel for fuel is formed, which passes through the contact surfaces and the high fuel pressure prevails. In the inlet channel there is at least one radial extension close to the contact surface of the relevant valve body part, so that this radial expansion experiences an expansion in the axial direction of the inlet channel due to the fuel pressure in the inlet channel. As a result, the area of the contact surface surrounding the passage of the inlet channel is pressed against the contact surface of the adjoining valve body part, so that the contact pressure of the contact surfaces increases. The passage of the inlet channel is thus better sealed and it can be correspondingly reduced the force of the clamping device.

In pressure compensated switching valves, the pressurized medium is usually enclosed in a closed pressure chamber in an annular pressure chamber. This chamber is bounded on one side by a guide and on the other side by a sealing seat, wherein guide and sealing seat have exactly the same diameter d. As a result, there is no force acting in the opening or in the closing direction on the valve element, which, for example, may be of a needle-shaped or sleeve-shaped design.

With progressive operation of the switching valve, it comes to an alignment between the sealing surface of the valve piece and the usually needle-shaped or sleeve senförmig trained valve element. Since the adjustment from the original diameter d starting, takes place only to one side, a change in the effective seat diameter and thus the generation of an opening force acting on the valve element the result. The pressure balance of the switching valve is disturbed and its dynamic behavior changes up to static leakage.

With pressure-balanced switching valves, usually only a small mechanical force is available to keep the valve tight. As the wear progresses, the components on the valve seat become increasingly similar to each other and a contact width between the components increases. As long as the sealing diameter at the valve seat still corresponds to the guide diameter, the valve function is maintained. However, if the sealing diameter is removed away from the guide diameter, an additional pressure stage is created on the valve, which generates a force directed in the opening direction. This can lead to the fact that with increasing wear, d. H. At the same time the valve unintentionally opens. In particular, in the case of switching valves for high-pressure applications, the deformation of the components in the closed state by the pressure load, d. H. the prevailing in the component system pressure, a major role. This deformation can massively increase the effect of the seat and thus lead to premature failure of the valve by static leakage.

Valves are known from the prior art, which are also used in injection valves for internal combustion engines. Especially with injection valves that are used in the automotive sector, fast-switching valves are required, which means that the Ventilhubweg must be traversed very quickly. Thus, such valves close at speeds of 0.5 to 1 m / s. If a valve member hits on the valve seat or a stroke stop in such a valve, mechanical vibrations in the valve are excited and the valve can bounce, which means that the valve is initially closed, but reopens after contact of the valve seat with the valve member and, for example, go through a ballistic phase of operation. Since the injection valve is not closed immediately, this can cause inaccuracies in the injection process. Similarly, in the subsequent control of the injection valve - for example in the case of a pre-and a main injection tion - the movement sequence are disturbed in such a way that this can be seen in a quantity deviation of the injection quantity.

Disclosure of the invention

According to the invention, an injection valve is provided in which the reproducible injection quantity accuracies from pilot injection phase to main injection phase to subsequent pilot injection phase are considerably increased compared with the fuel injectors known from the prior art. In particular, in the injection valve proposed according to the invention, the closing speed is considerably increased, as a result of which the achievable injection quality is considerably improved.

During the closing operation of an injection valve with, for example, a sleeve-shaped valve member, which moves on a housing-fixed stationary recorded valve guide, the closing movement of both the anchor bolt and the individual wings of the anchor plate runs uniformly in the direction of the valve seat. Upon impact of the lower edge of the armature assembly in the valve seat is a sudden deceleration of the valve member, ie, guided on the valve guide anchor bolt together with anchor plate. However, due to the inertia, the armature vanes of the armature plate continue to move in the direction of the seat. As a result, in the armature bolt, in turn, a force is produced which is opposite to the armature armature movement, ie, acts in the opening direction. The downwardly in the direction of downward, that is on the valve seat sagging armature wing, move from its biased position out back up, while the bottom, the impact side of the sleeve-shaped valve member remains in the valve seat. The force in the anchor bolt is reduced so far, until the anchor wings are bent back up, ie have completed a swinging operation and thus the anchor bolt is pulled out of the previously closed valve seat and the valve opens again. In this opening phase, the upwardly bent wings of the anchor plate generate tensile forces on the bolt. The timing of this bounce process depends crucially on the natural frequency of the anchor wings. If the coupling of the wings to the anchor bolt is very stiff, the valve member rebounds faster. Following the solution proposed according to the invention, several natural frequencies are realized in the region of the armature vanes, which means that the individual vanes of the armature plate, which are spaced apart in the circumferential direction, do not -A-

all be made the same, but specifically different, possibly designed according to a repetition pattern.

If the armature vanes of the armature plate are formed differently, another wing of the armature vanes can move upward again during the movement of one of the armature vanes. Ideally, the forces that exert the individual anchor wings on the anchor bolt cancel each other out. This makes it possible that the anchor bolt together anchor plate, d. H. the armature assembly, after the actual closing operation is hardly exposed in the opening direction acting forces, whereby the bouncing can be effectively suppressed. Possibly occurring oscillatory movements of individual armature blades are compensated by counter-oscillatory movements of other armature vanes.

The adjustment of the natural frequency of each armature wing on the anchor bolt, the mass moment of inertia of the wing or the flexural rigidity of the coupling to the anchor bolt can be done. The relationship of frequency as a function of wing mass and stiffness is in accordance with the relationship

f ≡ y / c / m with j = mass moment of inertia and c = bending stiffness,

wherein the moment of inertia is calculated with respect to the axis of rotation of the armature blade in the bending case, it applies: J = V _f i _uge ιJρr ² dV, where r is the distance of the respective volume element from the axis of rotation of the armature blade.

If, for example, two different natural frequencies are realized in the area of the armature wings, a favorable ratio of the natural frequencies to one another is the factor 2. This means that one of the armatures should, for example, be four times as heavy as another or the coupling of this armature wing should be four times as soft Depending on whether the realization of the mass or the rigidity takes place. Of course, combinations of stiffness and mass differences can be realized.

Brief description of the drawings

With reference to the drawing, the invention will be described below in more detail. It shows:

1 shows the schematic representation of an injection valve,

1.1, 1.2, 1.3 different phases of the closing movement of an externally guided sleeve-shaped valve member of an injection valve,

FIG. 2 shows the comparison of the movement of an anchor bolt and an armature wing received thereon,

FIG. 3 shows the plan view of a first embodiment variant of the armature assembly proposed according to the invention with a first cross section and a second cross section through the armature

Coupling the armature wings to an anchor bolt,

FIG. 4 shows a plan view of a further embodiment variant of the armature assembly proposed according to the invention,

FIG. 5 is a plan view of a direction of rotation of the anchor bolt weakened armature assembly,

FIG. 6 shows a further embodiment of flexurally rigid or bend-soft coupled armature wings,

FIG. 7 shows an embodiment of flexurally rigid and flexibly coupled armature blades with slot pairs,

Figure 8 shows the embodiment of a rigid or flexible coupling of vanes by material weakening by means of holes and

FIG. 9 shows a further embodiment of two armature wings of an anchor bolt which are connected softly with respect to the rotation. embodiments

It can be seen from the illustration according to FIG. 1 that an injection valve 10 has a valve guide 12 arranged essentially in the valve body. The valve guide 12 is fixed on a plan side 32 by a valve clamping nut 24, which is only indicated here, and received stationary in the valve body of the injection valve 10.

The injection valve 10 comprises the valve guide 12, whose lateral surface is identified by reference numeral 14. At this a sleeve-shaped here valve member 16 is guided movably in the vertical direction. The valve member 16 comprises an anchor bolt and an anchor plate 20, which in turn has individual armature wings 22.

The closing direction, in which the here sleeve-shaped valve member 16 is moved to close a seat 30 is indicated by reference numeral 26. The seat 30 is formed at the transition from the plan side 32 of the valve guide 12 in the guide portion for vertical guidance of the anchor bolt 18. A seat is closed by the sleeve-shaped valve member 16 moved in the closing direction 26, indicated by reference numeral 34.

From the figure sequence of Figures 1.1, 1.2 and 1.3 show different phases of a closing movement of an externally guided on a valve guide valve member.

FIG. 1.1 shows that the anchor bolt 18 with armature wings 22 formed thereon moves towards the seat 30 and closes it when it hits the seat 30. As a result, a high-pressure chamber 42 between the inside of the anchor bolt 18 and the outside of the valve guide 12, which is usually acted upon by fuel under system pressure, closed.

Figure 1.2 shows the movement of the armature assembly after impact of the anchor bolt 18 in the seat 30 and its closing. In the state of a closed seat 34 as shown in Figure 1.2, the lower end face of the anchor bolt 18 does not move further, as this rests against the seat surface of the seat 30. On the other hand, the at least one at the opposite end of the anchor bolt 18 performs formed valve vane 22 from a downward movement, from which a deflection 36 down the at least one armature blade 22 on the anchor bolt 18 results.

FIG. 1.3 shows that the deflection 36, indicated in FIG. 1.2, transitions upward, at the bottom of the at least one anchor blade 22 on the anchor bolt 18, into a deflection 38, which has a winding force 40, ie. H. a force acting in the axial direction of the sleeve-shaped valve member 16 opening force causes.

During the deflection 38 upwards of the at least one anchor bolt

18 trained anchor blade 22 acts an opening force on the sleeve-shaped valve member, which pulls this from the closed seat 34.

This process of swinging back of the at least one anchor blade 22 formed on the anchor bolt 18 of the anchor assembly is referred to as "bouncing".

The illustration according to FIG. 2 shows the movements of the at least one anchor wing and of the anchor bolt. During a first here indicated by reference numeral 1.1 section, move the at least one anchor bolt 22 and the anchor bolt 18 of the armature assembly of the injection valve 10 synchronously in the direction of the seat 30. From Figure 2 shows that a movement sequence 50 of the at least one armature blade 22 and a Motion sequence 60 of the anchor bolt 18 are synchronous.

In the phase indicated by the double arrow, which is dimensioned by reference numeral 1.2, which corresponds to the illustration according to FIG. 1.2, the downward deflection 36 of the at least one armature blade 22 on the anchor bolt 18 causes an increase in the closing force acting in the seat 30 ,

As a result of the return oscillation of the at least one armature wing 22 on the anchor bolt 18, indicated by the deflection 38 upward in FIG. 1.3, the arm pin 18 closing the seat 30 in the closed position is now moved in the opening direction, indicated by reference numeral 60 and FIG Dashed lines indicated movement sequence 50 of the at least one armature blade 22, which is formed on the side facing away from the seat 30 of the anchor bolt 18. Due to the bending 38 upwards of the at least one anchor blade 22, the anchor bolt 18 is pulled out of the seat 30, which ultimately leads to the undesired anchor bounce.

In order to counteract the anchor bounce, it is proposed according to the invention to realize mutually different natural frequencies in the area of the anchor plate on the at least one anchor wing 22. As can be seen from FIG. 3, four armature vanes 22 extending symmetrically to one another are formed on the armature plate 20, which has a central bore 72 and whose plan side is identified by reference numeral 70. The armature vanes 22 are separated from each other by slits 74. Two mutually opposite armature vanes 22 form an armature wing pair, wherein one of the armature arm pairs has a rigid coupling 76 on the armature bolt 18 and the remaining further armature arm pair of the armature arm 22 has a flexurally soft coupling 78 on the armature bolt 18. The details relating to the rigid coupling 76 are apparent from the section B-B, while the details of the flexible coupling 78 of the armature blades 22 on the anchor bolt 18 emerge from the sectional profile according to A-A. From this sectional profile, it can be seen that in the region of the flexible coupling 78 of the armature blade 22 a targeted weakening of the material of the armature bolt 18 in the region of the armature vanes 22 is formed, while in the case of the rigid coupling 76 of the armature vanes 22 this is formed on the armature bolt 18 of a material accumulation is, which finally allows the rigid coupling 76 of the armature blade 22 to the anchor bolt 18 only.

From the section BB shows that the attached to the anchor bolt 18 of the armature assembly, opposing armature blades 22 are connected by a rigid coupling 76 with the anchor bolt 18, resulting from the accumulation of material at the transition from the lateral surface 18 of the anchor bolt to the armature blades 22 ,

In contrast, it can be seen according to the sectional profile AA that the illustrated there anchor wings 22 are coupled to the flexible coupling 78 to the lateral surface of the anchor bolt, wherein the flexible coupling 78 is given by a targeted reduction in material in the coupling. The illustration according to FIG. 4 shows an anchor plate 20, which represents a base group 80 from which anchor assemblies proposed according to the invention, comprising the anchor plate 20 and the anchor bolt 18, can be designed. As can be seen from the view of Figure 4, the plan side 70 of the anchor plate 20 is divided by a slit 74 in four vanes 22. The armature wings 22, which are separated from each other by a slot 74, are in pairs opposite each other. In the base group 80 shown in plan view in FIG. 4, the coupling points of the armature vanes 22 on the armature bolts 18 in the region of the central bore 72 are all configured as rigid couplings.

From the illustration according to FIG. 5, it can be seen that, in this exemplary embodiment, two opposing armature vanes 22 are coupled to the armature bolt 18 via the rigid coupling 76, while armature vanes 22 turned by 90 ° are respectively connected by a first slot 84 and a second slot 84 Slit 86 are coupled to the anchor bolt 18. By the mutually oppositely oriented slits 84, 86, flexible couplings 78 of the two mentioned armature vanes 22 with respect to the anchor bolt 18 are realized on the plan side 70 thereof in the region of the two armature vanes 22.

Reference numeral 82 denotes a rotation axis with respect to the bend of the armature blade 22.

About the first slot 84 and the second slot 86 opposite this in the region of the armature blade 22 an off-center weakening is realized, so that degrees of freedom are excited in the direction of rotation. 5, due to the orientation of the two slots 84, 86, different natural frequencies of the two armature vanes 22, which are coupled to the flexible bolt 18 with the flexurally soft coupling 78, are achieved around the axis of rotation 82 shown in FIG.

FIG. 6 shows a further embodiment variant of flexurally soft and rigid coupling of armature blades of an armature plate to the armature bolt of an armature assembly. As is apparent from the illustration according to FIG. 6, according to this embodiment too, the plane side 70 of the anchor plate 20 is subdivided into four armature vanes 22 which are each oriented at right angles to one another with respect to the central bore 72. In each case two opposing armature wings 22 form an armature wing pair. As is apparent from the plan view of Figure 6, two opposing armature blades 22 are coupled via the rigid coupling 76 with the anchor bolt which extends in the plane parallel to the central bore 72, while the two of these armature blades 22 offset by 90 ° the armature wing 22nd are coupled via the flexurally soft coupling 78 with the anchor bolt 18 extending perpendicular to the drawing plane according to FIG.

From the illustration according to FIG. 6, it can be seen that, in the region of the rigid coupling 76, the respective armature vanes 22 are coupled to the core region of the armature plate 20 with a greater material width, while the two armature vanes 22, which are arranged at right angles to these armature vanes 22, have an in-plane contact Compared to much narrower material web are coupled to the core region of the anchor plate 20.

About the illustrated in Figure 6 training of flexible and rigidly coupled armature blades 22, natural frequencies are set, which leads to an opposite swing behavior of the two here with a rigid coupling 76 to the anchor bolt 18 coupled armature blade 22 in comparison to the two armature blades 22, which are coupled via the flexurally soft coupling 78 at the perpendicular to the plane of FIG 6 extending anchor bolt 18.

The illustration according to FIG. 7 shows a further embodiment of an armature plate of an armature assembly in which different natural frequencies are realized.

Also according to this embodiment of the armature plate 20 of an armature assembly, the plan side 70 of the armature plate 22 is divided into a number of armature blades 22, in the present example four armature blades 22. Of the total of four armature blades 22, two opposing armature vanes are coupled via a first pair of slots 88 and a second pair of slots 90 to the core region of the planar side 70 of the armature plate 20. The first pair of slots 88 and the second pair of slots 90 represents a targeted weakening of the coupling of the two opposing armature wings 22. In contrast, the two offset by 90 ° to each other arranged armature vanes 22 are coupled via the rigid coupling 76 with the core region of the armature plate 20. Also in the embodiment shown in Figure 7, different natural frequencies are achieved, whereby in the downward or upward movement of below the plan side 70 of the armature plate 20 perpendicular to the plane extending anchor bolt 18 different, ie opposite swinging movements of either rigidly coupled or flexibly coupled anchor wing pairs each two Anchor wings 22 comprising, realized.

FIG. 8 shows a further embodiment of the design of the plan side of the armature plate 20 of the armature assembly.

From the illustration according to FIG. 8, it can be seen that the planar side 70 of the anchor plate 20 is subdivided into four armature wings 22 via a quadruple slit 74. In the embodiment of the armature plate 20 of the armature assembly shown in FIG. 8, a flexurally soft coupling 78 of two opposing armature vanes 22 is achieved by introducing a first weakening bore 92 or a second weakening bore 94 into the plane side 70 of the armature plate 20. The two offset by 90 ° to the armature blade 22 oriented armature wings 22 without weakening holes 92 and 94 are coupled via a rigid coupling 76 with the core region of the armature plate 20. The softness of the coupling sites, d. H. The formation of a rigid coupling 76 or a flexible coupling 78 can thus be achieved in addition to the execution of slots or material thickness variations by the introduction of weakening holes 92, 94 in the solid material of the anchor plate 20 of the armature assembly in question here.

The embodiment according to FIG. 9 represents a variation of the embodiment according to FIG. 8, in which two armature vanes 22 of the armature plate 20 each have weakening bores 96 and 98 with respect to rotation in the region of their coupling points to the core region of the armature plate 20. In contrast to the embodiment according to FIG. 8, in which the first weakening bore 92 or the second weakening bore 94 is centered in the respective coupling point of the coupling point 78 of the armature blades 22 to the core region of the armature plate 20 is shown, the introduced in Figure 9 in the anchor plate material attenuation holes 96, 98 are mounted off-center. As a result, rotational degrees of freedom are excited. By off-center arrangement of the weakening holes 96, 98 in the embodiment shown in Figure 9, rotational degrees of freedom can be stimulated by which relatively different natural frequencies in the armature blades 22 can be constructed.

For all of the above-described embodiments of rigid coupling 76 or flexurally soft coupling 78 or flexurally soft coupling with respect to rotation, it is extremely advantageous to always construct two opposing armature vanes 22 the same. This prevents in particular that bending moments are introduced into the anchor bolt 18 of the armature assembly.

By inventively proposed embodiment of the couplings 76 and 78 or by a flexible design of the coupling points of the armature wing 22 to the anchor bolt 18 with respect to the rotation is achieved that at deflection 36 down a pair of vanes 22, during the closing movement of the Valve member 16, the other pair of the armature blade 22 already has a deflection 38 upwards, so that the force acting on the anchor bolt 18 of the armature assembly forces neutralize each other. Only thereby it is possible that the anchor bolt 18 experiences hardly any more opening forces acting in the opening direction 40 after the actual closing, so that the bouncing can be effectively suppressed.

Advantageously, following the solution proposed according to the invention, the plan side 70 of the armature plate of the armature assembly is divided into an even number of armature vanes 22, which is realized in a particularly simple manufacturing technology by the slot 74, which is preferably a quadruple slot can be. However, on the other hand, it is also possible to provide the plan side 70 of the anchor plate 20 with a triple slot, which is not shown in the drawing, and in this way the plan page 70 of the anchor plate 20 in 3 by 120 ° -Anordung to each other lying armature wings 22 to divide. In principle, an opposite movement of at least two wing wings also possible with this embodiment, without departing from the scope of the present invention. With regard to the embodiments of the solution proposed according to the invention shown in FIGS. 8 and 9, the moments of inertia j of the respective armature vanes 22 are designed differently so that different resonant frequencies of in each case two armature vanes 22 can be realized.

Claims

claims

1. Injection valve (10), in particular for injecting fuel in internal combustion engines, with a valve guide (12) and a valve member (16) and an armature assembly comprising an anchor bolt (18) and an anchor plate (20) and the armature assembly (18, 20) has a valve seat (30) of the

Injector (10) releases or closes, characterized in that at the anchor plate (20) formed anchor wings (22) have different natural frequencies.

2. Injection valve (10) according to claim 1, characterized in that the coupling points of the armature vanes (22) to the anchor plate (20) as rigid Ankoppelstellen (76), as flexible Ankoppelstellen (78) or as in the direction of rotation flexible Ankoppelstellen (82) are.

3. Injection valve (10) according to claim 1, characterized in that the armature vanes (22) in pairs rigid coupling points (76) or flexible Ankoppelstellen (78) to the anchor plate (20).

4. Injection valve (10) according to claim 1, characterized in that the anchor plate (20) with the anchor bolt (18) forms a one-piece armature assembly.

5. Injection valve (10) according to claim 1, characterized in that the rigid coupling (76) of the armature vanes (22) to the anchor plate (20) mutually oppositely oriented slits (84, 86), formed in an increased material width anchor wings ( 22), via slot pairs (88, 90) or over

Deflection holes (92, 94) in the material of the anchor plate (20) are formed.

6. Injection valve (10) according to claim 1, characterized in that the anchor wings (22) in pairs have rigid connections (76) or flexible couplings (78).

7. An injector according to claim 1, characterized in that the armature vanes (22) in pairs each have a high moment of inertia J and a low mass moment of inertia j, in each case based on the axis of rotation of the armature blade 22 at bending.

8. Injection valve (10) according to claim 1, characterized in that the armature vanes (22) seen in the circumferential direction of the armature plate (20), each have flexurally soft couplings (82).

9. Injection valve (10) according to claim 1, characterized in that the armature vanes (22) on the armature plate (20) by a slit (74) are formed and two opposing armature vanes (22) are constructed symmetrically.

10. Injection valve (10) according to one or more of the preceding claims, characterized in that upon impact of the armature assembly of armature plate (20) and anchor bolt (18) in the seat (30) on a valve guide (12) due to the different natural frequency of pairs of Anchor wing (22) the valve member (16) in the opening direction actuated Aufziehkräfte (40) are compensated.