DE102013225395A1 - Valve arrangement for a solenoid valve and associated solenoid valve - Google Patents

Abstract

The invention relates to a valve arrangement (1A) for a solenoid valve having a movable plunger (10A) which has a shaft (12) and a closing element (14A) with a sealing geometry (16A), the sealing geometry (16A) being connected to a valve seat (4 ) forms a valve which adjusts a fluid flow between an inflow (6) and at least one outflow (8). According to the invention, the sealing geometry (16A) comprises a circumferential elevation (18A) on the closing element (14A), which causes an increase in the effective hydraulic force on the closing element (14A).

Description

State of the art

The invention relates to a valve arrangement for a solenoid valve according to the preamble of independent claim 1 and an associated solenoid valve.

A conventional designed as normally open control valve solenoid valve is used for example as an inlet valve, which controls the pressure build-up in a Radbremszange during control operations in an antilock braking system (ABS) or a traction control system (ASR system) or an electronic stability program system (ESP system). With a fully energized inlet valve, a hydraulic connection between a master cylinder and the Radbremszange is interrupted. By energizing a closing element or plunger is pressed with a sealing geometry in a corresponding valve seat, so that no fluid can flow through the valve. Since it is the o.g. Inlet valve is an adjustable valve, it can take different valve lifts for different electrical currents. Depending on the valve current and the pressure difference applied to the valve, an equilibrium of forces arises, so that the closing element remains in a defined stroke position and a volume flow corresponding to the boundary condition can flow through the valve.

To close the valve, the magnet assembly of the conventional electroless open solenoid valve generates a magnetic force which moves the plunger axially against the force of a return spring via an armature and sealing the sealing geometry dips into the valve seat. Thus, the spring force of the return spring together with a force acting on the plunger, which is generated by the fluid flow and hereinafter also referred to as hydraulic force or fluid force, the valve opens in the de-energized state of the solenoid valve.

In the published patent application DE 10 2007 051 557 A1 are described a plunger for a solenoid valve and an associated solenoid valve. The described plunger for a solenoid valve comprises a shaft to which a closing element is integrally formed with a sealing element. The sealing element forms with a valve seat a main valve to adjust a fluid flow between an inlet and at least one outlet. The sealing element is embodied, for example, as a spherical cap and the closing element is designed, for example, as a truncated cone whose diameter increases conically starting from the sealing element. On the closing element deflecting means are formed, which in the installed state deflect the fluid flow guided along the wall of the closing element between the inflow and the at least one outflow of the magnetic valve directly in the direction of the at least one outflow. As a result, the emergence of armature space pressures when folding the flow to the closing element of the plunger can be almost completely avoided, or significantly reduced. By means of the deflection means arranged on the closing element of the tappet, the fluid flow can advantageously be directed away from the armature space in the direction of outflow. In addition, the deflection means act as a pressure-effective surface and increase the opening force acting on the plunger hydraulic force.

Disclosure of the invention

The valve arrangement according to the invention for a solenoid valve with the features of independent claim 1 and the corresponding solenoid valve having the features of independent claim 6 have the advantage that can be significantly reduced by the modification of the sealing geometry of the closing element, the steep drop in hydraulic power, especially in the lower stroke range , The dependent of a differential pressure hydraulic force-stroke characteristics are significantly flatter compared to typical hydraulic force-stroke characteristics of conventional valve assemblies. In addition, over the entire stroke range significantly more uniform hydraulic force-stroke curves. Due to the flatter force curve, the differential pressure-dependent control property of the valve arrangement or the solenoid valve improves, in particular in the lower stroke range. As a result, the valve assembly or the solenoid valve is able to correct printing errors faster again. As a result of the sealing geometry of the closing element according to the invention, the valve arrangement or the solenoid valve behaves "similar to a diaphragm", so that the flow at a given stroke is less viscous and thus temperature-dependent.

Embodiments of the present invention provide a valve assembly for a solenoid valve that includes a movable plunger. The movable plunger has a shank and a closing element with a sealing geometry. The sealing geometry forms with a valve seat a valve which adjusts a fluid flow between an inflow and at least one outflow. According to the invention, the sealing geometry comprises a circumferential increase on the closing element, which causes an increase in the effective hydraulic force on the closing element.

In addition, a solenoid valve with a magnet assembly and a valve arrangement according to the invention is proposed with a movably guided plunger, wherein one of the Magnetic assembly generated magnetic force moves the plunger axially via an armature. As a result, the sealing geometry can be moved from the normally open state in the direction of the valve seat. Depending on the energization of the magnet assembly for generating the magnetic force and the pressure difference applied to the valve, an equilibrium of forces is established, so that the plunger with the sealing geometry remain in a defined stroke position and a volume flow corresponding to the boundary condition can flow through the valve. For complete interruption of the fluid flow, the sealing geometry acts sealingly together with the valve seat.

The measures and refinements recited in the dependent claims advantageous improvements of the independent claim 1 valve assembly for a solenoid valve and the specified in the independent claim 6 solenoid valve are possible.

It is particularly advantageous that the increase can be performed as a circumferential ring with a circular cross-section. The running as a circumferential ring increase can for example be molded or placed on a designed as a spherical cap closing element. This allows a simple implementation of the increase to realize the constriction of the fluid flow over a much shorter range than in the prior art.

In an advantageous embodiment of the valve arrangement according to the invention, the valve seat can be introduced as a hollow truncated cone closing off the inflow into a valve body.

In an advantageous embodiment of the solenoid valve according to the invention, depending on a magnetic force generating electric current and a voltage applied between the inflow and the at least one outflow differential pressure can set a balance of power, so that the closing element with the sealing geometry can remain in a predetermined stroke position and the boundary conditions corresponding fluid flow can flow through the valve.

An embodiment of the invention is illustrated in the drawings and will be explained in more detail in the following description. In the drawings, like reference numerals designate components that perform the same or analog functions.

Brief description of the drawings

1 shows a schematic sectional view of an embodiment of a valve arrangement according to the invention for a solenoid valve.

2 shows a schematic sectional view of a conventional valve assembly for a solenoid valve.

3 shows a sectional view of a section of the valve arrangement according to the invention for a solenoid valve 1 and the conventional valve assembly for a solenoid valve 2 ,

4 shows a diagram with several typical hydraulic force-stroke characteristics for the conventional valve assembly 2 ,

5 shows a diagram with a typical hydraulic force-stroke characteristic for the valve arrangement according to the invention for a solenoid valve 1 and a typical hydraulic force-stroke characteristic for the conventional valve assembly 2 ,

Embodiments of the invention

How out 1 can be seen, the illustrated embodiment comprises a valve assembly according to the invention 1A for a solenoid valve a movable plunger 10A which is a shaft 12 and a closing element 14A with a sealing geometry 16A having. The sealing geometry 16A forms with a valve seat 4 a valve, which is a fluid flow between an inflow 6 and at least one drain 8th established. According to the invention, the sealing geometry comprises 16A a circumferential increase 18A on the closing element 14A , which is an increase in the effective hydraulic force on the closing element 14A causes.

How out 1 can be further seen, the shaft 12 in the illustrated embodiment, a predetermined diameter d and the closing element 14A is designed as a spherical cap with a predetermined radius R. The increase 18A is designed as a circumferential ring with a circular cross section and on the designed as a spherical cap closing element 14A placed. Alternatively, the elevation performed as a circumferential ring of circular cross-section 18A to the designed as a spherical cap closing element 14A be formed. A radius r of the circular cross section is substantially smaller than the radius R of the spherical cap. How out 1 is further apparent, is the valve seat 4 as one the inflow 6 in the direction of sealing geometry 16A final hollow truncated cone in a valve body 2 brought in. The sealing geometry 16A generated about increase 18A in conjunction with the valve seat 4 a corresponding sealing area 20A with a bottleneck 22A , on which in the raised state of the closing element 14A the narrowest flow cross-section is present in the valve. When closed, the sealing area is located 20A within the sealing region 20A at the valve seat 4 and interrupts the fluid flow between the inflow 6 and the at least one drain 8th ,

How out 2 can be seen, includes a conventional valve assembly 1B for a solenoid valve a movable plunger 10B which is a shaft 12 and a closing element 14B with a sealing geometry 16B and a valve body 2 with a valve seat 4 which the inflow 6 in the direction of sealing geometry 16B concludes. Analogous to the valve arrangement according to the invention 1A for a solenoid valve forms the sealing geometry 16B with the valve seat 4 a valve which controls the fluid flow between the inlet 6 and at least one drain 8th established. How out 2 can be further seen, the shaft 12 also a predetermined diameter D on. Unlike the in 1 illustrated valve assembly according to the invention 1A is the sealing geometry 16B the in 2 illustrated conventional valve assembly 1B executed only as a spherical cap with a predetermined radius R. Analogous to the valve arrangement according to the invention 1A creates the sealing geometry 16B in conjunction with the valve seat 4 a corresponding sealing area 20B with a bottleneck 22B , on which in the raised state of the closing element 14B the narrowest flow cross-section is present in the valve. When closed, the sealing area is located 20B within the sealing area 20B at the valve seat 4 and interrupts the fluid flow between the inflow 6 and the at least one drain 8th ,

3 shows a section with the sealing geometry 16A of the closing element 14A the valve assembly according to the invention 1A for a solenoid valve off 1 : In addition, the sealing geometry 16B of the closing element 14b the conventional valve assembly 1B out 2 shown dashed at the same hub. How out 3 can be seen, the fluid flow through the sealing geometry 16B the conventional valve assembly 1B constricted on a longer path than by the modified sealing geometry 16A the valve assembly according to the invention 1A , That means the sealing area 20B in the conventional valve assembly 1B larger than the sealing area 20A in the valve arrangement according to the invention 1A is trained. This increases the dynamic pressure in the conventional valve arrangement 1B and the static hydraulic force effective pressure decreases. The same applies to the area behind the bottleneck 22B with the narrowest flow cross-section. The pressure recovery extends to a long range. Due to the inventive design of the sealing geometry 16A the constriction of the fluid flow takes place at the bottleneck 22A over a much shorter range. Therefore exist up to the bottleneck 22A with the narrowest flow cross section higher static pressures. The same applies to the area behind the bottleneck 22A with the narrowest cross section. This has the consequence that at the same hub larger hydraulic forces on the closing element 14A Act. In total, this results in larger opening hydraulic forces, especially in the lower stroke range, since there the cross-sectional areas over the seat gap curve relative to the narrowest cross-section are larger than for larger strokes.

4 shows several typical hydraulic force-stroke characteristics for the conventional valve assembly 2 , How out 4 can be seen act on the valve opening hydraulic forces when between the inflow 6 and the at least one drain 8th a differential pressure dp ₁ , dp ₂ , dp ₃ is applied. Considering the differential pressures for different dp _1, dp _2, dp characteristics shown ₃ F _H1, F _{H2, H3} F F _H of the hydraulic force curve over the stroke h, the hydraulic forces fall off with increasing valve lift h. In the lower stroke range, the force characteristics F _H1 , F _H2 , F _H3 fall off very much, especially at a higher differential pressure (see (dF / dh) ₁ in 4 ). In 4 the following applies: dp ₁ > dp ₂ > dp ₃ . In the middle and upper stroke range, this waste becomes flatter (see (dF / dh) ₂ in 4 ). This is the case in particular with the intake valves currently in use with a "ball-and-cone seat closing geometry". This has a negative effect on the differential pressure-dependent control property of the intake valve.

5 shows the comparison of a hydraulic force-stroke characteristic F _{Ha of} the conventional valve assembly 1B and a hydraulic force-stroke characteristic F _{Hn of} the valve arrangement _{according to} the invention 1A with the modified sealing geometry 16A ,

How out 5 can be seen, by the modification of the sealing geometry 16A of the closing element 14A the valve assembly according to the invention 1A the steep drop in hydraulic power, especially in the lower stroke significantly reduced. As a result, the hydraulic force-stroke characteristic F _{Hn of} the valve arrangement _{according to} the invention runs 1A in comparison to the hydraulic force-stroke characteristic F _{Ha of} the conventional valve assemblies 1B much flatter. In addition, a much more uniform course of the hydraulic force-stroke characteristic F _Hn results over the entire stroke range. Due to the flatter force curve of the hydraulic force-stroke characteristic curve F _Hn , the differential pressure-dependent control property of the valve arrangement according to the invention improves 1A or a corresponding solenoid valve, in particular in the lower stroke range, in which the conventional hydraulic force-stroke characteristic F _{Ha has} a significantly steeper course. When improving the control property, it does not depend on the effective absolute hydraulic force F _H at the assumed operating point but on the slope of the respective hydraulic force-stroke characteristic F _Ha , F _Hn at the assumed operating point. This is the result valve assembly 1A or the solenoid valve in a position to correct printing errors faster. The advantage decreases with increasing stroke h, since the slopes of the hydraulic force-stroke characteristics F _Ha , F _Hn approach in the larger stroke range h.

The valve arrangement according to the invention 1A can be used, for example, in a solenoid valve, not shown, which has a magnetic assembly, not shown. With a corresponding energization, the magnet assembly generates a magnetic force which is the plunger 10A axially moved by an anchor, not shown. Depending on a magnetic force generating electric current and a between the inflow 6 and the at least one drain 8th applied differential pressure, adjusts itself to a balance of power, so that the closing element 14A remains in a predetermined stroke position and a boundary conditions corresponding fluid flow flows through the valve. To close the valve, the magnet assembly generates a magnetic force which pushes the plunger 10A axially moved by an armature against the force of a return spring until the sealing geometry 16A with the increase 18A sealing at the valve seat 4 is applied.

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 102007051557 A1 [0004]

Claims (7)

Valve arrangement for a solenoid valve with a movable plunger ( 10A ), which a shaft ( 12 ) and a closing element ( 14A ) with a sealing geometry ( 16A ), wherein the sealing geometry ( 16A ) with a valve seat ( 4 ) forms a valve, which is a fluid flow between an inflow ( 6 ) and at least one outflow ( 8th ), characterized in that the sealing geometry ( 16A ) an encircling increase ( 18A ) on the closing element ( 14A ), which increases the effective hydraulic force on the closing element ( 14A ) causes. Valve arrangement according to claim 1, characterized in that the increase ( 18A ) is designed as a circumferential ring with a circular cross-section. Valve arrangement according to claim 2, characterized in that the elevation executed as a circumferential ring ( 18A ) to a closing element ( 14A ) is formed. Valve arrangement according to claim 2, characterized in that the elevation executed as a circumferential ring ( 18A ) on a closing element ( 14A ) is attached. Valve arrangement according to one of claims 1 to 4, characterized in that the valve seat ( 4 ) as an inflow ( 6 ) final hollow truncated cone in a valve body ( 2 ) is introduced. Solenoid valve with a magnet assembly and a valve assembly ( 1A ) with a movably guided ram ( 10A ), which a shaft ( 12 ) and a closing element ( 14A ) with a sealing geometry ( 16A ), wherein the sealing geometry ( 16A ) with a valve seat ( 2.1 ) forms a valve, which is a fluid flow between an inflow ( 6 ) and at least one outflow ( 8th ), and wherein a magnetic force generated by the magnet assembly releases the plunger (10). 10 ) is moved axially via an armature, characterized in that the valve arrangement ( 1A ) is designed according to one of claims 1 to 5. Solenoid valve according to claim 6, characterized in that in dependence on a magnetic force generating electric current and between the inflow ( 6 ) and the at least one outflow ( 8th ) adjoining differential pressure adjusts a balance of forces, so that the closing element ( 14A ) remains in a predetermined stroke position and a boundary conditions corresponding fluid flow flows through the valve.

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