RU2592637C2 - Minimising chatter armature electromagnetic valve at closing thereof by inhibition of link in residual air gap - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering. Electromagnetic valve (1) with electromagnetic unit (2) has coil (5) and core consisting of inner (3) and external poles (4), with flat anchor (7), with anchor pin. Armature stroke limiter is formed in area of end side of core adjusting disc to set residual air gap between armature and electromagnetic unit. In such electromagnetic valve (1) it is possible to minimise anchor bounce when solenoid valve is closed residual air gap (18) in radial direction is closed in the section between external terminal (4) of core and external diameter of flat anchor (7).

EFFECT: technical result consists in reduction of anchor chatter when valve is closing.

9 cl, 4 dwg

Description

State of the art

The present invention relates to an electromagnetic valve with an electromagnetic assembly having a coil and a core consisting of an inner pole and an outer pole, with a flat armature, with an anchor pin and with an arm limiter formed in the area of the end side of the core by a spacer disk to create a residual air gap between flat anchor and electromagnetic unit.

A similar solenoid valve is known from DE 102008040073 A1. Such an electromagnetic valve should provide stabilization, i.e. a significant increase in reproducibility, its switching processes for controlling the fuel nozzle without the need for additional technological operations and at no additional cost. This is achieved due to the fact that the end side of the core or the opposite surface of the flat anchor has at least in one specific zone an inclined and / or curved surface that is different from the plane.

Another solenoid valve is known from DE 102009003213 A1. Such a solenoid valve has a spacer disk to create a residual air gap, fixed by force closure in places of clamping or pinching on the end side of the core facing the flat armature, adjacent to the sleeve. Such a spacer disk is made with simple geometry of a ferromagnetic or non-magnetic material, such as foil. The spacer disk due to its fixation in the places of clamping or pinching by means of a power circuit is installed in place after the assembly of the electromagnetic unit and before assembling the atomizer of the fuel injector, while the entire assembly process is not disturbed and therefore simplified. The spacer disk for its fastening has protruding tabs, which during the assembly process are bent at the points of clamping or pinching. A gap to the hub remains near these tabs and along the outer circumference of the spacer disc.

The present invention was based on the task of minimizing the bounce of the armature when closing the electromagnetic valve.

Summary of the invention

Advantages of the Invention

This problem is solved due to the fact that the residual air gap is blocked in the radial direction in the area between the outer pole of the core and the outer diameter of the flat armature. Thanks to this design, a reduction in pressure forces on the flat side parts of the armature is achieved, which is realized by closing the residual air gap in a certain area. Due to this closure of the residual air gap, a deceleration link is created in the form of a seal in the part of the residual air gap located on the outer pole side of the core, which reduces the further flow of fuel when the anchor is open in the residual air gap.

This design is primarily used in fuel injectors for common rail systems (fuel injection systems with a common high-pressure fuel line) with a pressure-balanced solenoid valve, in which it is possible to create a pressure reaching about 2200 bar. Such a pressure-balanced solenoid valve has a spacer disk to create a residual air gap that is created at the upper stroke limiter in the open state of the solenoid valve and which should provide quick closing of the armature. At the same time, problems create the bounce of the armature and sensitivity to backpressure during the reverse stroke, and such problems can arise primarily when the fuel injector repeatedly injects fuel. In the electromagnetic valves described above when considering the prior art, the radially outer part of the residual air gap is free for the fluid to continue to flow into it, and therefore pressure forces are transferred from the cavity of the flat armature installation to its upper side at any time and affect its closing characteristics and bounce. Proposed in the invention, the design allows to at least significantly reduce the degree of manifestation of such a negative property.

In one preferred embodiment, the residual air gap described above is covered by a spacer disk in cooperation with the outer pole of the core surrounding the electromagnetic assembly with a sleeve and a flat armature. Thanks to this option, tight closure of the residual air gap is ensured, especially in this critical radially outer part.

In yet another embodiment, the spacer disc is an annular washer. A spacer disk made in the form of an annular washer in this way, unlike the prior art, is not fixed on a flat anchor, but according to this general variant it is mounted on a freely floating landing between the flat anchor and the outer pole of the core. The spacer disc is fixed in position only by its outer diameter in the radial direction by the sleeve. The inner diameter of the annular washer is selected so that, on the one hand, there is no excessive hydraulic sticking of the flat armature, and on the other hand, sufficient overlap of the residual air gap in its radially outer part is ensured.

In solenoid valves of known designs, reaching under extremely high values under certain conditions, the pressure difference between the upper side of the flat armature and its lower side is the reason that the fuel that continues to flow externally while moving the flat armature in the closing direction exerts considerable force on it and gives it significant acceleration that lead to the bounce of a flat anchor.

Owing to the overlapping of the residual air gap in the radial direction in the area between the outer pole of the core and the outer diameter of the flat armature, further fuel supply during the movement of the flat armature in the closing direction is hindered, and therefore slows down, and therefore the flat armature at the moment of its impact on its saddle moves with a smaller acceleration, due to which the bounce is significantly reduced. In this case, the flat anchor quickly again reaches its dormant state even before the start of the next fuel injection process. The advantage associated with the reduction of the bounce of the armature when it reaches its saddle is manifested due to the greater linearity of the multi-parameter characteristic, primarily in dynamic high pressure hydraulics, small amplitudes of fluctuations in the amount of fuel during repeated injection, insignificant sensitivity to backpressure during reverse stroke and less wear on the saddle due to less forces when a flat anchor hits him.

In one embodiment of the invention, the annular washer has internal bridges connected to each other in its center, and in another embodiment, has an opening for the anchor pin to be passed through it. Thus, the spacer disk to create a residual air gap can be radially fixed with an anchor finger on a flat anchor and provides overlap of the residual air gap in the radial direction in the area between the outer pole of the core and the outer diameter of the flat anchor. In turn, according to another embodiment, it was found that the ring washer is preferably provided with four jumpers. As a result, sufficient area remains to form the residual air gap proper.

Alternatively, with the radial direction overlapping the residual air gap with a spacer disk between the outer pole of the core, the sleeve and the outer diameter of the flat armature, such overlapping of the residual air gap can be provided by a step on the flat armature or alternatively on the outer pole of the core. In this case, under certain conditions, the spacer disk is located only in the center of the electromagnetic unit and is made with a correspondingly smaller diameter. Such a reduced spacer disk is also preferably in the form of an annular washer with or without jumpers. The rest of the spacer disk to create a residual air gap is preferably made of non-magnetic material.

Other preferred embodiments of the invention are described in the following description of the drawings, in which exemplary embodiments of the invention are described in more detail below.

Brief Description of the Drawings

In FIG. 1 is a sectional view of a solenoid valve with a spacer disk to create a residual air gap overlapped by this spacer disk in a radial direction between the outer pole of the core of the electromagnetic assembly and the outer diameter of the armature.

In FIG. 2, a spacer disk made in the form of an annular washer is shown in plan view to create a residual air gap, and a simplified sectional view shows an electromagnetic valve with such an annular washer mounted.

In FIG. 3 shows in a plan view a spacer disk for creating a residual air gap in the form of an annular washer with internal jumpers and a sectional view of a simplified solenoid valve with such a spacer disk mounted.

In FIG. 4 is a plan view showing a spacer disk which is similar to that shown in FIG. 3 to the spacer disk to create a residual air gap, but made smaller, and which, according to the sectional view of a simplified depiction of the electromagnetic valve, is installed in the center of this electromagnetic valve, whose armature has a step that overlaps the air gap in the area of the outer pole of the core.

Description of Embodiments

Shown in FIG. 1, the electromagnetic valve 1, which primarily actuates the fuel nozzle of the common rail system, which is the fuel system of a diesel engine internal combustion engine, has an electromagnetic assembly 2. Such an electromagnetic assembly 2 has a core with an inner pole 3 and an outer pole 4 between which there is a coil 5. The electromagnetic unit 2 is entirely placed in the sleeve 6.

Opposite the end side of the inner pole 3 and the outer pole 4 of the core is a flat anchor 7, in which a central through hole 8 is made and into which the anchor pin 9 is inserted. The saddle of the flat anchor 7 overlaps the control cavity under the fuel pressure in the system or connects it to the valve cavity with the discharge of pressure into it. The valve cavity is connected by a connecting line to the control cavity. Depending on the position of the solenoid valve, pressure is generated in the control cavity or pressure is released from the control cavity. The control cavity further interacts with a needle provided in the fuel nozzle of the nozzle, which moves axially due to a change in pressure in the control cavity and which in its open position opens the spray holes in the fuel nozzle through which (under pressure in the system) the fuel enters the corresponding chamber combustion in an internal combustion engine.

The anchor pin 9 passes through the Central hole 10 in the inner pole 3 of the core and in this section is surrounded by a spring 11 of the electromagnetic valve. The spring 11 rests on the cover of the sleeve 6 not shown in the drawing and applies a pressing force to the flat armature 7, which thereby moves from the electromagnetic assembly 2.

When applying electric current to the coil 5, the flat armature 7 moves to the electromagnetic assembly 2 against the force of the spring 11. In this case, the flat armature 7 can move in the direction of the electromagnetic assembly 2 only until it stops in the spacer disk 12 to create a residual air gap located between the electromagnetic assembly 2 and by this flat anchor 7. Such a spacer disk 12 fits snugly against the sleeve 6 and prevents further fuel from entering the residual air gap 18 through the gap 13 between the flat anchor 7 and the bushing 6. Thanks to a similar design, the bounce of the flat armature 7 moving towards the electromagnetic unit 2 is prevented when it reaches its saddle. It should be borne in mind that, due to the partially very high pressure difference between the upper side of the flat armature facing the electromagnetic unit 2 and its lower side, in the conventional design and arrangement of the spacer disk 12, the fuel that continues to flow outside from the outside while the flat armature 7 moves in the closing direction considerable efforts are made to him and he informs him of significant accelerations that lead to the rattle of the flat anchor 7 upon reaching his saddle. Due to the overlapping of the residual air gap 18 in the radial direction in the area between the outer pole 4 of the core and the outer diameter of the flat armature 7, further fuel intake during the movement of the flat armature 7 in the closing direction is hindered, and accordingly slows down, and therefore the flat armature 7 at the moment of its impact about its saddle moves with less acceleration, due to which the bounce is significantly reduced. In this case, the flat anchor 7 quickly again reaches its dormant state even before the start of the next fuel injection process.

At the bottom of FIG. 2, a spacer disk 12 is shown in plan view, which in this embodiment is made in the form of an annular washer 14. Shown at the top in FIG. 2, a simplified sectional view of the solenoid valve 1 corresponds to the image in FIG. 1. The ring washer 14 is not fixed on the flat anchor 7, but instead is mounted on a freely floating in the direction of travel of the flat anchor 7 landing between it and the outer pole 4 of the core. The ring washer 14 is fixed in position only in the radial direction by the sleeve 6 in its outer diameter. The inner diameter of the ring washer 14 is selected so that, on the one hand, there is no excessive hydraulic sticking of the flat armature 7, and on the other hand, sufficient overlap of the residual air gap 18 in its radially outer part.

At the bottom of FIG. 3 shows a spacer disk 12, which is also in the form of an annular washer 14 ′ and has additional internal jumpers 15 that are interconnected in the center of the annular washer 14 ′. To pass the anchor pin 9, a hole 16 is made in this central part of the annular washer 16. Due to this design of the spacer disk 12, it is possible to easily mount it. In this case, when performing a flat anchor 7 of a convex shape, the inner pole 3 of the core can also serve as a limiter of its course.

At the top of FIG. 3 shows a corresponding section through the corresponding solenoid valve 1.

At the bottom of FIG. 4 shows reduced compared to that shown in FIG. In option 3, a spacer disk 12, in which the ring washer 14 ″ has a significantly smaller outer diameter. Such an annular washer 14 ″ also has lintels 15 ′ converging in its center and an opening for passing the anchor pin 9.

At the top of FIG. 4, a sectional view shows a solenoid valve 1 with a similar spacer disk 12 mounted in it, and the flat armature 7 ′ in this case has a step 17 overlapping the residual air gap between the outer pole 4 of the core and the flat armature 7 ′. In contrast to that shown in FIG. 1 of the option, the further flow of fuel from outside to the flat anchor 7 ′ is prevented, and accordingly reduced due to the step 17 on it. However, the height of such a step 17 on the flat anchor 7 ′ should be less than the thickness of the spacer disc so that the spacer disc serves as a limiter of the course of the armature. Alternative to this option, the step 17 can also be made integral with the electromagnetic node 2, especially with the outer pole 4 of the core.

Claims (9)

1. An electromagnetic valve (1) with an electromagnetic unit (2) having a coil (5) and a core consisting of an inner pole (3) and an outer pole (4), with a flat armature (7, 7 ′), with an anchor pin ( 9) and with an armature limiter formed in the area of the end side of the core by a spacer disk (12) to create a residual air gap (18) between the flat armature (7) and the electromagnetic unit (2), characterized in that the residual air gap (18) overlapped in the radial direction in the area between the outer pole (4) of the core and the outer diameter of the pl of the anchor (7) with a spacer disk (12) in cooperation with the outer pole (4) of the core surrounding the electromagnetic assembly (2) with a sleeve (6) and a flat armature (7), while the spacer disk (12) is mounted freely floating in the direction the course of the flat armature (7) landing between it and the outer pole (4) and fixed in position only in the radial direction by the sleeve (6) in its outer diameter. 2. An electromagnetic valve according to claim 1, characterized in that the residual air gap (18) is closed to prevent the influx of fuel. 3. The electromagnetic valve according to claim 1, characterized in that the spacer disk (12) is an annular washer (14, 14 ′, 14 ″). 4. The electromagnetic valve according to claim 3, characterized in that the annular washer (14, 14 ′, 14 ″) has internal jumpers (15, 15 ′) interconnected at its center. 5. An electromagnetic valve according to claim 4, characterized in that a hole (16) is provided in the center of the annular washer (14, 14 ′, 14 ″). 6. The electromagnetic valve according to claim 4, characterized in that four jumpers (15, 15 ′) are provided. 7. The electromagnetic valve according to one of paragraphs. 1-6, characterized in that the residual air gap (18) is closed by a ledge (17) on a flat anchor (7, 7 ′) in cooperation with the outer pole (4) of the core and the sleeve (6) surrounding the electromagnetic assembly (2). 8. The electromagnetic valve according to one of paragraphs. 1-6, characterized in that the residual air gap (18) is closed by a step on the outer pole (4) of the core in cooperation with a flat armature (7) and a sleeve (6) surrounding the electromagnetic assembly (2). 9. An electromagnetic valve according to claim 1, characterized in that the spacer disk (12) is made of non-magnetic material.

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