JP5638130B2 - Minimizing recoil when the armature is closed by a delay element in the residual void. - Google Patents

Description

Prior Art The present invention includes an electromagnetic coil, a magnet group including a magnetic core composed of a magnetic core inner pole and a magnetic core outer pole, an armature plate, and an armature pin, and is further formed by a residual gap in the end face region of the magnetic core. The present invention relates to an electromagnetic valve including a stopper, wherein a residual gap exists between the armature plate and the magnet group.

  A solenoid valve of this kind is known from German published patent application DE 102008040073A1. With this solenoid valve, the stability of the switching process of the solenoid valve for operating the fuel injection valve, that is, reproducibility, without requiring additional process steps and without additional cost Should be improved significantly. This is achieved by having the end face of the magnetic core or the end face of the armature plate opposite to the end face of the magnetic core at least in a predetermined region having an inclined surface different from a flat surface and / or a surface extending in a convex shape. Is done.

  Further electromagnetic valves are known from German published patent application DE 102009003213A1. This solenoid valve has a residual gap, and this residual gap is fixed to the magnet sleeve while being brought into contact with the end face of the magnetic core directed toward the armature plate by the pressing force at the sandwiched portion. . The residual gap is made from a ferromagnetic or non-magnetic material having a simple shape, such as a metal film. By fixing the residual gap at the clamping position by pressing force, the residual gap can be installed after attaching the magnet group and before installing the injector, and the entire installation process is disturbed. There is no simplification. The residual gap plate has tongues protruding to the side for fixation, and these tongues are bent at the pinching points during the attaching process. A gap for the magnet sleeve remains next to the tongue and on the outer periphery of the remaining gap.

  An object of the present invention is to minimize recoil when the armature is closed.

Summary of the Invention Advantages of the Invention This problem is solved by radially closing the residual air gap between the outer core of the magnet group and the outer diameter of the armature. With the above configuration, the pressure on the wing portion of the armature is reduced. This is achieved by closing the residual air gap in a defined area. This closure results in a delay element in the form of a sealing in the residual gap outside the pole, which reduces the inflow of fuel in the residual gap when the armature is opened.

  Such a configuration is used in fuel injectors for common rail systems, particularly with pressure compensated solenoid valves, which allow a system pressure of about 2200 bar. Such a pressure-compensated solenoid valve has a residual gap plate on the upper stroke stopper in order to form a residual gap that allows the armature to be quickly closed in the open state. The problem here is vulnerability to armature recoil and return back pressure, which can occur especially in multi-stage injection.

  In the case of the solenoid valve described with respect to the prior art, the outside of the residual gap is free for the inflow medium in the form of fuel, so that the pressure from the armature chamber always reaches the surface of the armature plate, and the closing action and It will affect the recoil movement. This property is at least significantly reduced by the configuration of the present invention.

  In one advantageous embodiment, the residual gap described above is closed by a residual gap disk that cooperates with the outer core pole, the magnet sleeve surrounding the magnet group, and the armature plate. According to this embodiment, a tight closure is formed in a particularly important outer region.

  In a development of the invention, the residual gap disc is an annular disc. The annular disk constructed in this way is not fixed on the armature plate as in the prior art. According to this general embodiment, the armature plate and the magnet outer pole are arranged in the stroke direction of the armature. Arranged to float between. Only the outer diameter of the residual gap is positioned radially by the magnet sleeve. The inner diameter of the annular disk is selected on the one hand so that excessive fluid sticking of the armature plate does not occur, and on the other hand it is selected so as to provide a sufficient closure of the outer residual air gap.

  In the case of the known structure, due to the very large pressure difference that may occur between the front and back surfaces of the armature plate, the fuel flowing from the outside is large with respect to the armature plate during the closing process of the armature plate. It exerts force and acceleration, and the armature plate recoils by this force and acceleration.

By closing the remaining air gap between the outer magnetic pole and the outer diameter of the armature plate in the radial direction, inflow of fuel becomes difficult or delayed during the closing process of the armature plate. Therefore, since the armature plate moves toward the seat with slower acceleration, the recoil is remarkably reduced. The armature plate quickly reaches a rest state again before further injection takes place. The benefits of reduced recoil when seated are recognized by:
In particular, the linearity of the characteristic map in dynamic high pressure hydraulic equipment is improved.
The amplitude of the bulk wave in the multistage injection becomes small.
The vulnerability to back pressure is reduced.
The reduced force reduces valve seat wear when the armature plate is seated.

  In a development of the invention, the annulus has a plurality of webs located therein, these webs being connected to each other at the center of the annulus, and in another embodiment, these webs Has an opening for the armature pin. Thus, the residual gap can be positioned on the armature plate by the armature pin, and the residual gap closes the residual gap between the outer magnetic core pole and the outer diameter of the armature plate in the radial direction. In another embodiment, it has been found advantageous to provide four webs. This leaves enough area for the original residual voids.

  In an alternative embodiment for radially closing the residual air gap between the magnetic outer pole, the pole sleeve and the armature plate, the closure is provided on the step provided on the armature plate or the magnetic outer pole. To implement. In this embodiment, the residual gap is optionally arranged only in the middle of the magnet group and is correspondingly formed with a smaller diameter. Advantageously, this smaller residual cavity is also formed as an annular disk with a web or as an annular disk without a web. In other respects, the residual gap is advantageously made from a non-magnetic material.

  Further advantageous embodiments of the invention will become apparent in the detailed description of the drawings. Here, the embodiments shown in the drawings are described in more detail.

It is sectional drawing of the solenoid valve which has the residual air gap disk which closes the residual air gap between the magnetic core outer pole of a magnet group, and the outer diameter of an armature in radial direction. It is the top view of the residual gap board formed as an annular disk, and the schematic sectional drawing of the solenoid valve to which the annular disk was attached. It is a top view of the residual gap board which consists of an annular disk which has a some web located inside, and a schematic sectional drawing of the solenoid valve to which the residual gap board was attached. FIG. 4 is a plan view of a smaller residual gap plate similar to FIG. 3, but a schematic cross-sectional view of a solenoid valve with a residual gap plate mounted in the center, in which the armature is located in the region of the magnetic core outer pole. And a step portion for closing the residual gap.

Embodiment of the Invention A solenoid valve 1 illustrated in FIG. 1 has a magnet group 2. This solenoid valve 1 is used to operate a fuel injection valve of a common rail injection system, particularly for an internal combustion engine driven by diesel fuel. The magnet group 2 has a magnetic core inner pole 3 and a magnetic core outer pole 4, and an electromagnetic coil 5 is embedded between the magnetic core inner pole 3 and the magnetic core outer pole 4. The magnet group 2 is disposed in the magnet sleeve 6 as a whole.

  The armature plate 7 is located opposite to the end surfaces of the magnetic core inner pole 3 and the magnetic core outer pole 4. A central through-opening 8 passes through the armature plate 7, and an armature pin 9 is inserted into the central through-opening 8. The armature seat portion of the armature plate 7 seals the control chamber to which the fuel system pressure is applied or opens the control chamber to the valve chamber. The valve chamber is connected to the control chamber via a connection pipe line. Depending on the switching position of the valve, pressure is applied to the control chamber or the pressure in the control chamber is released. The control chamber further cooperates with the needle valve of the fuel injection valve. The needle valve shifts in the axial direction according to the pressure difference in the control chamber, opens the injection port of the fuel injection valve in the open position, and fuel (under system pressure) passes through this injection opening to the combustion chamber of the internal combustion engine. Flows into.

  The armature pin 9 protrudes through the central opening 10 of the magnetic core inner pole 3 and is surrounded by a valve spring 11 in this region. The valve spring 11 is supported by a lid portion of the magnet sleeve 6 (not shown) and applies pressure to the armature plate 7, whereby the armature plate 7 moves in a direction away from the magnet group 2.

  When the electromagnetic coil 5 is energized, the armature plate 7 moves in the direction of the magnet group 2 against the force of the valve spring 11. At this time, the armature plate 7 can only move in the direction of the magnet group 2 until the armature plate 7 comes into contact with the residual gap 12 disposed between the magnet group 2 and the armature plate 7. Yes. The residual gap 12 is in close contact with the magnet sleeve 6 and prevents the fuel from flowing through the gap 13 of the residual gap 18 that exists between the armature plate 7 and the magnet sleeve 6. With such a configuration, recoil when the armature plate moved in the direction of the magnet group 2 is seated is prevented. What should be considered here is that, in the case of the conventional configuration, a partly very large pressure difference between the front surface and the back surface of the armature plate facing the magnet group, and the arrangement of the residual gap plate 12 Thus, during the closing process of the armature plate 7, the fuel flowing from the outside exerts a large force and acceleration on the armature plate 7, and the armature plate 7 recoils when seated due to this force and acceleration. That is. By closing the residual air gap 18 between the outer magnetic core pole 4 and the outer diameter of the armature plate 7 in the radial direction, inflow of fuel becomes difficult or delayed during the closing process of the armature plate 7. Accordingly, since the armature plate 7 is directed toward the seat with slower acceleration, the recoil at the time of sitting is significantly reduced. The armature plate 7 quickly reaches rest again before further injection takes place.

  The bottom view of FIG. 2 shows a plan view of the residual gap 12, and in this embodiment, the residual gap 12 is configured as an annular disc 14. A cross-sectional view of the electromagnetic valve 1 illustrated in the upper diagram of FIG. 2 corresponds to the drawing of FIG. The annular disk 14 is not fixed on the armature plate 7, but is arranged so as to float between the armature plate 7 and the magnetic core outer pole 4 in the stroke direction of the armature. Only the outer diameter of the annular disk 14 is positioned in the radial direction by the magnet sleeve 6. The inner diameter of the annular disk 14 is selected on the one hand so that excessive fluid sticking of the armature plate 7 does not occur, and on the other hand it is selected so that a sufficient closing of the outer residual gap 18 takes place. .

  In the lower part of FIG. 3, the residual cavity 12 is likewise configured as an annular disk 14 ′ and has a plurality of additional webs 15 located inside. These webs 15 are connected to each other at the center of the annular disk 14 '. In order to allow the armature pin 9 to pass therethrough, a hole 16 is provided in the central region of the annular disk 14 '. With such a configuration, the residual gap 12 can be easily attached. When the armature plate 7 has a convex shape, the stroke stop is also performed in the magnetic core inner pole 3.

  The upper diagram of FIG. 3 shows a corresponding cross-sectional view of the corresponding solenoid valve 1.

  The lower side view of FIG. 4 shows a residual gap 12 that is smaller than that of FIG. 3. In this residual gap, the outer diameter of the annular disc 14 ′ is significantly smaller. The annular disk 14 ″ also has a plurality of webs 15 ′, which are joined at the center of the annular disk 14 ″ and have a hole 16 through which the armature pin 9 passes. ing.

  The upper view of FIG. 4 shows a cross-sectional view of the electromagnetic valve 1 to which the residual gap plate 12 is attached. Here, the armature plate 7 ′ has a stepped portion 17 that closes the gap between the magnetic core outer pole 4 and the armature plate 7 ′. Unlike FIG. 1, in FIG. 4, inflow from the outside to the armature plate 7 ′ is prevented or reduced by a step portion 17 provided in the armature plate 7 ′. However, the step 17 on the armature plate 7 'must be smaller than the thickness of the residual gap so that blocking by the residual gap is performed. Instead of the above configuration, the stepped portion 17 can be configured integrally with the magnet group 2, particularly, integrated with the magnetic core outer pole 4.

Claims (10)

A magnet group (2) including an electromagnetic coil (5), a magnetic core composed of a magnetic core inner pole (3) and a magnetic core outer pole (4), an armature plate (7, 7 '), and an armature pin (9) A solenoid valve (1) comprising:
A stopper formed by a residual gap (12) in the end face region of the magnetic core;
There is a residual air gap (18) between the armature plate (7) and the magnet group (2).
In solenoid valve,
The residual air gap (18) between the magnetic core outer pole (4) and the outer diameter of the armature plate (7) is closed in the radial direction ;
The residual gap plate (12) is arranged so as to float between the armature plate (7) and the magnetic core outer pole (4) in the stroke direction of the armature plate (7).
A solenoid valve characterized by that. The residual air gap (18) is closed against the inflow of fuel from the radially outer side of the armature plate (7) ,
The electromagnetic valve according to claim 1. The residual voids Edition (12), said core outer electrode (4), a magnet sleeve which surrounds said magnet groups (2) (6), and, in cooperation with the armature plate (7), wherein the residual voids Close (18),
The solenoid valve according to claim 1 or 2, wherein The residual gap plate (12) is an annular plate (14, 14 ′, 14 ″).
The electromagnetic valve according to any one of claims 1 to 3, wherein The annular disk (14, 14 ′, 14 ″) has a plurality of webs (15, 15 ′) located inside,
The webs are connected to each other at the center of the annular disk (14, 14 ′, 14 ″).
The electromagnetic valve according to claim 4. A hole (16) is provided in the center of the annular disk (14, 14 ', 14'').
The electromagnetic valve according to claim 5. There are four webs (15,15 '),
The electromagnetic valve according to any one of claims 4 to 6, wherein The residual air gap (18) is a step (17) in the armature plate (7, 7 ') that cooperates with a magnet sleeve (6) surrounding the magnet group (2) and the magnetic core outer pole (4). Closed)
The electromagnetic valve according to any one of claims 1 to 7, wherein The residual gap (18) is closed by a step (17) in the magnetic core outer pole (4) which cooperates with a magnet sleeve (6) and the armature plate (7) surrounding the magnet group (2). Being
The electromagnetic valve according to any one of claims 1 to 7, wherein The residual gap plate (12) is made of a nonmagnetic material,
The electromagnetic valve according to any one of claims 1 to 9, wherein

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