JP2013507582A - Circuit for operating solenoid valve - Google Patents

Abstract

  The present invention operates as follows in the circuit (40) for operating the solenoid valve, that is, in the solenoid valve closing process, at least after the solenoid valve is closed, in the valve opening direction. The present invention relates to a circuit (40) having at least one component configured to realize a time characteristic in which a difference between a force and a force acting in a valve closing direction of the solenoid valve is reduced. The invention further relates to a method of operating a circuit for a solenoid valve.

Description

  The present invention relates to a circuit for operating a solenoid valve and a method of operating a circuit for a solenoid valve.

Prior Art In a solenoid valve for a common rail injector, the accuracy of the switching process of the solenoid valve, especially the accuracy of the shut-off process is particularly important for the metering accuracy of the injector. The role of the electromagnetic valve in the common rail injector is to control the valve opening movement of the needle valve by controlling the pressure condition in the control space located above the needle valve.

  DE102007003211A1 describes a method for controlling a solenoid valve. In this document, the needle of the solenoid valve takes a first position when no power is supplied, and takes a second position when power is supplied. When the needle moves from the second position to the first position, post-energization is performed for a predetermined time from a predetermined time point.

SUMMARY OF THE INVENTION The present invention operates in the following circuit for operating a solenoid valve, that is, in the solenoid valve closing process, at least after the solenoid valve is closed, in the valve opening direction. The present invention relates to a circuit having at least one component configured to realize a time characteristic in which a difference between a force and a force acting in a valve closing direction of the solenoid valve is reduced.

  The present invention further relates to a method of operating a circuit for a solenoid valve, wherein in the process of closing the solenoid valve, the solenoid valve is opened at least after the solenoid valve is closed. The difference between the force acting in the valve direction and the force acting in the valve closing direction of the solenoid valve is made to have a time characteristic that is reduced in time.

  In the dependent claims and the description, further embodiments of the invention are described.

  Usually, the solenoid valve is configured as a component part of an injection nozzle or an injector, and is opened and closed by a valve member. The valve member is placed in the valve seat by a force in a valve closing direction generated by at least one valve closing member. The valve member is pressed and opened by the force in the valve opening direction generated by the electromagnetic coil against the force of the at least one valve closing member.

  According to the present invention, passive shock attenuation can be realized by a network or series circuit having resistors and diodes.

  With the circuit realized in the present invention, in particular, the recoil of the valve member can be greatly reduced. As a result, the switching process of the solenoid valve can be remarkably stabilized with only a small additional cost.

  The circuit is configured to perform all the steps of the method described above. The individual steps of the method can also be performed by individual components of the circuit. Furthermore, the operation of this circuit or the operation of individual components of the circuit can be replaced by method steps, and the method steps described above can be replaced by the functions of the individual components of the circuit or the circuit described above. It can be realized by replacing the entire operation.

  Other advantages and embodiments of the present invention can be derived from the description and the description in the drawings.

  It will be appreciated that the features described above and further described below can be used not only in the respective combinations described herein, but also in other combinations or alone, without departing from the scope of the present invention.

It is the schematic which shows the detail of one Embodiment of a solenoid valve. It is a graph which shows an operation parameter when a reaction process arises in a solenoid valve of a prior art. 1 is a schematic diagram showing a first embodiment of a circuit of the present invention. It is the schematic which shows 2nd Embodiment of the circuit of this invention. A first graph showing operating parameters obtained during the reaction process of the solenoid valve in the first embodiment of the method of the present invention, and an operating parameter obtained during the reaction process of the solenoid valve in the second embodiment of the method of the present invention. It is the 2nd graph which shows.

Embodiments of the invention The invention is schematically illustrated in the drawings on the basis of several embodiments. Hereinafter, the present invention will be described in detail with reference to these drawings.

  In the drawings, the contents of the respective drawings are related to each other consistently, and the same components are denoted by the same reference numerals.

  The details of the electromagnetic valve 2 schematically shown in FIG. 1 include an electromagnetic coil 4 having a core 6 and a valve member 8. The electromagnetic valve 2 further has a valve closing member 10 provided as a valve closing spring and a packing sheet 12 or a valve seat simply shown. Although the embodiments of the present invention will be described with reference to FIGS. 3 to 6, the specific configuration of the packing sheet 12 for embodying these embodiments is not usually important.

  The electromagnetic valve 2 is opened and closed depending on the relative position of the valve member 8 with respect to the packing sheet 12. In order to close the electromagnetic valve 2, the valve member 8 is not pressed against the packing sheet 12, or the pressing force 14 or the closing force for sealing the packing sheet by pressing the valve member 8 is closed. It is configured to be generated by the valve member 10. In order to open the valve member 2, the electromagnetic coil 4 is energized. By this energization, a force 16 or electromagnetic force in the valve opening direction that opposes the force 14 in the valve closing direction. Force is generated. In this way, the electromagnetic valve 2 is opened. When the energization of the electromagnetic coil 4 is finished, the electromagnetic force disappears, and the valve member 8 is moved into the packing sheet 12 by the valve closing force of the valve member 8 and is closed. The valve closing force of the valve member 8 is usually the force 14 of the preloaded valve closing member.

  The valve member 8 usually has an armature. In that case, the valve member 8 and the armature can be manufactured integrally, but the valve member 8 and the armature can be manufactured by assembling a plurality of parts to constitute an assembly. The valve member 8 is usually surrounded by fuel in the electromagnetic valve 2. This fuel is under low pressure.

  In the graph of FIG. 2, the vertical axis 20 shows the characteristics of the electromagnetic force 24 of the electromagnetic valve obtained in the process of reaction in the electromagnetic valve of the prior art and the relative valve stroke of the valve member with respect to the packing sheet of the electromagnetic valve. 26 characteristics and valve speed 28 characteristics. The horizontal axis 30 indicates time, and the unit is μs.

  Normally, the valve member when reaching the packing sheet has a kinetic energy that cannot be ignored. Since both the packing sheet and the valve member are typically metal parts and eventually elastic parts, the kinetic energy of the valve member is converted into elastic deformation energy at the time of contact with the sheet 32 after the valve member hits the packing sheet. Is done. When the conversion into the elastic deformation energy is completed, the deformed members return to their original positions. At that time, elastic deformation energy is converted back into kinetic energy. At the first recoil 34 again, the valve member leaves the packing sheet. At this time, the speed at which the valve member moves away from the packing sheet is equal to the speed at which the valve member reaches the packing sheet immediately before that.

  Here, the typical recoil process of the prior art is shown in the graph of FIG. The time point t = 0 is the end point of the drive control of the electromagnetic valve. At this time, the disappearance of the coil current starts, and consequently the disappearance of the electromagnetic force 24 that has been constant in the electromagnetic coil starts. It can also be seen from the graph of FIG. 2 that the electromagnetic force is substantially lost before the valve member first reaches the packing sheet.

  The above process is repeated multiple times until the kinetic energy is completely removed from the apparatus or system having the components shown in FIG. This process is referred to as reaction 34. Since the packing sheet is released each time the valve member is removed from the packing sheet, the reaction 34 described above greatly affects the amount of injection finally injected from the injector.

  The components of the solenoid valve are made of metal, and the requirements for wear resistance of the valve seat are severe. Therefore, the reaction damping due to plastic deformation when the valve member reaches the valve seat or the packing sheet is not suitable. During the seat contact, a favorable flow condition in the surrounding fuel generates a hydrodynamic closing force that, when the valve member is removed, pushes the valve member when the valve member is removed. It is stronger, and a certain amount of reaction damping can be realized by pressing in the direction of the packing sheet. However, it is difficult to realize such a condition, and it greatly depends on the state of the surrounding medium.

  In an embodiment of the present invention, during the contact of the sheet 32, i.e., when the packing sheet is reached and during the period until it leaves the packing sheet, the reaction 34 Can be reduced. Such an action can be realized by the fact that the force still remaining in the valve opening direction disappears during the contact of the seat.

  In order to do this in an embodiment of the invention, the nominal electromagnetic force still exists when the packing sheet is reached, and the gradient of this electromagnetic force is negative nominal during the sheet contact period. It slows the disappearance of electromagnetic force. By doing so, the force for braking the valve member after the valve member reaches the valve seat becomes larger than the force for accelerating the valve member during the subsequent elastic repulsion. As a result, the energy converted back to kinetic energy at the time of elastic repulsion is smaller than the energy extracted from the valve member when the valve member is pushed in. In this way, the reaction speed is smaller than the speed at which it is pushed in.

A first embodiment of the circuit 40 of the present invention is shown schematically in FIG. The circuit 40 has an electromagnetic coil 42 of an electromagnetic valve, and a coil voltage 44U _Spool is applied to the electromagnetic coil 42. A damping resistor 46R _Daempf is connected to the electromagnetic coil 42 in parallel. A current I47 is supplied to the electromagnetic coil 42 and the damping resistor 46R _Daempf .

The circuit 40 in FIG. 3 further includes a freewheeling diode 48, a booster diode 50, a semiconductor valve configured as a high-side switch 52 and switchable on and off, and a switch-on and switch configured as a low-side switch 54. It has a semiconductor valve that can be turned off and a semiconductor valve that can be switched on and off as a booster switch 56. The above-described switch-on and switch-off semiconductor valves are usually configured as field effect transistors (FETs), insulated gate electronic bipolar transistors (IGBT), or similar electronic components. Further, the circuit 40 includes a booster capacitor _{58C Boost} for producing a booster voltage _{60U Boost,} and a DC / DC converter or the DC converter 62. The circuit 40 is further connected to a battery not shown. This battery is provided to supply a battery voltage 62U _Batt to the circuit components of the circuit 40.

  A second embodiment of the circuit 70 of the present invention is shown schematically in FIG. The circuit 70 has all the components of the circuit 40 of the first embodiment of the present invention already described with reference to FIG. The circuit 70 of the second embodiment further includes a diode 72 connected in series with the attenuation resistor 46. Therefore, the diode 72 is also connected to the electromagnetic coil 42 in parallel.

  In one embodiment of the present invention, the desired characteristic course of the electromagnetic force is achieved by connecting the damping resistor 46 and the electromagnetic coil 42 in parallel. As a result, the coil current does not disappear completely at the end of the drive control. Rather, the coil current further flows through the network composed of the electromagnetic coil 42 and the damping resistor 46, and the damping resistor 46. It disappears slowly against the voltage drop. This also makes the disappearance of electromagnetic force slower.

  The damping resistor 46 can also be incorporated in the output stage, but in one embodiment of the invention the damping resistor 46 can also be arranged in a solenoid valve, and particularly advantageously the damping resistor is connected to the connector member of this solenoid valve. 46 can also be provided. In that case, a damping resistor 46 can be placed between the contact lugs of the connector, and then surrounded by injection molding, similar to a bleeder resistor used in, for example, a piezoelectric injector. Further, by using a conductive synthetic resin such as a conductive synthetic resin that can be used in place of the bleeder resistance discrete component provided in the piezoelectric injector as the injection molding surrounding material or the synthetic resin material of the connector member, the damping resistor 46 is provided. It can also be provided.

  In the circuit 70 according to the second embodiment shown in FIG. 4, the diode 72 limits the action of the damping resistor 46 until the cutoff period of the magnetic circuit including the electromagnetic coil 42 is reached. In particular, this makes it possible to prevent the damping resistor 46 from slowing down the formation of electromagnetic force at the start of drive control. Furthermore, the diode 72 can avoid having to extract more energy from the booster capacitor 58 or the battery in order to pass current through the damping resistor 46 during the generation of the electromagnetic force.

  As a result, the damping resistor 46 does not function while the voltage applied to the electromagnetic coil 42 is larger than the limit voltage of, for example, −0.8V. This is typically true for the entire drive control period. Only when the magnetic field is interrupted does the damping resistor have the desired effect.

  FIG. 5a is a graph showing operating parameters of the solenoid valve obtained in the recoil process of the solenoid valve in the first embodiment of the method of the present invention. Also in this graph, the vertical axis 22 is plotted against the time axis 30 on the horizontal axis. This graph shows the characteristic course of the electromagnetic force 80, the characteristic course of the stroke 82 of the valve member of the solenoid valve, and thus the distance between the valve member and the valve seat. The graph further shows the characteristic course of the speed 84 of the valve member, the period of time indicating the seat contact 86, and the first reaction 88 when the damping resistance value is the first value.

  Another graph in FIG. 5 b shows the characteristic course of the electromagnetic force 90, the characteristic course of the valve stroke 92, the characteristic course of the valve speed 94, the seat contact period 96, and the first reaction 98. In this case, these operating parameters are adjusted by the second value of the damping resistor connected in parallel to the electromagnetic coil.

  The characteristic course of the electromagnetic forces 80 and 90, the characteristic course of the valve strokes 82 and 92, and the characteristic course of the valve speeds 84 and 94 shown in FIGS. 5a and 5b are two different values of damping resistance. Is obtained when not different from FIG. From these graphs it can be clearly seen that during the sheet contacts 86, 96, the electromagnetic forces 80, 90 disappear as nominal, which causes the reaction speed to be lower than the indentation speed. Overall, the kinetic energy of the valve member at the start of the first reaction 88, 98 is reduced by up to 64% due to damping resistance.

  It can be clearly seen that the reaction period is shorter and the magnitude of the reaction is smaller than in the prior art (FIG. 2).

  It can also be seen that the indentation speed alone is already smaller than in the prior art, and that when moving away from the packing sheet, the speed away from the packing sheet is further reduced by about 5% from the indentation speed. At first glance, this seems trivial, but this reduction in push-in speed means that the kinetic energy of the valve member during seat contact is reduced by 10%. When combined with the damping action of the hydrodynamic elements, the reaction can be reduced overall to the extent that the adverse effect of the reaction process on the metering accuracy is completely and robustly avoided.

The circuit 40 in FIG. 3 further includes a freewheeling diode 48, a booster diode 50, a semiconductor valve configured as a high-side switch 52 and switchable on and off, and a switch-on and switch configured as a low-side switch 54. It has a semiconductor valve that can be turned off and a semiconductor valve that can be switched on and off as a booster switch 56. Switching on and off can be semiconductor valve described above is typically a field effect transistor (FET), insulated gate Toba Lee polar transistors (IGBT, insulated-gate-biopolartransistor ) or similar configured as an electronic component. Further, the circuit 40 includes a booster capacitor _{58C Boost} for producing a booster voltage _{60U Boost,} and a DC / DC converter or the DC converter 62. The circuit 40 is further connected to a battery not shown. This battery is provided to supply a battery voltage 62U _Batt to the circuit components of the circuit 40.

Claims (10)

A circuit for operating the solenoid valve (2),
In the valve closing process of the electromagnetic valve (2), the circuit includes a force (16) in the valve opening direction of the electromagnetic valve (2) and the electromagnetic valve (2) at least after the electromagnetic valve (2) is closed. ) Having at least one component configured to realize a time characteristic in which the difference from the force (14) in the valve closing direction is reduced.   The circuit of claim 1, wherein the at least one component includes a damping resistor (46) connected in parallel to an electromagnetic coil (4, 42) of the solenoid valve (2).   The circuit of claim 2, wherein the circuit comprises a diode (72) connected in series with the damping resistor (46).   The circuit according to claim 2 or 3, wherein the damping resistor (46) is arranged in a spatial correspondence fixed with respect to the solenoid valve (2).   The circuit according to any one of claims 2 to 4, wherein the damping resistor (46) is provided on a connector member of the electromagnetic valve (2).   6. The circuit according to claim 1, wherein the valve-closing member (10) is provided as a valve-closing spring. A method of operating a circuit for a solenoid valve (2), comprising:
In the valve closing process of the electromagnetic valve (2), at least after the closing time of the electromagnetic valve (2), the force (16) in the valve opening direction of the electromagnetic valve (2) and the closing of the electromagnetic valve (2). An operation method characterized by realizing a time characteristic in which a difference from a force (14) in a valve direction is reduced.   The operation method according to claim 7, wherein the circuit according to any one of claims 1 to 6 is operated.   The operating method according to claim 7 or 8, wherein the force (14) in the valve closing direction increases.   The operating method according to any one of claims 7 to 9, wherein the force (16) in the valve opening direction is eliminated.

Images