JP6607095B2 - Control device for electrostatic collection type oil mist separator - Google Patents

Description

The present invention, by introducing a blow-by gas of an internal combustion engine in a case separated from the oil mist, relates to a control device for an electrostatic trapping oil mist Se Palais capacitor for discharging the separated oil component to the outside of the case.

  The internal combustion engine is provided with a return passage for returning the blow-by gas in the crank chamber to the intake passage. An oil mist separator that separates oil mist contained in blow-by gas is provided in the middle of such a reflux passage (see, for example, Patent Document 1).

  In the case of the oil semistopper described in Patent Document 1, two net-like electrodes are arranged to face each other, and a potential difference is applied to these electrodes by a power supply device. According to such an oil separator, when blow-by gas passes through one electrode, moisture contained in the blow-by gas is charged. The charged moisture is adsorbed to the other electrode by electrostatic force. At this time, the oil mist contained in the blow-by gas is adsorbed to the electrode together with moisture. In this way, oil mist contained in blow-by gas is separated. Note that the oil component and water component adsorbed on the electrode fall by their own weight and are discharged out of the case through an oil discharge port formed in the bottom wall of the case.

Japanese Unexamined Patent Publication No. 3-141811

  By the way, in the case of the oil mist separator described in Patent Document 1, when the flow rate of blow-by gas is large, the oil does not collide with the electrode and easily passes through the electrode. Therefore, it is difficult to collect oil mist efficiently.

  On the other hand, in the oil separator, it is conceivable to make the oil mist easily collide with the electrode by making the mesh of the electrode fine. However, in this case, the resistance to ventilation is increased by making the mesh of the electrode finer, resulting in a contradiction that the pressure loss due to the oil mist separator increases.

An object of the present invention is to provide a control device for an electrostatic trapping oil mist Se Palais motor capable of efficiently collecting oil mist.

  An electrostatically collecting oil mist separator for achieving the above object is formed of a plurality of electrode plates arranged opposite to each other and an electrically insulating material, and is interposed between the facing surfaces of the plurality of electrode plates. A collecting unit having a filter; a case that houses the collecting unit; and a voltage generator that applies a voltage between the plurality of electrode plates to apply a potential difference, and the potential difference is applied between the plurality of electrode plates. In this state, the blow-by gas of the internal combustion engine is introduced into the case and allowed to pass through the filter, whereby oil mist contained in the blow-by gas is separated by electrostatic adsorption force and the separated oil component is Discharge outside the case. Inside the case, a plurality of the collection units are arranged at intervals in the flow direction of the blow-by gas.

  By applying a potential difference between the electrode plates by the voltage generator, an electrostatic field is generated between the electrode plates, and the surface of the filter (or the surface of the fiber if the filter is made of fibers) is positive due to dielectric polarization. Or a negative charge is generated. For this reason, the charged oil mist included in the blowby gas is bent in the moving direction by electrostatic force when passing between the electrode plates, and is easily captured by the filter.

  Moreover, when the oil mist contained in the blow-by gas is not charged, it passes through the filter gap (the gap between the fibers when the filter is made of fibers) interposed between the electrode plates. Dielectric polarization causes a positive or negative charge on the surface of the oil mist. For this reason, such oil mist is also attracted to negative or positive charges generated on the surface of the filter by electrostatic force, and is easily captured by the filter.

For these reasons, oil mist can be captured effectively even with a coarse filter, and an increase in ventilation resistance due to the filter can be suppressed.
Here, blow-by gas is greatly affected by an electrostatic field when flowing into a filter interposed between electrode plates. At this time, since the moving direction of the oil mist is greatly bent, the oil mist is easily captured by the filter.

  According to the said structure, since the several collection unit is arrange | positioned at intervals in the flow direction of blow-by gas inside a case, blow-by gas will flow into a collection unit in multiple times. For this reason, the frequency with which the moving direction of the oil mist is greatly bent can be increased, and the oil mist is easily captured by the filter.

  In addition, a control device for an electrostatic collection type oil mist separator for achieving the above object is applied to the electrostatic collection type oil mist separator, and controls a voltage application mode to a plurality of the collection units. It is a control apparatus, Comprising: The control part which variably sets the application mode of the voltage to the said several collection unit according to an engine operating state is provided.

  According to this configuration, it is possible to set the mode of voltage application to the plurality of collection units according to the engine operating state having a correlation with the flow rate of the blowby gas at that time. Therefore, it is possible to suppress the voltage from being applied to the collecting unit more than necessary, and to reduce power consumption.

  According to the present invention, oil mist can be collected efficiently.

The perspective view which shows the whole oil mist separator about one Embodiment of an electrostatic collection type oil mist separator. The perspective view which shows only the several collection unit provided in the oil mist separator in the same embodiment. The wiring diagram which shows the electrical connection aspect of the electrode plate and voltage generator which comprise the some collection unit in the embodiment. The electric circuit diagram centering on the voltage generator in the embodiment. The schematic diagram for demonstrating the effect | action of an oil mist separator. The graph which shows the relationship between the applied voltage in the same embodiment, and the collection capability of an oil mist separator.

Hereinafter, an embodiment will be described with reference to FIGS.
<Oil mist separator 10>
As shown in FIG. 1, the oil mist separator 10 is provided in a recirculation passage for recirculating blowby gas in a crank chamber of an in-vehicle internal combustion engine to an intake passage, and is made of an electrically insulating synthetic resin material such as nylon 66, for example. It has a case 11 formed.

  The case 11 includes a case main body 20 having an opening in the upper portion and a lid body 26 that closes the opening of the case main body 20. The case body 20 includes a bottom wall 22 and a side wall 21 that are rectangular in plan view. In the following description, the longitudinal direction of the bottom wall 22 is simply referred to as the longitudinal direction.

  On the side wall 21 on one end side in the longitudinal direction, a cylindrical introduction port 23 that communicates the inside and outside of the case 11 protrudes outward. In addition, a cylindrical outlet 24 that communicates the inside and outside of the case 11 protrudes outward from the side wall 21 on the other end side in the longitudinal direction. An oil discharge port 25 that communicates the inside and the outside of the case 11 protrudes downward from a position of the bottom wall 22 close to the outlet port 24.

  As shown in FIGS. 1 and 2, a first collection unit 31 and a second collection unit 32 are accommodated in the case 11 at intervals in the longitudinal direction, that is, the blow-by gas flow direction.

  As shown in FIG. 2, the 1st collection unit 31 and the 2nd collection unit 32 have the same structure. That is, each of the collecting units 31 and 32 is made of stainless steel, and is composed of four electrode plates 40 arranged to face each other with a space therebetween, and a non-woven fabric of polyester fibers 51 (see FIG. 5) that is an electrically insulating material. And three filters 50 interposed between the opposing surfaces of each electrode plate 40. The entire side surface of the filter 50 is in contact with the opposing surfaces of a pair of adjacent electrode plates 40. An electrically insulating material such as polyester is also a dielectric material in which dielectric polarization occurs.

  The 1st collection unit 31 is arrange | positioned at intervals with respect to the side wall 21 in which the inlet 23 was formed (illustration omitted). The 2nd collection unit 32 is arrange | positioned at intervals with respect to the side wall 21 in which the outlet 24 was formed (refer FIG. 1).

<Voltage generator 60 and electronic controller 80>
As shown in FIG. 3, the voltage generator 60 is electrically connected to each electrode plate 40 which comprises the 1st collection unit 31 via the conducting wire. The anode (+) of the voltage generator 60 is connected to the odd-numbered electrode plates 40 from the left in FIG. In addition, the negative electrode (−) of the voltage generator 60 is connected to the even-numbered electrode plates 40 from the left in FIG.

The voltage generator 60 is also electrically connected to each electrode plate 40 constituting the second collection unit 32 through a conducting wire in the same manner as the first collection unit 31.
The first collection unit 31 and the second collection unit 32 are connected in parallel to the voltage generator 60.

The voltage generator 60 can apply a potential difference between the electrode plates 40 adjacent to each other of the collection units 31 and 32.
As shown in FIG. 4, an in-vehicle DC power supply (hereinafter referred to as power supply 61) includes a primary coil 63 for boosting transformer 62, a field effect transistor (hereinafter referred to as FET 64) as a switching element in this example, and an overcurrent detection function. The detection resistors 66 are sequentially connected in series. A first drive circuit 65 for switching and driving the FET 64 is connected to the gate terminal of the FET 64.

  The secondary coil 68 of the transformer 62 is connected in series with a diode 69, the electrode plate 40 of the first collection unit 31, and the first relay 71. Further, the electrode plate 40 of the second collection unit 32 and the second relay 72 are connected in series to the secondary coil 68. The electrode plate 40 and the first relay 71 of the first collection unit 31 and the electrode plate 40 and the second relay 72 of the second collection unit 32 are connected in parallel to the secondary coil 68.

A smoothing capacitor 70 is connected to the secondary coil 68.
The first drive circuit 65 has a comparison circuit that compares the voltage V of the detection resistor 66 with the limit value Vmax. When the voltage V of the detection resistor 66 becomes equal to or higher than the limit value Vmax, the first drive circuit 65 The FET 64 is turned off when an overcurrent caused by a short circuit flows. Thereby, application of a potential difference between the electrode plates 40 is stopped.

  In the first relay 71 and the second relay 72, the first relay 71 and the second relay 72 are controlled, and the first drive circuit 65 is controlled to change the voltage application mode to the collection units 31 and 32. Two drive circuits 67 are connected. In addition, an electronic control unit 80 is connected to the second drive circuit 67.

  The electronic control unit 80 controls the operation of the internal combustion engine, and temporarily stores a central processing control unit (CPU), a read-only memory (ROM) in which various programs and maps are stored in advance, and a calculation result of the CPU. A random access memory (RAM), a timer counter, an input interface, an output interface, and the like are provided.

  The electronic control unit 80 receives detection signals from various sensors for detecting the engine operating state. Such sensors include an engine speed sensor that detects the engine speed NE, an accelerator sensor that detects the accelerator pedal operation amount ACCP, a throttle sensor that detects the throttle valve opening TA, and an intake air amount GA. There are an air flow meter, a water temperature sensor for detecting the temperature T of the engine cooling water, and the like.

  The electronic control unit 80 includes a control unit 81 that variably sets a voltage application mode to the two collection units 31 and 32 according to an engine operating state such as the engine rotation speed NE and the engine load KL. In the present embodiment, as the engine load KL, a ratio “GA / between the intake air amount GA at that time and the maximum intake air amount GAmax that is the maximum value of the intake air amount obtained at the engine rotational speed NE at that time. GAmax "is used.

As indicated by a two-dot chain line in FIG. 6, the oil mist separator 10 is required to have a higher collection capability as the flow rate of blow-by gas introduced into the case 11 increases.
Moreover, if the applied voltage is the same, the voltage is applied to one of the collection units 31 (32) when the voltage is applied to both of the collection units 31, 32 (solid line in the figure) ( The collecting ability of the oil mist separator 10 becomes higher than the wavy line in FIG.

  Therefore, the control unit 81 of the present embodiment, for example, for both the collection units 31 and 32 when the engine is in an engine operating state in which the blow-by gas introduced into the case 11 is at a high flow rate, such as during high load and high rotation. The voltage of the third predetermined value V3 is applied.

  In addition, when the engine 81 is in an engine operating state in which the blow-by gas introduced into the case 11 is at a medium flow rate, such as during medium load rotation, the control unit 81 sets a third predetermined value for both the collection units 31 and 32. A voltage having a first predetermined value V1 (<V3) lower than V3 is applied.

  In addition, the control unit 81 performs only the first collection unit 31 when the engine is in an engine operating state in which the blowby gas introduced into the case 11 is low in low load and low rotation or during idle operation. 3 A voltage having a second predetermined value V2 (V1 <V2 <V3) lower than the predetermined value V3 and higher than the first predetermined value V1 is applied.

Moreover, the control part 81 stops the application of the voltage to all the collection units 31 and 32 at the time of idling stop of an internal combustion engine.
Next, the operation of the oil mist separator 10 will be described.

As shown in FIG. 1, the blow-by gas introduced into the case 11 through the inlet 23 flows toward the outlet 24.
By applying a potential difference between the electrode plates 40 by the voltage generator 60, an electrostatic field is generated between the electrode plates 40 as shown in FIG. Dielectric polarization causes a positive (+) or negative (-) charge. For this reason, the charged oil mist M contained in the blow-by gas is bent in the moving direction by the electrostatic force when passing between the electrode plates 40, and is easily captured by the filter 50.

  In addition, the oil mist M contained in the blow-by gas is not charged, and oil mist is caused by dielectric polarization when passing through a gap between the fibers 51 of the filter 50 interposed between the electrode plates 40. A positive (+) or negative (-) charge is generated on the surface of M. For this reason, the oil mist M is also attracted to the negative (−) or positive (+) charge generated on the surface of the fiber 51 of the filter 50 by electrostatic force, and is easily captured by the filter 50.

For these reasons, the oil mist M can be effectively captured even with the coarse filter 50, and an increase in ventilation resistance due to the filter 50 can be suppressed.
The blow-by gas from which the oil mist M has been separated flows out to the reflux passage through the outlet 24. On the other hand, the oil component accumulated on the bottom wall 22 moves along the bottom wall 22 and is discharged out of the case 11 through the oil discharge port 25.

  Here, the blow-by gas is greatly affected by the electrostatic field when flowing into the filter 50 interposed between the electrode plates 40. At this time, since the moving direction of the oil mist M is greatly bent, the oil mist M is easily captured by the filter 50.

  In the present embodiment, the two collection units 31 and 32 are arranged in the case 11 at intervals in the blow-by gas flow direction. For this reason, blow-by gas will flow into the collection units 31 and 32 twice. For this reason, the frequency with which the moving direction of the oil mist M is greatly bent can be increased, and the oil mist M is easily captured by the filter 50.

  Further, when the blow-by gas introduced into the case 11 is in the engine operation state where the flow rate is medium, the applied voltage to the collection units 31 and 32 is made smaller than in the engine operation state where the flow rate is high. For this reason, it is suppressed that a voltage larger than necessary is applied when the blow-by gas has a medium flow rate.

  In addition, the number of collecting units 31 and 32 for applying a voltage is reduced when the blow-by gas introduced into the case 11 is in an engine operating state where the flow rate is low, compared to when the engine is operating in a medium or high flow rate. It is. For this reason, it is suppressed that a voltage is applied to many collection units 31 and 32 more than necessary when blow-by gas is a low flow rate.

According to the electrostatic collecting oil mist separator and the electrostatic collecting oil mist separator control device according to the present embodiment described above, the following effects can be obtained.
(1) Inside the case 11, two collection units 31 and 32 are arranged at intervals in the flow direction of the blow-by gas.

  According to such a configuration, since the two collection units 31 and 32 are arranged in the case 11 at intervals in the flow direction of the blowby gas, the blowby gas is supplied to the collection units 31 and 32 twice. Will flow in. For this reason, the frequency with which the moving direction of the oil mist is greatly bent can be increased, and the oil mist can be easily captured by the filter 50. Therefore, oil mist can be collected efficiently. Therefore, the applied voltage required for collecting oil mist can be lowered, and the power consumption can be reduced.

(2) The electronic control unit 80 includes a control unit 81 that variably sets a voltage application mode to the two collection units 31 and 32 according to the engine operating state.
According to such a configuration, it is possible to set the voltage application mode to the two collection units 31 and 32 according to the engine operating state having a correlation with the flow rate of the blowby gas at that time. Therefore, an unnecessarily high voltage is suppressed from being applied to the collection units 31 and 32, and power consumption can be reduced.

  (3) The control unit 81 is a collection unit that applies a voltage when the flow rate of the blow-by gas introduced into the case 11 is low compared to when the engine is in a high flow rate of the blow-by gas. Reduce the number of 31, 32.

  According to such a configuration, it is possible to suppress the voltage from being applied to more collection units 31 and 32 than necessary when the flow rate of blow-by gas is small. Therefore, it is possible to reduce power consumption while effectively collecting oil mist.

  (4) The control unit 81 causes the collection units 31 and 32 to be more effective when the flow rate of the blow-by gas introduced into the case 11 is low than when the engine is in the high-flow rate of the blow-by gas. Reduce the applied voltage.

  According to such a configuration, it is possible to suppress an unnecessarily large voltage from being applied when the flow rate of blow-by gas is small. Therefore, it is possible to reduce power consumption while effectively collecting oil mist.

(5) The controller 81 stops the application of voltage to all the collection units 31 and 32 when idling of the internal combustion engine is stopped.
When idling is stopped, blow-by gas is not introduced into the case 11. According to the above configuration, useless power consumption can be suppressed and power consumption can be further reduced.

<Modification>
In addition, the said embodiment can also be changed as follows, for example.
-The electrode plate 40 which comprises each collection unit 31 and 32 should just be 2 or more, and the number of the electrode plates 40 can be changed arbitrarily.

A voltage can be applied only to the second collection unit 32 when the blow-by gas introduced into the case 11 is in an engine operating state where the flow rate is low.
In the above embodiment, the collecting unit 31 that applies a voltage when the engine is in an engine operating state with a low flow rate of blow-by gas introduced into the case 11 as compared with when the engine is in an operating state with a high flow rate of the blow-by gas. The number of 32 was reduced. Further, the voltage applied to the collection units 31 and 32 is made smaller when the engine is operating with a low flow rate of blow-by gas than when the engine is operating with a high flow rate of blow-by gas. Instead, the voltage applied to each of the collection units 31 and 32 may be made smaller when the engine is operating with a low flow rate of blow-by gas than when the engine is operating with a higher flow rate of blow-by gas. Alternatively, the number of collection units 31 and 32 to which a voltage is applied may be reduced when the engine operating state is low in the flow rate of blow-by gas compared to when the engine is operating in the state where the flow rate of the blow-by gas is high.

  -The number of collection units is not limited to two, Three or more collection units can also be arrange | positioned at intervals in the flow direction of blow-by gas.

  DESCRIPTION OF SYMBOLS 10 ... Oil mist separator, 11 ... Case, 20 ... Case main body, 21 ... Side wall, 22 ... Bottom wall, 23 ... Inlet port, 24 ... Outlet port, 25 ... Oil discharge port, 26 ... Lid body, 31 ... First catch Collection unit, 32 ... second collection unit, 40 ... electrode plate, 50 ... filter, 51 ... fiber, 60 ... voltage generator, 61 ... power source, 62 ... transformer, 63 ... primary coil, 64 ... FET, 65 ... first DESCRIPTION OF SYMBOLS 1 drive circuit, 66 ... detection resistor, 67 ... 2nd drive circuit, 68 ... secondary coil, 69 ... diode, 70 ... capacitor | condenser, 71 ... 1st relay, 72 ... 2nd relay, 80 ... electronic control apparatus (control apparatus) ), 81... Control unit.

Claims (2)

A collection unit having a plurality of electrode plates arranged opposite to each other, and a filter formed of an electrically insulating material and interposed between the opposed surfaces of the plurality of electrode plates, and a case for housing the collection unit And a voltage generating device that applies a voltage between the plurality of electrode plates to apply a potential difference, and introduces blow-by gas of the internal combustion engine into the case in a state where the potential difference is applied between the plurality of electrode plates. and by passing the filter, the oil component separated with the separation by electrostatic adsorption force oil mist contained in the blow-by gas discharged to the outside of the case, the inside of the front SL case, a plurality of the collection unit is applied to the electrostatic collecting oil mist separator are arranged spaced apart from each other in the flow direction of the blow-by gas, a plurality A control apparatus for controlling application aspects of a voltage to the collecting unit,
A control unit that variably sets the application mode of the voltage to the plurality of collecting units according to the engine operating state,
The control unit applies a voltage of a second predetermined value V2 to the collection unit when the second engine operating state in which the flow rate of blow-by gas introduced into the case is small, and from the second engine operating state, When the first engine operating state in which the flow rate of blow-by gas is large, a voltage of a first predetermined value V1 is applied to the collection unit, and in the third engine operating state in which the flow rate of blow-by gas is higher than that in the first engine operating state. A voltage of a third predetermined value V3 is applied to the collection unit;
The control unit reduces the number of the collection units to which the voltage is applied when the second engine is operating compared to when the first engine is operating and the third engine is operating.
The control device for an electrostatically collecting oil mist separator , wherein the first predetermined value V1, the second predetermined value V2, and the third predetermined value V3 satisfy a relational expression of V1 <V2 <V3 . The control unit stops application of voltage to all the collection units at the time of idling stop of the internal combustion engine.
The control device of the electrostatic collection type oil mist separator according to claim 1 .

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