JP2007198344A - Oil separator for blowby gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil separator for blowby gas which reliably separates from the blowby gas an oil mist having very small particle-size without increasing a pressure loss. <P>SOLUTION: A discharge electrode 30 is placed in the upstream of flow of the blowby-gas in a separator body 12 made up of an insulating material. The oil mist in the blowby gas is charged by a corona discharge caused by the discharge electrode 30. A counter electrode 34 is placed in the downstream. The counter electrode 34 separates attractively the charged oil mist from the blowby gas by the Coulomb force. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an oil separator for blow-by gas, and more particularly to a novel structure of an oil separator for blow-by gas that separates oil mist contained in blow-by gas generated inside an internal combustion engine.

  As is well known, in an internal combustion engine such as an automobile engine, blowby gas containing a large amount of unburned hydrocarbons is formed in the crankcase from the gap between the piston ring and the cylinder wall during operation. Inevitable leakage. For this reason, in many of such automobile engines, a connection flow path is provided between the crankcase and the intake pipe to connect them in a communication state, and the crankcase is connected to the inside of the crankcase through the connection flow path. The blow-by gas is forcibly circulated into the intake pipe using the negative pressure in the intake pipe, and is then returned to the combustion chamber for re-combustion.

  By the way, the blow-by gas includes oil mist in which lubricating oil such as engine oil is in a mist form. Therefore, in order to reduce the amount of oil carried away by mixing into the blow-by gas and to prevent contamination with oil in the intake pipe, etc., it is in the middle of the connecting flow path connecting the crankcase and the intake pipe. Conventionally, oil separators for separating oil mist from blow-by gas have been provided with various structures.

  As such an oil separator, for example, (a) a plurality of baffle plates are arranged in a separator body (oil separation chamber) in which blow-by gas is circulated so as to meander the flow of blow-by gas. The so-called labyrinth system in which the oil mist in the blow-by gas is attached to each baffle plate when the blow-by gas circulates while colliding with a plurality of baffle plates (for example, The following patent document 1) and (a) The blow-by gas is allowed to flow in the cylindrical separator body while being swirled in the circumferential direction. , Adopting a so-called cyclone system that separates oil mist in blow-by gas (for example, the following patent document) 2) and (c) when a collision plate is erected in the separator body, and blow-by gas that circulates linearly in the separator body in one direction collides with the collision plate, A so-called inertial collision method in which an oil mist is attached to a collision plate (for example, see Non-Patent Document 1 below) is known.

  However, these conventional oil separators have the following drawbacks. That is, in an oil separator employing the labyrinth method (a) or the inertial collision method (c), an oil mist having a fine particle size of 1 μm or less is used as a baffle plate or a collision plate, for example. It was very difficult to adhere and separate from blow-by gas. Further, in the oil separator adopting the cyclone system (b), for example, if the flow velocity of the swirling flow of blow-by gas is increased, the separation efficiency of the oil mist having a particle size of 1 μm or less can be improved. However, this would inevitably increase the pressure loss.

Japanese Utility Model Publication No. 63-105712 JP 2001-246216 A Japan Society for Invention and Innovation Open Technical Report No. 86-15379

  Here, the present invention has been made in the background as described above, and the problem to be solved is an oil mist having a fine particle diameter of 1 μm or less without increasing pressure loss. To provide an improved oil separator structure for blowby gas so that oil mist separation performance from blowby gas can be improved more advantageously. is there.

  In the present invention, in order to solve such a problem, the gist of the present invention is an oil separator that separates oil mist contained in blow-by gas generated inside the internal combustion engine from the blow-by gas. And (a) an inlet for introducing the blow-by gas and an outlet for discharging the introduced blow-by gas to the outside, and the blow-by gas introduced from the inlet is A separator main body made of an insulating material that circulates in the interior toward the outlet; and (b) positioned at an upstream portion in the flow direction of the blowby gas inside the separator main body to generate corona discharge. A discharge electrode for charging the oil mist in the blow-by gas; and (c) the blow-byger inside the separator body. A counter electrode separated from the blow-by gas by adsorbing the charged oil mist in the blow-by gas by a Coulomb force. It is in the oil separator for blow-by gas.

  That is, in the blow-by gas oil separator according to the present invention, by generating corona discharge between the discharge electrode and the counter electrode, the oil mist contained in the blow-by gas can be reliably obtained regardless of the particle size. Can be charged. On the other hand, the smaller the particle size of the oil mist that can flow in the separate body together with the blow-by gas, the smaller the kinetic energy that is retained.

  Therefore, in such an oil separator for blow-by gas, an oil mist having a particle diameter of, for example, 1 μm or less, which is charged by corona discharge and flows in the separator main body, is efficiently applied to the counter electrode by Coulomb force. It is possible to make it adsorbed reliably and reliably.

  In addition, in the oil separator for blow-by gas according to the present invention, unlike the case where the cyclone method or the like is adopted, at the time of separating the oil mist from the blow-by gas, what is used is the circular center separation action of the swirl flow of the blow-by gas Therefore, in order to separate the oil mist having a minute particle diameter of 1 μm or less from the blow-by gas, an increase in pressure loss accompanying an increase in the flow velocity of the swirling flow of the blow-by gas is not caused.

  Therefore, in such an oil separator for blow-by gas according to the present invention, oil mist having a minute particle diameter of 1 μm or less can be reliably separated from blow-by gas without increasing pressure loss. As a result, excellent separation performance of oil mist from blow-by gas, which is not found in conventional products, can be exhibited extremely advantageously.

Aspects of the Invention

  By the way, the present invention can be suitably implemented at least in various aspects as listed below.

<1> An oil separator for separating oil mist contained in blow-by gas generated inside an internal combustion engine from the blow-by gas, (a) an introduction port into which the blow-by gas is introduced, and the introduced oil separator A separator body made of an insulating material, having a discharge port for discharging blow-by gas to the outside, and allowing the blow-by gas introduced from the introduction port to circulate in the interior toward the discharge port; and (b) A discharge electrode which is positioned in an upstream portion in the flow direction of the blow-by gas inside the separator body and generates corona discharge to charge the oil mist in the blow-by gas; and (c) the separator It is positioned in the downstream side portion in the flow direction of the blow-by gas inside the main body, and the front in the blow-by gas The charged oil mist, and attracted by the Coulomb force, blowby gas oil separator, characterized in that configured to include a counter electrode separated from the blow-by gas.

<2> In the above aspect <1>, the separator main body includes a pipe body that connects the crankcase of the internal combustion engine and an intake pipe in a communicating state, and the introduction port is opened in the crankcase. One end side opening portion of the tube body is configured, and the discharge port is configured by the other end side opening portion of the tube body connecting tube opening into the intake pipe line. According to this aspect, the entire oil separator that exhibits the excellent characteristics as described above can be installed compactly with respect to the internal combustion engine.

<3> In aspect <1> or aspect <2> described above, the discharge electrode is constituted by a needle-like electrode having a needle-like form. According to this aspect, it can be advantageously eliminated or reduced that the flow of blow-by gas in the separator main body is hindered by the collision with the discharge electrode. As a result, the pressure loss occurring in the separator body can be reduced more effectively.

<4> In any one of the above aspects <1> to <3>, a plurality of the discharge electrodes are provided on an upstream side portion of the inner peripheral surface of the separator body in the flow direction of the blowby gas. In the circumferential direction, the electrode rows are arranged in a row so as to be adjacent to each other with a space therebetween, and are positioned in the upstream portion inside the separator body. thing. In this aspect, the plurality of discharge electrodes are exposed to the flow of blow-by gas on the entire circumference on the inner peripheral surface side in the upstream portion inside the separator body. Therefore, the oil mist in the blow-by gas can be more efficiently and sufficiently charged in the entire circumference on the inner peripheral surface side in the upstream portion inside the separator body by the corona discharge generated in each discharge electrode. An improvement in the mist separation efficiency can be realized more advantageously.

<5> In the above aspect <4>, a plurality of the discharge electrodes may be arranged at a plurality of locations spaced in the flow direction of the blowby gas in the upstream portion of the inner peripheral surface of the separator body. Must be erected with each row formed. According to this embodiment, the oil mist can be charged more efficiently, and the oil mist separation performance can be further improved.

<6> In any one of the above-described aspects <1> to <3>, a mesh portion including a plurality of meshes through which the blow-by gas can circulate is provided in the upstream portion inside the separator body. A support member having a plurality of meshes of the mesh part arranged in a direction intersecting with a flow direction of the blow-by gas, and a plurality of the discharge electrodes are fixed to the mesh part of the support member. It is fixed to the wire surrounding the mesh and is supported by the support member. In this embodiment, the plurality of discharge electrodes are exposed to the flow of blow-by gas not only on the inner peripheral surface side in the upstream portion inside the separator body but also on the central portion side separated from the inner peripheral surface. become. Thereby, charging of the oil mist in the blow-by gas by corona discharge generated at each discharge electrode can be performed more efficiently and sufficiently, and the improvement of the oil mist separation efficiency can be realized more advantageously.

<7> In the above aspect <6>, the support member that supports the plurality of discharge electrodes may be fixed to the upstream portion inside the separator body at intervals in the flow direction of the blowby gas. That it is established. According to this embodiment, the oil mist can be charged more efficiently, and the oil mist separation performance can be further improved.

<8> In any one of the aspects <1> to <7> described above, the counter electrode is formed of a cylindrical electrode having a cylindrical shape, and the cylindrical electrode is the separator. By being positioned at the downstream portion inside the main body, the entire surface of the downstream portion in the blow-by gas flow direction on the inner peripheral surface of the separator main body is configured by the inner peripheral surface of the cylindrical electrode. It has become. According to this aspect, for example, the oil mist is adsorbed by the counter electrode as compared with the case where the counter electrode is provided on a part of the circumference of the downstream portion in the blow-by gas circulation direction on the inner peripheral surface of the separator body. Efficiency can be advantageously increased. As a result, the oil mist separation performance can be further improved.

<9> In any one of the modes <1> to <7> described above, the counter electrode is configured by a mesh electrode having a mesh shape including a number of meshes through which the blow-by gas can flow. The mesh electrode is fixed to the downstream portion in the separator main body in a state where the meshes are arranged in a direction intersecting the flow direction of the blow-by gas.

  In such a mode, for example, unlike the case where the inner peripheral surface of the downstream portion of the separator body is configured by a counter electrode, the counter electrode is only on the inner peripheral surface side of the downstream portion of the separator body. In addition, even in the central part separated from the inner peripheral surface, it is exposed to the flow of blow-by gas, so that the oil mist contained in the blow-by gas causes the downstream part of the separator body to be directed to the counter electrode. , It will be able to flow more closely. As a result, the Coulomb force that acts between the oil mist in the blow-by gas that causes the downstream portion of the separator body to flow in a charged state and the counter electrode can be effectively increased. Moreover, since the blow-by gas flows through the downstream portion of the separator body while passing through the mesh of the mesh electrode constituting the counter electrode, an increase in pressure loss in the separator body is avoided or avoided as much as possible. Can be suppressed.

  Therefore, according to this aspect, oil mist can be more efficiently and reliably adsorbed to the counter electrode without increasing the pressure loss. As a result, further improvement in oil mist separation performance can be achieved very advantageously.

<10> In the above aspect <9>, a plurality of the counter electrodes made of the mesh electrode are fixed to the downstream portion inside the separator body at intervals in the flow direction of the blow-by gas. That. According to this aspect, the oil mist can be more sufficiently and reliably adsorbed to the counter electrode.

<11> In any one of the above-described modes <1> to <10>, the counter electrode is positioned with respect to a downstream portion of the inner peripheral surface of the separator body in the flow direction of the blowby gas. On the other hand, the flow of the blow-by gas in the separator body from the introduction port to the inside or the inner peripheral surface on the upstream side in the flow direction of the blow-by gas with respect to the arrangement position of the counter electrode in the separator body. There is provided a changing unit for changing from a unidirectional flow that flows linearly in one direction toward the discharge port to a non-unidirectional flow or a swirling flow that flows in a direction crossing the one direction.

  In this embodiment, when the flow of the blow-by gas is changed from the one-way flow to the non-one-way flow by the changing unit, the blow-by gas is the counter electrode at the downstream side in the flow direction of the blow-by gas in the separator body. As a result, the oil mist contained in the blow-by gas approaches the downstream portion of the separator body closer to the counter electrode. It becomes fluid. Further, even when the flow of the blow-by gas is changed from the one-way flow to the swirl flow by the changing unit, the oil mist in the blow-by gas is separated from the downstream portion of the separator body by the circular center separation action of the swirl flow. Can be made to flow closer to the counter electrode.

  Therefore, in this embodiment, the counter electrode is not provided with a special structure, and the coulomb that is allowed to act between the oil mist in the blow-by gas that allows the downstream portion of the separator body to flow in a charged state and the counter electrode. The force is effectively increased, so that the oil mist can be more efficiently and reliably adsorbed to the counter electrode. As a result, further improvement in the oil mist separation performance can be advantageously achieved.

<12> In the above aspect <11>, the change unit has a change surface extending in a spiral shape along the flow direction of the blow-by gas, and is more than an arrangement site of the counter electrode in the separator body. It is composed of a swirling ribbon plate made of an insulating material fixed to the upstream side portion in the flow direction of the blow-by gas, and the flow of the blow-by gas in the separator main body is changed on the changing surface of the swirling ribbon plate. The unidirectional flow is changed to the swirl flow. According to this aspect, it becomes possible to change the flow of blow-by gas into the swirl flow more reliably in the separator body.

<13> In the above aspect <11>, the change portion is arranged in a flow direction of the blow-by gas in an upstream portion of the flow direction of the blow-by gas with respect to the arrangement portion of the counter electrode on the inner peripheral surface of the separator body. The flow of the blow-by gas in the separator body is formed in the spiral groove and / or the spiral protrusion. The unidirectional flow is changed to the swirl flow. According to this aspect, for example, by configuring the separator body with a synthetic resin material, it is possible to easily integrally form the spiral groove and the spiral protrusion on the inner peripheral surface of the separator body. . As a result, an increase in the number of parts due to the addition of the changed portion can be advantageously avoided, and an increase in the manufacturing cost of the oil separator and a decrease in manufacturability due to the addition of the changed portion can be effectively suppressed. .

<14> In the above aspect <11>, the changing unit has a shielding surface that partially blocks the flow of the blow-by gas in the separator body, and the arrangement of the counter electrode inside the separator body The blow-by gas flow in the separator body is formed on a shielding surface of the shielding member. The unidirectional flow is changed to the non-unidirectional flow. According to this aspect, it becomes possible to change the flow of blow-by gas into the non-unidirectional flow more reliably in the separator body.

<15> In the above aspect <14>, the shielding surface of the shielding member is a tapered surface that gradually increases in diameter from the upstream side to the downstream side in the flow direction of the blow-by gas. According to this aspect, the flow of blow-by gas can be changed to a non-unidirectional flow while suppressing an increase in pressure loss as much as possible.

<16> In any one of the above-described modes <11> to <15>, the change portion is more of the blow-by gas than an arrangement site of the counter electrode on the inside or the inner peripheral surface of the separator body. It is provided in a portion on the upstream side in the flow direction and on the downstream side in the flow direction of the blow-by gas with respect to the portion where the discharge electrode is disposed. In this embodiment, the flow of blow-by gas can be changed to a non-unidirectional flow or a swirl flow on the downstream side of the portion where the discharge electrode is disposed. Therefore, for example, when the flow of the blow-by gas is changed to a non-unidirectional flow or a swirl flow upstream from the arrangement part of the discharge electrode, the corona discharge is generated in the discharge electrode. The oil mist can be reliably and efficiently charged. Thereby, the improvement of the oil mist separation efficiency can be realized more effectively.

<17> In any one of the modes <1> to <16> described above, any one of the discharge electrode and the counter electrode is connected to a positive power supply unit that applies a positive voltage. On the other hand, either one of them is connected to a negative power supply means for applying a negative voltage. According to this aspect, between the oil mist charged by the occurrence of corona discharge at the discharge electrode and the counter electrode, the Coulomb force that acts to attract each other is advantageously increased. The oil mist can be more efficiently and reliably adsorbed to the counter electrode. As a result, further improvement in the oil mist separation performance can be advantageously achieved.

  Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

  First, in FIG. 1, an oil separator for an automobile engine as an embodiment of an oil separator for blow-by gas according to the present invention is schematically shown in a longitudinal sectional form in a state assembled to the automobile engine. . As is clear from FIG. 1, the oil separator 10 according to the present embodiment includes a separator body 12.

  More specifically, the separator body 12 constituting the oil separator 10 is formed using an insulating material, for example, a glass fiber reinforced resin using a polyamide resin as a matrix. And as a whole, it consists of a large-diameter tubular body having a cylindrical shape with bottoms on both sides, and extends in the horizontal direction in the assembled state to the engine, and the axial direction of the cylindrical wall portion 14 The first and second bottom wall portions 15 and 16 that respectively close the opening portions on both sides are integrally provided.

  Of these two bottom wall portions 15, 16, a gas introduction is formed in the central portion of the first bottom wall portion 15 through an opening that passes through the central portion and communicates the internal space of the separator body 12 to the outside. The mouth 18 is provided with a circular shape. A cylindrical gas introduction pipe 20 is connected to the gas introduction port 18 at one end in a communicating state.

  On the other hand, the gas discharge port 22 including an opening that penetrates the second bottom wall portion 16 and allows the internal space of the separator body 12 to communicate with the outside is substantially the same size as the gas introduction port 18. It is formed with a circular shape. A cylindrical gas discharge pipe 24 is connected to the gas discharge port 22 in a communicating state at one end.

  Further, in the lower part of the cylindrical wall portion 14, the oil discharge port 26 is smaller in the circular shape than the gas discharge port 22 in a portion located close to the second bottom wall portion 16 where the gas discharge port 22 is provided. It is provided with. An oil discharge pipe 28 having a smaller diameter than the gas introduction pipe 20 and the gas discharge pipe 24 is connected to the oil discharge port 26 at one end portion thereof in a communicating state.

  Here, the gas introduction pipe 20, the gas discharge pipe 24, and the oil discharge pipe 28 are all formed using the same insulating material as that of the separate body 12, for example, a glass fiber reinforced resin having a polyamide resin matrix. Has been. Further, the gas introduction pipe 20, the gas discharge pipe 24, and the oil discharge pipe 28 are integrated with the gas introduction port 18, the gas discharge port 22, and the oil discharge port 26 by, for example, adhesion or welding. By being joined and connected, airtightness between the outer peripheral surface of each of the introduction pipes or discharge pipes 20, 24, and 28 and the inner peripheral surface of each of the introduction openings or discharge outlets 18, 22, 264 is achieved. The liquid-tightness is ensured.

  And in this separator main body 12, it is needle | hook as a whole on the internal peripheral surface of the part located in proximity to the 1st bottom wall part 15 in which the gas inlet 18 is provided among the lower parts of the cylinder wall part 14. FIG. A needle-like electrode 30 serving as a discharge electrode is provided upright. Further, the needle electrode 30 has an edge portion 32 having a sharp tip, and the edge portion 32 is provided at an intermediate portion in the radial direction (vertical direction in FIG. 1) of the cylindrical wall portion 14 in the internal space of the separator body 12. It is positioned. In addition, if the forming material of the acicular electrode 30 is an electroconductive material, it will not specifically limit.

  Further, a thin cylindrical shape having an outer diameter slightly smaller than the inner diameter of the cylindrical wall portion 14 as a whole on the second bottom wall portion 16 side where the gas discharge port 22 is provided in the cylindrical wall portion 14. A cylindrical electrode 34 serving as a counter electrode is disposed. The cylindrical electrode 34 has an axial length that is slightly less than half of the axial length of the cylindrical wall portion 14, and is provided at one end side portion in the length direction (left-right direction in FIG. 1). A circular through hole 36 having substantially the same size as the oil discharge port 26 provided in the cylindrical wall portion 14 is provided at one location on the circumference.

  Then, such a cylindrical electrode 34 positions the through hole 36 corresponding to the oil discharge port 26, and positions the end surface of the formation side end portion of the through hole 36 in contact with the inner surface of the second bottom wall portion 16. In this state, the outer peripheral surface is fixed to the inner peripheral surface portion of the cylindrical wall portion 14 on the second bottom wall portion 16 side. Thereby, the cylindrical electrode 34 is separated from the needle electrode 30 erected on the gas inlet 18 side in the separator main body 12 by a predetermined distance in the axial direction, and the entire inner peripheral surface of the cylindrical electrode 34 is separated from the separator main body 12. It is disposed in an exposed state in the internal space. In other words, of the inner peripheral surface of the separator main body 12, the entire part of the inner peripheral surface of the cylindrical electrode 34 that is a little less than half of the gas discharge port 22 side is configured. In addition, even if it exists in this cylindrical electrode 34, if the formation material is an electroconductive material, it will not be limited at all.

  And the gas introduction pipe | tube 20 connected to the gas inlet 18 of the separator main body 12 which has such a structure is connected in the communication state with the connection hole 40 provided in the side wall part of the crankcase 38 of an engine. On the other hand, the gas discharge pipe 24 connected to the gas discharge port 22 is connected in communication with a connection hole 44 provided in the pipe wall of the intake pipe line 42 of the engine. As a result, the crankcase 38 and the intake pipe 42 are connected to each other via the oil separator 10 in a communication state. The oil discharge pipe 28 connected to the oil discharge port 26 is connected in communication with a connection hole 48 provided in the side wall portion of the oil pan 46 located at the lower portion of the crankcase 38.

  On the other hand, the needle electrode 30 and the cylindrical electrode 34 provided in the separator body 12 are electrically connected to a high voltage generator 50 having a known structure, and the needle electrode 30 is connected to the high voltage generator 50. A negative high voltage (for example, about 2 to 10 kV) is applied to 30. Then, by applying a negative high voltage to the needle electrode 30, corona discharge is generated between the needle electrode 30 and the cylindrical electrode 34.

  Thus, in this embodiment, blow-by gas containing a large amount of oil mist leaked into the crankcase 38 from a gap between a piston ring (not shown) and the cylinder wall is caused by the negative pressure in the intake pipe line 42. Through the gas introduction pipe 20 of the separator 10, the internal space of the separator body 12, and the gas discharge pipe 24, it is forced to circulate from the crankcase 38 to the intake pipe 42, and further returned to the combustion chamber (not shown). It can be reburned. Here, the separator body 12 is communicated to the outside through the oil discharge port 26 in addition to the gas introduction port 18 and the gas discharge port 22, but the oil discharge pipe 28 connected to the oil discharge port 26. Since the engine oil 51 in the oil pan 46 is infiltrated therein, the leakage of blow-by gas to the outside through the oil discharge port 26 is prevented.

  As is clear from these, in the present embodiment, the needle-like electrode 30 provided on the gas inlet 18 side in the separator body 12 is positioned in the upstream portion of the separator body 12 in the flow direction of blow-by gas. On the other hand, the cylindrical electrode 34 provided on the gas discharge port 22 side is positioned in the downstream side portion in the flow direction of the blow-by gas in the separator body 12. 1, 52 is a known PCV for controlling the flow rate of blow-by gas circulated in the gas discharge pipe 24, that is, blow-by gas forcedly circulated from the crankcase 38 into the intake pipe 42. (Positive crankcase ventilation) Valve.

  Thus, in the present embodiment, a negative high voltage (for example, from the high voltage generator 50 to the needle electrode 30), for example, under the forced circulation of blow-by gas through the oil separator 10. 2 is applied to generate a corona discharge between the needle electrode 30 and the cylindrical electrode 34, so that the edge portion of the needle electrode 30 is schematically shown in FIG. The gas component of blow-by gas existing in the vicinity of 32 is ionized. A large number of electrons 54 generated by this ionization collide with and adhere to the oil mist 56 in the blow-by gas, so that the oil mist 56 is negatively charged.

  Further, when the blow-by gas including the oil mist 56 thus negatively charged is caused to flow inside the cylindrical electrode 34 toward the gas discharge port 22, the negatively charged oil mist 56 causes the Coulomb force. By this, it is attracted to the inner peripheral surface of the cylindrical electrode 34. As a result, the oil mist 56 contained in the blow-by gas forcedly circulated from the crankcase 38 into the intake pipe 42 is separated from the blow-by gas.

  The oil mist 56 adsorbed on the inner peripheral surface of the cylindrical electrode 34 aggregates on the inner peripheral surface of the cylindrical electrode 34 while being pushed away by the flow of blow-by gas toward the gas discharge port 22 side. It becomes a droplet. The oil mist 56 that has become droplets is discharged into the oil discharge pipe 28 through the through hole 36 and the oil discharge port 26 that are provided so as to correspond to the cylindrical electrode 34 and the separator body 12. Further, the oil is returned to the oil pan 46 through the oil discharge pipe 28.

  As described above, in the oil separator 10 of the present embodiment, the corona discharge is generated between the needle electrode 30 and the cylindrical electrode 34, thereby being introduced into the separator body 12 through the gas inlet 18. Since the oil semist 56 in the blow-by gas is charged and adsorbed to the cylindrical electrode 34, the oil mist 56 having a large particle size is of course, for example, an extremely small particle size of 1 μm or less. The oil mist 56 it has can also be charged reliably. Further, such a very small oil mist 56 can be adsorbed to the cylindrical electrode 34 more reliably because the kinetic energy to be held is small as much as the mass is small.

  Moreover, in the oil separator 10, since the needle-like electrode 30 is merely erected in the separator body 12, for example, by causing blow-by gas to collide with a plurality of baffle plates or collision plates, Unlike the conventional apparatus that employs the labyrinth method or the inertial collision method as described above, the separator body 12 is substantially free of obstacles that obstruct the flow of blow-by gas. Nothing exists. Moreover, unlike the conventional apparatus which employs the cyclone system, the circular center separation action of the swirling flow of blow-by gas is not utilized at all.

  Therefore, in the oil separator 10 of the present embodiment, the pressure loss generated during the flow of blow-by gas in the separator body 12 can be effectively suppressed, and unlike the conventional apparatus, the fine particles In order to separate the oil mist 56 having a diameter from the blow-by gas, the pressure loss can be increased by increasing the number of baffle plates or collision plates or increasing the flow velocity of the swirling flow of the blow-by gas. Can be advantageously eliminated.

  Therefore, in the oil separator 10 according to this embodiment as described above, the oil mist 56 contained in the blow-by gas has an extremely small particle diameter of, for example, 1 μm or less regardless of the particle diameter thereof. However, it can be reliably separated from the blow-by gas without increasing the pressure loss. As a result, the excellent separation performance that cannot be obtained by the conventional apparatus can be exhibited extremely advantageously.

  Further, in the oil separator 10, the entire surface of the inner peripheral surface of the separator body 12 that is slightly less than half of the gas discharge port 22 side is configured by the inner peripheral surface of the cylindrical electrode 34. Therefore, a portion capable of adsorbing the charged oil mist 56 in the separator body 12 can be advantageously secured with a sufficiently large area, and thereby the adsorption efficiency of the oil mist 56 can be more effectively increased. As a result, further improvement in the separation performance of the oil semist 56 can be effectively achieved.

  Further, in the present embodiment, the separator body 12 is directly connected to the crankcase 38 and the intake pipe line 42 through the gas introduction pipe 20 and the gas discharge pipe 24, respectively, so that the entire oil separator 10 is provided. However, since the crankcase 38 and the intake pipe 42 are connected to form a part of a connecting flow path through which the blow-by gas is circulated, an increase in the size of the engine associated with the installation of the oil separator 10 is advantageous. There is also an advantage that it can be suppressed.

  Next, in FIG. 3 and FIG. 4, another embodiment of the oil separator for blow-by gas according to the present invention, which is different in the structure of the discharge electrode from the first embodiment described above, has a longitudinal sectional form and a transverse sectional form. Are respectively schematically shown. In the embodiments shown in FIGS. 3 and 4 and in some embodiments shown in FIGS. 5 to 12, which will be described later, the same as the first embodiment shown in FIGS. The members and parts having a simple structure are denoted by the same reference numerals as those in FIGS. 1 and 2, and detailed description thereof is omitted.

  That is, as is apparent from FIGS. 3 and 4, the oil separator 10 according to the present embodiment is upstream of the intermediate portion in the flow direction of the blow-by gas (the left-right direction in FIG. 3) in the cylindrical wall portion 14 of the separator body 12. An electrode array 58 is formed on the inner peripheral surface portion on the left side in FIG.

  The electrode array 58 includes a plurality (eight in this case) of needle-like electrodes 30 serving as discharge electrodes. The plurality of needle-like electrodes 30 extend toward one point on the central axis of the cylindrical wall portion 14 at each position spaced apart by a certain distance in the circumferential direction on the inner peripheral surface of the cylindrical wall portion 14. Is erected. In other words, the plurality of needle-shaped electrodes 30 are arranged so as to extend radially with the respective edge portions 32 positioned in the intermediate portion in the radial direction of the cylindrical wall portion 14. It is fixed on the peripheral surface. That is, the electrode row 58 is constituted by the plurality of needle-like electrodes 30 fixed on the inner peripheral surface of the cylindrical wall portion 14 with such an arrangement form. Note that each of the plurality of needle electrodes 30 constituting the electrode array 58 is electrically connected to a high voltage generator (50) (not shown).

  On the other hand, on the inner peripheral surface portion of the cylindrical wall portion 14 of the separator main body 12 on the downstream side of the middle portion in the flow direction of the blow-by gas, a cylindrical electrode 34 having a cylindrical shape as a counter electrode is provided on the separator main body 12. It is fixed in the axial direction with a predetermined distance from each needle electrode 30 in the electrode array 58 and with the entire inner peripheral surface exposed to the internal space of the separator body 12. The cylindrical electrode 34 is also electrically connected to a high voltage generator (50) (not shown).

  Thus, in the oil separator 10 of the present embodiment, a high negative voltage is applied to each of the plurality of needle-like electrodes 30 in the electrode array 58 from the high voltage generator (50). Corona discharge is generated between each needle electrode 30 and the cylindrical electrode 34.

  Therefore, in such an oil separator 10, the blow-by gas containing a large amount of oil mist leaked into the crankcase (38) is introduced into the gas separator 10 due to the negative pressure in the intake pipe (42). The electrode from the high voltage generator 50 is forced through the pipe 20 and the internal space of the separator body 12 and the gas discharge pipe 24 under the condition that the crankcase (38) is forced to flow into the intake pipe (42). An oil mist contained in the blow-by gas is generated by applying a negative high voltage to each needle electrode 30 in the row 58 to generate a corona discharge between each needle electrode 30 and the cylindrical electrode 34. Can be negatively charged. The negatively charged oil mist is adsorbed on the cylindrical electrode 34 by the Coulomb force and separated from the blow-by gas. The oil mist adsorbed by the cylindrical electrode 34 eventually becomes droplets and returns to the engine oil pan (46) from the separator body 12 through the oil discharge pipe 28.

  Therefore, also in the oil separator 10 of this embodiment having such a structure, the oil mist contained in the blow-by gas has a very small particle diameter of 1 μm or less, for example, as in the first embodiment. Even so, it can be reliably separated from the blow-by gas without increasing the pressure loss, and therefore the oil mist separation performance can be improved extremely advantageously.

  In the oil separator 10 according to this embodiment, in particular, the needle electrode 30 is provided in the separator main body 12 at a plurality of intervals in the circumferential direction. Compared with the case where only one electrode 30 is provided in the separator body 12, the oil mist can be more efficiently and sufficiently charged. As a result, the improvement of the oil mist adsorption efficiency at the cylindrical electrode 34, and hence the oil mist separation efficiency from the blow-by gas, can be realized extremely advantageously.

  In the present embodiment, the electrode array 58 including the plurality of needle-like electrodes 30 is provided only at one location on the upstream side in the flow direction of the blow-by gas on the inner peripheral surface of the cylindrical wall portion 14 of the separator body 12. For example, as shown in FIG. 5, the inner peripheral surface portion on the upstream side (left side in FIG. 5) on the upstream side (left side in FIG. 5) of the blowby gas distribution direction (left-right direction in FIG. 5) in the cylindrical wall portion 14 of the separator body 12. In addition, a plurality of sets (here, three sets) of electrode arrays 58 may be provided at a predetermined distance from each other in the blow-by gas flow direction.

  According to such a structure, a plurality of needle-like electrodes 30 are provided in the separator body 12 not only in the circumferential direction but also in the axial direction at a predetermined interval. Therefore, the oil mist can be more efficiently and sufficiently charged by the corona discharge generated between each of the needle electrodes 30 and the cylindrical electrode 34. The oil mist adsorption efficiency and the oil mist separation efficiency from the blow-by gas can be greatly improved.

  It should be noted that the arrangement intervals of the plurality of sets of electrode rows 58 may or may not be equal to each other, for example, the size of the separator body 12 (the axial length of the cylindrical wall portion 14), etc. Depending on the situation, it is determined appropriately.

  Next, in FIGS. 6 and 7, another embodiment of the oil separator for blow-by gas according to the present invention, in which the structure of the discharge electrode is further different from the first and second embodiments described above, is shown in a longitudinal sectional form. Each is shown schematically in cross-sectional form.

  As apparent from FIGS. 6 and 7, in the oil separator 10 of the present embodiment, the upstream side of the intermediate part in the flow direction (left and right direction in FIG. 6) of the blowby gas in the cylindrical wall part 14 of the separator body 12. An electrode support member 60 is fixed to the inner peripheral surface portion (left side in FIG. 6).

  The electrode support member 60 has a cylindrical frame portion 62 having an outer diameter and a low height that are substantially the same as or slightly smaller than the inner diameter of the cylindrical wall portion 14 of the separator body 12, and an inner side of the cylindrical frame portion 62. In order to form a large number of rectangular meshes large enough to allow blow-by gas to pass therethrough, the conductive metal wires 64 are combined vertically and horizontally and integrally provided with the provided mesh portion 66. Configured. Then, in such a state that the electrode support member 60 has the mesh of the mesh part 66 arranged vertically and horizontally in a direction perpendicular to the flow direction of the blow-by gas, the cylindrical wall part 14 of the separator body 12 is formed in the cylindrical frame part 62. It is fixed by being press-fitted into, or bonded to.

  Thus, in the present embodiment, in particular, a plurality of needle-like electrodes 30 as discharge electrodes are fixed to each of the plurality of electrode support members 60 fixed in the separator body 12 and supported. Has been.

  In other words, here, each of the plurality of needle-like electrodes 30 is positioned inside one of several meshes formed on the mesh-like portion 66 of the electrode support member 60, one by one. Is fixed to a metal wire 64 surrounding the. As a result, a plurality of needle-like electrodes 30 are provided in the separator body 12 at a portion upstream of the intermediate portion in the flow direction of the blow-by gas, with an interval in the radial direction and the circumferential direction of the separator body 12. It is. The plurality of needle electrodes 30 are all electrically connected to the high voltage generator (50).

  On the other hand, on the inner peripheral surface portion of the cylindrical wall portion 14 of the separator main body 12 on the downstream side of the middle portion in the flow direction of the blow-by gas, a cylindrical electrode 34 having a cylindrical shape as a counter electrode is provided on the separator main body 12. In the axial direction, each needle electrode 30 is fixed at a predetermined distance and the entire inner peripheral surface is exposed to the internal space of the separator body 12. The cylindrical electrode 34 is also electrically connected to the high voltage generator (50).

  Thus, in the oil separator 10 of the present embodiment, a negative high voltage is applied from the high voltage generator (50) to each of the plurality of needle-like electrodes 30 supported by the electrode support member 60. As a result, corona discharge is generated between the needle electrodes 30 and the cylindrical electrode 34.

  Therefore, also in the present embodiment, corona discharge is generated between the plurality of needle-like electrodes 30 provided in the separator body 12 and the cylindrical electrode 34 under the forced circulation of blow-by gas through the oil separator 10. As a result, oil mist in the blow-by gas can be negatively charged and adsorbed by the cylindrical electrode 34 to be separated from the blow-by gas. Therefore, as in some of the embodiments described above, the oil mist contained in the blow-by gas is reliably separated from the blow-by gas regardless of its particle size and without increasing the pressure loss. Therefore, the excellent separation performance of oil mist can be exhibited very advantageously.

  In the present embodiment, in particular, a plurality of needle-like electrodes 30 are provided in the separator main body 12 at intervals in the circumferential direction and the radial direction. More fully and reliably exposed to blow-by gas, so that the oil mist can be more efficiently and fully charged. As a result, the oil mist adsorption efficiency at the cylindrical electrode 34, and hence the oil mist separation efficiency from the blow-by gas, can be further advantageously improved.

  In the present embodiment, the electrode support member 60 that supports the plurality of needle-like electrodes 30 is provided only at one location on the upstream side in the flow direction of the blow-by gas in the cylindrical wall portion 14 of the separator body 12. As shown in FIG. 8, on the inner peripheral surface portion on the upstream side (left side in FIG. 8) of the middle part of the flow direction of blowby gas in the cylindrical wall portion 14 of the separator body 12 (left and right direction in FIG. 8), A plurality (three in this case) of electrode support members 60 may be provided at a predetermined distance from each other in the blow-by gas flow direction.

  According to such a structure, a plurality of needle-like electrodes 30 are provided in the separator body 12 at predetermined intervals in the axial direction as well as in the circumferential direction and the radial direction. As a result, the oil mist can be charged more efficiently and sufficiently, so that the oil mist adsorption efficiency at the cylindrical electrode 34 and, moreover, the oil mist separation efficiency from the blow-by gas can be further increased. It can be improved.

  It should be noted that the arrangement intervals of the plurality of electrode support members 60 may or may not be equal to each other. For example, the size of the separator main body 12 (the axial length of the cylindrical wall portion 14). It is a place that is appropriately determined according to the above.

  Next, FIGS. 9 and 10 show another embodiment of the oil separator for blow-by gas according to the present invention in which the structure of the counter electrode is different from some of the embodiments described above. Are respectively schematically shown.

  As is clear from FIGS. 9 and 10, in the oil separator 10 of the present embodiment, the flow direction of blow-by gas in the cylindrical wall portion 14 of the separator body 12 (the left-right direction in FIG. 9) is downstream of the intermediate portion. A mesh electrode 68 as a counter electrode is fixedly provided on the right side in FIG.

  The mesh electrode 68 includes a cylindrical frame portion 70 having an outer diameter that is substantially the same as or slightly smaller than the inner diameter of the cylindrical wall portion 14 of the separator body 12 and a low height, and a blow-by on the inside of the cylindrical frame portion 70. The conductive metal wires 72 are combined vertically and horizontally so as to form a large number of rectangular meshes large enough to allow gas to pass through, and integrally provided with the provided net-like portions 74. ,It is configured. And, such a mesh electrode 68 is a state in which the mesh of the mesh portion 74 is arranged vertically and horizontally in a direction perpendicular to the flow direction of the blow-by gas, in other words, a metal wire 72 surrounding the mesh of the mesh electrode 68 is applied. In a state of being stretched vertically and horizontally in the radial direction of the cylindrical wall portion 14, the cylindrical frame portion 70 is fixed by being press-fitted into the cylindrical wall portion 14 of the separator main body 12 or bonded. . Such a mesh electrode 68 is electrically connected to a high voltage generator (50) (not shown).

  On the other hand, on the inner peripheral surface upstream of the middle portion in the flow direction of the blow-by gas in the cylindrical wall portion 14 of the separator main body 12, a needle-like electrode 30 as a discharge electrode is a net-like shape in the axial direction of the separator main body 12. The edge portion 32 is erected with a predetermined distance from the electrode 68 and in a state where the edge portion 32 is positioned at the radial intermediate portion of the cylindrical wall portion 14 in the internal space of the separator body 12. The needle electrode 30 is also electrically connected to a high voltage generator (50) (not shown).

  Thus, in the oil separator 10 according to the present embodiment, when the negative high voltage is applied to the needle electrode 30 from the high voltage generator (50), the needle electrode 30 and the mesh electrode 68 are Corona discharge is generated between the two.

  Therefore, in this embodiment as well, in the blow-by gas that is forced to circulate through the oil separator 10 by the corona discharge generated between the needle-like electrode 30 and the mesh-like electrode 68, as in the above-described embodiments. The oil mist can be reliably separated from the blow-by gas regardless of its particle size, without negative pressure increase, and negatively charged and adsorbed on the mesh electrode 68. Therefore, the excellent separation performance of oil mist can be exhibited extremely advantageously.

  In this embodiment, in particular, the blow-by gas is allowed to flow through the downstream side in the flow direction of the blow-by gas in the cylindrical wall portion 14 of the separator body 12 so as to pass through the mesh of the mesh electrode 68. become. Therefore, for example, among the blow-by gas flowing in the blow-by gas flow direction downstream side of the separator body 12, even in the blow-by gas flowing through the portion proximal to the inner peripheral surface of the cylindrical wall portion 14, the inner peripheral surface thereof Even in the blow-by gas flowing in the distal axial center portion, the metal wire 72 of the mesh portion 74 in the mesh electrode 68 is brought into contact with or in close proximity to the metal wire 72. Accordingly, the negatively charged oil mist can be more efficiently and reliably adsorbed by the mesh electrode 68. As a result, the separation efficiency of oil mist from blow-by gas can be further effectively increased.

  In the present embodiment, the mesh electrode 68 is provided only at one location on the upstream side in the flow direction of the blow-by gas in the cylindrical wall portion 14 of the separator body 12, but for example, as shown in FIG. A plurality of (four in this case) mesh electrodes 68 are provided on the inner peripheral surface portion upstream of the intermediate portion of the flow direction of the blow-by gas in the 12 cylindrical wall portions 14 (left and right direction in FIG. 11). They can also be provided at a predetermined distance from each other in the flow direction.

  According to such a structure, the blow-by gas flowing in the downstream side of the separator body 12 in the flow direction of the blow-by gas comes into contact with or close to the plurality of mesh electrodes 68, thereby Thus, the oil mist charged in a positive direction can be more reliably adsorbed by the plurality of mesh electrodes 68, and therefore, the separation efficiency of the oil mist from the blow-by gas can be improved at a higher level.

  It should be noted that the arrangement intervals of the plurality of mesh electrodes 68 may be equal to each other or not, and may be, for example, the size of the separator body 12 (the axial length of the cylindrical wall portion 14) or the like. Accordingly, it is determined appropriately.

  Next, FIG. 12 shows an oil for blow-by gas according to the present invention that is different in structure from some of the embodiments described above in that a changer for changing the flow of blow-by gas is provided inside the separator body. Yet another embodiment of the separator is shown schematically in longitudinal section.

  As apparent from FIG. 12, in the oil separator 10 of the present embodiment, the blowby gas flow direction (left and right direction in FIG. 12) in the cylindrical wall portion 14 of the separator body 12 is upstream (FIG. 12). In the middle, left side), the needle-like electrode 30 is erected in a state where the edge portion 32 is located at the radial intermediate portion of the cylindrical wall portion 14. Further, on the downstream side, a cylindrical electrode 34 as a counter electrode is disposed at a position spaced apart from the needle-like electrode 30 by an inner peripheral surface of the downstream side portion of the cylindrical wall portion 14 on the inner peripheral surface thereof. It is fixed so as to constitute. The needle electrode 30 and the cylindrical electrode 34 are electrically connected to a high voltage generator (50) (not shown).

  Accordingly, even in the oil separator 10, a negative high voltage is applied to the needle electrode 30 from the high voltage generator (50), so that the gap between the needle electrode 30 and the cylindrical electrode 34 is reduced. Corona discharge can be generated.

  And in this embodiment, the turning ribbon board 76 as a change part is being fixed between each installation site | parts of the acicular electrode 30 and the cylindrical electrode 34 in the blowby gas distribution direction intermediate part of the separator main body 12. Yes. The swivel ribbon plate 76 is formed using, for example, an insulating material such as a synthetic resin material similar to the material for forming the separator body 12. Further, as a whole, a long rectangular thin flat plate having a width substantially the same as or slightly smaller than the inner diameter of the cylindrical wall portion 14 of the separator body 12 is twisted so that one end portion and the other end portion in the longitudinal direction are mutually inverted. The both sides in the thickness direction are changed surfaces 78a and 78b that extend in a spiral shape. And in such a turning ribbon board 76, one end part and the other end part are the intermediate part of the separator main body 12, and the upstream upstream site | part and downstream site | part are each left-right in a horizontal direction, respectively. The change surfaces 78a and 78b are positioned so as to be partitioned, and are fixed by press-fitting, bonding, welding, or the like in a state where the change surfaces 78a and 78b are positioned so as to extend spirally along the flow direction of blow-by gas.

  Thus, the flow of the blow-by gas introduced into the separator main body 12 through the gas inlet 18 passes through the portion where the needle-like electrode 30 is disposed, and then guides or guides it to the change surfaces 78a and 78b of the swiveling ribbon plate 76. Thus, the unidirectional flow that flows linearly in one direction along the axial direction of the separator body 12 from the gas inlet 18 toward the gas outlet 22 is easily and reliably changed to the swirl flow. Then, as indicated by arrows in FIG. 12, the blow-by gas that has turned into a swirl flow is discharged from the gas discharge port 22 into the gas discharge pipe 24 through the portion where the cylindrical electrode 34 is disposed. . As a result, the oil mist in the blow-by gas that is allowed to flow in the separator main body 12 has a downstream portion in the separator main body 12 on the inner peripheral surface thereof, that is, the cylindrical electrode 34 based on the circular center separation action of the swirl flow. It is made to flow so that it may come closer to the inner peripheral surface.

  As described above, in this embodiment as well, the blow-by gas that is forced to circulate through the oil separator 10 by corona discharge generated between the needle electrode 30 and the cylindrical electrode 34 as in the above-described embodiments. The oil mist contained therein is negatively charged regardless of its particle size and without increasing the pressure loss, and is adsorbed by the cylindrical electrode 34 to be reliably separated from the blow-by gas. Therefore, the excellent separation performance of the oil mist can be exhibited very advantageously.

  In this embodiment, in particular, the negatively charged oil mist causes the downstream portion in the separator main body 12 to move to the inner peripheral surface of the cylindrical electrode 34 by the flow of blow-by gas that is swirled. On the other hand, since the fluid flows closer to each other, the distance between the charged oil mist and the cylindrical electrode 34 can be advantageously made small, and it acts between them. The effective Coulomb force is effectively increased, so that the oil mist can be more efficiently and reliably adsorbed to the cylindrical electrode 34. As a result, the effect of improving the oil mist separation performance can be achieved at a higher level.

  In the present embodiment, only one swivel ribbon plate 76 is provided between the site of the needle electrode 30 and the site of the cylindrical electrode 34 in the separator body 12. A plurality of needle electrodes 30 and the cylindrical electrode 34 may be provided so as to be arranged side by side in the flow direction of the blowby gas or in the direction intersecting therewith. As a result, the blow-by gas can be more reliably turned into a swirl flow, so that the oil mist adsorption efficiency at the cylindrical electrode 34 can be further enhanced.

  It is also possible to dispose one or a plurality of swirling ribbon plates 76 on the upstream side in the flow direction of the blow-by gas from the disposition site of the needle-shaped electrode 30 in the separator body 12. However, in order to efficiently make the flow of blow-by gas at the site where the cylindrical electrode 34 is disposed in the separator main body 12 into a swirl flow, one or a plurality of swirl ribbon plates 76 are formed in the separator main body 12. It is desirable that the needle electrode 30 and the cylindrical electrode 34 are disposed between the respective disposed portions. That is, by adopting such an arrangement, the oil mist adsorption efficiency at the cylindrical electrode 34 can be more sufficiently enhanced.

  Next, FIG. 13 schematically shows another embodiment of the oil separator for blow-by gas according to the present invention, which is different from the embodiment shown in FIG. Has been.

  As is clear from FIG. 13, also in the oil separator 10 of the present embodiment, the upstream side (left side in FIG. 13) of the blow-by gas flow direction (left and right direction in FIG. 13) in the cylindrical wall portion 14 of the separator body 12. ) And the downstream side, a needle electrode 30 as a discharge electrode and a cylindrical electrode 34 as a counter electrode are provided in the same manner as in the embodiment shown in FIG. The needle electrode 30 and the cylindrical electrode 34 are electrically connected to a high voltage generator (50) (not shown). Thereby, a negative high voltage is applied to the needle electrode 30 from the high voltage generator (50), so that a corona discharge is generated between the needle electrode 30 and the cylindrical electrode 34. It has become.

  In the present embodiment, the blow-by gas is disposed on the inner peripheral surface portion of the separator body 12 located between the installation portions of the needle electrode 30 and the cylindrical electrode 34 in the middle part of the separator body 12 in the blow-by gas flow direction. Are integrally formed with a substantially trapezoidal vertical cross section extending in a spiral manner toward the flow direction (that is, the direction from the gas inlet 18 side toward the gas outlet 22 side). Yes. Moreover, in the flow direction of blow-by gas by the mutually opposing surface of the adjacent ones in the flow direction of blow-by gas in the spiral protrusion 80 and the inner peripheral surface portion of the separator body 12 positioned between them. A spiral groove 82 extending continuously in a spiral shape is formed.

  The separator body 12 provided with the spiral protrusions 80 and the spiral grooves 82 on the inner peripheral surface thereof uses, for example, a mold having a molding cavity having a shape corresponding to the separator body 12, and the cavity of the mold is used. It can be easily formed by setting a core or the like having a spiral groove corresponding to the spiral protrusion 80 and performing injection molding or the like. Further, the height of the spiral protrusion 80 is appropriately set at a height at which pressure loss can be suppressed as much as possible.

  Thus, the flow of blow-by gas introduced into the separator main body 12 through the gas inlet port 18 is guided or guided to the spiral protrusion 80 or the spiral groove 82 after passing through the portion where the needle electrode 30 is disposed. The unidirectional flow from the gas inlet 18 toward the gas outlet 22 is easily and reliably changed from the swirl flow. Then, as indicated by arrows in FIG. 13, the blow-by gas that has turned into a swirl flow is discharged from the gas discharge port 22 into the gas discharge pipe 24 through the portion where the cylindrical electrode 34 is disposed. As a result, the oil mist in the blow-by gas that is allowed to flow in the separator main body 12 causes the downstream portion in the separator main body 12 to move away from the inner peripheral surface of the cylindrical electrode 34 based on the circular center separation action of the swirling flow. And can be made to flow closer. As is clear from this, here, the changing portion is constituted by the spiral protrusion 80 and the spiral groove 82.

  Thus, in this embodiment as well, as in the above embodiment, oil in blow-by gas that is forced to circulate through the oil separator 10 by corona discharge generated between the needle electrode 30 and the cylindrical electrode 34. The mist can be negatively charged regardless of the particle size and without increasing the pressure loss, and can be adsorbed to the cylindrical electrode 34 by the Coulomb force. Moreover, the charged oil mist is caused to flow in the downstream portion in the separator body 12 so as to be closer to the inner peripheral surface of the cylindrical electrode 34 by the flow of blow-by gas that has been swirled. As a result, the distance between the charged oil mist and the cylindrical electrode 34 can be advantageously reduced, and the Coulomb force acting between them can be effectively increased. Mist can be more efficiently and reliably adsorbed to the cylindrical electrode 34. Therefore, the oil mist separation performance can be improved more effectively.

  In the oil separator 10 according to the present embodiment, in particular, the spiral protrusion 80 and the spiral groove 82 that change the flow of blow-by gas flowing through the separator body 12 into a swirling flow are provided in the separator body 12. Unlike the case where, for example, a separate member is attached in the separator main body 12 so as to make the flow of blow-by gas a swirl flow, It can be advantageously dispensed with the need to carry out the cumbersome and costly work of preparing an extra member and mounting it in the separator body 12. Therefore, the effect produced by making the flow of blow-by gas into a swirl flow can be enjoyed very advantageously without causing a decrease in manufacturability of the oil separator 10 and an increase in production cost.

  In this embodiment, the spiral groove 82 is formed by providing the spiral protrusion 80 on the inner peripheral surface of the separator main body 12, but the bottom surface that is one step deeper than that is formed on the inner peripheral surface. Of course, it is also possible to provide the spiral groove 82 and to configure the side wall portion of the spiral groove 82 as the spiral protrusion 80.

  Further, such spiral protrusions 80 and spiral grooves 82 may be formed at a site upstream of the portion where the needle-like electrode 30 is disposed on the inner peripheral surface of the separator main body 12 in the blow-by gas flow direction. However, in order to make the flow of blow-by gas at the portion where the cylindrical electrode 34 is disposed in the separator main body 12 more efficiently into a swirl flow, as shown in FIG. 82 is preferably disposed between the respective portions of the needle electrode 30 and the cylindrical electrode 34 in the separator body 12. That is, by adopting such an arrangement, the oil mist adsorption efficiency at the cylindrical electrode 34 can be more sufficiently enhanced.

  Next, FIGS. 14 and 15 show another embodiment of the oil separator for blow-by gas according to the present invention, in which the structure of the changing portion is further different from the two embodiments shown in FIGS. , Schematically shown in longitudinal section.

  As apparent from FIGS. 14 and 15, also in the oil separator 10 of the present embodiment, the upstream side in the flow direction of the blow-by gas (left and right direction in FIG. 14) in the cylindrical wall portion 14 of the separator body 12 (FIG. 14). The needle electrode 30 as the discharge electrode and the cylindrical electrode 34 as the counter electrode are provided in the state of being electrically connected to the high voltage generator (50) on the middle and left side) and the downstream side. Thus, a negative high voltage is applied to the needle electrode 30 from the high voltage generator (50), so that a corona discharge is generated between the needle electrode 30 and the cylindrical electrode 34. ing.

  And in this embodiment, the shielding member 84 as a change part is provided between each installation site | parts of the acicular electrode 30 and the cylindrical electrode 34 in the blowby gas distribution direction intermediate part of the separator main body 12. FIG. . The shielding member 84 is made of, for example, an insulating material such as a synthetic resin material similar to the material for forming the separator main body 12, and a plurality of (here, eight) the attachment frame portion 86 and the shielding portion 88 are connected to each other. The connecting portion 90 is integrally formed.

  More specifically, the mounting frame portion 86 of the shielding member 84 has a cylindrical shape having an outer diameter that is substantially the same as or slightly smaller than the inner diameter of the cylindrical wall portion 14 of the separator body 12 and a low height. . The shielding portion 88 has a tapered cylindrical shape that gradually increases in diameter from one side in the height direction of the mounting frame portion 86 toward the other side. The base frame is disposed coaxially with the mounting frame 86 in a state where the base portion side portion is positioned. And the outer peripheral surface of such a shielding part 88 is made into the shielding surface 92 which consists of a taper surface corresponding to the whole shape of the shielding part 88. FIG.

  On the other hand, the plurality of connecting portions 90 that integrally connect the mounting frame portion 86 and the shielding portion 88 are mutually connected between the inner peripheral surface of the mounting frame portion 86 and the outer peripheral surface on the base side of the shielding portion 88. It is positioned so as to extend radially from the shielding portion 88 toward the mounting frame portion 86 with an equal distance in the direction, and the inner peripheral surface of the mounting frame portion 86 and the shielding portion at both ends in the extending direction. It is made to integrate with 88 base side outer peripheral surfaces, respectively. And thereby, the fan-shaped through-hole 94 is each provided between the connection parts 90 adjacent to the circumferential direction.

  Thus, in the shielding member 84 having such a structure, it is press-fitted into the cylindrical wall portion 14 of the separator body 12 at the attachment frame portion 86 at the middle portion in the blowby gas flow direction in the separator body 12. Alternatively, they are fixed by bonding or welding. Further, under such a fixed state, the distal end side having a small diameter in the shielding portion 88 is positioned on the gas introduction port 18 side, and the tapered shielding surface 92 is formed from the gas introduction port 18 side to the gas discharge port 22 side. The plurality of through holes 94 are arranged so as to gradually increase in diameter toward the downstream side, that is, from the upstream side to the downstream side in the flow direction of the blow-by gas. However, they are arranged in the circumferential direction of the separator main body 12 in a direction perpendicular to the flow direction of the blow-by gas, and the blow-by gas is arranged so as to be able to flow in each through hole 94. The height of the tapered shielding surface, the diameter of the large diameter portion, and the like are appropriately set in dimensions that can suppress pressure loss as much as possible.

  Thus, in the oil separator 10 of the present embodiment, the blow-by gas introduced into the separator body 12 through the gas introduction port 18 has passed through the site where the needle-like electrode 30 is disposed, as shown by the arrows in FIG. After that, the guide member is guided or guided to the tapered shielding surface 92 of the shielding member 84 and crosses such a flow from the one-way flow from the gas inlet port 18 toward the gas outlet port 22. It is easily and reliably changed to a non-unidirectional flow that flows toward the entire circumference of the peripheral surface. The blow-by gas that has become such a non-unidirectional flow passes through the plurality of through holes 94 of the shielding member 84, passes through the portion where the cylindrical electrode 34 is disposed, and passes through the gas discharge port 22 to the inside of the gas discharge pipe 24. Will be discharged. Thereby, the oil mist in the blow-by gas allowed to flow in the separator main body 12 rides on the flow of the blow-by gas and flows so that the downstream portion of the separator main body 12 comes closer to the cylindrical electrode 34. You will be tempted.

  As described above, also in this embodiment, the corona discharge is generated between the needle electrode 30 and the cylindrical electrode 34, so that the oil separator 10 is similar to the above embodiments. The oil mist in the blow-by gas forced to circulate through can be adsorbed to the cylindrical electrode 34 by the Coulomb force regardless of the particle size and without increasing the pressure loss. In addition, the charged oil mist flows so that the downstream side portion in the separator body 12 is closer to the inner peripheral surface of the cylindrical electrode 34 due to the flow of blow-by gas that is a non-unidirectional flow. As a result, the distance between the charged oil mist and the cylindrical electrode 34 can be effectively reduced, and the Coulomb force acting between them can be effectively increased. As a result, the oil mist separation performance can be further effectively improved.

  In the oil separator 10 according to this embodiment, in particular, the shielding surface 92 of the shielding member 84 has a tapered shape in which the diameter gradually increases from the upstream side to the downstream side in the flow direction of the blow-by gas. Therefore, the blow-by gas is guided relatively smoothly by the shielding surface 92, so that the pressure loss due to the collision of the blow-by gas with the tapered shielding surface 92 is possible. Can be kept low.

  In the present embodiment, only one shielding member 84 is provided between the site of the needle electrode 30 and the site of the cylindrical electrode 34 in the separator body 12. A plurality of the electrodes 30 and the cylindrical electrode 34 may be arranged in the direction in which the blow-by gas flows or the direction intersecting the blow-by gas. Thereby, the blow-by gas can be surely made into a unidirectional flow that flows toward the inner peripheral surface of the separator body 12, so that the oil mist adsorption efficiency at the cylindrical electrode 34 can be further enhanced. .

  It is also possible to dispose one or a plurality of shielding members 84 on the upstream side in the flow direction of the blow-by gas from the disposition site of the needle electrode 30 in the separator body 12. However, in order to efficiently make the flow of blow-by gas at the portion where the cylindrical electrode 34 is disposed in the separator body 12 into a swirl flow, one or more of the shielding members 84 are used as needles in the separator body 12. It is desirable that the electrode 30 and the cylindrical electrode 34 are disposed between the respective disposed portions. That is, by adopting such an arrangement, the oil mist adsorption efficiency at the cylindrical electrode 34 can be more sufficiently enhanced.

  Further, the shielding surface 92 provided on the shielding member 84 changes the flow of the blow-by gas from a one-way flow to a non-one-way flow, and causes the oil mist in the blow-by gas to flow close to the cylindrical electrode 34 serving as the counter electrode. If it can be obtained, the shape is not limited to that shown in the embodiment. However, in order to reduce the pressure loss as much as possible, a shape in which the outer peripheral dimension gradually increases from the upstream side to the downstream side in the flow direction of the blow-by gas is desirable. Therefore, as the shape of the shielding surface 92, for example, a pyramid shape, a spindle shape, a spherical shape, or the like can be adopted instead of the illustrated tapered shape.

  Next, FIG. 16 schematically shows another embodiment of the oil separator for blow-by gas according to the present invention in a longitudinal cross-sectional form, which is different from the above-mentioned embodiments in the structure for supplying electricity to the discharge electrode and the counter electrode. Is shown in

  That is, in the oil separator 10 of the present embodiment shown in FIG. 16, the needle-like electrode 30 as the discharge electrode and the counter electrode as the discharge electrode on the upstream side and the downstream side in the blow-by gas flow direction in the separator body 12. The cylindrical electrodes 34 are disposed in the same manner as in the embodiment shown in FIG.

  And especially here, among these two types of electrodes 30 and 34, the needle-like electrode 30 is for the first high voltage generator 96 that generates a negative high voltage (for example, about 2 to 10 kV). The cylindrical electrode 34 is electrically connected to a second high voltage generator 98 that generates a positive high voltage (for example, about 10 V to 1 kV).

  Thus, in the oil separator 10 of the present embodiment, a negative high voltage is applied to the needle electrode 30 from the first high voltage generator 96, while the cylindrical electrode is supplied from the second high voltage generator 98. By applying a positive high voltage to 34, corona discharge is generated between the needle electrode 30 and the cylindrical electrode 34. Further, when blow-by gas is circulated through the oil separator 10, corona discharge is generated between the needle electrode 30 and the cylindrical electrode 34, so that oil mist in the blow-by gas has a particle size of Regardless of the size, it is negatively charged without being accompanied by an increase in pressure loss and is adsorbed by the cylindrical electrode 34.

  In the present embodiment, in particular, when corona discharge is generated, high voltages having opposite potentials are applied to the needle electrode 30 and the cylindrical electrode 34, so that they are charged by generation of corona discharge. The product of the amount of charge of the oil mist and the amount of charge of the cylindrical electrode 34 is made sufficiently large, so that the Coulomb force that acts to attract the oil mist to the cylindrical electrode 34 can be effectively increased. . As a result, the oil mist can be more efficiently and reliably adsorbed to the counter electrode, and as a result, further improvement in the oil mist separation performance can be achieved extremely advantageously. It becomes.

  The specific configuration of the present invention has been described in detail above. However, this is merely an example, and the present invention is not limited by the above description.

  For example, the discharge electrode is not limited to the needle-like electrode 30 exemplified in the above-described embodiments, and an electrode having a conventionally known structure having an edge portion is appropriately employed. obtain.

  Further, the counter electrode is not particularly limited to the cylindrical electrode 34, the mesh electrode 68 and the like exemplified in the above embodiments, and can be changed to a counter electrode generally used conventionally.

  Furthermore, the shape of the separator body 12 may be any shape.

  Furthermore, in the above-described embodiments, the separator body is configured in a separate form independent of the engine components. For example, the separator body is assembled to an engine component such as a cylinder head cover. There is no problem even if it is done.

  In addition, in the said embodiment, although the specific example of what applied this invention to the oil separator for motor vehicle engines was shown, this invention is the oil in blow-by gas generated inside internal combustion engines other than a motor vehicle engine. Of course, the present invention is applicable to any blowby gas oil separator that separates mist.

  In addition, although not enumerated one by one, the present invention can be carried out in a mode to which various changes, modifications, improvements, etc. are added based on the knowledge of those skilled in the art. It goes without saying that all are included in the scope of the present invention without departing from the spirit of the present invention.

It is a section explanatory view showing one embodiment of an oil separator for blowby gas according to the present invention. It is explanatory drawing which shows typically the principle which isolate | separates oil mist from blow-by gas by the oil separator shown by FIG. It is a blow-by gas oil separator according to the present invention, and is a longitudinal sectional explanatory view showing another embodiment provided with discharge electrodes having different structures. FIG. 4 is an enlarged explanatory view taken along the line IV-IV in FIG. 3. FIG. 5 is a view corresponding to FIG. 3 showing still another embodiment of the oil separator for blow-by gas according to the present invention, which is further provided with discharge electrodes having different structures. FIG. 5 is a view corresponding to FIG. 3 showing another embodiment of the oil separator for blow-by gas according to the present invention and having a discharge electrode having a different structure. FIG. 7 is an enlarged explanatory view in a VII-VII cross section of FIG. 6. FIG. 5 is an explanatory view corresponding to FIG. 3, showing still another embodiment of the blow-by gas oil separator according to the present invention, further including a discharge electrode having a different structure. It is an oil separator for blowby gas according to the present invention, and is explanatory drawing corresponding to Drawing 3 showing another embodiment provided with a counter electrode of a different structure. FIG. 10 is an enlarged explanatory view in the XX section of FIG. 9. It is explanatory drawing corresponding to FIG. 3 which shows further another embodiment which is the oil separator for blow-by gas according to this invention, and was further provided with the counter electrode of a different structure. FIG. 4 is an explanatory view corresponding to FIG. 3 showing another embodiment of the oil separator for blow-by gas according to the present invention, in which a rotating ribbon plate as a changing portion is provided in the separator body. FIG. 4 is an explanatory view corresponding to FIG. 3, showing still another embodiment of the oil separator for blow-by gas according to the present invention, in which a spiral protrusion and a spiral groove as a changing portion are provided on the inner peripheral surface of the separator body. is there. It is an oil separator for blow-by gas according to the present invention, and is an explanatory view corresponding to FIG. 3 showing another embodiment in which a shielding member as a changing portion is provided in the separator body. It is an expansion explanatory view in the XV-XV cross section of FIG. It is explanatory drawing corresponding to FIG. 1 which shows the oil separator for blow-by gas according to this invention, Comprising: Another embodiment provided with the structure where a high voltage of a reverse electric potential is applied with respect to each of a discharge electrode and a counter electrode. .

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Oil separator 12 Separator main body 18 Gas introduction port 22 Gas discharge port 30 Needle-shaped electrode 34 Cylindrical electrode 50, 96, 98 High voltage generator 56 Oil mist 58 Electrode row 60 Electrode support member 68 Reticulated electrode 76 Turning ribbon board 78 Change Surface 80 Spiral ridge 82 Spiral groove 84 Shield member 92 Shield surface

Claims (17)

An oil separator for separating oil mist contained in blow-by gas generated inside an internal combustion engine from the blow-by gas,
An inlet for introducing the blow-by gas; and an outlet for discharging the introduced blow-by gas to the outside, and the blow-by gas introduced from the inlet is directed toward the outlet. A separator body made of an insulating material that can be distributed;
A discharge electrode for charging the oil mist in the blowby gas by being positioned at an upstream portion in the flow direction of the blowby gas in the separator body and generating a corona discharge;
A counter electrode that is positioned in a downstream portion of the separator main body in the flow direction of the blow-by gas, adsorbs the charged oil mist in the blow-by gas by Coulomb force, and separates it from the blow-by gas When,
An oil separator for blow-by gas characterized by comprising   The separator body is formed of a pipe that connects the crankcase of the internal combustion engine and an intake pipe in a communicating state, and the introduction port is an opening at one end of the pipe that opens into the crankcase. 2. The blow-by gas oil separator according to claim 1, wherein, on the other hand, the discharge port is configured by an opening on the other end side of the pipe connecting pipe that opens into the intake pipe.   The blow-by gas oil separator according to claim 1, wherein the discharge electrode is configured by a needle-like electrode having a needle-like shape.   An electrode in which a plurality of the discharge electrodes are arranged in a row so as to be adjacent to each other in the circumferential direction with respect to the upstream side portion in the flow direction of the blow-by gas on the inner circumferential surface of the separator body. The blow-by gas oil separator according to any one of claims 1 to 3, wherein the oil separator is erected in a state in which a row is formed, and is positioned at the upstream portion inside the separator body.   A plurality of the discharge electrodes are erected in a state where the electrode rows are respectively formed at a plurality of positions spaced in the flow direction of the blow-by gas in the upstream portion of the inner peripheral surface of the separator body. The blow-by gas oil separator according to claim 4.   A support member having a mesh portion provided with a plurality of meshes through which the blow-by gas can circulate in the upstream portion inside the separator body intersects with the flow direction of the blow-by gas. A plurality of the discharge electrodes are fixed to a wire surrounding the mesh of the mesh portion of the support member and supported by the support member. Item 4. The blowby gas oil separator according to any one of Items 3 to 4.   The blow-by according to claim 6, wherein a plurality of the support members that support the plurality of discharge electrodes are fixed to the upstream portion inside the separator body at intervals in the flow direction of the blow-by gas. Oil separator for gas.   The counter electrode is formed of a cylindrical electrode having a cylindrical shape, and the cylindrical electrode is positioned at the downstream portion inside the separator body, so that the inner surface of the separator body The blowby gas according to any one of claims 1 to 7, wherein an entire surface of a downstream portion in the blowby gas flow direction is configured by an inner peripheral surface of the cylindrical electrode. Oil separator.   The counter electrode is composed of a mesh electrode having a mesh shape with a large number of meshes through which the blow-by gas can flow, and the mesh electrode is disposed on the downstream portion inside the separator body. The oil separator for blow-by gas according to any one of claims 1 to 7, wherein the oil separators are fixed in a state in which they are arranged in a direction crossing the flow direction of the blow-by gas.   10. The blow-by gas use according to claim 9, wherein a plurality of the counter electrodes made of the mesh electrode are fixed to the downstream portion inside the separator body at intervals in the flow direction of the blow-by gas. Oil separator.   The counter electrode is positioned with respect to the downstream side portion in the flow direction of the blow-by gas on the inner peripheral surface of the separator body, while the flow direction of the blow-by gas is more than the portion where the counter electrode is disposed in the separator body. The flow of the blow-by gas in the separator main body intersects the one direction from the one-way flow that flows linearly in one direction from the inlet to the outlet on the upstream or inner peripheral surface. The oil separator for blow-by gas according to any one of claims 1 to 10, further comprising a changing portion that changes to a non-unidirectional flow or a swirling flow that flows in a direction in which the air flows.   The change part has a change surface extending in a spiral shape along the flow direction of the blow-by gas, and is located on an upstream side portion in the flow direction of the blow-by gas with respect to the arrangement portion of the counter electrode inside the separator body. The blow-by gas flow in the separator body is changed from the one-way flow to the swirl flow on the changing surface of the swirl ribbon plate. The blow-by gas oil separator according to claim 11, wherein the oil separator is blown gas.   The changing portion is formed on the upstream side portion in the flow direction of the blowby gas with respect to the arrangement portion of the counter electrode on the inner peripheral surface of the separator body so as to extend spirally along the flow direction of the blowby gas. The flow of the blow-by gas in the separator body is changed from the one-way flow to the swirl flow in the spiral groove and / or the spiral protrusion. The oil separator for blow-by gas according to claim 11, wherein the oil separator is changed.   The changing portion has a shielding surface that partially blocks the flow of the blow-by gas in the separator body, and is upstream of the flow-by direction of the blow-by gas from the location of the counter electrode in the separator body. The blow-by gas flow in the separator body is fixed to the side portion, and the flow of the blow-by gas in the separator body is changed from the one-way flow to the non-unidirectional direction on the shielding surface of the shielding member. The oil separator for blow-by gas according to claim 11, wherein the oil separator is changed to a flow.   The blow-by gas oil separator according to claim 14, wherein the shielding surface of the shielding member is a tapered surface that gradually increases in diameter from the upstream side to the downstream side in the flow direction of the blow-by gas.   The change part is located upstream in the flow direction of the blow-by gas with respect to the arrangement portion of the counter electrode on the inner or inner peripheral surface of the separator body and downstream in the flow direction of the blow-by gas with respect to the arrangement portion of the discharge electrode. The oil separator for blow-by gas according to any one of claims 11 to 15, which is provided on a side portion. Either one of the discharge electrode and the counter electrode is connected to a positive power supply means for applying a positive voltage, and one of them is connected to a negative power supply means for applying a negative voltage The blowby gas oil separator according to any one of claims 1 to 16, wherein the blowby gas oil separator is used.

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