JP2014070535A - Crankcase emission control system - Google Patents

Abstract

A blow-by gas reduction device capable of reliably recovering mist-like oil by centrifugation.
A gas-liquid separation unit and a blow-by gas passage unit are provided. The gas-liquid separator is formed by a rotating body 53 provided at one end of a second balancer shaft that rotates at the same speed as the crankshaft in the crank chamber below the engine. The rotator 53 includes an annular space 62, an inlet passage 66 that extends from the inner periphery of the annular space 62 toward the axial center and opens into the crank chamber, and a gas outlet that extends from the inner periphery of the annular space 62 to the axial center. A passage 74 and an oil outlet passage 63 that communicates the outer periphery of the annular space 62 and the crank chamber are formed. The blow-by gas passage portion 56 includes a gas extraction portion formed on the wall of the crank chamber so that the gas outlet passage 74 is rotatably and airtightly connected and the blow-by gas is guided outside the crank chamber, and the gas extraction portion and the intake passage. And a communication passage that communicates with each other.
[Selection] Figure 5

Description

  The present invention relates to a blow-by gas reduction device including a gas-liquid separation unit that separates mist-like oil and blow-by gas floating in a crank chamber by centrifugal separation.

  A conventional engine includes a blow-by gas reduction device for guiding blow-by gas generated in the crank chamber to an intake device. Mist oil drifts in the crank chamber of the engine during operation. For this reason, this mist-like oil is also contained in the blow-by gas sucked out from the crank chamber by the blow-by gas reducing device. This oil needs to be collected so as not to be sucked into the intake device.

  As a conventional blow-by gas reducing device having a function of collecting mist-like oil flowing together with the blow-by gas in the middle, there is one described in Patent Document 1, for example. The blow-by gas reduction device disclosed in Patent Document 1 sucks blow-by gas from a crank chamber by a so-called centrifugal blower and sends it to an intake device. The centrifugal blower includes a large number of vanes that rotate integrally with the balancer shaft of the engine, and a bottomed cylindrical vane housing that surrounds these vanes. A large number of vanes are arranged radially around the balancer axis with the balancer axis as the center.

  In this blow-by gas reduction device, blow-by gas and mist-like oil in the crank chamber are sucked into the vane housing from a blow-by gas inflow passage formed in the balancer shaft. The blow-by gas is sent to the outer peripheral side of the vane housing by the vane rotating at a high speed and flows along the inner peripheral surface of the vane housing. And this blowby gas is sent out of a centrifugal blower from the blowby gas outflow passage provided in the perimeter part of a vane housing. On the other hand, the mist-like oil sucked into the centrifugal blower is blown through the centrifugal blower toward the inner peripheral surface of the vane housing together with blow-by gas. The oil adhering to the inner peripheral surface flows down along the inner peripheral surface of the vane housing by gravity and is recovered from an oil recovery passage connected to the lowermost portion of the vane housing.

JP 2009-2222043 A

  In the blow-by gas reducing device shown in Patent Document 1, there is a possibility that mist-like oil is sent from the centrifugal blower to the intake device side together with the blow-by gas. The reason for this is considered to be that mist-like oil is pushed by the blow-by gas flowing at high speed in the centrifugal blower and cannot flow onto the inner peripheral surface of the vane housing and flows into the blow-by gas outflow passage.

  The present invention has been made to solve such problems, and an object of the present invention is to provide a blow-by gas reduction device that can reliably recover mist-like oil by centrifugation.

  In order to achieve this object, a blow-by gas reduction device according to the present invention is provided at one end of a balancer shaft that rotates at the same speed as the crank shaft in a crank chamber at the bottom of the engine, and rotates blow-by gas to centrifuge oil. A gas-liquid separation part that is separated by force, and a blow-by gas passage part that guides blow-by gas from which oil has been removed by the gas-liquid separation part to an intake passage, wherein the gas-liquid separation part is formed by a rotating body, and the rotation The body includes an annular space located on the same axis as the balancer shaft, an inlet passage extending from the inner peripheral portion of the annular space toward the axial center and having a tip opened into the crank chamber, and an inner peripheral portion of the annular space A gas outlet passage extending from the outer periphery of the annular space to the crank chamber, and an oil outlet passage communicating with the outer periphery of the annular space and the crank chamber. Is formed by a gas extraction part formed in the wall of the crank chamber so that the blow-by gas is guided to the outside of the crank chamber, and a communication passage that connects the gas extraction part and the intake passage. It is what.

  The present invention is characterized in that, in the above invention, the gas-liquid separator is positioned adjacent to a transmission device that transmits rotation of a crankshaft to a camshaft.

  According to the present invention, in the above invention, the balancer shaft is one balancer shaft of two balancer shafts provided in parallel to each other at a position below the engine and sandwiching the crankshaft from both sides. A cooling water pump is provided at one end of the balancer shaft.

  The present invention is characterized in that, in the above invention, the blow-by gas passage portion includes a check valve in which blow-by gas flows only to the intake passage side.

  According to the present invention, when the rotating body rotates at a high speed together with the balancer shaft, blow-by gas and mist-like oil flow from the inlet passage of the rotating body toward the outside in the radial direction and flow into the annular space. A gas outlet passage is also communicated with the annular space. An intake negative pressure is propagated to the gas outlet passage through the communication passage and the gas extraction portion. For this reason, the blow-by gas that has flowed into the annular space flows into the gas outlet passage from the annular space, flows in the rotary body toward the inside in the radial direction, and then passes through the blow-by gas passage portion from the axial center portion of the rotary body. Sucked into. On the other hand, the mist-like oil that has flowed into the annular space is blown off by centrifugal force, adheres to the radially outer wall of the annular space, is separated from the blow-by gas, and is discharged out of the rotating body from the oil outlet passage. .

  Therefore, according to the present invention, the blow-by gas flows in the opposite direction with respect to the oil radially outward due to the centrifugal force, so that the blow-by capable of reliably separating the mist-like oil from the blow-by gas. A gas reduction device can be provided.

It is a side view of an engine provided with a blowby gas reduction device concerning the present invention. 2 is a cross-sectional view of the crankshaft and the first and second balancer shafts, which is a cross-sectional view taken along the line II-II in FIG. It is a longitudinal cross-sectional view of an engine. The fracture position in the figure is indicated by the line III-III in FIG. It is a side view of the engine which shows the structure of the blowby gas reduction apparatus which concerns on this invention. It is a front view of a rotary body, and the same figure is drawn by cutting a part of a disk member and a cylindrical body. It is the VI-VI sectional view taken on the line in FIG. FIG. 2 is a perspective view of a rotating body, in which the disk member and a part of the cylinder are cut away.

Hereinafter, an embodiment of a blow-by gas reduction apparatus according to the present invention will be described in detail with reference to FIGS.
An engine 1 shown in FIG. 1 is a two-cylinder DOHC type mounted on a vehicle (not shown). The phase difference between the two pistons 2 of the engine 1 is 360 degrees. In FIG. 1, reference numeral 3 is a cylinder block, 4 is an oil pan, 5 is a cylinder head, and 6 is a head cover.
A crankshaft 11 and first and second balancer shafts 12 and 13 are rotatably provided below the cylinder block 3.

  The crankshaft 11 is rotatably supported by the cylinder block 3 at three positions, that is, both end portions and a central portion in the axial direction. As shown in FIGS. 2 and 3, the bearing portions that rotatably support the crankshaft 11 include first to third bearing portions 14 to 16 of the cylinder block 3, and these first to third bearings. It is comprised by the 1st-3rd main bearing caps 17-19 (refer FIG. 3) which pinch | interpose the crankshaft 11 in cooperation with the parts 14-16.

  Both end portions of the crankshaft 11 are formed so as to protrude from the first and third bearing portions 14 and 16 toward the outside of the engine 1. An oil pump 21, a balancer shaft driving gear 22, and a timing chain sprocket 23 are arranged in this order at one end portion (the upper end portion in FIG. 2) of the crankshaft 11 protruding from the first bearing portion 14. It is provided in a lined up state. A flywheel 24 is attached to the other end of the crankshaft 11 as shown in FIG.

The oil pump 21 sucks up the oil in the oil pan 4 as the crankshaft 11 rotates, and supplies the oil to each lubricated portion of the engine 1.
The balancer shaft driving gear 22 is for rotating first and second balancer shafts 12 and 13, which will be described later, and meshes with driven gears 25 and 26 of the balancer shafts 12 and 13, respectively.

  The timing chain sprocket 23 is for rotating the timing chain 27, and the timing chain 27 is wound around the timing chain 27. As shown in FIG. 1, the timing chain 27 extends above the engine 1 and is wound around a driven sprocket 32 of the intake camshaft 31 and a driven sprocket 34 of the exhaust camshaft 33. The timing chain sprocket 23, the timing chain 27, and the driven sprockets 32 and 34 constitute a transmission 35 that transmits the rotation of the crankshaft 11 to the intake camshaft 31 and the exhaust camshaft 33. is there. The timing chain 27 according to this embodiment is accommodated inside a chain cover 36 located at one end of the engine 1.

  As shown in FIGS. 1 and 2, the chain cover 36 is formed in a shape that also covers shaft end portions of a pair of balancer shafts 12 and 13 to be described later. Further, the chain cover 36 closes the lower portion of the crank chamber 37 in cooperation with the oil pan 4 as shown in FIG. In this embodiment, the chain cover 36 constitutes a “crank chamber wall” in the present invention.

The intake camshaft 31 drives an intake valve 41, and the exhaust camshaft 33 drives an exhaust valve 42. The intake valve 41 opens and closes the intake port 43, and the exhaust valve 42 opens and closes the exhaust port 44.
The intake port 43 opens to one side of the cylinder head 5 and is connected to the downstream end of the intake manifold 45. The upstream end of the intake manifold 45 is connected to a surge tank 46. The surge tank 46 is formed on the side of the cylinder head 5 so as to extend in the axial direction of the crankshaft 11.

An intake outlet portion of the throttle valve 47 is connected to one end portion of the surge tank 46 in the longitudinal direction. An air inlet portion of the throttle valve 47 is connected to an air cleaner (not shown) via an intake pipe 48. In this embodiment, the intake passage 48 a in the intake pipe 48 constitutes an “intake passage” according to the first aspect of the present invention.
The exhaust port 44 opens at one side of the cylinder head 5 and is connected to the upstream end of the exhaust manifold 49.

  As shown in FIGS. 2 and 3, the first and second balancer shafts 12 and 13 are located below the engine 1 and sandwich the crankshaft 11 from both sides in the horizontal direction perpendicular to the axial direction. Are provided in parallel to each other. Each of these first and second balancer shafts 12 and 13 includes two balance weights 12a and 13a, respectively, as shown in FIG. The balance weights 12a and 13a are positioned so as to rotate between a pair of crank webs 11a and 11b for each cylinder of the crankshaft 11.

  The first and second balancer shafts 12 and 13 are rotatably supported by the cylinder block 3 at both ends. The bearing portions that rotatably support the balancer shafts 12 and 13 cooperate with the first and third bearing portions 14 and 16 of the cylinder block 3 and the first and third bearing portions 14 and 16. A balancer shaft bearing cap (not shown) sandwiching the balancer shafts 12 and 13 is formed.

  One end portions of the balancer shafts 12 and 13 facing the chain cover 36 are formed so as to protrude from the first bearing portion 14 toward the outside of the engine 1. Of the first and second balancer shafts 12 and 13, the driven gear 25 is attached to the one end portion of the first balancer shaft 12 located on the right side in FIG. Is connected. The cooling water pump 51 sucks the cooling water and supplies it to a cooling water jacket (not shown) of the engine 1 when the impeller 52 rotatably supported by the chain cover 36 rotates. The impeller 52 is connected to the shaft end of the first balancer shaft 12 so as to rotate integrally.

  The driven gear 26 is attached to one end portion of the second balancer shaft 13 and a rotating body 53 is attached. The driven gears 25 and 26 of the first and second balancer shafts 12 and 13 are formed so that the first and second balancer shafts 12 and 13 rotate in the reverse direction at the same rotational speed as the crankshaft 11. ing.

The rotating body 53 constitutes a part of the blow-by gas reducing device 54 according to the present invention, and is positioned inside the chain cover 36, that is, in the crank chamber 37.
As shown in FIG. 4, the blow-by gas reduction device 54 according to this embodiment includes a gas-liquid separation unit 55 formed by the rotating body 53 and a blow-by gas that guides blow-by gas from the gas-liquid separation unit 55 to the intake passage 48a. And a gas passage portion 56.

As shown in FIGS. 2 and 7, the rotating body 53 is formed in a disc shape, and is attached to the shaft end portion of the second balancer shaft 13 so as to rotate integrally with a mounting bolt 57. Yes. The rotating body 53 is positioned adjacent to the transmission device 35 connecting the crankshaft 11 and the intake / exhaust camshafts 31 and 33, that is, at the same position in the axial direction.
As shown in FIGS. 5 and 6, the rotating body 53 according to this embodiment includes a disk member 58 and a cylindrical body 59 attached to the outer periphery of the disk member 58. The disc member 58 is attached to the second balancer shaft 13 so as to be positioned on the same axis. An annular groove 61 opening toward the outer side in the radial direction is formed on the outer peripheral portion of the disk member 58.

The annular groove 61 is formed in the entire circumferential direction of the disk member 58. The cylindrical body 59 is fixed in a state of being fitted to the outer peripheral portion of the disc member 58. The cylindrical body 59 closes the opening portion of the annular groove 61. For this reason, an annular space 62 located on the same axis as the second balancer shaft 13 is formed in the outer peripheral portion of the rotating body 53.
A plurality of oil outlet passages 63 are formed in the cylindrical body 59. These oil outlet passages 63 are formed to be arranged at equal intervals in the circumferential direction. The rotating body 53 is located in the crank chamber 37. For this reason, the oil outlet passage 63 communicates the outer peripheral portion of the annular space 62 with the inside of the crank chamber 37.

  As shown in FIGS. 5 to 7, the disk member 58 includes a first axial hole 64 that passes through the disk member 58 in the axial direction, the first axial hole 64, and the annular space 62. Are formed with an inlet passage 66 including a first radial hole 65 communicating therewith, and a bolt hole 67 through which the mounting bolt 57 is passed. The inlet passage 66 is formed so as to extend from the inner peripheral portion of the annular space 62 toward the axial center side and to open in the crank chamber 37 at the tip. The bolt hole 67 is positioned on the same axis as the disk member 58.

The inlet passages 66 according to this embodiment are respectively formed at positions that divide the disc member 58 into four equal parts in the circumferential direction. Further, these four inlet passages 66 are positioned at positions shifted in the circumferential direction from the oil outlet passage 63 in the circumferential direction of the disc member 58.
The rotating body 53 is positioned in the crank chamber 37. The blow-by gas in the crank chamber 37 and the mist-like oil drifting in the crank chamber 37 enter the inlet passage 66 of the rotating body 53 from the opening of the first axial hole 64. For this reason, when the rotating body 53 rotates at a high speed, centrifugal force acts on the blow-by gas and mist-like oil in the inlet passage 66, and these substances move radially inside the first radial hole 65. Moving.

  The inertial mass of oil is larger than that of blowby gas. For this reason, the oil blown into the annular space 62 by the centrifugal force from the first radial hole 65 adheres to the radially outer wall (the inner surface of the cylindrical body 59) of the annular space 62, and what is blow-by gas? To be separated. The oil flows along the inner surface of the cylindrical body 59 and scatters around the rotating body 53 from the oil outlet passage 63.

As shown in FIG. 6, a cylinder 71 that protrudes on the opposite side of the second balancer shaft 13 is provided at the axial center of the disc member 58. The inside of the cylinder 71 has a second axial hole 72 extending toward the second balancer shaft 13 in the axial center portion of the disk member 58, and outward from the second axial hole 72 in the radial direction. And communicated with the annular space 62 through a plurality of second radial holes 73 extending radially. A space in the cylinder 71, the second axial hole 72, and the second radial hole 73 constitute a gas outlet passage 74 extending from the annular space 62 of the rotating body 53 to the axial center portion. Yes.
The gas-liquid separation unit 55 according to this embodiment includes the annular space 62, the inlet passage 66, the gas outlet passage 74, and the oil outlet passage 63.

  As shown in FIG. 2, the cylinder 71 is inserted into a cylindrical portion 75 of the chain cover 36. The cylindrical portion 75 is formed in a cylindrical shape that is located on the same axis as the second balancer shaft 13. A seal member 76 is provided between the cylindrical portion 75 and the cylinder 71. That is, the cylinder 71 is connected to the cylindrical portion 75 in a rotatable and airtight manner. A hole 77 that communicates the inside and the outside of the chain cover 36 is formed in a portion of the chain cover 36 that is located inside the cylindrical portion 75. In this embodiment, the hole 77, the cylindrical portion 75, and the seal member 76 constitute the “gas extraction portion formed on the wall of the crank chamber” in the present invention. In other words, this gas extraction portion is formed on the wall (chain cover 36) of the crank chamber 37 so that the gas outlet passage 74 is rotatably and airtightly connected, and blow-by gas is guided outside the crank chamber.

  A cup-shaped lid 81 is attached around the hole 77 on the outer surface of the chain cover 36 so as to be airtight. A blow-by gas chamber 82 is formed between the lid 81 and the chain cover 36. A reed valve 83 is attached to the outer surface of the chain cover 36 located inside the lid 81. The reed valve 83 closes when the pressure in the hole 77 is equal to or lower than the pressure in the blow-by gas chamber 82, and opens when the pressure in the hole 77 is higher than the pressure in the blow-by gas chamber 82. In this embodiment, the reed valve 83 constitutes a “check valve” according to the fifth aspect of the present invention.

  The blow-by gas chamber 82 is connected to an intake passage 48 a in the intake pipe 48 by a pipe 84 (see FIG. 4) attached to the lid 81. In this embodiment, the blow-by gas chamber 82 and the pipe 84 constitute a “communication passage that connects the gas extraction portion and the intake passage” in the present invention. Further, the blow-by gas passage portion 56 according to this embodiment includes the gas extraction portion constituted by the cylindrical portion 75 of the chain cover 36, the seal member 76 and the hole 77, the blow-by gas chamber 82 and the pipe 84. It is comprised by the communicating path which becomes.

  In the blowby gas reduction device 54 configured as described above, the negative pressure in the intake pipe 48 is propagated to the blowby gas chamber 82 through the pipe 84 during engine operation. When the pressure in the blow-by gas chamber 82 is lower than the pressure in the cylindrical portion 75, the reed valve 83 is opened, and the negative pressure flows from the blow-by gas chamber 82 into the cylindrical portion 75 and the gas outlet passage 74 of the rotating body 53. Then, it is propagated into the annular space 62.

  On the other hand, the rotating body 53 rotates at a high speed integrally with the second balancer shaft 13 at the same rotational speed as the crankshaft 11 during engine operation. As the rotating body 53 rotates at a high speed, blow-by gas and mist-like oil in the inlet passage 66 are blown into the annular space 62 by centrifugal force. The blow-by gas flows in the direction indicated by the white arrow in FIG. The oil flows in a direction indicated by an arrow indicated by a thick line in FIG. At this time, blow-by gas and mist-like oil in the crank chamber 37 are newly sucked into the first axial hole 64 of the inlet passage 66. The oil that is blown into the annular space 62 and attached to the inner peripheral surface of the cylindrical body 59 with the rotation of the rotating body 53 is discharged out of the rotating body 53 from the oil outlet passage 63 by centrifugal force.

  The blow-by gas separated from the oil in the annular space 62 is sent into the annular space 62 by centrifugal force and the pressure is increased, and the intake negative pressure is guided to the gas outlet passage 74 as described above. Together, the gas flows into the gas outlet passage 74 from the annular space 62. This blow-by gas flows in the gas outlet passage 74 inward in the radial direction of the rotating body 53, and from the rotating body 53 into the cylindrical portion 75 → the hole 77 → the reed valve 83 → the blow-by gas chamber 82 → the pipe 84. To the intake passage 48a on the upstream side of the throttle valve 47.

That is, the blow-by gas flows in the rotating body 53 toward the outside in the radial direction, then reverses in the annular space 62, and flows in the rotating body 53 toward the inside in the radial direction.
Therefore, according to this embodiment, the blow-by gas flows in the opposite direction with respect to the oil that goes to the outside in the radial direction of the rotating body 53 by centrifugal force, so that the mist-like oil is reliably separated from the blow-by gas. It is possible to provide a blow-by gas reduction device that can be made to operate.

  The gas-liquid separator 55 according to this embodiment is formed by a rotating body 53. An annular space 62, an inlet passage 66, a gas outlet passage 74, and an oil outlet passage 63 are formed in the rotating body 53. The annular space 62 is located on the same axis as the second balancer shaft 13. The inlet passage 66 extends from the inner peripheral portion of the annular space 62 toward the axial center and opens at the tip into the crank chamber 37. The gas outlet passage 74 extends from the annular space 62 of the rotating body 53 to the axial center portion. The oil outlet passage 63 communicates the outer periphery of the annular space 62 with the inside of the crank chamber 37.

  In addition, the blow-by gas passage portion 56 according to this embodiment is formed by a gas extraction portion (cylindrical portion 75, seal member 76, hole 77) and a communication passage (blow-by gas chamber 82, pipe 84). . The gas outlet is formed in the wall (chain cover 36) of the crank chamber 37 so that the gas outlet passage 74 is rotatably and airtightly connected, and blow-by gas is guided outside the crank chamber. The communication passage communicates the gas extraction portion and the intake passage 48a.

  Therefore, according to the blow-by gas reduction device 54 according to this embodiment, the blow-by gas and the oil are separated inside the rotating body 53, and only the blow-by gas is guided from the rotating body 53 to the intake passage 48a. Can do. Therefore, the blow-by gas reduction device 54 does not require a housing surrounding the rotating body as described in Patent Document 1, and can be formed compactly.

Further, according to the blow-by gas reduction device 54 according to this embodiment, the second balancer shaft 13 which is one of the components constituting the engine 1 serves as a driving source for the rotating body 53 (gas-liquid separation unit 55). The rotating body 53 can be rotated without newly providing a drive source for rotating the rotating body 53 exclusively.
For this reason, according to this embodiment, it is possible to provide a blow-by gas reduction device with a low manufacturing cost. Further, in this embodiment, since the second balancer shaft 13 rotates at the same speed as the crankshaft 11, the rotating body 53 (gas-liquid separator 55) rotates at a high speed, and oil is blown from blow-by gas. It is possible to separate them efficiently. In addition, since the rotating body 53 (gas-liquid separation portion 55) is provided on the second balancer shaft 13 arranged alongside the crankshaft 11 in the crank chamber 37 below the engine, this blow-by gas reduction device is provided. 54 can reduce the center of gravity of the engine 1.

  Since the gas-liquid separator 55 according to this embodiment is provided at one end of the balancer shaft, it can be mounted on the engine 1 without forming the crankshaft 11 longer. Therefore, according to this embodiment, it is possible to provide a blow-by gas reduction device that can be assembled to the engine 1 without hindering the downsizing of the engine 1.

  The gas-liquid separator 55 according to this embodiment is positioned at a position adjacent to the transmission device 35 that transmits the rotation of the crankshaft 11 to the camshaft. For this reason, according to this embodiment, the gas-liquid separation part 55 can be arrange | positioned using the dead space formed in the side of the said transmission apparatus 35 effectively. Therefore, according to this embodiment, it is possible to provide a blow-by gas reduction device that can be assembled to the engine 1 in a compact manner.

The second balancer shaft 13 is one balancer shaft of the two balancer shafts 12 and 13 provided in parallel to each other at a position below the engine 1 and sandwiching the crankshaft 11 from both sides. A cooling water pump 51 is provided at one end of the other first balancer shaft 12.
For this reason, the gas-liquid separation part 55 of the blow-by gas reduction device 54 and the cooling water pump 51 can balance the weight between one side and the other side of the crankshaft 11. Therefore, the blow-by gas reduction device 54 according to this embodiment can be assembled at a low position of the engine 1 and can balance the weight of the engine 1 in cooperation with the cooling water pump 51. The center of gravity of the engine 1 can be lowered so that the center of gravity is located at the center of the engine 1.

  The blow-by gas passage portion 56 according to this embodiment includes a reed valve 83 (a check valve) through which blow-by gas flows only to the intake passage side. For this reason, according to this embodiment, it is possible to provide a blow-by gas reduction device that can reliably maintain a negative pressure in the crank chamber 37 of the engine 1.

  DESCRIPTION OF SYMBOLS 1 ... Engine, 12 ... 1st balancer shaft, 13 ... 2nd balancer shaft, 11 ... Crankshaft, 23 ... Timing chain sprocket, 27 ... Timing chain, 31 ... Intake cam shaft, 32, 34 ... Drive side sprocket 33 ... Exhaust cam shaft, 35 ... Transmission device, 36 ... Chain cover, 37 ... Crank chamber, 48a ... Intake passage, 51 ... Cooling water pump, 53 ... Rotating body, 54 ... Blow-by gas reduction device, 55 ... Gas-liquid separation 56, blow-by gas passage, 58 ... disc member, 59 ... cylinder, 62 ... annular space, 66 ... inlet passage, 63 ... oil outlet passage, 74 ... gas outlet passage, 75 ... cylindrical portion, 76 ... Seal member, 77 ... hole, 82 ... blow-by gas chamber, 83 ... reed valve, 84 ... pipe.

Claims (4)

A gas-liquid separator that is provided at one end of a balancer shaft that rotates at the same speed as the crankshaft in the crank chamber at the bottom of the engine, and rotates the blow-by gas to separate the oil by centrifugal force;
A blow-by gas passage section that guides the blow-by gas from which oil has been removed by the gas-liquid separation section to an intake passage;
The gas-liquid separation part is formed by a rotating body,
The rotating body includes an annular space located on the same axis as the balancer shaft,
An inlet passage extending from the inner periphery of the annular space toward the axial center and having a tip opened into the crank chamber;
A gas outlet passage extending from the inner periphery of the annular space to the axial center;
An oil outlet passage communicating the outer periphery of the annular space and the crank chamber is formed;
The blow-by gas passage section includes a gas extraction portion formed on a wall of the crank chamber so that the gas outlet passage is rotatably and airtightly connected and the blow-by gas is guided outside the crank chamber;
A blow-by gas reduction device, characterized in that the blow-by gas reduction device is formed by a communication passage communicating the gas extraction portion and the intake passage.   2. The blow-by gas reduction device according to claim 1, wherein the gas-liquid separator is positioned at a position adjacent to a transmission device that transmits rotation of the crankshaft to the camshaft. 3. The blow-by gas reduction device according to claim 1, wherein the balancer shaft is one of two balancer shafts provided in parallel to each other at a position below the engine and sandwiching the crankshaft from both sides. Balancer shaft,
A blow-by gas reduction device, wherein a cooling water pump is provided at one end of the other balancer shaft.   4. The blow-by gas reduction device according to claim 1, wherein the blow-by gas passage portion includes a check valve in which blow-by gas flows only to the intake passage side. 5. Blow-by gas reduction device.

Images