JP2016003620A - engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine separating oil mist contained in blow-by gas in a breather chamber so as to be able to reduce the blow-by gas to intake air as an air-fuel mixture without providing a mist separator.SOLUTION: An engine in which blow-by gas generated in a crankcase is reduced to intake air via a breather chamber, is configured so that the breather chamber includes a meander channel formed therein by providing partition plates upright from a bottom surface and an upper surface of the breather chamber in a staggered fashion, and a tip end of the partition plate provided from the bottom surface of the breather chamber is bent toward a downstream side of the channel.

Description

  The present invention relates to an engine.

  Conventionally, blow-by gas generated in the crankcase has removed oil mist contained in blow-by gas in a mist separator provided outside the engine via a breather chamber provided in a cylinder head cover that covers the top of the cylinder head. After that, the intake air is reduced.

JP 2013-79621 A

Mountability deteriorated because the mist separator was provided outside the engine.
Therefore, the present invention provides an engine that separates oil mist contained in blow-by gas in a breather chamber so that the intake-air reduction can be performed using the blow-by gas as an air-fuel mixture without providing a mist separator.

  The present invention is an engine in which blow-by gas generated in a crankcase is intake-reduced through a breather chamber, and the breather chamber has partition plates erected alternately from the bottom surface and the top surface thereof. A serpentine flow path is formed, and the tip of the partition plate provided from the bottom surface of the breather chamber is curved toward the downstream side of the flow path.

  The flow path cross-sectional area of the conversion part in which the flow direction of the blow-by gas in the flow path changes is configured to be smaller than the cross-sectional area of the flow path located on the upstream side of the conversion part.

  A dividing plate that divides the flow path along the flow direction of the blow-by gas is provided on the upstream side surface of the partition plate provided upright from the bottom surface of the breather chamber.

  The upstream side surface of the partition plate erected from the upper surface of the breather chamber includes a receiving portion that receives oil adhering to the partition plate, and the received oil is provided on the bottom surface of the breather chamber. A guide plate is provided to guide the hole.

  According to the present invention, the mist separator is not necessary, so that the engine can be made compact.

It is a perspective view of an engine. It is a fragmentary sectional view of a head cover. It is a fragmentary sectional view showing the inside of a breather room. It is a fragmentary sectional view showing the inside of a breather room. It is a figure which shows the flow direction of the oil mist which flows across the partition plate standingly arranged from the bottom face of a breather chamber. It is sectional drawing in the 1st path | route of a breather chamber. It is a figure which shows another embodiment of the 1st path | route of a breather chamber. It is a figure which shows another embodiment of the 1st path | route of a breather chamber.

The engine 1 according to the present invention will be described with reference to FIGS. 1 to 3.
The engine 1 has a cylinder block 11 at the top of the main body and a crankcase 12 at the bottom.
The upper part of the cylinder block 11 is covered with a cylinder head 13. The upper portion of the cylinder head 13 is covered with a head cover 21 that protects the inside of the cylinder head 13 and prevents the lubricating oil from flowing out. The head cover 21 includes a breather chamber 22 and a valve arm chamber 23 by being partitioned by a bottom plate and a side plate.

  The breather chamber 22 communicates with the atmosphere outside the machine so that the pressure in the crankcase 12 and the valve arm chamber 23 does not increase or decrease. In this embodiment, the blower gas is not discharged outside the machine. The intake manifold 34 communicates with the joint 33.

  The blow-by gas refers to an air-fuel mixture blown out from a combustion chamber (not shown) composed of a piston (not shown), a cylinder (not shown), and a cylinder head 13 to the crankcase 12 side. The blow-by gas contains lubricating oil in the crankcase 12 as oil mist. The blow-by gas rises to the cylinder head 13 via the cylinder block 11. Then, the cylinder head 13 rises to the head cover 21 and flows into the breather chamber 22 through the valve arm chamber 23.

  In the breather chamber 22, oil mist contained in the blow-by gas is separated, and the blow-by gas is reduced to the intake manifold 34 as an unburned air-fuel mixture and burned in the combustion chamber.

As shown in FIG. 2, the breather chamber 22 is configured as a substantially rectangular parallelepiped space in the head cover 21 by a baffle plate 31 that divides the inside of the head cover 21 up and down and a partition wall 32 that divides in the front and rear. Specifically, the inside of the head cover 21 is constituted by a partition wall 32 provided downward from the front-rear direction midway portion on the upper surface of the breather chamber 21 and a baffle plate 31 provided to connect the lower end of the partition wall 32 and the rear surface of the head cover 21. A breather chamber 21 is formed above the rear part.
In the present embodiment, the partition wall 32 is formed integrally with the head cover 21.
As shown in FIGS. 3 and 4, an opening 31 a communicating with the valve arm chamber 23 is provided at the left end of the baffle plate 31 that forms the bottom surface of the breather chamber 22, and blow-by gas is provided in the opening 31 a. Flows into the breather chamber 22.
The blow-by gas flowing into the breather chamber 22 is reduced to the intake manifold 34 via a joint 33 provided at the right end of the breather chamber 22.

As shown in FIGS. 3 and 4, the breather chamber 22 has a meandering channel formed by alternately arranging partition plates 41 a and partition plates 41 b from the bottom and top surfaces thereof.
The partition plate 41a disposed upward from the bottom surface of the breather chamber 22 and the partition plate 41b disposed downward from the top surface of the breather chamber 22 are alternately disposed, whereby a meandering flow path is formed. It is formed.

First, by arranging the partition plate 41a upward from the bottom surface on the opening 31a side in the breather chamber 22, a path (first path 51) through which blow-by gas flows upward from the opening 31a is formed. .
Next, the partition plate 41b is disposed on the right side of the partition plate 41a from the upper surface of the breather chamber 22 downward, so that the blow-by gas flows downward (second route 52) across the partition plate 41a. ) Is formed.
That is, by arranging the partition plate 41a and the partition plate 41b in order, the blow-by gas flows in the flow direction from above to below through the switching portion 53a that connects the end of the first path 51 and the start of the second path 52. Switch.
Then, the partition plate 41a is disposed on the right side of the partition plate 41b upward from the bottom surface of the breather chamber 22, so that the blow-by gas flows upward across the partition plate 41b (first route 51). Is formed.
That is, by arranging the partition plate 41b and the partition plate 41a in order, the blow-by gas flows in the flow direction from below to above through the switching portion 53b that connects the end of the second path 52 and the start of the first path 51. Switch.

In this way, by arranging the partition plates 41a and the partition plates 41b alternately from the opening 31a of the breather chamber 22 toward the joint 33, blow-by gas alternately flows through the first path 51 and the second path 52. A path is formed.
In the present embodiment, the breather chamber 22 is configured by arranging the partition plates 41a and the partition plates 41b alternately two by two.

In this embodiment, the partition plate 41a and the partition plate 41b are integrally molded. A substantially rectangular plate has a substantially U-shape by bending twice so that one end and the other end in the longitudinal direction face each other, and one end in the longitudinal direction serves as a partition plate 41a. The other end in the longitudinal direction is configured as a partition plate 41b. A central portion in the longitudinal direction connecting the partition plate 41 a and the partition plate 41 b is fixed to the bottom surface (baffle plate 31) of the breather chamber 22. The upper end of the partition plate 41 b is fixed to the upper surface of the breather chamber 22. The partition plate 41a is set to a predetermined height so that blow-by gas flows above the tip (the upper surface side of the breather chamber 22). The partition plate 41b is provided with a flow hole 42 at the bottom so that blow-by gas flows with the length of the upper surface from the bottom surface of the breather chamber 22 being the height.
In addition, you may form the partition plate 41a and the partition plate 41b separately, respectively.

The meandering path refers to a path whose direction is changed at least once from the first path 51 to the second path 52 via the switching portion 53a.
That is, the partition plate 41a and the partition plate 41b are arranged in order from the opening 31a side to form a meandering path.

As shown in FIGS. 3, 4, and 5, the partition plate 41 a is curved with the tip (one end on the upper surface side of the breather chamber 22) facing the downstream side of the flow path.
As shown in FIG. 5, the blow-by gas flows smoothly along the curved portion of the partition plate 41a in the conversion portion 53a, so that the blow-by gas is smoothly guided to the downstream side without decreasing the flow velocity. Moreover, since the flow of blow-by gas is not disturbed, the flow rate of blow-by gas can be increased. As the flow rate of blow-by gas increases, the centrifugal force of the oil mist generated when passing through the conversion part 53a increases. Due to the increased centrifugal force, the oil mist is moved outward in the conversion portion 53a and collides with the upper surface on the upstream side of the partition plate 41b, so that more oil mist is liquefied and becomes oil in the partition plate 41b. Adhere to.
Thus, by providing a curved portion at the tip of the partition plate 41a, more oil mist contained in the blow-by gas can be separated.

As described above, the engine 1 can perform intake air reduction using the blowby gas as an air-fuel mixture by separating more oil mist contained in the blowby gas in the breather chamber 22. Therefore, it is not necessary to mount a mist separator on the outside of the engine 1 and the mountability is improved.
In addition, the above structure can also be applied to the partition plate 41b.

As shown in FIGS. 3 and 4, the inner wall of the breather chamber 22 that forms the upstream flow path in the switching portion 53a is the inner wall so that the blow-by gas flowing from the opening portion 31a smoothly flows to the downstream side of the switching portion 53a. It is formed in a curved shape from the side surface (left surface) to the upper surface of the inner wall.
By forming the upstream flow path in the conversion part 53a in a curved shape, the blowby gas can be smoothly guided toward the downstream flow path of the conversion part 53a without reducing the flow velocity. Therefore, more oil mist can be separated from the blow-by gas by centrifugal force in the downstream channel and collide with the upstream side surface of the partition plate 41b.

  In addition, in this embodiment, although the upstream flow path of the conversion part 53a provided above the opening part 31a is formed in the curved shape, the flow path of the conversion part 53a provided in the joint 33 side is comprised similarly. By forming the partition plate 41b to be curved, the upstream flow path of the conversion part 53a provided on the joint side 33 can be curved.

As shown in FIG. 6, the flow path cross-sectional area of the conversion part 53a where the flow direction of the blow-by gas is changed from the upper side to the lower side is configured to be smaller than the cross-sectional area of the flow path located on the upstream side of the conversion part 53a. Is done.
The flow path located on the upstream side of the conversion portion 53a refers to the first path 51 located on the upstream side with the partition plate 41a interposed therebetween.

  The flow path cross-sectional area of the conversion part 53a in which the flow direction of the blow-by gas changes from the upper side to the lower part refers to the area of a substantially vertical plane with respect to the flow direction of the blow-by gas in the conversion part 53a. The cross-sectional area of the first path 51 located on the upstream side of the conversion part 53a is a substantially vertical plane with respect to the flow direction of blow-by gas in the first path 51 located on the upstream side across the partition plate 41a constituting the conversion part 53a. Refers to the area.

In the present embodiment, an inclined surface 61 a that is inclined rearward is provided on the upper portion of the front surface (partition wall 32) of the breather chamber 22. Similarly, an inclined surface 61b that is inclined forward is provided on the upper portion of the rear surface of the breather chamber 22 (the surface facing the partition wall 32).
That is, the flow path cross-sectional area in the conversion part 53a is made small by inclining the partition 32 which forms the conversion part 53a, and the surface facing the partition 32 mutually toward the center in the front-back direction of the breather chamber 22.

By reducing the cross-sectional area of the flow path, the blow-by gas flowing into the conversion part 53a collides with the inclined surfaces 61a and 61b to promote liquefaction of the oil mist, and the oil mist collects on the upper surface of the flow path in the conversion part 53a. Oil mist lump tends to be large.
Moreover, the flow velocity of blow-by gas can be increased by narrowing the cross-sectional area of the flow path from the first path 51 to the conversion part 53a.

In the conversion part 53a, more oil mist can be centrifuged from blow-by gas by the centrifugal force which increases as the flow rate increases.
Further, since the oil mist having a large lump is affected by centrifugal force and liquefaction is easily promoted, more oil mist is separated from the blow-by gas at the conversion part 53a and collides with the partition plate 41b and adheres as oil. To do.

  Thus, the oil mist contained in more blow-by gas is made by making the cross-sectional area of the conversion part 53a in which the flow direction of blow-by gas changes is smaller than the cross-sectional area of the flow path located on the upstream side of the conversion part 53a. Can be separated.

As described above, the engine 1 can perform intake air reduction using the blowby gas as an air-fuel mixture by separating more oil mist contained in the blowby gas in the breather chamber 22. Therefore, it is not necessary to mount a mist separator on the outside of the engine 1 and the mountability is improved.
In addition, the above structure is also applicable to the conversion part 53b in which the flow direction of blow-by gas changes from the downward direction to the upward direction.

As shown in FIGS. 3 and 4, the partition plate 41 b disposed from the upper surface of the breather chamber 22 includes a receiving portion 71 that receives oil attached to the upper portion thereof.
The receiving portion 71 has a shape extending upward while curving from a midway portion on the upstream side surface of the partition plate 41b. A guide plate 73 that guides the received oil to a return hole 72 provided in the baffle plate 31 of the breather chamber 22 is provided at one end of the connection portion of the partition plate 41 b in the receiving portion 71.
The upstream side surface of the partition plate 41b refers to a surface constituting the first path 51 in the partition plate 41b.

The return hole 72 is provided in the baffle plate 31 that forms the bottom surface of the breather chamber 22, and communicates the breather chamber 22 with the valve arm chamber 23.
The guide plate 73 has a shape obtained by curving a substantially rectangular plate into a curved surface so that the upper surface cross-section is about a quarter of a perfect circle. One end of the guide plate 73 is fixed to the receiving portion 71 and the other end is fixed to the baffle plate 31.
In addition, it is preferable that the receiving portion 71 is provided with a slightly inclined connection portion of the partition plate 41b in the receiving portion 71 so that the received oil flows to the guide plate 73 side.

In the conversion portion 53a, the receiving portion 71 receives the oil adhering to the upper portion of the partition plate 41b, and the oil is guided to the return hole 72 through the guide plate 73. The oil is guided to the valve arm chamber 23 through the return hole 72. The oil guided to the valve arm chamber 23 is reused as lubricating oil in the crankcase 12 or the like.
As described above, the consumption efficiency of the oil mist captured in the breather chamber 22 is increased, so that consumption of the lubricating oil can be suppressed.

  As shown in FIG. 7, on the upstream side surface of the partition plate 41a provided from the bottom surface of the breather chamber 22, a plurality of division plates 81 that divide the flow path (first path 51) that flows upward are arranged side by side.

  As shown in FIG. 7A, two partition plates 81, which are substantially rectangular plates, are arranged side by side on the partition plate 41a so that the flow path of the blow-by gas in the first path 51 can be divided into three. .

  By dividing the flow path of the first path 51 into three parts, disturbance in the flow direction of the blow-by gas can be adjusted. By determining the directionality of the blow-by gas, the oil mist contained in the blow-by gas is collided with each other in the conversion part 53a to increase the mass and promote liquefaction.

As shown in FIG. 7B, a plurality of dividing plates 81 are arranged side by side on the partition plate 41a so that the flow path of the blow-by gas in the first path 51 can be divided into a large number.
By dividing the flow path of the first path 51 into a large number, the directionality of the blow-by gas can be further determined, and the oil mist contained in the blow-by gas can be collided with the conversion part 53a to increase the mass and promote liquefaction. .
Moreover, when blow-by gas flows through the first path 51 where the dividing plate 81 is provided, oil mists included in the blow-by gas collide with each other, leading to promotion of liquefaction and a lump of oil mist tends to increase. Therefore, the oil mist contained in more blow-by gas can be isolate | separated in the conversion part 53a.

  As shown in FIG. 8, the blow-by gas flow path in the first path 51 is divided, and the substantially U-shaped plate 82 connecting the same ends of the two divided plates 81 is narrowed so as to narrow the flow path. It is provided at the center of the partition plate 41a so that the end is disposed on the bottom side of the breather chamber 22.

  By disposing the substantially U-shaped plate 82, the flow path of blow-by gas is divided into two. By disposing the same end connecting the two divided plates 81 on the bottom surface side of the breather chamber 22, the flow path in the first path 51 is narrowed. By narrowing the channel, it is possible to increase the momentum at which the oil mist collides with the inclined surfaces 61a and 61b and the partition plate 41b by increasing the flow velocity. Therefore, the oil mist contained in more blow-by gas can be isolate | separated in the conversion part 53a.

  1: engine, 13: cylinder head, 21: head cover, 22: breather chamber, 23: valve arm chamber, 31: baffle plate, 31a: opening, 33: joint, 34: intake manifold, 41a: partition plate, 41b: Partition plate, 51: first path, 52: second path, 53a: conversion part, 53b: conversion part, 61a: inclined surface, 61b: inclined surface, 71: receiving part, 72: return hole, 73: guide plate, 81: division plate, 82: substantially U-shaped plate

Claims (4)

An engine in which blow-by gas generated in the crankcase is reduced by intake through a breather chamber,
The breather chamber has a serpentine flow path formed by alternately arranging partition plates from the bottom surface and the top surface,
The engine, wherein a tip of the partition plate provided from a bottom surface of the breather chamber is curved toward a downstream side of the flow path.   The flow path cross-sectional area of the conversion part where the flow direction of the blowby gas in the flow path changes is configured to be smaller than the cross-sectional area of the flow path located on the upstream side of the conversion part. engine.   The engine according to claim 1 or 2, wherein a dividing plate that divides the flow path along the flow direction of the blow-by gas is provided on an upstream side surface of the partition plate provided upright from a bottom surface of the breather chamber. The upstream side surface of the partition plate erected from the upper surface of the breather chamber includes a receiving portion that receives oil attached to the partition plate,
The engine according to any one of claims 1 to 3, wherein the receiving portion is provided with a guide plate that guides the received oil to a return hole provided in a bottom surface of the breather chamber.

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