JP2005220883A - Upper body structure of engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problems that external piping is required, configuration is complicated and the number of assembling processes is increased, to send blow-by gas to an intake manifold, since a rocker arm chamber and the intake manifold are constituted separately in an engine. <P>SOLUTION: A rocker arm case 7 and the intake manifold 12 mounted to a cylinder head 4 are constituted by an upper body case 13 integrally forming the rocker arm case 7 and the intake manifold 12. A breather chamber 10 is formed in an upper part of the rocker arm case 7, and a return passage 17 connecting the inside of the breather chamber 10 and the inside of the intake manifold 12 to communicating with each other is formed in the upper body case 13. A throttle is formed in the intake manifold side of the return passage 17. In addition, a rectifying plate 20 is provided in a position opposing to an outlet hole 17a of the return passage 17 inside the intake manifold 12. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a technique for forming an upper body of an engine compactly by integrally forming a valve arm case and an intake manifold attached to an upper portion of an engine cylinder head, eliminating an external pipe for returning blow-by gas to the intake manifold.

  Conventionally, an intake valve, an exhaust valve, a valve arm, a fuel injection nozzle, and the like are arranged at the upper part of a cylinder head of a diesel engine, and these are covered with a valve arm case, and a breather chamber is provided in or near the valve arm case. It is well known that a blow-by gas including oil mist generated in a crankcase or the like is guided to a breather chamber to be separated into a gas component and an oil component, and the gas component is returned to the intake manifold.

In order to return this gas component to the intake manifold, an external pipe is provided and communicated between the breather chamber formed in the valve arm chamber and the intake manifold. (For example, refer to Patent Document 1).

JP 2003-90206 A

In such an engine, since the valve arm chamber and the intake manifold are configured separately, in order to send gas components to the intake manifold, it is necessary to communicate external piping between them. A joint portion for connecting external piping to the intake manifold had to be formed, and the shape was complicated. For this reason, the number of parts is large and the number of assembling steps is increased.
Therefore, the present invention is configured such that the valve arm chamber and the intake manifold are integrally configured to reduce the number of assembling steps and reduce the cost.

  The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.

  That is, in the first aspect, the valve arm case and the intake manifold attached to the cylinder head are constituted by an upper body case in which the valve arm case and the intake manifold are integrally formed.

  According to a second aspect of the present invention, a breather chamber is formed in an upper portion of the valve arm case, and a return passage communicating the breather chamber and the intake manifold is formed in the upper body case.

  According to a third aspect of the present invention, a breather chamber is formed in an upper portion of the valve arm case, an intake manifold is disposed on a side portion of the breather chamber, and a return passage communicating the breather chamber and the intake manifold is provided from the upper surface of the breather chamber. Opening toward the intake manifold side wall.

  According to a fourth aspect of the present invention, a throttle is formed on the intake manifold side of the return passage.

  According to a fifth aspect of the present invention, in a valve arm case and an intake manifold attached to a cylinder head having a plurality of cylinders, the valve arm case and the intake manifold are integrally formed as an upper body case, and a breather is provided above the valve arm case. The chamber and the intake manifold are communicated with each other by a return passage, and an outlet hole of the return passage is opened on a side wall opposite to the inlet of the intake manifold.

  According to a sixth aspect of the present invention, a rectifying plate is provided at a position facing the outlet hole of the return passage in the intake manifold.

  According to a seventh aspect of the present invention, the rectifying plate is integrally formed on the inner wall of the intake manifold.

As effects of the present invention, the following effects can be obtained.
By configuring as in claim 1, the valve arm case and the intake manifold are integrally formed, the number of parts can be reduced, and the number of assembling steps can be reduced. Therefore, the cost can be reduced.

  By configuring as in claim 2, it is possible to omit the external piping that communicates the breather chamber and the intake manifold, it is possible to eliminate joints and the like for connecting the external piping, reduce the number of parts, The assembly man-hours were reduced and the cost could be reduced. In addition, the passage connecting the breather chamber and the intake manifold can be shortened, the configuration can be simplified, clogging is unlikely to occur, maintenance can be performed easily, and reliability can be improved.

  According to the third aspect of the present invention, the breather return passage can be formed by a single straight hole, and the structure is simple, and can be easily formed by die cutting or drilling.

  According to the fourth aspect of the present invention, the throttle serves as a nozzle for discharging blow-by gas, mist can be atomized and ejected into the intake manifold, and easily mixed with air. Further, the aperture can be easily formed by hole processing (such as a die or a drill).

  When the valve arm case and the intake manifold are configured separately as in the prior art, the return pipe is attached to the side wall opposite to the intake port of the intake manifold. Since the valve arm case and the intake manifold are integrally formed and the external piping can be eliminated, the return passage outlet can be arranged at an optimal position on the opposite side of the intake port to the intake manifold. And since an exit hole is located in the middle part of the air current which is sucked into the intake manifold and exits, air and blow-by gas are easily mixed and can be distributed substantially evenly to each cylinder.

  By configuring as in claim 6, it is possible to promote the return gas entering the intake manifold hitting the rectifying plate and atomizing the mist. Then, the air sucked by the rectifying plate is increased in flow velocity, promotes mixing, and can be distributed to each cylinder substantially evenly.

  By configuring as in the seventh aspect, the current plate can be formed at the same time when the upper body case is formed, so that post-processing and mounting are not required, and it can be easily configured. And since a baffle plate can be easily comprised with a type | mold, it can be formed in low cost.

Next, embodiments of the invention will be described.
1 is a front sectional view of the upper part of the engine, FIG. 2 is a plan view of the upper body case, FIG. 3 is a sectional view taken along line AA in FIG. 2, FIG. 4 is a sectional view taken along line BB in FIG. FIG. 6 is a cross-sectional view taken along the line CC in FIG. 5.

First, the whole structure of the diesel engine which has the upper body of this invention is demonstrated using FIG. In addition, although a 3 cylinder diesel engine is demonstrated in a present Example, the number of cylinders is not limited.
In the engine 1, a cylinder is formed on an upper part of a cylinder block 2 to accommodate a piston 3, and a cylinder head 4 is placed and fixed on the upper part of the cylinder block 2. The cylinder head 4 is provided with an intake valve 5, an exhaust valve, a fuel injection nozzle 6, and the like.

  A valve arm chamber 8 is formed in the upper part of the cylinder head 4, and in the valve arm chamber, the valve arm 9 and the like which are in contact with the upper ends of the intake valve 5, the exhaust valve and the push rod 14 are arranged. It is stored in the arm case 7.

  A breather chamber 10 is formed in the upper part of the valve arm case 7, and an oil trap material for catching oil mist is arranged in the breather chamber 10 and is stored in a booter case 11. A wall projects from the inner surface of the breather case 11 toward the gas passage to form a labyrinth-like passage so that an oil component (oil mist) can be easily captured. The breather case 11 is fixed on the valve arm case 7. The breather chamber 10 can also be configured in the valve arm chamber 8, and the breather case 11 and the valve arm case 7 can be configured integrally.

An intake manifold 12 is disposed on the side of the valve arm case 7. One end of the intake manifold 12 communicates with the intake port of the intake valve 5, and the other end communicates with an air cleaner.
In this embodiment, the valve arm case 7 and the intake manifold 12 are integrally formed as an upper body case 13.

Next, the structure of the upper body case 13 will be described in detail with reference to FIGS.
The upper body case 13 is integrally formed of aluminum die casting or the like, forms a space opened upward and downward so as to pass through the mold in the vertical direction, forms a side wall around the valve body case, and a valve arm case at the center of the left and right A partition wall 14 is formed to separate the intake manifold 12 and the intake manifold 12. In this embodiment, in FIG. 3, the valve arm case 7 is arranged on the right side, the intake manifold 12 is arranged on the left side, and a plurality (three in this embodiment) of cylinders are arranged in the vertical direction in the front-rear direction. It is said.

  The valve arm case 7 is opened downward to form a space for accommodating the valve arm and the like, and bolt holes 7a, 7a... For fixing the cylinder arm 4 on the outer periphery of the valve arm case 7 are opened. Yes. Then, a passage 15 communicating with the breather chamber 10 is formed in the upper part of the valve arm chamber on the front and rear side (the rear side in the present embodiment). To communicate with.

  The opening formed in the upper surface of the valve arm case 7 is disposed in the mounting portion 16 of the breather case 11, and the lower surface of the breather case 11 is mounted on the mounting portion 16 and fixed with a bolt or the like. A seal is disposed on the mating surface with the breather case 11 around the mounting portion 16 so that the mounting portion 16 can be fixed tightly so that no leakage occurs. In the breather case 11, a trap material made of a wire mesh or the like that catches an oil component is stored.

  One end, that is, the upper end of the breather return passage 17 is opened at the center of the mounting portion 16, and the other end of the breather return passage 17 is opened in the side wall of the intake manifold 12. That is, the breather return passage 17 increases the thickness of a part of the partition wall 14 that separates the valve arm chamber 8 and the intake manifold 12 in the upper body case 13, so that the lower side wall of the intake manifold 12 extends from the upper left and right center of the valve arm chamber 8. The center line of the breather return passage 17 opens in the direction perpendicular to the line connecting the center lines of the cylinders (cylinders) in the plan view. The opening area of the outlet hole 17a on the intake manifold 12 side in the breather return passage 17 is made smaller than the cross-sectional area of the other passages to form a throttle, and the tip portion is configured in a tapered nozzle shape. ing. In the present embodiment, the breather return passage 17 is simultaneously formed by a mold when the upper body case 13 is formed. However, the breather return passage 17 may be formed by drilling using a tool such as a drill.

  The intake manifold 12 is formed with an air passage in the front-rear direction at the top, the upper part is opened, and the opening is closed by a lid (not shown). A suction port 12 a for communicating with an air cleaner is opened on the rear side surface of the intake manifold 12. However, the suction port 12a can also be provided on the upper surface. In addition, intake ports 12 b, 12 c, and 12 d are opened on the lower surface of the intake manifold 12 in accordance with the position of the introduction portion to the intake valve 5 disposed in the cylinder head 4. Thus, the air purified by the air cleaner enters the intake manifold 12 from the intake port 12a, is distributed by the intake manifold 12, and is sent to the intake valves 5, 5, 5 from the intake ports 12b, 12c, 12d.

  An outlet hole 17a serving as an outlet of the breather return passage 17 is opened on the side wall opposite to the suction port 12a between the first suction port 12b and the second suction port 12c on the side close to the suction port 12a. ing. The front / rear and top / bottom positions of the outlet hole 17a are set to positions where blow-by gas discharged from the outlet hole 17a is most easily mixed with the airflow flowing from the inlet 12a to the inlets 12b, 12c, and 12d. In order to open the straight breather return passage 17 toward the side wall (partition wall 14) between the first air inlet 12b and the second air inlet 12c, the breather chamber 10 has a first air inlet. At the upper side position between 12b and the second air inlet 12c, the valve arm case 7 is disposed above.

  Accordingly, when the engine is operating, the intake valves 5, 5, and 5 are sequentially opened and closed at predetermined intervals, so that air from the air cleaner enters the intake manifold 12 through the intake port 12a, and the intake ports 12b, 12c, and so on. 12d are sent in order. At this time, since the outlet hole 17a is located in the middle between the inlet 12a and the inlets 12b, 12c, and 12d, the blow-by gas discharged from the outlet 17a is finely divided by the nozzle even if it contains mist. Furthermore, blow-by gas is easily discharged and mixed while air is flowing, and can be distributed almost evenly to each cylinder. The mixed gas is sucked into the combustion chamber and burned. become.

Further, the mist discharged from the outlet hole 17a of the breather return passage 17 of the intake manifold 12 can be further atomized to prepare the mixed airflow.
That is, as shown in FIGS. 5 and 6, the rectifying plate 20 is placed at a position facing the outlet hole 17 a of the breather return passage 17 provided on the side wall (partition wall 14) on the valve arm case 7 side in the intake manifold 12. Provided.

  The rectifying plate 20 is formed in a crescent shape in a plan view, and is arranged so that the outlet hole 17a is located at the approximate center of the rectifying plate 20 in a side view, so that the convex curved surface side of the rectifying plate 20 faces the outlet hole 17a. Is arranged. In plan view, one end of the rectifying plate 20 extends toward the suction port 12a, the other end extends toward the second suction port, and a position perpendicular to the tangent to the convex curved surface of the central recess. Are arranged so that the center line of the breather return passage 17 is located.

  The rectifying plate 20 is erected from the inner wall on the bottom side of the intake manifold 12 and is formed integrally with the upper body case 13 so that it can be easily manufactured. However, the current plate 20 may be configured separately from the upper body case 13 and fixed to the bottom surface by welding, bolts, or the like. Moreover, it is also possible to hang down from the lower surface of the lid that closes the upper opening of the intake manifold 12, and it may be configured integrally with the lid or separately.

  Thus, the blow-by gas discharged from the outlet hole 17a of the breather return passage 17 is atomized by the nozzle portion, and immediately after coming out of the outlet hole 17a, it hits the rectifying plate 20 disposed facing the outlet hole 17a. As a result, it becomes possible to further atomize, and it becomes easy to mix with air so that it can be combusted in the combustion chamber. The flow of air from the suction port 12a toward the suction ports 12b, 12c, and 12d is adjusted by the rectifying plate 20, the flow velocity flowing through the convex curved surface is increased, and the mixing of air and atomized mist is further promoted. It is done.

Front sectional view of the upper part of the engine. The top view of an upper body case. AA sectional drawing in FIG. BB sectional drawing in FIG. The top view which provided the baffle plate in the intake manifold of the upper body case. CC sectional drawing in FIG.

Explanation of symbols

4 Cylinder head 7 Valve arm case 12 Intake manifold 13 Upper body case 10 Breather chamber 17 Breather return passage 17a Outlet hole 20 Current plate 20

Claims (7)

  An engine upper body structure comprising a valve arm case and an intake manifold attached to a cylinder head, wherein the valve arm case and the intake manifold are integrally formed.   The engine upper body structure according to claim 1, wherein a breather chamber is formed in an upper portion of the valve arm case, and a return passage communicating the breather chamber and the intake manifold is formed in the upper body case. .   A breather chamber is formed in the upper part of the valve arm case, an intake manifold is disposed on a side of the breather chamber, and a return passage communicating the breather chamber and the intake manifold is formed from the upper surface of the breather chamber toward the intake manifold side wall. The upper body structure of the engine according to claim 1, wherein the upper body structure is opened.   The upper body structure of an engine according to claim 3, wherein a throttle is formed on the intake manifold side of the return passage.   In the valve arm case and the intake manifold attached to the cylinder head having a plurality of cylinders, the valve arm case and the intake manifold are integrally formed as an upper body case, and the breather chamber and the intake manifold provided at the upper part of the valve arm case are returned. An upper body structure of an engine, characterized in that it is communicated by a passage and an outlet hole of the return passage is opened on a side wall opposite to an inlet of an intake manifold.   6. The engine upper body structure according to claim 5, wherein a rectifying plate is provided at a position facing the outlet hole of the return passage in the intake manifold. The engine upper body structure according to claim 6, wherein the rectifying plate is formed integrally with an inner wall of the intake manifold.

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