JP5416534B2 - Exhaust gas recirculation device for internal combustion engine - Google Patents

Description

The present invention, in an internal combustion engine, to an apparatus which Ru is recirculated to the intake system part of the exhaust gas.

  In recent internal combustion engines, a part of the exhaust gas recirculation path from the exhaust system to the intake system is formed inside the cylinder head so as to extend in a direction crossing the cylinder head from the intake side toward the exhaust side. That is running.

In this case, the exhaust gas recirculation path is provided with a recirculation control valve that controls the recirculation amount of the exhaust gas to the intake system in accordance with the operating range of the internal combustion engine.

Therefore, Patent Document 1 as a prior art, the upper surface to the opening and closing valve body portion of the recirculation control valve of the valve housing recess formed by the previous SL cylinder head is inserted into the valve housing, in said valve housing, said cylinder proposes the upstream return passage from the exhaust system of the exhaust gas recirculation passage formed inside the head, to the structure of Ru is communicatively opening both the downstream recirculation passage to the intake system side .

JP 2002-242767 A

However, according to this prior art, the recirculation control valve, by which is mounted so as to output collision on the upper surface of the cylinder head, high overall height of the minute's only the inner combustion engine of the recirculation control valve There is a problem of becoming.

  In addition, in the exhaust gas recirculation path formed inside the cylinder head, condensed water with high acidity due to moisture in the exhaust gas is generated when the operation of the internal combustion engine is stopped. A large amount of water is generated mainly in the downstream recirculation passage to the intake system side in the exhaust gas recirculation path.

Then, the prior art, the valve housing for accommodating the on-off valve body portion of the recirculation control valve, by the a configuration in which recessed formed in the upper surface of the cylinder head, inside the valve housing, the operation of the internal combustion engine When the engine is stopped, condensed water with high acidity due to moisture in the exhaust gas accumulates, and this condensed water adheres to the on-off valve body portion inserted into the valve housing. the when startup, not only cause serious trouble in opening and closing control and flow rate control by the return control valve, durability opened closing body corrodes is lowered.

  The present invention has a technical problem to solve these problems.

In order to achieve this technical problem, claim 1
“ Upstream side of a cylinder head having one long side surface with an exhaust port open and one short side surface perpendicular thereto, sandwiching a reflux control valve attached to one short side surface of the cylinder head In an internal combustion engine that forms an exhaust gas recirculation passage divided into a recirculation passage and a downstream recirculation passage ,
The upstream recirculation passage has a communicating portion extending along one short side surface of the cylinder head, while the downstream recirculation passage extends along one short side surface of the cylinder head. And its starting end is located below the communicating part of the upstream reflux passage,
Further, on one short side surface of the cylinder head, a valve housing that communicates with the end of the communication portion in the upstream recirculation passage and the start end of the downstream recirculation passage is connected to the communication portion and the downstream of the upstream recirculation passage. The open / close valve body portion of the return control valve is located in the valve housing, and the start end portion of the downstream return passage is positioned below the open / close valve body portion. So that it is inserted . "
It is characterized by that.

Claim 2
In the description "of claim 1, a portion having a shorter side of said one of said cylinder head, a cylinder block in which the cylinder head is fastened has an overhang laterally in this overhang portion , the valve housing, the communicating portion of the cylinder head of the upstream return passage is provided with 及 beauty the downstream return passage. "
It is characterized by that.

  According to the first aspect, the exhaust gas flowing in the exhaust gas recirculation passage formed inside the cylinder head from the exhaust system side to the intake system side is appropriately controlled to open and close and the flow rate is controlled by the recirculation control valve.

In this case, the recirculation control valve, by which is attached to the side surface of the cylinder head can be avoided that the overall height increases by the amount of the recirculation control valve in an internal combustion engine.

On the other hand, the condensed water generated in the valve housing for accommodating the closing valve body portion of the recirculation control valve, sequentially discharged on the lower stream side recirculation passage you located lower site than the on-off valve body portion Therefore, it is possible to prevent the condensed water from adhering to the opening / closing valve body, so that the accuracy of the opening / closing control and the flow rate control can be improved, and corrosion of the opening / closing valve body can be suppressed, thereby improving the durability of the reflux control valve. It can be improved.

  According to claim 2, in addition to the above-described effect, the valve housing, the upstream-side return passage, and the downstream-side return passage are provided in a portion of the cylinder head that overhangs from the cylinder block to the side. Therefore, there is an advantage that the cooling performance for the exhaust gas recirculated from the exhaust system to the intake system can be improved.

It is a partially cutaway top view which shows a part of cylinder head in an internal combustion engine. FIG. 2 is an enlarged side view taken along the line II-II in FIG. 1. FIG. 3 is an enlarged sectional view taken along line III-III in FIG. 1. FIG. 4 is an enlarged sectional view taken along line IV-IV in FIGS. 1 and 2.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  In these drawings, reference numeral 1 denotes a cylinder block constituting the internal combustion engine, and reference numeral 2 denotes a cylinder head constituting the internal combustion engine.

  The cylinder block 1 is provided with a plurality of cylinders 3 along the crank axis 4.

Meanwhile, the cylinder head 2, said a busy instrument configuration being fastened each cylinder 3 on the upper surface of the cylinder block 1, the one end portion along the crankshaft axis 4 of the cylinder head 2, the cylinder block the crank axis 4 part 5 only Oh Bahangu's dimension L appropriately laterally along the crank axis 4 from one side face 1a extending at right angles to one of 1 is provided. A cooling water jacket 6 is provided inside the cylinder head 2.

Also, on one of the longitudinal sides 7 of the crank axis 4 parallel to the left and right longitudinal sides 7 and 8 in the cylinder head 2, an exhaust port 9 are opened with the exhaust valves (not shown) In addition, the exhaust manifold 10 is detachably attached by fastening with a plurality of bolts 11.

  An intake port 12 having an intake valve (not shown) to each cylinder 3 is opened on the other longitudinal side surface 8 of the left and right longitudinal side surfaces 7 and 8 of the cylinder head 2, and an intake manifold. 13 is attached.

The inside of the overhang portion 5 of the cylinder head 2, the exhaust gas recirculation passage 14 is formed so as to extend toward the longitudinal side 8 of the intake side from the one longitudinal side surface 7 of the exhaust side.

Further, the perpendicular sides 5a and the crank axis 4 of the overhang portion 5 in the cylinder head 2, so that the cylindrical valve housing 15 which has an axis sideways are open to the side surface 5a of the overhang portion 5 The dent is formed.

The exhaust gas recirculation passage 14 formed inside the overhang portion 5 includes an upstream recirculation passage 16 between the valve housing 15 and one longitudinal side surface 7 on the exhaust side, the valve housing 15 and the intake air. It is divided into a downstream-side reflux passage 17 between the longitudinal side surface 8 on the side.

On the other hand, on one short side surface 5a of the overhang portion 5, a reflux control valve 18 whose axis is oriented horizontally is attached by bolt fastening.

The recirculation control valve 18 includes an actuator 18a and a valve body portion 18b that is opened and closed by the actuator 18a. The open / close valve body portion 18b is inserted into the valve housing 15. Yes. Further, the flange portion 18c provided integrally with the reflux control valve 18 is in close contact with one short side surface 5a of the overhang portion 5 and is detachably attached by fastening with a bolt or the like. A seal member 19 such as an O-ring or a gasket is provided.

Of the exhaust gas recirculation passage 14, the upstream recirculation passage 16 extends from the overhang portion 5 toward the exhaust port 9, and an inlet end 16 a that is a start end thereof communicates with the exhaust port 9, or It is communicated to the exhaust manifold 10. On the other hand, pre-Symbol communicating portion facing the valve housing 15 (communication port) 16b extends along one shorter side 5a in as overhangs 5 of FIG. Communicating portion 16b is located upstream of the closing valve body 18b of the front Symbol recirculation control valve 18.

Incidentally, in the illustrated embodiment, the upstream return passage 16, one recess to form a Mizogata passage 16c in the longitudinal side 7 in the cylinder head 1, bolts 11 to the said grooved passage 16c longitudinal side 7 The lid plate 16d is fastened with a lid plate 16d . Although the cover plate 16d is pre Symbol exhaust manifold 10 and the integral structure, it may be configured separately from the exhaust manifold 10.

On the other hand, the downstream recirculation passage 17 of the exhaust gas recirculation passage 14 extends along one short side surface 5a of the overhang 5 as shown in FIG. 1, and further, as shown in FIG. 5 has a portion Ru extending along the lower surface 5b, the opening of the starting end which communicates with the valve housing 15 (communication port) 17a of the one end, the recirculation control of the said valve housing 15 The valve 18 is located downstream of the on-off valve body 18b and lower than the on-off valve body 18b.

The valve housing 15 is formed by drilling from one side surface 5a of the overhang portion 5 after the cylinder head 2 is cast.

Further, the upstream reflux communication portion of the passage 1 6 (communication port) 16b also after the cast cylinder head 2, are formed by drilling from the longitudinal side 7.

Furthermore, a part of the downstream side reflux passage 17 below the valve housing 15 is formed by drilling from the longitudinal side surface 7 after casting the cylinder head 2, and then one end of the ball 20 It is comprised by plugging up with plugs, such as .

In the above configuration, part of the exhaust gas discharged from the exhaust port 9, reaches enters the upper flow side return passage 16 from the inlet mouth end 16a than the end of the communication portion 16b to valves housing 15, wherein Thus, the flow rate is appropriately controlled according to the operating range of the internal combustion engine by the on-off valve body 18 b in the recirculation control valve 18, and then recirculated to the intake manifold 13 via the downstream recirculation passage 17.

In this case, by being attached to one side 5a of the recirculation control valve 18 starve cylinder head 2, can be avoided that the entire height increases by the amount of the recirculation control valve 18 in an internal combustion engine.

The opening 17a into the valve housing 15 before Symbol downstream recirculation passage 17, by which is located lower have sites than the recirculation control valve 1 8 of the said valve housing 15, the valve Condensed water generated in the housing 15 is sequentially discharged from the opening 17a to the downstream reflux passage 17 without accumulating in the valve housing 15, so that condensed water is generated in the opening / closing valve body 18b. Adhesion can be avoided.

Furthermore, the valve housing 15, a part of the upstream reflux path 16 , and the downstream reflux path 17 are provided in a portion 5 of the cylinder head 2 that overhangs from the cylinder block 1 to the side. Thus, the cooling performance of the exhaust gas recirculated from the exhaust system to the intake system can be improved.

1 Cylinder block 2 Cylinder head 3 Cylinder 4 Crank axis 5 Overhang
5a One short side surface 7 Long side surface on one side (exhaust side) 8 Long side surface on the other side (intake side) 9 Exhaust port 10 Exhaust manifold 12 Intake port 13 Intake manifold 14 Exhaust gas recirculation passage 15 Valve housing 16 Upstream recirculation passage 16b Communication part of upstream reflux path 17 Downstream reflux path 17a Start end (opening) of downstream reflux path
18 Reflux control valve 18a Reflux control valve actuator 18b Reflux control valve body

Claims (2)

Upstream recirculation with a recirculation control valve attached to one short side surface of the cylinder head inside a cylinder head having one long side surface with an exhaust port opened and one short side surface perpendicular thereto In an internal combustion engine forming an exhaust gas recirculation passage divided into a passage and a downstream recirculation passage ,
The upstream recirculation passage has a communicating portion extending along one short side surface of the cylinder head, while the downstream recirculation passage extends along one short side surface of the cylinder head. And its starting end is located below the communicating part of the upstream reflux passage,
Further, on one short side surface of the cylinder head, a valve housing that communicates with the end of the communication portion in the upstream recirculation passage and the start end of the downstream recirculation passage is connected to the communication portion and the downstream of the upstream recirculation passage. The open / close valve body portion of the return control valve is located in the valve housing, and the start end portion of the downstream return passage is positioned below the open / close valve body portion. An exhaust gas recirculation device for an internal combustion engine, which is inserted as described above . In the description of claim 1, the portion having the one short side surface of the cylinder head is overhanging sideways from the cylinder block to which the cylinder head is fastened . said valve housing, an exhaust gas recirculation system of an internal combustion engine, characterized in that it communicating portion of the cylinder head, the 及 beauty the downstream return passage provided within the upstream return passage.

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