JPH0330617Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an exhaust gas recirculation device for a V-type engine equipped with two banks.

(Prior art) Conventionally, in a V-type engine, the intake ports of each cylinder for two banks were formed so as to face each other inside both banks, and the intake ports were connected to independent intake passages. The structure of the intake system is known, for example, as seen in US Pat. No. 2,845,912.

Furthermore, it is generally practiced to recirculate a portion of the exhaust gas to the intake system to suppress _NOx emissions.
In this exhaust gas recirculation device, an exhaust gas recirculation passage is provided to guide part of the exhaust gas from the exhaust system to the intake system, and an exhaust gas recirculation amount control valve is provided to control the amount of exhaust gas recirculation according to the operating state. installation is required.

On the other hand, when performing the exhaust gas recirculation mentioned above, unless the exhaust gas is evenly distributed and introduced to each cylinder in both banks, the combustion state between the cylinders will differ and the generated torque will fluctuate. Shock,
This will cause vibrations. Also, V
In order to make the V-type engine compact, it is necessary to arrange the exhaust gas recirculation amount control valve and exhaust gas recirculation passage of the exhaust gas recirculation device together with the intake device in a compact manner in accordance with the unique structure of the V-type engine. be done.

In particular, the intake system has an intake manifold connected to the intake port of each bank's cylinder between the banks on both sides. A passage must be provided, and an exhaust gas recirculation amount control valve must be installed in the middle of the passage, and it is important to construct these in a compact manner while still achieving the desired effect of the intake system.

(Purpose of the invention) In view of the above-mentioned circumstances, the present invention has been developed to uniformly distribute the recirculated exhaust gas to each cylinder in a case where the intake manifold is arranged between both banks, and to make the entire engine more compact. It is an object of the present invention to provide an exhaust gas recirculation device for a V-type engine in which the exhaust gas recirculation passage is formed short.

(Structure of the invention) The exhaust gas recirculation device of the invention has an intake manifold having an independent intake passage connected to the cylinders of each bank arranged between both banks, and a surge tank to which the upstream end of the independent intake passage is connected. is arranged above one bank so as to extend in the output shaft direction, and intake air is introduced from one end in the output shaft direction; An exhaust gas recirculation amount control valve for controlling the amount of exhaust gas recirculation is disposed at the end and on the inner side of the bank than the surge tank, and intake air is introduced from the exhaust gas recirculation amount control valve to the surge tank of the intake manifold. An exhaust gas recirculation passage extending upstream of the intake air along the independent intake passage at the side end is formed integrally with the intake manifold, and the downstream end of this exhaust gas recirculation passage is opened to the intake air gathering part on the intake air introduction side of the surge tank. It is characterized by the fact that

(Effects of the invention) According to the invention, intake manifolds are provided inside both banks in a V-type engine, and a surge tank is arranged on one bank, and furthermore,
The banks on both sides are arranged offset in the direction of the output shaft, and the exhaust gas recirculation amount control valve is located in the space formed inside the banks from the surge tank at the end of the output shaft of the intake manifold. As a result, the exhaust gas recirculation amount control valve can be installed compactly.

In addition, intake air is introduced from one end in the output shaft direction to a surge tank disposed above one bank extending in the output shaft direction, and the exhaust gas In addition to providing a recirculation amount control valve, an exhaust gas recirculation passage is formed along and integrally with the independent intake passage at the end of the intake manifold, and extends to the intake upstream side, and the upstream end thereof is connected to the intake intake side of the surge tank. By introducing the recirculated exhaust gas into the intake system through the opening in the intake collecting part of the cylinder, the recirculated exhaust gas is evenly distributed to each cylinder, and the exhaust gas recirculated downstream of the exhaust gas recirculation amount control valve is The passage can be shortened, recirculated exhaust gas can be quickly introduced with little pressure loss, the diameter of the exhaust gas recirculation passage can be reduced, and the entire engine can be made more compact.

(Example) Hereinafter, an example of the present invention will be described along with the drawings.

FIG. 1 is a partially sectional side view of the upper structure of a six-cylinder V-type engine equipped with an exhaust gas recirculation device, and FIG. 2 is a plan view thereof. The V-type engine in this example is an example of a so-called horizontal type engine, which is placed in the engine room formed at the front of the car body so that its output shaft is oriented horizontally.
The right side in FIG. 1 (lower side in FIG. 2) is the front of the vehicle body.

A six-cylinder V-type engine 1 has a front cylinder head 3 and a rear cylinder head 4 arranged obliquely on a cylinder block 2 at the lower center, and cylinders C ₁ to _{C 6} ( In FIG. 2, a front bank 1A and a rear bank 1B having cylinders 1 to 6 in order from the right are formed.
That is, the cylinders C ₁ to C ₆ are arranged in a V-shape at a predetermined angle, and the six cylinders C ₁ to _{C 6} are alternately divided into two groups of three cylinders each: odd-numbered cylinders and even-numbered cylinders. These constitute front and rear banks 1A and 1B. Cylinder C ₁ of two banks 1A, 1B ~
C ₆ will be arranged offset from each other in the output shaft direction (horizontal direction in Fig. 2), and correspondingly, the front cylinder head 3 will be arranged offset to the right when viewed from the front than the rear cylinder head 4. has been done.

An intake port 8 and an exhaust port (not shown) are opened in the combustion chamber 7 formed above the piston 5 of each of the cylinders _C1 to _C6 , and both ports are connected to an intake valve 9 and an exhaust valve (not shown), respectively. (not shown) opens and closes at predetermined timing. The above-mentioned intake port 8 in the front and rear cylinder heads 3 and 4
are formed with openings facing each other on the inner surface side. Head covers 3a and 4a are attached to the upper portions of the front and rear cylinder heads 3 and 4 to cover the valve mechanism and the like.

Each cylinder in the front and rear banks 1A and 1B on both sides of the above
The intake device that supplies intake air to C ₁ to _{C 6} includes an intake manifold 6 that constitutes front and rear independent intake passages 10 and 11 connected to each intake port 8 of cylinder heads 3 and 4 on both sides, respectively, and a rear bank. 1B, the independent intake passage 10,
The upstream end of the surge tank 11 is connected to the surge tank 12.

The surge tank 12 is configured as a box-like body that is long in the output shaft direction, that is, in the lateral direction of the vehicle, and is divided into upper and lower sections, an upper surge tank 13 and a lower surge tank 14, by a partition wall 15 that extends in a substantially horizontal direction. divided into spaces. The front independent intake passage 10 from the front bank 1A that is farther from the surge tank is connected to the lower surge tank 14, and the rear independent intake passage 11 from the rear bank 1B that is closer to the upper surge tank 13 is connected to the lower surge tank 14. are connected to each other, and independent intake passages 10 and 11 are assembled for each bank 1A and 1B to form an intake collection section.

Further, both independent intake passages 10 and 11 of the intake manifold 6 are divided by a substantially horizontal connecting surface F at the middle upper part of the banks 1A and 1B on both sides, and the upstream surge tank side is connected to the surge tank 12. It is divided into two passages 10a and 11a and a downstream intake port side passage 10b and 11b connected to the intake port 8.

That is, the front independent intake passage 10 connected to both banks 1A extends diagonally rearward and upward toward an intermediate position between both banks 1A and 1B by the intake port side passage 10b, and extends through the substantially horizontal connecting surface F. The surge tank side passage 10a extends from above to the rear with a slight curvature and further slightly downward, and is connected to the lower surge tank 14 from the side. On the other hand, the rear independent intake passage 11 is connected to the rear bank 1B.
is connected to both banks 1 by the intake port side passage 11b.
It extends diagonally forward and upward toward approximately the same position between A and 1B as described above, and extends rearward approximately horizontally from above with a slight curvature through the common connection surface F by the surge tank side passage 11a. The upper surge tank 13 extends from the side and is connected to the upper surge tank 13 from the side. Due to the above connection structure, the independent intake passages 10 and 11 are connected in reverse.
This prevents large bending and suppresses the increase in intake resistance.

Furthermore, the connection positions of the independent intake passages 10 and 11 to the upper and lower surge tanks 13 and 14 correspond to the fact that the front bank 1A is shifted to the right side from the rear bank 1B, and the front independent intake passages 10 and 11 are connected to the lower surge tank 14. The connection position of the passage 10 is shifted to the right side from the connection position of the rear independent intake passage 11 with respect to the upper surge tank 13. Accordingly, the right side of the upper surge tank 13 is formed low, and a communication control valve 27, which will be described later, is provided at the left end of the lower surge tank 14.

Furthermore, as shown in FIG. 2, a portion of the surge tank side passages 10a, 11a of each of the independent intake passages 10, 11 is arranged so that the passages 10a of the first and third cylinders are on the right side, and the passages 10a of the fourth and third cylinders are on the right side, as shown in FIG. The passage 11a of the sixth cylinder is curved to the left, and there is a gap on the left side of the surge tank side passage 10a of the odd numbered cylinder (front bank 1A) and the surge tank side passage 11a of the even numbered cylinder (rear bank 1B). is formed.

The surge tank side passages 10a, 11a are formed integrally with the surge tank 12, and the intake port side passages 10b, 11b of each cylinder have mounting flanges 10c, 11c at the downstream end connected to the front and rear banks by mounting bolts 20, respectively. It is fixed to 1A and 1B. In addition, the surge tank side passages 10a, 11a and the intake port side passages 10b, 11b are connected by joining upper and lower connecting flanges 16, 17 common to each cylinder, which are formed approximately horizontally at the respective connecting ends. be done.

The surge tank side passage 10 curves backward when the above-mentioned connecting flanges 16 and 17 are fastened with the front and rear mounting bolts 18 and 19.
a, 11a are located above the rear boss portion 16a
The surge tank side passages 10a, 11a are formed to extend upward from the flange portion 16 in the gap formed by bending them to the left and right in a plane, and are formed high, so that the bolts 19 can be tightened from above. There is.

On the other hand, the upper and lower surge tanks 13 and 14 of the surge tank 12 have upstream introduction passages 13a and 14a that extend to the right, curve forward in a cylindrical shape, and extend upward and downward to the throttle body 21, respectively. Throttle valves 22 and 23 installed above and below within the throttle body 21 control the respective intake flow rates. This throttle body 2
The intake passages 24 further upstream from 1 merge on the upstream side (not shown) to form one main intake passage,
Connected to the air cleaner. Further, the surge tank 12 is connected and supported to the rear cylinder head 4 by a rear connecting fitting 25.

As shown in FIGS. 3 and 4, the upper surge tank 13 and lower surge tank 14 of the surge tank 12 communicate with each other via a communication passage 26 formed at the left end of the lower surge tank 14. A communication control valve 27 that changes the communication area in the middle of the communication path 26
is interposed. That is, the partition wall 15 below the connection opening portion of the independent intake passage 11 of the sixth cylinder C ₆ to the upper surge tank 13 is formed low toward the lower surge tank 14 side, and a communication passage 26 is formed in this portion. A shaft portion 27a of a butterfly-type communication control valve 27 is supported through the communication passage 26 in the front-rear direction, and the degree of opening by rotation of the control valve 27 is changed and adjusted by the operation of an actuator 28. . The actuator 28 is controlled mainly in response to the engine speed, and its opening degree is adjusted to increase the communication area as the engine speed increases.

In addition, in order to discharge water generated by condensation or the like to the outside of the surge tank 12, the surge tank 12 is provided with a valve connected to the upper surge tank 13 through a communication passage 26 when the communication control valve 27 is in the open state. The water flows down into the lower surge tank 14 and is discharged together with the water in the lower surge tank 14 from a drain hole 29 formed at the bottom of the surge tank 12.

On the other hand, as shown in FIGS. 5 and 6, an exhaust gas recirculation device is installed in the above-mentioned intake device to recirculate exhaust gas for _NOx suppression from the exhaust system.

An EGR adapter 31 is disposed at one end of the intake manifold 6 in the output shaft direction on the right side of the engine between the front and rear banks 1A and 1B.
An exhaust gas recirculation amount control valve 33 that opens and closes the exhaust gas recirculation passage 30 to control the amount of exhaust gas recirculation is installed in the adapter 31, and a pipe 34 (see Fig. 2) that guides exhaust gas from an exhaust passage (not shown). is connected to the EGR adapter 31.

An exhaust gas recirculation passage 30 that guides the exhaust gas that has passed through the exhaust gas recirculation amount control valve 33 is formed integrally with the intake manifold 6. That is, in the exhaust gas recirculation passage 30, the lead-out portion 30a from the EGR adapter 31 is connected to the flange portion 17 of the intake port side passages 10b, 11b of the intake manifold 6.
from the surge tank side passage 10 via the connection surface F.
communicates with the flange part 16 of a, 11a, and the intermediate part 3
0b extends toward the intake upstream side along the side of the surge tank side passage 10a of the independent intake passage 10 for the first cylinder _C1 , and both are integrally formed.
It is extended to the intake collecting part of No. 2. The downstream end of the exhaust gas recirculation passage 30 is connected to the upper and lower surge tanks 13 and 14 of the surge tank 12 at upstream introduction passage portions 13a and 14a where the independent intake passages 10 and 11 of each bank 1A and 1B gather, respectively. They communicate with each other through introduction portions 30c and 30d formed by drill holes.

Note that the recirculation of the exhaust gas is controlled by the operation of the exhaust gas recirculation amount control valve 33 according to the operating state of the engine 1, and the control is performed according to conventionally known control characteristics, for example, at low and medium loads. This system recirculates exhaust gas and controls the recirculation to stop when the load is high.

Further, in the banks 1A and 1B on both sides, an intake port side passage 10 of each of the independent intake passages 10 and 11 is provided.
Mounting flanges 10c, 11 at the downstream end of b, 11b
An injector 36 for injecting fuel into the intake port 8 of each cylinder C ₁ to _{C 6} is installed at c. Fuel supply pipes 37, 37 arranged for each bank 1A, 1B are connected to the injector 36, and fuel is supplied thereto. Further, above the engine 1, a bonnet 38 that covers the engine room is arranged so as to be inclined downward from the rear toward the front.

In the 6-cylinder V-type engine 1 in this example, the ignition order is set in the order of 1-2-3-4-5-6 cylinders, with the 1st, 3rd, and 5th cylinders in the front bank 1A, and the 2nd, 4th, and 5th cylinders in the forward bank 1A. Six cylinders each belong to rear bank 1B. Therefore, in the upper surge tank 13 and the lower surge tank 14, each surge tank 1
The intake order is not consecutive between the cylinders connected to cylinders 3 and 14, and no intake interference occurs.

Additionally, pressure waves in the intake passage upstream of the surge tank 12 are utilized to improve output. That is, the negative pressure waves accompanying the opening/closing operation of the intake valve 9 have a phase relationship that is opposite to each other in the cylinders of the banks 1A and 1B on both sides, and propagate upstream through the independent intake passages 10 and 11 to the upper and lower surge tanks 13 and 14. reach.
The independent intake passages 10 and 11 downstream of the surge tank are
Since the length is set to be the same for each cylinder, the pressure waves in the upper and lower surge tanks 13 and 14 are also shifted by half a wavelength between the cylinders belonging to the two banks 1A and 1B. The negative pressure waves that have reached the upper and lower surge tanks 13, 14 propagate upstream from the introduction passages 13a, 14a, respectively, pass through the throttle body 21, interfere at the confluence of the intake passage 24 on the upstream side, and are reversed to become positive pressure waves. It then returns to the combustion chamber 7. This inverted positive pressure wave provides a so-called resonance effect that increases the filling efficiency of intake air, thereby making it possible to obtain high output.

Furthermore, since the length of each independent intake passage 10, 11 downstream of the surge tank 12 can be ensured sufficiently, the output can be sufficiently improved due to the inertial effect using the pressure waves reflected by the upper and lower surge tanks 13, 14. Obtainable. Furthermore, the resonant frequency characteristics of the upper and lower surge tanks 13 and 14 are varied by adjusting the opening degree of the communication control valve 27, so that the characteristics of the inertial effect and the resonant effect are adapted to the rotational speed in a wide range.

According to the above embodiment, the exhaust gas recirculation amount control valve 33 of the exhaust gas recirculation device is arranged in the banks 1A and 1 on both sides.
Since B is installed offset, by arranging it in a space formed at one end of the intake manifold 6 in the output shaft direction, it can be installed compactly with respect to the intake device. In addition, the exhaust gas recirculation passage 30
is integrated with the intake manifold 6 to easily form a passage structure that guides the intake upstream, and by introducing the recirculated exhaust gas into the intake collecting section, this exhaust gas is distributed to each cylinder of both banks 1A and 1B.
It is refluxed with evenly good distribution for C ₁ to _{C 6} .

On the other hand, in the above embodiment, each independent intake passage 10,
11 is divided into surge tank side passages 10a, 11a and intake port side passages 10b, 11b, the connecting surface F of both is set approximately horizontal, and a part of the surge tank side passages 10a, 11a is curved. By forming a gap between the lever passages and arranging the mounting bolt 19 in this part to attach the surge tank side passages 10a and 11a, the structure is compact and the ease of assembly is improved. are doing.

Furthermore, in the above intake structure, one bank 1B
A surge tank 12 is disposed above the
Since the independent intake passages 10 and 11 that communicate the surge tank 12 and the intake ports 8 of the banks 1A and 1B are curved, the surge tank 12 can be installed in accordance with the slope of the bonnet 38. The overall height of the engine can be made low and compact,
Moreover, since the curvature of the independent intake passages 10 and 11 is small, the passage resistance of intake air is small, and the problem of insufficient intake air does not occur at high engine speeds.

In addition, in the above embodiment, the case where the present invention is applied to a horizontally mounted V-type engine has been explained, but the present invention is not limited to this and can be similarly applied to various other V-type engines. It is something that can be done.

Further, the surge tank may be arranged not only above and below as in the above embodiment, but also may be arranged front and back, or may be integrated into both banks without being divided.

[Brief explanation of the drawing]

FIG. 1 is a left side view partially sectionally showing the main parts of a V-type engine equipped with an exhaust gas recirculation device according to an embodiment of the present invention, FIG. 2 is a plan view of the main parts, and FIG.
The figure is a sectional view taken along the - line in Fig. 1, Fig. 4 is a sectional view taken along the - line in Fig. 3, and Fig. 5 is a plan view of main parts showing the structure of the exhaust gas recirculation passage that recirculates exhaust gas. , FIG. 6 is a cross-sectional view showing the side structure of the exhaust gas recirculation passage along with the - cross section of FIG. 5. 1...V-type engine, 1A, 1B...bank,
2...Cylinder block, _C1 to _C6 ...Cylinder, 3,
4...Cylinder head, 6...Intake manifold, 8...Intake port, 10, 11...Independent intake passage, 10a, 11a...Surge tank side passage,
10b, 11b...Intake port side passage, 12...
Surge tank, 13, 14... Upper and lower surge tanks, 13a, 14a... Introduction passage section, 15... Partition wall, F... Connection surface, 16, 17... Connection flange section, 21... Throttle body, 22, 23 …
... Throttle valve, 30 ... Exhaust gas recirculation passage, 3
1...EGR adapter, 33...Exhaust gas recirculation amount control valve.

Claims (1)

[Scope of utility model registration request] An intake manifold comprising two banks and having independent intake passages connected to the intake ports of the cylinders of each bank is arranged between the two banks, and a surge tank to which the upstream ends of the independent intake passages are connected is connected to the intake manifold of one bank. An exhaust gas recirculation device for a V-type engine, which is disposed extending upwardly in the direction of the output shaft, and in which intake air is introduced into the surge tank from one end in the direction of the output shaft, the intake air introduction side of the surge tank in the intake manifold. An exhaust gas recirculation amount control valve for controlling the amount of exhaust gas recirculation is installed at the same end in the output shaft direction and on the inside of the bank than the surge tank. An exhaust gas recirculation passage extending upstream of the intake air along the independent intake passage at the intake introduction side end of the surge tank is formed integrally with the intake manifold, and the downstream end of the exhaust gas recirculation passage is connected to the intake air introduction side of the surge tank. An exhaust gas recirculation device for a V-type engine, characterized by opening at a side intake collecting section.