JP2523127B2 - V-type engine intake device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake system for a V-type engine, and more particularly to an improvement of an intake system in which a passage length of an intake passage is variable according to an engine speed.

(Prior Art) Conventionally, as an intake device for a V-type engine, for example, as disclosed in US Pat. No. 2,845,912, two independent intake passages are provided for each cylinder and a surge tank is provided on one bank. It is known that each intake passage of each bank is arranged between the intake passages of the other bank and the intake passages of both banks are connected to the surge tank. According to this, each intake passage is made straight and intake resistance can be reduced as compared with the case where two intake passages of the cylinders facing each other are arranged so as to bypass the two intake passages. .

(Problems to be Solved by the Invention) By the way, in such an intake device, one of the intake passages of each cylinder is lengthened to be a low-speed intake passage, and the other intake passage is shortened to achieve high speed. A shutter valve is provided in the high-speed intake passage, and the shutter valve is closed at low engine speed to obtain the intake inertia effect matched to the low speed range by the low-speed intake passage, while the shutter valve is opened at high engine speed. It is also known that an intake passage for high speed which is opened and functions predominantly provides an intake inertia effect matched with a high rotation speed range.

However, in this case, since the low-speed intake passage and the high-speed intake passage have different passage lengths, for example, it is necessary to bend the low-speed intake passage having a long passage to connect it to the surge tank. The problem that straightening becomes difficult arises. Further, in the above-mentioned conventional one, since the surge tank is provided on one bank, there is a problem that the workability is significantly impaired when the spark plug is attached and detached in this bank.

The present invention has been made in view of the above point, and an object of the present invention is to straighten the intake passage by arranging the arrangement of the intake passage and the connection position of the intake passage to the surge tank and to ignite the surge tank. It is to ensure the serviceability of the spark plug by providing a service hole communicating with the plug.

(Means for Solving the Problems) In order to achieve the above object, the solving means of the present invention is to provide a high-speed intake passage independent for each cylinder and a low-speed intake passage having a passage length longer than the high-speed intake passage. A surge tank is arranged on one bank, and the above-mentioned low speed intake passages are provided on the lower surface of the surge tank, and the high speed intake passages are provided on the outside of the bank. While shifting the position to the inside of the bank and connecting,
The low-speed intake passages and the high-speed intake passages of the facing cylinders of each bank are connected in parallel.

(Operation) With the above configuration, in the present invention, by utilizing only the low speed intake passage at the time of low engine speed, intake air is supplied from the surge tank to the cylinder through the low speed intake passage, and the intake air matched to the low speed region is obtained. Inertial effect is obtained. On the other hand, when the engine is running at high speed, by utilizing only the high speed intake passage, the intake air is supplied from the surge tank to the cylinder through the high speed intake passage, and the intake inertia effect matching the high speed region is obtained.

In that case, since the low-speed intake passages of the facing cylinders of each bank and the high-speed intake passages of the high-speed cylinders are connected in parallel with each other, the both intake passages of the respective cylinders are arranged so as to bypass both the intake passages of the facing cylinders. Rather than doing so, each intake passage is made straight.

Moreover, since the connection position of the low-speed intake passage to the lower surface of the surge tank is displaced to the outside of the bank from the connection position of the high-speed intake passage to the lower surface of the surge tank, the difference between the passage lengths of the two intake passages is It is absorbed by the width of the lower surface in the direction orthogonal to the crankshaft, and each intake passage is made straighter.

Further, the low speed intake passages and the high speed intake passages of the facing cylinders of each bank are connected in parallel, and the connection positions of the low speed intake passage group and the high speed intake passage group to the surge tank are deviated. Therefore, a service hole communicating with the spark plug can be provided in the surge tank between the high speed intake passage groups of one bank, and the serviceability of the spark plug is secured.

(Example) Hereinafter, the Example of this invention is described based on drawing.

1 and 2 show a V-type 6-cylinder engine equipped with an intake device according to an embodiment of the present invention, in which 1 is a cylinder block and 2 and 3 are arranged on banks L and R of the cylinder block 1. An installed cylinder head, the cylinder block 1
And a plurality of cylinders 4, 4 between each cylinder head 2, 3 ...
Pistons 5 are fitted into the respective cylinders 4, and combustion chambers 6 are formed above the respective cylinders 3. Each of the cylinder heads 2 and 3 is provided with a primary port 7 and a secondary port 8 for supplying intake air to the cylinder 4 for each cylinder 4. Each of the primary ports 7 is provided on the rear side in the crankshaft direction of each cylinder 4, and each of the secondary ports 8 is provided on the front side in the crankshaft direction of each cylinder 4, both ends of which open into the combustion chamber 6. The ends open to the inside of the banks of the cylinder heads 2 and 3. Further, the cylinder heads 2 and 3 are provided with exhaust ports 9 and 9 for exhausting exhaust gas from the cylinder 4 for each cylinder 4. Each of the above primary port 7 and secondary port 8
An intake valve 10 is provided in each of the exhaust ports 9 and an exhaust valve 11 is provided in each of the exhaust ports 9 and is driven by a valve train member at a predetermined timing. Further, the combustion chamber 6 of each cylinder 4
An ignition plug 12 for igniting the air-fuel mixture is arranged at the center of the top of the. Further, 13 and 14 are cylinder head covers arranged on the cylinder heads 2 and 3, respectively, and 15 is an injector for supplying fuel to the primary port 7 of each cylinder 4.

Further, above the cylinder head cover 14 of the right bank R, a surge tank 16 is provided to buffer the pulsation of intake air. As shown in FIG. 1, the surge tank 16 is formed in a substantially triangular shape in cross section and has an upper surface 16a provided horizontally and a lower surface 16b provided parallel to the upper surface of the cylinder head 3.

Further, between the banks, a low-speed intake passage 17 for supplying the intake air of the surge tank 16 to the primary port 7 of each cylinder 4 and a high-speed intake passage for supplying it to the secondary port 8 are provided.
18 and 18 are arranged independently for each cylinder 4.
Each low speed intake passage 17 has a longer passage length than the high speed intake passage 18, and when intake air is supplied to each cylinder 4 through each low speed intake passage 17, an intake inertia effect matched with a low engine speed region. On the other hand, when the intake air is supplied to each cylinder 4 through each high speed intake passage 18, the passage lengths are set so that the intake inertia effect matching the high speed region can be obtained.

Each of the low-speed intake passages 17 has one end connected to the primary port 7 of each cylinder 4 and the other end extending toward the upper part between the banks and then bent to the right bank R side to form the lower surface 16b of the surge tank 16. Is formed in the connecting portion 19 by extending to the outside of the bank along the above and opening to the short portion on the outside of the bank on the lower surface 16b. On the other hand, each of the above high speed intake passages 18
Has one end connected to the secondary port 8 of each cylinder 4 and the other end extending toward the upper part between the banks and then bending toward the right bank R side, and while remaining substantially horizontal, the inside of the bank on the lower surface of the surge tank 16 Open at the side end and connect
Formed in 20. And these low speed intake passages
The high-speed intake passages 18, 18 ... Are fixed to the cylinder heads 2, 3 via flanges in the upper portion between the banks. The low speed intake passage 17 of each cylinder 4 of the left bank L is located between the low speed intake passage 17 of the cylinder 4 facing the right bank R and the high speed intake passage 18 of the cylinder 4 behind the cylinder 4. The high speed intake passages 18 of the cylinders 4 of the left bank L are arranged between the low speed intake passages 17 and the high speed intake passages 18 of the cylinders 4 of the right bank R facing each other. Therefore, the low speed intake passages 17 and 17 and the high speed intake passages 18 and 18 of the cylinders 4 and 4 facing each other in the banks L and R are collectively connected in parallel between the flange and the surge tank 16. There is.

Further, in each of the low-speed intake passages 17, the low-speed intake passage 17 is provided in a portion facing the bank outer side end portion of the surge tank lower surface 16b, that is, a portion connected to the connection portion 20 of the high-speed intake passage 18. A high-speed connecting portion 21 that opens to the bottom surface 16b of the surge tank is provided, and when the intake air of the surge tank 16 is supplied from each high-speed connecting portion 21 to each cylinder 4 through the low-speed intake passage 17, the high-speed range of the engine is reached. The matching intake inertia effect is obtained.

Further, shutter valves 22 and 23 are provided at the high speed connecting portion 21 of each low speed intake passage 17 and the connecting portion 20 of each high speed intake passage 18, respectively. The shutter valves 22, 22, ..., 2
3,23 ... are connected by the same valve shaft 24 arranged in the crankshaft direction so as to interlock with each other, and are controlled by an actuator (not shown) connected to the valve shaft 24. The shutter valves 22 and 23 are opened in a substantially horizontal state as shown by the solid line in FIG. 1 so that the intake air of the surge tank 16 is connected to the high speed side intake passage 18 and the low speed side intake passage 17 at the high speed connection portion 21.
While supplying to each cylinder 4 through the downstream side, when the engine speed is low, the shutter valves 22 and 23 are closed as shown by phantom lines in FIG.
It is configured to be supplied to each cylinder 4 via.

Further, between the groups of low-speed intake passages 17, 17 connected in parallel in the surge tank 16, one end is opened to the surge tank upper surface 16a and the other end is connected to the surge tank 16 in each cylinder 4.
Penetrating toward the spark plug 12 of the surge tank bottom surface 16b
The plug service ports 25, 25 opening to the are provided to ensure workability when attaching and detaching the spark plug 12.

Therefore, in the above embodiment, when the engine speed is low, both shutter valves 22 and 23 are closed so that each low speed intake passage 17 is closed.
While the intake inertia effect matched with the low rotation speed region is obtained, the shutter valves 22 and 23 are opened at the time of high engine speed to open not only each high speed intake passage 18 but also each low speed intake passage 17 at the high speed connection portion 21 downstream side. Since the intake inertia effect matched to the high engine speed is obtained, both the improvement of filling efficiency at low engine speed and reduction of pumping loss and the improvement of charging efficiency at high engine speed and reduction of intake resistance are achieved. be able to.

In that case, the low-speed intake passages 17, 17 of the cylinders 4, 4 facing each other in the banks L, R and the high-speed intake passages 18, 18 are collectively connected in parallel between the flange and the surge tank 16. Therefore, both the low speed intake passage 17 and the high speed intake passage 18 of each cylinder 4 face each other.
The intake passages 17 and 18 can be straightened and intake resistance can be reduced as compared with the case where the intake valves 17 and 18 are bypassed.

Moreover, since the low speed intake passages 17 are connected to the outer side end of the bank and the high speed intake passages 18 are connected to the inner side end of the bank on the lower surface 16b of the surge tank, respectively,
The difference between the passage lengths of the intake passages 17 and 18 is absorbed by the width of the surge tank lower surface 16b in the direction orthogonal to the crankshaft, and
17,18 is straightened further.

In addition, such a low-speed intake passage 17 and a high-speed intake passage
Due to the parallel arrangement with 18 and the arrangement in which the connecting portion 19 of the low speed intake passage 17 and the connecting portion 20 of the high speed intake passage 18 are offset, a plug service port 25 is provided between the group of low speed intake passages 17 and 17 arranged in parallel. Can be provided, and workability when attaching and detaching the spark plug 12 can be secured.

Further, since both the high speed connecting portion 21 of each low speed intake passage 17 and the connecting portion 20 of each high speed intake passage 18 are opened in the lower surface 16b of the surge tank 16, they are arranged in each connecting portion 20, 21. The shutter valves 22 and 23 can be connected by the same valve shaft 24, and the structure of the intake device that obtains the above-mentioned intake inertia effect is simplified, its reliability is enhanced, and the size is reduced.

Further, since the surge tank 16 is arranged on one of the banks R, the low-speed intake passage 17 and the high-speed intake passage 18 are bent at the upper portions between the banks to secure a sufficient pipe length without increasing the overall height of the engine. can do.

Further, since the upper surface 16a of the surge tank 16 is provided horizontally and the lower surface 16a is provided parallel to the upper surface of the cylinder head 3, the surge is avoided while avoiding interference with the bonnet or the like when the engine is mounted on an automobile or the like. Tank 16
The capacity of can be made as large as possible, and the effect of the intake inertia effect can be enhanced.

Further, since the surge tank lower surface 16b is inclined upward toward the inner side of the bank and the position of the inner end of the bank is high, the bending of the high-speed intake passage 18 opening at this end becomes gentle. , Can contribute to the reduction of the intake resistance.

Further, the shutter valves 22 and 23 disposed at the high speed connection portion 21 of the low speed intake passage 17 and the connection portion 20 of the high speed intake passage 18 have intake passages 17 near the respective connection portions 21 and 20 during the opening operation, 18
Since it is maintained horizontally so as to be substantially parallel to, it is possible to reduce intake resistance during high engine speed.

(Effects of the Invention) As described above, according to the intake system for the V-type engine of the present invention, the high-speed intake passage independent of each cylinder and the low-speed intake passage having a passage length longer than the high-speed intake passage. And a surge tank on one bank,
The low speed intake passages are connected to the outside of the bank and the high speed intake passages are connected to the lower surface of the surge tank so that the high speed intake passages are located inside the bank, and the low speed intake passages of the cylinders facing each other are connected to each other. Since the high-speed intake passages and the high-speed intake passages are connected in parallel to each other, the low-speed intake passages and the high-speed intake passages can be straightened while effectively obtaining two types of high-low intake inertia effects according to the engine speed. In addition, a service hole for the spark plug can be provided in the surge tank, and the serviceability of the spark plug can be ensured.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a vertical sectional front view of an engine, and FIG. 2 is a plan view of the engine. 4 …… Cylinder, 16 …… Surge tank, 16b …… Bottom surface, 1
7 …… Low speed intake passage, 18 …… High speed intake passage, L ……
Left bank, R ... right bank.

Claims (1)

(57) [Claims] 1. An intake system for a V-type engine, comprising an intake passage for high speed, which is independent of each other for each cylinder, and an intake passage for low speed, the passage length of which is longer than the intake passage for high speed. A surge tank is arranged, and the low speed intake passages are connected to the outside of the bank on the lower surface of the surge tank, and the high speed intake passages are connected to the inside of the bank by shifting their positions. An intake system for a V-type engine, characterized in that low speed intake passages of a cylinder and high speed intake passages of a cylinder are connected in parallel.