JPH0439386Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to an engine intake system, and in particular,
A surge tank is provided between the left and right banks that extends in the direction of cylinder arrangement and is internally divided into left and right chambers by a partition wall, and the two chambers in the surge tank are controlled to be switched between communicating and non-communicating states. This invention relates to an improved technique for inertial supercharging or resonance supercharging of intake air into cylinders.

(Prior Art) Engine intake systems that utilize the dynamic effects of intake air to increase its charging efficiency have been well known, and are broadly classified into an inertial supercharging system and a resonance supercharging system. In other words, the inertial supercharging method reverses the negative pressure wave of the intake air that occurs at the beginning of the intake stroke into a positive pressure wave at the upstream open end of the intake passage, and forces the intake air of this positive pressure wave into the cylinder at the end of the intake stroke. , which increases the filling efficiency of intake air.

On the other hand, in the resonant supercharging method, cylinders with non-consecutive firing orders are connected together to a single independent surge tank, and the intake air is vibrated at a natural frequency throughout the intake system including this surge tank. By making the natural vibration of the intake air correspond to the stroke of the engine, the filling efficiency of the intake air is increased.

As an example of an intake system that supercharges intake air into a cylinder by such an inertial supercharging method or a resonant supercharging method, conventionally, as disclosed in Japanese Patent Application Laid-open No. 115818/1983, the ignition order of an engine is known. The two chambers in the surge tank with which the discontinuous cylinders communicate are communicated by a communication passage, and a communication valve is provided to open and close the communication passage, and when the communication valve is closed, the two chambers in the surge tank are made independent; The natural frequency of the intake air is lowered to supercharge the intake air in the low engine speed range, while when the communication valve is opened, the natural frequency is raised and the intake air is supercharged in the high engine speed range, allowing the engine to be supercharged over a wide range of engine speeds. There is a known system that exerts its supercharging effect in the operating range of .

(Problem to be solved by the invention) Therefore, by applying this conventional concept to the intake system of a V-type engine, a surge tank extending in the cylinder arrangement direction is provided between the left and right banks of the V-type engine. The interior of the surge tank is divided into left and right surge tank chambers connected to cylinders with non-consecutive ignition orders by a partition wall, and a chamber is provided in the partition wall to extend in a direction perpendicular to the cylinder arrangement direction and communicate with the left and right surge tank chambers. By providing a first communication passage and a second communication passage extending in the cylinder arrangement direction and communicating the two surge tank chambers, and controlling the opening and closing of the first communication passage, the resonance length of the intake passage can be adjusted to two sizes. It is conceivable that the intake air supercharging may be carried out over substantially the entire range of the engine rotational speed.

By the way, due to the layout in the engine room, a pair of intake passages that supply intake air from one end side in the cylinder arrangement direction of the surge tank to both chambers in the surge tank are connected to a plane (horizontal plane) passing through both chambers in the surge tank. ) may be arranged so that they are curved in the same direction. In that case, the amount of intake air flowing through each intake passage will be larger on the outside of the curved intake passage than on the inside due to centrifugal force. Therefore, depending on how the second communication passage is provided, most of the intake air supplied to one chamber in the surge tank flows directly into the other chamber through the second communication passage. A problem arises in that the amount of intake air flowing into both chambers in the surge tank is different, resulting in poor distribution of intake air between the left and right cylinder groups.

The present invention has been made in view of the above points, and its purpose is to appropriately link each opening end of a communication passage provided in the partition wall of a surge tank and extending in the cylinder arrangement direction to a curved intake passage. By arranging the curved intake passage, it is possible to evenly supply intake air to both chambers in the surge tank. The purpose is to ensure a communication path.

(Means for Solving the Problems) In order to achieve the above object, the solution means of the present invention includes a surge tank extending in the cylinder arrangement direction between both left and right banks, and the surge tank The present invention is directed to an intake system for a V-type engine, which is divided into left and right surge tank chambers connected to cylinders whose ignition order is not consecutive by a partition wall extending in the cylinder arrangement direction.

For this intake device, a pair of intake passages that supply intake air to both chambers of the surge tank from one end side in the cylinder arrangement direction of the surge tank are respectively curved in the same direction within a plane passing through both chambers in the surge tank. let A communication passage extending substantially parallel to the partition wall is provided in the partition wall, one end of the communication passage is placed on one end side in the cylinder arrangement direction of the surge tank in the chamber connected to the curved outer intake passage, and the other end is placed on the inner side. The surge tank in the chamber connected to the intake passage is opened at the other end in the cylinder arrangement direction.

(Function) With this configuration, in the present invention, a communication passage as a resonance passage for resonance supercharging of intake air is formed in the bulkhead in the surge tank, and the communication passage extends in the direction of the cylinder arrangement of the engine. By ensuring a long communication path, the intake air can be effectively supercharged in the low speed range of the engine.

Further, one end of the surge tank in the cylinder arrangement direction of the chamber in which one end of the communication passage is connected to the outside curved intake passage, and the cylinder arrangement direction of the surge tank in the chamber whose other end is connected to the inside intake passage. Because they are open at each end, when the intake air flowing through the outer intake passages and the intake air closer to the inside, where the intake flow rate per unit area is smaller, flows into the surge tank chamber, it immediately flows into one end of the communication passage, and the intake air flows into the communication passage. The passage leads to a chamber connected to the inner intake passage. Therefore, the amount of movement of this intake air can be suppressed as much as possible, and the intake air amounts in both chambers in the surge tank can be balanced as equally as possible. Therefore, even if the intake passage is curved due to the layout, it is possible to improve the distribution between the left and right cylinder groups of the engine.

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

FIGS. 1 and 2 show a six-cylinder V-type engine A according to an embodiment of the present invention. In Figures 1 and 2, the right side of the diagram is the left side for engine A)
It consists of two cylinder heads 2a and 2b respectively joined to the upper end surface of the cylinder head. And engine A
The 6 cylinders are fired in the order of 1st, 4th, 2nd, 6th, 3rd, and 5th cylinders every 120° of crank angle.
It has six cylinders 3a, 3a,..., 3b, 3b..., and these six cylinders 3a, 3a,..., 3b, 3
b,... are the first to third ignitions whose ignition order is not consecutive, that is, the opening periods of the intake valves do not overlap.
It is divided into a cylinder group consisting of the cylinders 3a, 3a, . . . and a cylinder group consisting of the fourth to sixth cylinders 3b, 3b, . . . on the left and right. Furthermore, the corresponding cylinders 3a and 3b (for example, the first cylinder 3a and the fourth cylinder 3b) in the left and right cylinder groups of this engine A are displaced from each other due to the crank arrangement of the crankshaft, and the front end of the left cylinder group The first cylinder 3a of the right side cylinder group protrudes further forward than the fourth cylinder 3b at the front end of the right cylinder group, and conversely, the sixth cylinder 3b at the rear end of the right side cylinder group is rearward than the third cylinder 3a at the rear end of the left side cylinder group. in a prominent position.

Both banks A ₁ on the left and right sides of the engine A above,
A surge tank 5 is disposed between A ₁ and extends in the cylinder arrangement direction (front-rear direction), forming an enlarged portion of the intake passage 4 for supplying intake air into each cylinder 3a, 3b. Inside the surge tank 5, there is a partition wall 6 extending in the longitudinal direction (cylinder arrangement direction) at the left and right center portions thereof.
The chamber is divided into two chambers: a left chamber 7a and a right chamber 7b. In addition, each chamber 7 in the surge tank 5 is provided on the left and right side walls of the surge tank 5.
A, 7b are connected to independent intake pipes 8, 8, . . . , 9, 9, . The independent intake pipes 8, 9 are connected to extension portions 8a, 9a whose upstream ends are connected to the surge tank 5 and are curved in a substantially U-shape, and to downstream ends of the extension portions 8a, 9a. Intersection 8 whose ends open to each cylinder 3a, 3b of engine A
b, 9b, and each of the crossing portions 8b, 9b is arranged below the surge tank 5 so as to intersect with the other crossing portion 9b, 8b.

On the other hand, intake air is supplied from the rear end side of the surge tank 5 to both chambers 7a and 7b of the surge tank 5 on the side wall of the rear end side (upper end side in Fig. 1) of the surge tank 5 in the longitudinal direction (cylinder arrangement direction). and a pair of intake passages 4, 4
Two upstream intake pipes 10a and 10b on the left and right sides forming the upstream portion of the surge tank 5 are connected to communicate with a left chamber 7a and a right chamber 7b in the surge tank 5, respectively. These upstream intake pipes 10a, 10b (intake passages 4, 4) are the same in a horizontal plane passing through both chambers 7a, 7b of the surge tank 5 so that the radius of curvature of the right intake pipe 10b is larger than that of the left intake pipe 10a. The upstream ends are overlapped to form an air cleaner (not shown).
It is connected to the.

Furthermore, in the partition wall 6 in the surge tank 5,
The first chamber communicates both the left and right chambers 7a and 7b.
and two second communication passages 11 and 12 are formed, the first communication passage 11 extending in a direction perpendicular to the partition wall 6 at the front end of the partition wall 6 in the cylinder arrangement direction, and the ends thereof are connected to the two chambers 7a, respectively. , 7b are opened at the front ends in the cylinder arrangement direction. Also, this first
The communication passage 11 is shifted toward the right side chamber 7b with respect to the partition wall 6. On the other hand, the second communication path 12 extends substantially parallel to the partition wall 6 and is longer than the first communication path,
One end of the surge tank 5 is located at the rear end in the cylinder arrangement direction of the surge tank 5 in the right chamber 7b connected to the outside right independent intake pipe 10b (intake passage 4) which is curved with a large radius of curvature, and the other end is located inside where the radius of curvature is small. They are opened at the front end in the cylinder arrangement direction of the surge tank 5 in the left chamber 7a connected to the left independent intake pipe 10a (intake passage 4).

The first communication passage 11 is opened and closed by a communication valve 13 made of a butterfly valve.
One end of the valve shaft 13a of the communication valve 13 passes through the front side wall of the surge tank 5 in the cylinder arrangement direction and extends outward, and a diaphragm device as an actuator is disposed on the front end surface of the surge tank 5. 14 are connected via a lever 15, a pin 16 and a rod 17. This diaphragm device 14 is connected to an electromagnetic three-way valve 18 attached to the front end face of the surge tank 5, and by switching the three-way valve 18, intake negative pressure or atmospheric pressure is introduced into the diaphragm device 14, and the diaphragm device 14 is activated. , this diaphragm device 14
When the communication valve 13 is closed, the communication valve 13 is controlled to open and close depending on the rotation range of the engine A to change the natural frequency of the intake air in the intake passage 4. When the communication valve 13 is closed, the intake air is transferred to both chambers in the surge tank 5. 7a, 7
By causing the intake air to resonate through the second communication path 12 between the valves 12 and 12 to lower the natural frequency of the intake air, the intake air is supercharged in the low rotation range of the engine A, and when the communication valve 13 is opened, the intake air is By causing resonance through the shorter first communication path 11 and increasing its natural frequency, supercharging is performed in the high rotation range of engine A, that is, the intake air is supercharged over the entire range of engine A's height. is configured to do so.

Reference numerals 19 denote a three-way valve 18 disposed on the front end surface of the surge tank 5, an outer end of the valve shaft 13a of the communication valve 13, a lever 15, a pin 16, and a rod 1.
This is a cover that covers 7th grade.

Therefore, in the embodiment described above, by operating the electromagnetic three-way valve 18 to control the opening and closing of the communication valve 13, the natural frequency of the intake air in the intake passage 4 changes, and the engine A performs intake supercharging. When the rotation range changes and the engine A is in a low rotation range, for example, negative pressure is introduced into the diaphragm device 14 and the communication valve 13 is closed, thereby creating a second communication between the chambers 7a and 7b in the surge tank 5. The natural frequency of the intake air which communicates only through the passage 12 and resonates between the chambers 7a and 7b of the surge tank 5 is lowered, and the intake air is supercharged to the engine A in the low rotation range. On the other hand, in the high rotation range, the diaphragm device 14 is exposed to the atmosphere and the communication valve 13 is opened, so that both chambers 7a and 7b in the surge tank 5 are connected to both the first and second communication passages 11 and 12. The intake air resonates through the shorter first communication path 11, its natural frequency increases, and the engine A is supercharged with the intake air. Therefore, the intake air can be supercharged over the entire height range of the engine A.

In this case, the second communication path 12 used as a resonance path during intake vibration in the partition wall 6 of the surge tank 5 is located in the longitudinal direction of the partition wall 6 (in the cylinder arrangement direction).
Since the communication path 12 is formed to extend for a long time, the length of the communication path 12 can be increased, and accordingly, the intake air can be effectively resonantly supercharged up to the low rotational speed range of the engine A.

Furthermore, since the right upstream intake pipe 10b and the left upstream intake pipe 10a that supply intake air into the surge tank 5 are curved within a plane passing through both chambers 7a and 7b, the centrifugal force causes the intake air to flow into the surge tank 5. is biased,
The intake air flow rate per unit area on the outer side of the upstream intake pipes 10a and 10b is greater than that on the inner side. However, in this embodiment, the second communication passage 12 formed in the partition wall 6 of the surge tank 5 and extending in the cylinder arrangement direction is arranged to communicate the rear end of the right chamber 7b and the front end of the left chamber 7a. Therefore, among the intake air flowing into the right chamber 7b of the surge tank 5 from the right upstream intake pipe 10b,
Intake air closer to the inside, where the intake air flow rate per unit area is smaller, flows through the second communication passage 12 to the left chamber 7a, and the exchange of intake air through the second communication passage 12 is suppressed as much as possible. becomes. Moreover, since the first communication passage 11 is shifted to the right with respect to the left-right center of the surge tank 5, the front end opening portion of the second communication passage 12 bulges into the left side chamber 7a, causing the left side chamber 7a to bulge into the left side chamber 7a. The decrease in volume is compensated for,
A large volume is ensured in the left chamber 7a, where the amount of intake air tends to decrease due to the difference in ventilation resistance due to the difference in the radius of curvature of the upstream intake pipes 10a and 10b, and it is connected to the fourth cylinder 3b at the front end of the right cylinder group. The space near the opening of the independent intake pipe 8 to the left chamber 7a of the surge tank 5 becomes larger, and the supply of intake air to the fourth cylinder 3b becomes smoother. The amount can be equally balanced, and good distribution of intake air to the left and right cylinder groups of engine A can be ensured.

Furthermore, as described above, the cylinders 3a and 3b in the left and right cylinder groups of engine A are misaligned with each other, and the first cylinder 3a at the front end of the left cylinder group is located further forward than the fourth cylinder 3b at the front end of the right cylinder group. Due to this arrangement, an extra dead space is formed on the front end side and the rear end side of the surge tank 5 in the cylinder arrangement direction. 14 and the electromagnetic three-way valve 18 that controls its operation are both centrally installed, so these devices can be deployed by making effective use of dead space.

Furthermore, since the diaphragm device 14 that operates the communication valve 13 and the electromagnetic three-way valve 18 that controls the operation thereof are attached to the front end surface of the surge tank 5 and placed close to each other, the distance between them can be greatly reduced. The communication valve 13 can be made shorter, and the operational response of the diaphragm device 14 to the switching control of the three-way valve 18 can be increased accordingly.
Opening/closing control can be performed accurately.

In addition, since the connecting mechanisms such as the three-way valve 18, rod 17, and lever 15 attached to the front end surface of the surge tank 5 are covered from the outside by the cover 19, these devices are hidden and the appearance is improved. can be done.

(Effects of the invention) As described above, according to the invention, the interior of the surge tank disposed between both banks is divided into two chambers by a partition wall extending in the direction of cylinder arrangement, and a communication passage connecting both chambers to the partition wall. are provided in the cylinder arrangement direction, and a pair of intake passages that supply intake air from one end side of the surge tank in the cylinder arrangement direction to both chambers in the surge tank are provided in the same direction within a plane passing through both chambers in the surge tank. In an intake system for a V-type engine, which is curved in a curved manner and uses the communication passage as a resonance passage for inertial or resonance supercharging of intake air, in a chamber in which one end of the communication passage is connected to the curved outer intake passage. By opening one end of the surge tank in the cylinder arrangement direction and the other end of the surge tank in the cylinder arrangement direction in a chamber connected to the inner intake passage, the intake air is deflected by centrifugal force, and the intake passage The intake flow rate closer to the outside of the surge tank increases than the intake flow rate closer to the inside, and the intake air closer to the inside, where the intake flow rate is lower, is sent to the chamber corresponding to the inner intake passage through the communication passage, and both chambers in the surge tank are It is possible to reduce the difference in the amount of intake air between the cylinders as much as possible, thereby improving the distribution of intake air between the left and right cylinder groups of the engine, and ensuring a communication passage of sufficient length to perform resonance supercharging of the intake air. It is something that can be done.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is an enlarged sectional view taken along the line -- in FIG. 2, and FIG. 2 is a partially cutaway front view of a V-type engine. A...Engine, _A1 ...Bank, 1...Cylinder block, 2a, 2b...Cylinder head,
3a, 3b... Cylinder, 4... Intake passage, 5... Surge tank, 6... Partition wall, 7a, 7b... Chamber, 1
0a, 10b... Upstream intake pipe, 11... First communication path, 12... Second communication path, 13... Communication valve, 14... Diaphragm device, 18... Electromagnetic three-way valve.

Claims (1)

[Scope of utility model registration request] A V-type engine equipped with a surge tank extending in the direction of the cylinder arrangement between both left and right banks, and partitioned into left and right chambers connected to cylinders with non-consecutive firing orders by a partition wall extending in the direction of the cylinder arrangement. In an engine intake system, a pair of intake passages that supply intake air to both chambers of the surge tank from one end side in the cylinder arrangement direction of the surge tank are each curved in the same direction within a plane passing through both chambers in the surge tank. , the partition wall has a cylinder of the surge tank in the chamber that opens toward one end in the cylinder arrangement direction of the surge tank in the chamber whose one end is connected to the curved outer intake passage, and whose other end is connected to the inner intake passage. An intake device for an engine, characterized in that a communication path is provided that is open at the other end in the arrangement direction and extends substantially parallel to the partition wall.