JP3997598B2 - Variable intake system for V-type internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an intake device for a V-type internal combustion engine, and more particularly, a variable intake system that has independent volume chambers for each bank and can switch both volume chambers to a separated state and a communication state according to engine operating conditions. It relates to the improvement of the apparatus.
[0002]
[Prior art]
For example, in a V-type 6-cylinder internal combustion engine, the intake strokes of cylinders # 1, # 3, and # 5 in one bank and cylinders # 2, # 4, and # 6 in the other bank do not overlap. By separating the intake system of the bank, a large intake dynamic effect can be obtained in the low and medium speed regions. In the high speed and high load range, it is known that the charging efficiency is improved by connecting the volume chambers of the left and right banks to each other so as to shorten the substantial intake pipe length.
[0003]
Therefore, for example, as described in JP-A-7-324658, etc., the inside of the collector is partitioned into a pair of volume chambers by a partition wall, and each volume chamber is connected to the intake ports of the left and right banks, respectively. Various variable intake devices have been proposed in the past in which a communication port is formed in the partition wall between the two volume chambers, and the communication port can be opened and closed with an on-off valve. Specifically, in the apparatus described in the above publication, the interior of the elongated box-shaped collector is partitioned into upper and lower volume chambers by a partition wall at the center, and three branches are provided on one side of the collector. Are connected to each other, and a communication opening is formed at one end of the partition wall, and a butterfly valve on-off valve is provided there. This on-off valve closes the communication port in the low / medium speed region of the engine and opens so that the volume chambers of the banks communicate with each other in the high speed region.
[0004]
[Problems to be solved by the invention]
In the conventional configuration as described above, the valve body of the on-off valve is located in a shape substantially along the wall surface of the partition wall in the closed state, and thus does not provide ventilation resistance in the collector. Since it is located away from the wall and intersects the partition wall at an angle of, for example, about 90 °, a large ventilation resistance is generated in the collector. In particular, the high-speed area where the on-off valve opens has a large intake flow rate, and the intake air flows at a high speed in the collector. There is a problem that the output is reduced.
[0005]
In addition, as described above, since the valve body is likely to become a ventilation resistance at the open position, it is difficult to dispose the on-off valve in the vicinity of the branch opening in the collector. For example, in the device described in the above publication, the opening / closing valve is disposed at the end of the collector, and the distance from the opening of the branch of each cylinder, particularly the opening of the cylinder located at the end opposite to the collector, is The communication effect at the time of opening becomes low that much. In other words, from the viewpoint of the performance of the engine when the communication port is opened, it is desirable that the position of the communication port is in the center of the collector and near the branch opening, but if the communication port is provided at such a position, The valve body of the on-off valve becomes a ventilation resistance, which causes a further decrease in output. Similarly, since the valve body tends to be a ventilation resistance in the open position, the size of the valve body of the on-off valve is restricted, and it is difficult to secure a sufficient opening area of the communication port. Therefore, the optimum intake dynamic effect at high speed cannot be obtained, and the output in the high speed range cannot be sufficiently increased.
[0006]
[Means for Solving the Problems]
Therefore, the present invention divides the inside of the collector into two volume chambers by partition walls, and connects the branch portions of each bank to each volume chamber, and opens a communication port for communicating both volume chambers to the partition wall. In a variable intake device for a V-type internal combustion engine that is formed and provided with an on-off valve that opens and closes this communication port according to engine operating conditions,
The on-off valve is provided with an end valve shaft portion of the plate-shaped valve body, said valve shaft with pivots about a collector in the wall in which the valve body is opened intake inlet in the open position to open the communication port It is comprised so that it may be in the state which adjoined along the same inner wall surface .
[0007]
The on-off valve is controlled to be closed in the low / medium speed range and closes the communication port. As a result, the intake system of each bank is separated and independent, and the torque is improved by the intake dynamic effect in the low and medium speed ranges. Further, in the high speed range, the communication port is opened and both volume chambers are in communication. Thereby, the volume efficiency in a high-speed area improves.
[0008]
Here, in the above configuration, the valve body is attached to the valve shaft in a so-called cantilever shape, and when the valve body is rotated about the valve shaft to the open position, the valve body is moved along the inner wall surface of the collector. It becomes a state close to the inner wall surface.
[0009]
In other words, the valve body is in a state close to the shape attached to the inner wall surface of the collector. Therefore, the airflow resistance due to the valve body becomes very small with respect to the intake air flow flowing toward the branch opening in the collector, and the output in the high speed region is not reduced.
[0011]
The intake air enters the collector through an intake inlet that opens in one inner wall surface, and flows out to the opening of each branch portion. That is, it mainly flows from the intake inlet to the branch opening in the collector. Therefore, if the valve body comes close to the inner wall surface on the intake inlet side when the on-off valve is opened, the main flow of intake air does not collide with the valve body, and the ventilation resistance is further reduced.
[0012]
Further, the invention of claim 2 is characterized in that a pair of the communication port and the on-off valve are provided, and the intake inlet is disposed at an intermediate portion of the pair of on-off valves.
[0013]
In the invention of claim 3 , a pair of valve bodies is attached to the same valve shaft arranged along the partition wall.
[0014]
By providing the pair of communication ports in this way, the total opening area at the time of opening is ensured very large.
[0015]
Moreover, in the invention which concerns on Claim 4 , the opening part of a some branch part is arrange | positioned along with the longitudinal direction of the volume chamber, In the range which does not protrude in the volume chamber longitudinal direction rather than the opening part of the both ends, A communication port is arranged.
[0016]
That is, the communication port is provided at a position relatively close to the opening of each branch portion and closer to the center of the collector. As a result, the pressure in the communication state is more evenly balanced, and the output in the high speed range is improved.
[0017]
In the invention according to claim 5 , a concave portion into which the valve body is fitted is formed on the collector inner wall surface close to the valve body. Accordingly, when the valve body is opened, the ventilation resistance is further reduced because the valve body enters the recess of the inner wall surface of the collector.
[0018]
【The invention's effect】
According to the variable intake device for a V-type internal combustion engine according to the present invention, when the on-off valve opens the communication port, the valve body of the on-off valve does not protrude into the collector, so that there is no ventilation resistance. It is possible to avoid a decrease in output in a high speed range due to ventilation resistance. Further, the degree of freedom of the formation position and the opening area of the communication port is increased, and a sufficiently large communication port can be secured near the opening of the branch portion, for example, as in claim 4 .
[0019]
Also, since the valve element opens on the side that does not mainstream and interference of the intake, it is possible to further reduce the airflow resistance.
[0020]
According to the invention of claim 2 or claim 3 , the total opening area of the communication port can be further increased, which is further advantageous in terms of performance in a high speed region where the on-off valve opens.
[0021]
Furthermore, according to the invention of claim 5, the ventilation resistance is further reduced by fitting the valve body into the recess.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
[0023]
FIG. 1 shows the overall configuration of a V-type 6-cylinder internal combustion engine equipped with a variable intake system according to the present invention. This internal combustion engine has six cylinders 2 arranged in a V shape in a cylinder block 1, and pistons 3 are slidably fitted to the cylinder blocks 1. Each is attached. The cylinder head 4 is provided with an intake port 5 on the inner side of the bank and an exhaust port (not shown) on the outer side of the bank. In the figure, 6 is an intake valve and 7 is a fuel injection valve.
[0024]
The intake port 5 is connected to one end of an independent branch portion 8 for each cylinder, and the other end of each branch portion 8 is connected to one side surface of a box-like collector 11. The collector 11 is partitioned into a pair of upper and lower volume chambers 13 and 14 by a partition wall 12 provided in a central portion in a substantially horizontal direction, and the three branch portions 8 of the bank on the right side of the figure are the upper volume chamber 13. In addition, the three branch portions 8 of the bank on the left side of the figure are connected to the lower volume chamber 14. Resonant tubes 15 and 16 serving as intake passages communicating with the respective volume chambers 13 and 14 are connected to the side surface of the collector 11 opposite to the branch portion 8. The pair of resonance tubes 15 and 16 are gathered in a single passage on the upstream side, and are provided with a throttle valve 20 (see FIGS. 2 and 3) on the upstream side, as well as an air flow meter and an air cleaner (not shown). Is arranged upstream.
[0025]
2 and 3 show details of the collector 11. The collector 11 includes a box-shaped body 17 having one side opened, and a base plate 18 attached to the opening surface of the body 17. Six branch portions 8 are integrally formed on the body 17. In addition, the resonance tubes 15 and 16 are connected to the base plate 18. Each of these members is cast from, for example, an aluminum alloy. In addition, as shown in FIG. 1, you may comprise the downstream part of each branch part 8 as another member.
[0026]
The partition wall 12 is formed integrally with the base plate 18 and is abutted against the inner wall surface of the body 17 via a seal member 19 attached to the periphery thereof. As shown in FIG. 3, the partition wall 12 has an elongated and substantially rectangular shape in a plan view, but substantially rectangular communication ports 21 and 22 are formed at both ends thereof. In addition, as shown in FIG. 3, each communication port 21 and 22 is an opening of two branch parts 8 located at both ends among the six branch parts 8 connected to the upper and lower volume chambers 13 and 14. It is in a position substantially corresponding to the portion 8a. And in order to open and close each communicating port 21 and 22 according to engine operating conditions, the on-off valves 23 and 24 are provided, respectively. The on-off valves 23 and 24 are composed of a valve shaft 25 rotatably supported on the base plate 18 and substantially rectangular plate-like valve bodies 23a and 24a attached to the valve shaft 25. That is, in this embodiment, a pair of on-off valves 23 and 24 are constituted by the same valve shaft 25. Here, the valve shaft 25 is disposed along the longitudinal direction of the partition wall 12 at a base portion of the partition wall 12, that is, a portion intersecting with the bottom wall of the base plate 18. The one ends of 23a and 24a are fixed by screws 26 so as to be in a so-called cantilever shape. As shown in FIG. 4, a diaphragm negative pressure actuator 27 on the side of the base plate 18 is linked to one end of the valve shaft 25, and along with the operation of the negative pressure actuator 27, the valve shaft 25 is It is designed to turn slightly 90 °. As the valve shaft 25 rotates, the valve bodies 23 a and 24 a rotate as shown in FIG. 2, but the communication ports 21 and 22 are closed at positions along the partition wall 12 and separated from the partition wall 12. Then, the communication ports 21 and 22 are opened at a position along the side wall of the base plate 18. In addition, the opening edge of the communication ports 21 and 22 is provided with a stepped portion 28 that comes into contact with the periphery of the valve bodies 23a and 24a when the valve bodies 23a and 24a are closed. Further, a recess 29 corresponding to each valve body 23a, 24a is provided on the side wall of the base plate 18, and when the valve bodies 23a, 24a are rotated to the open position as shown in FIG. It fits in the recess 29.
[0027]
As described above, the resonance pipes 15 and 16 are connected to the base plate 18. The intake inlets 30 and 31 to which the resonance pipes 15 and 16 are connected are collectors sandwiched between a pair of on-off valves 23 and 24. 11 is located in the center in the longitudinal direction. Specifically, as shown in FIG. 4, in the upper volume chamber 13, an intake port 30 having an oval shape is formed between a pair of recesses 29 corresponding to the valve bodies 23a and 24a, and the lower volume is formed. In the chamber 14, an intake inlet 31 is formed so as to be symmetrical with respect to the partition wall 12.
[0028]
In the above configuration, the intake air enters the volume chambers 13 and 14 in the collector 11 from the pair of resonance tubes 15 and 16 and is supplied to the cylinders via the branch portions 8. In a low / medium speed region of the engine, for example, a region of 4000 rpm or less, the pair of on-off valves 23 and 24 are controlled to be closed, and the two volume chambers 13 and 14 are in an independent state. That is, the intake systems of the left and right banks are separated and independent, and the torque in the low and medium speed ranges is improved by the intake dynamic effect. Further, in a high speed region of the engine, for example, a region of 4000 rpm or more, the pair of on-off valves 23 and 24 are controlled to the open position, and both the volume chambers 13 and 14 communicate with each other through the communication ports 21 and 22. Become. As a result, the pressures in both the volume chambers 13 and 14 become uniform, and the volumetric efficiency in the high speed region is improved.
[0029]
At this time, in the above configuration, the valve bodies 23 a and 24 a are in a state of sticking to the side wall surface of the base plate 18 in the collector 11, particularly in a state of being fitted in the recess 29, and hardly protrude into the volume chamber 13. . Therefore, there is no airflow resistance against the intake air flow that flows through the collector 11. In particular, in the above configuration, since the valve bodies 23a and 24a open along the inner wall surface on the intake inlets 30 and 31 side, the intake flow flowing from the intake inlets 30 and 31 toward the branch portion 8 and the valve bodies 23a and 24a Is more reliably avoided.
[0030]
Moreover, in the said Example, since the communication ports 21 and 22 are provided in a pair and the total opening area becomes large enough, the pressure balance effect | action via the communication ports 21 and 22 becomes still better. . In particular, the distance from the opening 8a of each branch portion 8 to the communication ports 21 and 22 becomes very short compared to the case where the communication ports are arranged at one end as in the prior art, and the valve bodies 23a and 24a Combined with the reduction in ventilation resistance, the output at high speeds is improved.
[0031]
FIG. 5 is a characteristic diagram showing the torque characteristics of an internal combustion engine using the intake device of this embodiment in comparison with that of a conventional intake device. Can be suppressed. In the illustrated example, the communication port is switched from closed to open at 4000 rpm.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an entire V-type internal combustion engine equipped with an intake device according to the present invention.
FIG. 2 is an enlarged cross-sectional view showing a collector portion.
3 is a cross-sectional view taken along line AA in FIG.
4 is a cross-sectional view taken along line BB in FIG. 2 showing only the base plate.
FIG. 5 is a characteristic diagram showing torque characteristics of an internal combustion engine equipped with an intake device according to the present invention in comparison with a conventional intake device.
[Explanation of symbols]
8 ... branch portion 11 ... collector 12 ... partition walls 13, 14 ... volume chambers 21, 22 ... communication ports 23, 24 ... open / close valves 23a, 24a ... valve body 25 ... valve shaft 29 ... recesses 30, 31 ... intake inlet

Claims (5)

The interior of the collector is partitioned into two volume chambers by partition walls, and the branch portions of the banks are connected to the respective volume chambers, and a communication port for communicating both volume chambers is formed in the partition wall. In a variable intake device for a V-type internal combustion engine provided with an on-off valve that opens and closes according to engine operating conditions,
The on-off valve is provided with an end valve shaft portion of the plate-shaped valve body, said valve shaft with pivots about a collector in the wall in which the valve body is opened intake inlet in the open position to open the communication port A variable intake device for a V-type internal combustion engine, which is configured to be close to each other along the same inner wall surface . The communicating port and a pair of the opening and closing valve, the variable intake apparatus for a V-type internal combustion engine according to claim 1, characterized in that the intake inlet is disposed in an intermediate portion of the pair of opening and closing valves. 3. A variable intake system for a V-type internal combustion engine according to claim 2 , wherein a pair of valve bodies are attached to the same valve shaft arranged along the partition wall. The openings of the plurality of branch portions are arranged side by side in the longitudinal direction of the volume chamber, and the communication port is arranged in a range that does not protrude in the longitudinal direction of the volume chamber from the openings at both ends thereof. The variable intake device for a V-type internal combustion engine according to any one of claims 1 to 3 . The variable intake device for a V-type internal combustion engine according to any one of claims 1 to 4 , wherein a concave portion into which the valve body is fitted is formed on a collector inner wall surface close to the valve body.

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